WorldWideScience

Sample records for native fish communities

  1. Trophic interactions between native and introduced fish species in a littoral fish community.

    Science.gov (United States)

    Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

    2014-11-01

    The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. © 2014 The Fisheries Society of the British Isles.

  2. Native fish conservation areas: a vision for large-scale conservation of native fish communities

    Science.gov (United States)

    Jack E. Williams; Richard N. Williams; Russell F. Thurow; Leah Elwell; David P. Philipp; Fred A. Harris; Jeffrey L. Kershner; Patrick J. Martinez; Dirk Miller; Gordon H. Reeves; Christopher A. Frissell; James R. Sedell

    2011-01-01

    The status of freshwater fishes continues to decline despite substantial conservation efforts to reverse this trend and recover threatened and endangered aquatic species. Lack of success is partially due to working at smaller spatial scales and focusing on habitats and species that are already degraded. Protecting entire watersheds and aquatic communities, which we...

  3. Invasive lionfish harbor a different external bacterial community than native Bahamian fishes

    Science.gov (United States)

    Stevens, J. L.; Olson, J. B.

    2013-12-01

    The introduction and subsequent spread of lionfish into the Atlantic Ocean and Caribbean Sea has become a worldwide conservation issue. These highly successful invaders may also be capable of introducing non-native microorganisms to the invaded regions. This study compared the bacterial communities associated with lionfish external tissue to those of native Bahamian fishes and ambient water. Terminal restriction fragment length polymorphism analyses demonstrated that lionfish bacterial communities were significantly different than those associated with three native Bahamian fishes. Additionally, all fishes harbored distinct bacterial communities from the ambient bacterioplankton. Analysis of bacterial clone libraries from invasive lionfish and native squirrelfish indicated that lionfish communities were more diverse than those associated with squirrelfish, yet did not contain known fish pathogens. Using microscopy and molecular genetic approaches, lionfish eggs were examined for the presence of bacteria to evaluate the capacity for vertical transmission. Eggs removed from the ovaries of gravid females were free of bacteria, suggesting that lionfish likely acquire bacteria from the environment. This study was the first examination of bacterial communities associated with the invasive lionfish and indicated that they support different communities of environmentally derived bacteria than Caribbean reef fishes.

  4. Fish community of the river Tiber basin (Umbria-Italy: temporal changes and possible threats to native biodiversity

    Directory of Open Access Journals (Sweden)

    Carosi A.

    2015-01-01

    Full Text Available The introduction of exotic fish species in the river Tiber basin has probably caused a serious alteration of original faunal composition. The purpose of this research was to assess the changes occurred over time in the state of the fish communities with particular reference to the reduction of local communities of endemic species. The study area comprised 68 watercourses of the Umbrian portion of the River Tiber basin; the analyses were carried out using the data of the Regional Fish Map of 1st and 2nd level and the 1st update, respectively collected during the periods between the 1990–1996, 2000–2006 and 2007–2014, in 125 sampling stations. The results show a progressive alteration of the fish communities’ structure, as confirmed by the appearance in recent times of new alien species. A total of 40 species was found, only 14 native. The qualitative change of the fish communities appear to be closely related to the longitudinal gradient of the river. The results shows that particularly in the downstream reaches, the combined action of pollution and introduction of exotic species resulted in a gradual decrease in the indigenous component of fish communities. The information collected are the indispensable premise for taking the necessary strategies for conservation of endangered species.

  5. Native freshwater species get out of the way: Prussian carp (Carassius gibelio) impacts both fish and benthic invertebrate communities in North America.

    Science.gov (United States)

    Ruppert, Jonathan L W; Docherty, Cassandra; Neufeld, Kenton; Hamilton, Kyle; MacPherson, Laura; Poesch, Mark S

    2017-10-01

    Prussian carp ( Carassius gibelio ) are one of the most noxious non-native species in Eurasia. Recently, Prussian carp, a non-native freshwater fish species, were genetically confirmed in Alberta, Canada and have been rapidly expanding their range in North America since establishment. Given their rapid range expansion, there is an increasing need to determine how Prussian carp may impact native species. We assessed the severity of the Prussian carp invasion by (i) determining their impact on fish communities, (ii) assessing their impact on benthic invertebrate communities, (iii) evaluating if Prussian carp alter abiotic conditions, and (iv) identifying where we find higher abundances of Prussian carp. When Prussian carp were established, we found significant changes to the fish community. Correspondingly, the degree of impact to benthic invertebrate communities was related to the stage of invasion (none, early or recent), where changes in fish communities were significantly concordant with changes in benthic invertebrate communities. Finally, we found that higher abundances of Prussian carp were significantly associated with lower abundances of a majority of native fish species. Altogether, using three lines of evidence, we determine that Prussian carp can have wide-ranging impacts on freshwater ecosystems in North America, pressing the need for management intervention.

  6. MBS Native Plant Communities

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data layer contains results of the Minnesota County Biological Survey (MCBS). It includes polygons representing the highest quality native plant communities...

  7. Offshore Fish Community: Ecological Interactions

    Science.gov (United States)

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  8. Native Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for...

  9. Fishing Community Profiles

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To enable fisheries managers to comply with National Standard 8 (NS8), NMFS social scientists around the nation are preparing fishing community profiles that present...

  10. Native Fish Sanctuary Project - Sanctuary Development Phase, 2007 Annual Report

    Science.gov (United States)

    Mueller, Gordon A.

    2007-01-01

    Notable progress was made in 2007 toward the development of native fish facilities in the Lower Colorado River Basin. More than a dozen facilities are, or soon will be, online to benefit native fish. When this study began in 2005 no self-supporting communities of either bonytail or razorback sucker existed. Razorback suckers were removed from Rock Tank in 1997 and the communities at High Levee Pond had been compromised by largemouth bass in 2004. This project reversed that trend with the establishment of the Davis Cove native fish community in 2005. Bonytail and razorback sucker successfully produced young in Davis Cove in 2006. Bonytail successfully produced young in Parker Dam Pond in 2007, representing the first successful sanctuary established solely for bonytail. This past year, Three Fingers Lake received 135 large razorback suckers, and Federal and State agencies have agreed to develop a cooperative management approach dedicating a portion of that lake toward grow-out and (or) the establishment of another sanctuary. Two ponds at River's Edge Golf Course in Needles, California, were renovated in June and soon will be stocked with bonytail. Similar activities are taking place at Mohave Community College, Cerbat Cliffs Golf Course, Cibola High Levee Pond, Office Cove, Emerald Canyon Golf Course, and Bulkhead Cove. Recruitment can be expected as fish become sexually mature at these facilities. Flood-plain facilities have the potential to support 6,000 adult razorback suckers and nearly 20,000 bonytail if native fish management is aggressively pursued. This sanctuary project has assisted agencies in developing 15 native fish communities by identifying specific resource objectives for those sites, listing and prioritizing research opportunities and needs, and strategizing on management approaches through the use of resource-management plans. Such documents have been developed for Davis Cove, Cibola High Levee Pond, Parker Dam Pond, and Three Fingers Lake. We

  11. Long-term trends of native and non-native fish faunas in the American Southwest

    Directory of Open Access Journals (Sweden)

    Olden, J. D.

    2005-06-01

    Full Text Available Environmental degradation and the proliferation of non-native fish species threaten the endemic, and highly unique fish faunas of the American Southwest. The present study examines long-term trends (> 160 years of fish species distributions in the Lower Colorado River Basin and identifies those native species (n = 28 exhibiting the greatest rates of decline and those non-native species (n = 48 exhibiting the highest rates of spread. Among the fastest expanding invaders in the basin are red shiner (Cyprinella lutrensis, fathead minnow (Pimephales promelas, green sunfish (Lepomis cyanellus, largemouth bass (Micropterus salmoides, western mosquitofish (Gambussia affinis and channel catfish (Ictalurus punctatus; species considered to be the most invasive in terms of their negative impacts on native fish communities. Interestingly, non-native species that have been recently introduced (1950+ have generally spread at substantially lower rates as compared to species introduced prior to this time (especially from 1920 to 1950, likely reflecting reductions in human-aided spread of species. We found general agreement between patterns of species decline and extant distribution sizes and official listing status under the U.S. Endangered Species Act. ‘Endangered’ species have generally experienced greater declines and have smaller present-day distributions compared to ‘threatened’ species, which in turn have shown greater declines and smaller distributions than those species not currently listed. A number of notable exceptions did exist, however, and these may provide critical information to help guide the future listing of species (i.e., identification of candidates and the upgrading or downgrading of current listed species that are endemic to the Lower Colorado River Basin. The strong correlation between probability estimates of local extirpation and patterns of native species decline and present-day distributions suggest a possible proactive

  12. DNA metabarcoding of fish larvae for detection of non-native fishes

    Science.gov (United States)

    Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy approaches to investigate potential efficiencies. Fish larvae present an interesting opportunity for non-native fish early detection because...

  13. Will Tidal Wetland Restoration Enhance Populations of Native Fishes?

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available Restoration of tidal wetlands might enhance populations of native fishes in the San Francisco Estuary of California. The purpose of this paper is to: (1 review the currently available information regarding the importance of tidal wetlands to native fishes in the San Francisco Estuary, (2 construct conceptual models on the basis of available information, (3 identify key areas of scientific uncertainty, and (4 identify methods to improve conceptual models and reduce uncertainty. There are few quantitative data to suggest that restoration of tidal wetlands will substantially increase populations of native fishes. On a qualitative basis, there is some support for the idea that tidal wetland restoration will increase populations of some native fishes; however, the species deriving the most benefit from restoration might not be of great management concern at present. Invasion of the San Francisco Estuary by alien plants and animals appears to be a major factor in obscuring the expected link between tidal wetlands and native fishes. Large-scale adaptive management experiments (>100 hectares appear to be the best available option for determining whether tidal wetlands will provide significant benefit to native fishes. Even if these experiments are unsuccessful at increasing native fish populations, the restored wetlands should benefit native birds, plants, and other organisms.

  14. Richness patterns in the parasite communities of exotic poeciliid fishes.

    Science.gov (United States)

    Dove, A D

    2000-06-01

    Three species of poeciliids (Gambusia holbrooki, Xiphophorus helleri and X. maculatus) and 15 species of ecologically similar native freshwater fishes (mainly eleotrids, ambassids, melanotaeniids and retropinnids) were examined for parasite richness to investigate parasite flux, qualitative differences, quantitative differences and the structuring factors in parasite communities in the 2 fish types in Queensland, Australia. Theory suggests that poeciliids would harbour depauperate parasite communities. Results supported this hypothesis; poeciliids harboured more species-poor parasite infracommunities and regional faunas than natives (P analysis of presence/absence data for poeciliids and the 6 most-sampled native fishes revealed that parasite communities of the 2 fish groups are qualitatively distinct; the proportion of parasite species with complex life-cycles was lower in poeciliids than in native species, and Myxosporea, Microspora, Coccidia and parasitic Crustacea were all absent from poeciliids. Limited exchange of parasite species has occurred between natives and poeciliids. Logistic ordinal regression analysis revealed that fish origin (exotic or native), environmental disturbance and host sex were all significant determinants of parasite community richness (P competitive advantage over native fishes because of their lack of parasites.

  15. Non-native fishes in Florida freshwaters: a literature review and synthesis

    Science.gov (United States)

    Schofield, Pamela J.; Loftus, William F.

    2015-01-01

    Non-native fishes have been known from freshwater ecosystems of Florida since the 1950s, and dozens of species have established self-sustaining populations. Nonetheless, no synthesis of data collected on those species in Florida has been published until now. We searched the literature for peer-reviewed publications reporting original data for 42 species of non-native fishes in Florida that are currently established, were established in the past, or are sustained by human intervention. Since the 1950s, the number of non-native fish species increased steadily at a rate of roughly six new species per decade. Studies documented (in decreasing abundance): geographic location/range expansion, life- and natural-history characteristics (e.g., diet, habitat use), ecophysiology, community composition, population structure, behaviour, aquatic-plant management, and fisheries/aquaculture. Although there is a great deal of taxonomic uncertainty and confusion associated with many taxa, very few studies focused on clarifying taxonomic ambiguities of non-native fishes in the State. Most studies were descriptive; only 15 % were manipulative. Risk assessments, population-control studies and evaluations of effects of non-native fishes were rare topics for research, although they are highly valued by natural-resource managers. Though some authors equated lack of data with lack of effects, research is needed to confirm or deny conclusions. Much more is known regarding the effects of lionfish (Pterois spp.) on native fauna, despite its much shorter establishment time. Natural-resource managers need biological and ecological information to make policy decisions regarding non-native fishes. Given the near-absence of empirical data on effects of Florida non-native fishes, and the lengthy time-frames usually needed to collect such information, we provide suggestions for data collection in a manner that may be useful in the evaluation and prediction of non-native fish effects.

  16. Introduced brown trout alter native acanthocephalan infections in native fish.

    Science.gov (United States)

    Paterson, Rachel A; Townsend, Colin R; Poulin, Robert; Tompkins, Daniel M

    2011-09-01

    1. Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the 'spillback' of infection increasing the parasite burdens of native hosts) or sinks (with the 'dilution' of infection decreasing the parasite burdens of native hosts) of infection. 2. In New Zealand, negative correlations between the presence of introduced brown trout (Salmo trutta) and native parasite burdens of the native roundhead galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used a multiple-scale approach combining field observations, experimental infections and dynamic population modelling to investigate whether native Acanthocephalus galaxii acquisition by brown trout alters host-parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout. Experimental infections also demonstrated that A. galaxii does not mature in trout, although parasite establishment and initial growth were similar in the two hosts. Taken together, these results support the hypothesis that trout may serve as an infection sink for the native parasite. 5. However, dynamic population modelling predicts that A. galaxii infections in native galaxias should at most only be slightly reduced by dilution in the presence of trout. Rather, model exploration indicates parasite densities in galaxias are highly sensitive to galaxias predation on infected amphipods, and to relative abundances of galaxias and trout. Hence, trout presence may instead reduce parasite burdens in galaxias by either reducing galaxias density or by altering galaxias foraging behaviour. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

  17. Kalispel Non-Native Fish Suppression Project 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department

    2008-11-18

    Non-native salmonids are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of some native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi) populations. In 2007, the Kalispel Natural Resource Department (KNRD) initiated the Kalispel Nonnative Fish Suppression Project. The goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated. These projects have previously been identified as critical to recovering native bull trout and westslope cutthroat trout (WCT). Lower Graham Creek was invaded by non-native rainbow (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) after a small dam failed in 1991. By 2003, no genetically pure WCT remained in the lower 700 m of Graham Creek. Further invasion upstream is currently precluded by a relatively short section of steep, cascade-pool stepped channel section that will likely be breached in the near future. In 2008, a fish management structure (barrier) was constructed at the mouth of Graham Creek to preclude further invasion of non-native fish into Graham Creek. The construction of the barrier was preceded by intensive electrofishing in the lower 700 m to remove and relocate all captured fish. Westslope cutthroat trout have recently been extirpated in Cee Cee Ah Creek due to displacement by brook trout. We propose treating Cee Cee Ah Creek with a piscicide to eradicate brook trout. Once eradication is complete, cutthroat trout will be translocated from nearby watersheds. In 2004, the Washington Department of Fish and Wildlife (WDFW) proposed an antimycin treatment within the subbasin; the project encountered significant public opposition and was eventually abandoned. However, over the course of planning this 2004 project, little public

  18. Freshwater Fish Communities

    Science.gov (United States)

    Freshwater fish are ecologically important in stream ecosystems, and they provide people with significant food, recreation, and conservation value as biological indicator of freshwater streams. Historically, the streams and rivers of southern New England supported moderately dive...

  19. Systemic and intensifying drought induces collapse and replacement of native fishes: a time-series approach

    Science.gov (United States)

    Ruhi, A.; Olden, J. D.; Sabo, J. L.

    2015-12-01

    In the American Southwest, hydrologic drought has become a new normal as a result of increasing human appropriation of freshwater resources and increased aridity associated with global warming. Although drought has often been touted to threaten freshwater biodiversity, connecting drought to extinction risk of highly-imperiled faunas remains a challenge. Here we combine time-series methods from signal processing and econometrics to analyze a spatially comprehensive and long-term dataset to link discharge variation and community abundance of fish across the American Southwest. This novel time series framework identifies ongoing trends in daily discharge anomalies across the Southwest, quantifies the effect of the historical hydrologic drivers on fish community abundance, and allows us to simulate species trajectories and range-wide risk of decline (quasiextinction) under scenarios of future climate. Spectral anomalies are declining over the last 30 years in at least a quarter of the stream gaging stations across the American Southwest and these anomalies are robust predictors of historical abundance of native and non-native fishes. Quasiextinction probabilities are high (>50 %) for nearly ¾ of the native species across several large river basins in the same region; and the negative trend in annual anomalies increases quasiextinction risk for native but reduces this risk for non-native fishes. These findings suggest that ongoing drought is causing range-wide collapse and replacement of native fish faunas, and that this homogenization of western fish faunas will continue given the prevailing negative trend in discharge anomalies. Additionally, this combination of methods can be applied elsewhere as long as environmental and biological long-term time-series data are available. Collectively, these methods allow identifying the link between hydroclimatic forcing and ecological responses and thus may help anticipating the potential impacts of ongoing and future hydrologic

  20. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  1. Invasive lionfish reduce native fish abundance on a regional scale

    Science.gov (United States)

    Ballew, Nicholas G.; Bacheler, Nathan M.; Kellison, G. Todd; Schueller, Amy M.

    2016-08-01

    Invasive lionfish pose an unprecedented threat to biodiversity and fisheries throughout Atlantic waters off of the southeastern United States, the Caribbean, and the Gulf of Mexico. Here, we employ a spatially replicated Before-After-Control-Impact analysis with temporal pairing to quantify for the first time the impact of the lionfish invasion on native fish abundance across a broad regional scale and over the entire duration of the lionfish invasion (1990-2014). Our results suggest that 1) lionfish-impacted areas off of the southeastern United States are most prevalent off-shore near the continental shelf-break but are also common near-shore and 2) in impacted areas, lionfish have reduced tomtate (a native forage fish) abundance by 45% since the invasion began. Tomtate served as a model native fish species in our analysis, and as such, it is likely that the lionfish invasion has had similar impacts on other species, some of which may be of economic importance. Barring the development of a control strategy that reverses the lionfish invasion, the abundance of lionfish in the Atlantic, Caribbean, and Gulf of Mexico will likely remain at or above current levels. Consequently, the effect of lionfish on native fish abundance will likely continue for the foreseeable future.

  2. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    Science.gov (United States)

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

    2014-01-01

    Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

  3. Invasive lionfish reduce native fish abundance on a regional scale

    OpenAIRE

    Ballew, Nicholas G.; Bacheler, Nathan M.; Kellison, G. Todd; Schueller, Amy M.

    2016-01-01

    Invasive lionfish pose an unprecedented threat to biodiversity and fisheries throughout Atlantic waters off of the southeastern United States, the Caribbean, and the Gulf of Mexico. Here, we employ a spatially replicated Before-After-Control-Impact analysis with temporal pairing to quantify for the first time the impact of the lionfish invasion on native fish abundance across a broad regional scale and over the entire duration of the lionfish invasion (1990?2014). Our results suggest that 1) ...

  4. Ongoing removals of invasive lionfish in Honduras and their effect on native Caribbean prey fishes.

    Science.gov (United States)

    Peiffer, Friederike; Bejarano, Sonia; Palavicini de Witte, Giacomo; Wild, Christian

    2017-01-01

    The invasion of Indo-Pacific lionfish is one of the most pressing concerns in the context of coral reef conservation throughout the Caribbean. Invasive lionfish threaten Caribbean fish communities by feeding on a wide range of native prey species, some of which have high ecological and economic value. In Roatan (Honduras) a local non-governmental organisation (i.e. Roatan Marine Park) trains residents and tourists in the use of spears to remove invasive lionfish. Here, we assess the effectiveness of local removal efforts in reducing lionfish populations. We ask whether reefs subject to relatively frequent removals support more diverse and abundant native fish assemblages compared to sites were no removals take place. Lionfish biomass, as well as density and diversity of native prey species were quantified on reefs subject to regular and no removal efforts. Reefs subject to regular lionfish removals (two to three removals month -1 ) with a mean catch per unit effort of 2.76 ± 1.72 lionfish fisher -1 h -1 had 95% lower lionfish biomass compared to non-removal sites. Sites subject to lionfish removals supported 30% higher densities of native prey-sized fishes compared to sites subject to no removal efforts. We found no evidence that species richness and diversity of native fish communities differ between removal and non-removal sites. We conclude that opportunistic voluntary removals are an effective management intervention to reduce lionfish populations locally and might alleviate negative impacts of lionfish predation. We recommend that local management and the diving industry cooperate to cost-effectively extend the spatial scale at which removal regimes are currently sustained.

  5. Ongoing removals of invasive lionfish in Honduras and their effect on native Caribbean prey fishes

    Directory of Open Access Journals (Sweden)

    Friederike Peiffer

    2017-10-01

    Full Text Available The invasion of Indo-Pacific lionfish is one of the most pressing concerns in the context of coral reef conservation throughout the Caribbean. Invasive lionfish threaten Caribbean fish communities by feeding on a wide range of native prey species, some of which have high ecological and economic value. In Roatan (Honduras a local non-governmental organisation (i.e. Roatan Marine Park trains residents and tourists in the use of spears to remove invasive lionfish. Here, we assess the effectiveness of local removal efforts in reducing lionfish populations. We ask whether reefs subject to relatively frequent removals support more diverse and abundant native fish assemblages compared to sites were no removals take place. Lionfish biomass, as well as density and diversity of native prey species were quantified on reefs subject to regular and no removal efforts. Reefs subject to regular lionfish removals (two to three removals month−1 with a mean catch per unit effort of 2.76 ± 1.72 lionfish fisher−1 h−1 had 95% lower lionfish biomass compared to non-removal sites. Sites subject to lionfish removals supported 30% higher densities of native prey-sized fishes compared to sites subject to no removal efforts. We found no evidence that species richness and diversity of native fish communities differ between removal and non-removal sites. We conclude that opportunistic voluntary removals are an effective management intervention to reduce lionfish populations locally and might alleviate negative impacts of lionfish predation. We recommend that local management and the diving industry cooperate to cost-effectively extend the spatial scale at which removal regimes are currently sustained.

  6. Offshore Fish Community: Ecological Interactions | Science ...

    Science.gov (United States)

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone. Bloater is abundant in the offshore zone but appears restricted to depths shallower than 150 m (Selgeby and Hoff 1996; Stockwell et al. 2010), although it occuppied greater depths several decades ago (Dryer 1966; Peck 1977). Shortjaw is relatively rare in the offshore zone (Hoff and Todd 2004; Gorman and Hoff 2009; Gorman and Todd 2007). Lake whitefish is also known to frequent bathymetric depths >100 m (Yule et al. 2008b). In this chapter, we develop a conceptual model of the offshore food web based on data collected during 2001-2005 and on inferences from species interactions known for the nearshore fish community. We then develop a framework for examination of energy and nutrient movements within the pelagic and benthic habitats of the offshore zone and across the offshore and nearshore zones. To document research results.

  7. Current Conditions in American Indian and Alaska Native Communities.

    Science.gov (United States)

    Szasz, Margaret Connell

    The school experience of American Indian and Alaska Native children hinges on the context in which their schooling takes place. This context includes the health and well-being of their families, communities, and governments, as well as the relationship between Native and non-Native people. Many Native children are in desperate straits because of…

  8. Fishing degrades size structure of coral reef fish communities.

    Science.gov (United States)

    Robinson, James P W; Williams, Ivor D; Edwards, Andrew M; McPherson, Jana; Yeager, Lauren; Vigliola, Laurent; Brainard, Russell E; Baum, Julia K

    2017-03-01

    Fishing pressure on coral reef ecosystems has been frequently linked to reductions of large fishes and reef fish biomass. Associated impacts on overall community structure are, however, less clear. In size-structured aquatic ecosystems, fishing impacts are commonly quantified using size spectra, which describe the distribution of individual body sizes within a community. We examined the size spectra and biomass of coral reef fish communities at 38 US-affiliated Pacific islands that ranged in human presence from near pristine to human population centers. Size spectra 'steepened' steadily with increasing human population and proximity to market due to a reduction in the relative biomass of large fishes and an increase in the dominance of small fishes. Reef fish biomass was substantially lower on inhabited islands than uninhabited ones, even at inhabited islands with the lowest levels of human presence. We found that on populated islands size spectra exponents decreased (analogous to size spectra steepening) linearly with declining biomass, whereas on uninhabited islands there was no relationship. Size spectra were steeper in regions of low sea surface temperature but were insensitive to variation in other environmental and geomorphic covariates. In contrast, reef fish biomass was highly sensitive to oceanographic conditions, being influenced by both oceanic productivity and sea surface temperature. Our results suggest that community size structure may be a more robust indicator than fish biomass to increasing human presence and that size spectra are reliable indicators of exploitation impacts across regions of different fish community compositions, environmental drivers, and fisheries types. Size-based approaches that link directly to functional properties of fish communities, and are relatively insensitive to abiotic variation across biogeographic regions, offer great potential for developing our understanding of fishing impacts in coral reef ecosystems. © 2016

  9. Functional diversity measures revealed impacts of non-native species and habitat degradation on species-poor freshwater fish assemblages.

    Science.gov (United States)

    Colin, Nicole; Villéger, Sébastien; Wilkes, Martin; de Sostoa, Adolfo; Maceda-Veiga, Alberto

    2018-06-01

    Trait-based ecology has been developed for decades to infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive dataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N=389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have ≤3 species (specialization, FSpe; originality, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native:total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive datasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is

  10. Diversity, distribution, and conservation status of the native freshwater fishes of the Southern United States

    Science.gov (United States)

    Melvin L. Warren; Brooks M. Burr; Stephen J. Walsh; Henry L. Bart; Robert C. Cashner; David A. Etnier; Byron J. Freeman; Bernard R. Kuhajda; Richard L. Mayden; Henry W. Robison; Stephen T. Ross; Wayne C. Starnes

    2000-01-01

    The Southeastern Fishes Council Technical Advisory Committee reviewed the diversity, distribution, and status of all native freshwater and diadromous fishes across 51 major drainage units of the Southern United States. The Southern United States supports more native fishes than any area of comparable size on the North American continent north of Mexico, but also has a...

  11. Alaska Native Villages and Rural Communities Water Grant Program

    Science.gov (United States)

    Significant human health and water quality problems exist in Alaska Native Village and other rural communities in the state due to lack of sanitation. To address these issues, EPA created the Alaska Rural and Native Villages Grant Program.

  12. Does Habitat Restoration Increase Coexistence of Native Stream Fishes with Introduced Brown Trout: A Case Study on the Middle Provo River, Utah, USA

    OpenAIRE

    Mark C. Belk; Eric J. Billman; Craig Ellsworth; Brock R. McMillan

    2016-01-01

    Restoration of altered or degraded habitats is often a key component in the conservation plan of native aquatic species, but introduced species may influence the response of the native community to restoration. Recent habitat restoration of the middle section of the Provo River in central Utah, USA, provided an opportunity to evaluate the effect of habitat restoration on the native fish community in a system with an introduced, dominant predator—brown trout (Salmo trutta). To determine the ch...

  13. 78 FR 36237 - Proposed Information Collection; Federal Fish and Wildlife Permit Applications and Reports-Native...

    Science.gov (United States)

    2013-06-17

    ...--Native Endangered and Threatened Species AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice... requested in accordance with various Federal wildlife conservation laws, including: Endangered Species Act.... [[Page 36238

  14. Assessing the impact of non-native freshwater fishes on native species using relative weight

    Directory of Open Access Journals (Sweden)

    Giannetto D.

    2012-01-01

    Full Text Available The aim of the research was to test relative weight (Wr, a condition index which allows evaluation of fish well-being, as a tool to investigate the impact of the presence of non native species (NNS on the condition of the key native species (NS of the Tiber River basin (Italy: Barbustyberinus Bonaparte, Leuciscus cephalus (Linnaeus, Leuciscus lucumonis Bianco, Rutilus rubilio (Bonaparte and Telestes muticellus (Bonaparte. By means of Canonical Correlation Analysis, data from 130 sampling sites, distributed throughout Tiber River basin, were examined. Wr of NS was related to densities of NNS and to environmental variables. Moreover, the correlation between Wr of NS and density of NNS was investigated through linear regression analysis and covariance analysis. Preliminary results encourage the use of Wr as a tool to assess the relationship between NS and ecological factors (such as the presence of NNS and to explain the changes that occur along the longitudinal gradient of a river.

  15. Parasites of native and nonnative fishes of the Little Colorado River, Grand Canyon, Arizona

    Science.gov (United States)

    Choudhury, A.; Hoffnagle, T.L.; Cole, Rebecca A.

    2004-01-01

    A 2-yr, seasonal, parasitological study of 1,435 fish, belonging to 4 species of native fishes and 7 species of nonnative fishes from the lower Little Colorado River (LCR) and tributary creeks, Grand Canyon, Arizona, yielded 17 species of parasites. These comprised 1 myxozoan (Henneguya exilis), 2 copepods (Ergasilus arthrosis and Lernaea cyprinacea), 1 acarine (Oribatida gen. sp.), 1 piscicolid leech (Myzobdella lugubris), 4 monogeneans (Gyrodactylus hoffmani, Gyrodactylus sp., Dactylogyrus extensus, and Ligictaluridus floridanus), 4 nematodes (Contracaecum sp., Eustrongylides sp., Rhabdochona sp., and Truttaedacnitis truttae), 3 cestodes (Bothriocephalus acheilognathi, Corallobothrium fimbriatum, and Megathylacoides giganteum), and 2 trematodes (Ornithodiplostomum sp. and Posthodiplostomum sp.). Rhabdochona sp. was the only adult parasite native to the LCR. Infection intensities of Ornithodiplostomum sp. and B. acheilognathi were positively correlated with length of the humpback chub Gila cypha. Adult helminths showed a high degree of host specificity, except B. acheilognathi, which was recovered from all fish species examined but was most abundant in cyprinids. Abundance of B. acheilognathi in the humpback chub was highest in the fall and lowest in the summer in both reaches of the LCR. There was no major taxonomic difference in parasite assemblages between the 2 different reaches of the river (LC1 and LC2). Parasite community diversity was very similar in humpback chub, regardless of sampling site or time. The parasite fauna of the LCR is numerically dominated by B. acheilognathi and metacercariae of Ornithodiplostomum sp. The richest and most diverse component community occurred in a nonnative species, the channel catfish Ictalurus punctatus, but infracommunity species richness was highest in a native host, humpback chub.

  16. Isotope niche dimension and trophic overlap between bigheaded carps and native filter-feeding fish in the lower Missouri River, USA

    Science.gov (United States)

    Wang, Jianzhu; Chapman, Duane C.; Xu, Jun; Wang, Yang; Gu, Binhe

    2018-01-01

    Stable carbon and nitrogen isotope values (δ13C and δ15N) were used to evaluate trophic niche overlap between two filter-feeding fishes (known together as bigheaded carp) native to China, silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), and three native filter-feeding fish including bigmouth buffalo (Ictiobus cyprinellus), gizzard shad (Dorosoma cepedianum) and paddlefish (Polyodon spathula) in the lower Missouri River, USA, using the Bayesian Stable Isotope in R statistics. Results indicate that except for bigmouth buffalo, all species displayed similar trophic niche size and trophic diversity. Bigmouth buffalo occupied a small trophic niche and had the greatest trophic overlap with silver carp (93.6%) and bighead carp (94.1%) followed by gizzard shad (91.0%). Paddlefish had a trophic niche which relied on some resources different from those used by other species, and therefore had the lowest trophic overlap with bigheaded carp and other two native fish. The trophic overlap by bigheaded carp onto native fish was typically stronger than the reverse effects from native fish. Average niche overlap between silver carp and native species was as high as 71%, greater than niche overlap between bighead carp and native fish (64%). Our findings indicate that bigheaded carps are a potential threat to a diverse and stable native fish community.

  17. Non-native fishes of the central Indian River Lagoon

    Science.gov (United States)

    Schofield, Pamela J.; Loftus, William F.; Reaver, Kristen M.

    2018-01-01

    We provide a comprehensive review of the status of non-native fishes in the central Indian River Lagoon (from Cape Canaveral to Grant-Valkaria, east of I-95) through literature review and field surveys. Historical records exist for 17 taxa (15 species, one hybrid, one species complex). We found historical records for one additional species, and collected one species in our field survey that had never been recorded in the region before (and which we eradicated). Thus, we evaluate 19 total taxa herein. Of these, we documented range expansion of four salt-tolerant cichlid species, extirpation of six species that were previously recorded from the area and eradication of three species. There was no noticeable change in geographic range for one widespread species and the records for one species are doubtful and may be erroneous. Currently, there is not enough information to evaluate geographic ranges for four species although at least one of those is established.

  18. Factors mediating co-occurrence of an economically valuable introduced fish and its native frog prey.

    Science.gov (United States)

    Hartman, Rosemary; Pope, Karen; Lawler, Sharon

    2014-06-01

    Habitat characteristics mediate predator-prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co-occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co-occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co-occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue-effect dispersal from nearby populations may maintain co-occurrence, within-lake factors proved more important for predicting co-occurrence. Learning which factors allow co-occurrence between economically important introduced species and their native prey enables managers to make better-informed stocking decisions. © 2013 Society for Conservation Biology.

  19. Local extinction and colonisation in native and exotic fish in relation to changes in land use

    OpenAIRE

    Kopp , Dorothée; Figuerola , Jordi; Compin , Arthur; Santoul , Frédéric; Céréghino , Régis

    2011-01-01

    International audience; Distribution patterns of many native and exotic fish species are well documented, yet little is known about the temporal dynamics of native and exotic diversity in relation to changes in land use. We hypothesised that colonisation rates would be higher for exotic fish species and that extinction rates would be higher for native species in large stream systems. We also predicted that cold-water species would be more impacted than thermally tolerant species. To test thes...

  20. Invasive lionfish had no measurable effect on prey fish community structure across the Belizean Barrier Reef.

    Science.gov (United States)

    Hackerott, Serena; Valdivia, Abel; Cox, Courtney E; Silbiger, Nyssa J; Bruno, John F

    2017-01-01

    Invasive lionfish are assumed to significantly affect Caribbean reef fish communities. However, evidence of lionfish effects on native reef fishes is based on uncontrolled observational studies or small-scale, unrepresentative experiments, with findings ranging from no effect to large effects on prey density and richness. Moreover, whether lionfish affect populations and communities of native reef fishes at larger, management-relevant scales is unknown. The purpose of this study was to assess the effects of lionfish on coral reef prey fish communities in a natural complex reef system. We quantified lionfish and the density, richness, and composition of native prey fishes (0-10 cm total length) at sixteen reefs along ∼250 km of the Belize Barrier Reef from 2009 to 2013. Lionfish invaded our study sites during this four-year longitudinal study, thus our sampling included fish community structure before and after our sites were invaded, i.e., we employed a modified BACI design. We found no evidence that lionfish measurably affected the density, richness, or composition of prey fishes. It is possible that higher lionfish densities are necessary to detect an effect of lionfish on prey populations at this relatively large spatial scale. Alternatively, negative effects of lionfish on prey could be small, essentially undetectable, and ecologically insignificant at our study sites. Other factors that influence the dynamics of reef fish populations including reef complexity, resource availability, recruitment, predation, and fishing could swamp any effects of lionfish on prey populations.

  1. Invasive lionfish had no measurable effect on prey fish community structure across the Belizean Barrier Reef

    Directory of Open Access Journals (Sweden)

    Serena Hackerott

    2017-05-01

    Full Text Available Invasive lionfish are assumed to significantly affect Caribbean reef fish communities. However, evidence of lionfish effects on native reef fishes is based on uncontrolled observational studies or small-scale, unrepresentative experiments, with findings ranging from no effect to large effects on prey density and richness. Moreover, whether lionfish affect populations and communities of native reef fishes at larger, management-relevant scales is unknown. The purpose of this study was to assess the effects of lionfish on coral reef prey fish communities in a natural complex reef system. We quantified lionfish and the density, richness, and composition of native prey fishes (0–10 cm total length at sixteen reefs along ∼250 km of the Belize Barrier Reef from 2009 to 2013. Lionfish invaded our study sites during this four-year longitudinal study, thus our sampling included fish community structure before and after our sites were invaded, i.e., we employed a modified BACI design. We found no evidence that lionfish measurably affected the density, richness, or composition of prey fishes. It is possible that higher lionfish densities are necessary to detect an effect of lionfish on prey populations at this relatively large spatial scale. Alternatively, negative effects of lionfish on prey could be small, essentially undetectable, and ecologically insignificant at our study sites. Other factors that influence the dynamics of reef fish populations including reef complexity, resource availability, recruitment, predation, and fishing could swamp any effects of lionfish on prey populations.

  2. Effects of fire on fish populations: Landscape perspectives on persistance of native fishes and nonnative fish invasions

    Science.gov (United States)

    Dunham, J.B.; Young, M.; Gresswell, Robert E.; Rieman, B.

    2003-01-01

    Our limited understanding of the short and long-term effects of fire on fish contributes to considerable uncertainty in assessments of the risks and benefits of fire management alternatives. A primary concern among the many potential effects of fire is the effects of fire and fire management on persistence of native fish populations. Limited evidence suggests vulnerability of fish to fire is contingent upon the quality of affected habitats, the amount and distribution of habitat (habitat fragmentation), and habitat specificity of the species in question. Species with narrow habitat requirements in highly degraded and fragmented systems are likely to be most vulnerable to fire and fire-related disturbance. In addition to effects of fire on native fish, there are growing concerns about the effects of fire on nonnative fish invasions. The role of fire in facilitating invasions by nonnative fishes is unknown, but experience with other species suggests some forms of disturbance associated with fire may facilitate invasion. Management efforts to promote persistence of fishes in fire-prone landscapes can take the form of four basic alternatives: (1) pre-fire management; (2) post-fire management; (3) managing fire itself (e.g. fire fighting); and (4) monitoring and adaptive management. Among these alternatives, pre-fire management is likely to be most effective. Effective pre-fire management activities will address factors that may render fish populations more vulnerable to the effects of fire (e.g. habitat degradation, fragmentation, and nonnative species). Post-fire management is also potentially important, but suffers from being a reactive approach that may not address threats in time to avert them. Managing fire itself can be important in some contexts, but negative consequences for fish populations are possible (e.g. toxicity of fire fighting chemicals to fish). Monitoring and adaptive management can provide important new information for evaluating alternatives, but

  3. Managing conflicts arising from fisheries enhancements based on non-native fishes in southern Africa.

    Science.gov (United States)

    Ellender, B R; Woodford, D J; Weyl, O L F; Cowx, I G

    2014-12-01

    Southern Africa has a long history of non-native fish introductions for the enhancement of recreational and commercial fisheries, due to a perceived lack of suitable native species. This has resulted in some important inland fisheries being based on non-native fishes. Regionally, these introductions are predominantly not benign, and non-native fishes are considered one of the main threats to aquatic biodiversity because they affect native biota through predation, competition, habitat alteration, disease transfer and hybridization. To achieve national policy objectives of economic development, food security and poverty eradication, countries are increasingly looking towards inland fisheries as vehicles for development. As a result, conflicts have developed between economic and conservation objectives. In South Africa, as is the case for other invasive biota, the control and management of non-native fishes is included in the National Environmental Management: Biodiversity Act. Implementation measures include import and movement controls and, more recently, non-native fish eradication in conservation priority areas. Management actions are, however, complicated because many non-native fishes are important components in recreational and subsistence fisheries that contribute towards regional economies and food security. In other southern African countries, little attention has focussed on issues and management of non-native fishes, and this is cause for concern. This paper provides an overview of introductions, impacts and fisheries in southern Africa with emphasis on existing and evolving legislation, conflicts, implementation strategies and the sometimes innovative approaches that have been used to prioritize conservation areas and manage non-native fishes. © 2014 The Fisheries Society of the British Isles.

  4. Fish consumption behavior and rates in native and non-native people in Saudi Arabia

    KAUST Repository

    Burger, Joanna; Gochfeld, Michael; Batang, Zenon B.; Mannalamkunnath Alikunhi, Nabeel; Aljahdali, Ramzi; Al-Jebreen, Dalal Hamad; Aziz, Mohammed A M; Al-Suwailem, Abdulaziz M.

    2014-01-01

    eat fish at home (over 90%), and many eat fish at restaurants (65% and 48%, respectively for Saudis and expatriates). Fish eaten at home comes from local fish markets, followed by supermarkets. Saudis included fish in their diets at an average of 1

  5. Response of native insect communities to invasive plants.

    Science.gov (United States)

    Bezemer, T Martijn; Harvey, Jeffrey A; Cronin, James T

    2014-01-01

    Invasive plants can disrupt a range of trophic interactions in native communities. As a novel resource they can affect the performance of native insect herbivores and their natural enemies such as parasitoids and predators, and this can lead to host shifts of these herbivores and natural enemies. Through the release of volatile compounds, and by changing the chemical complexity of the habitat, invasive plants can also affect the behavior of native insects such as herbivores, parasitoids, and pollinators. Studies that compare insects on related native and invasive plants in invaded habitats show that the abundance of insect herbivores is often lower on invasive plants, but that damage levels are similar. The impact of invasive plants on the population dynamics of resident insect species has been rarely examined, but invasive plants can influence the spatial and temporal dynamics of native insect (meta)populations and communities, ultimately leading to changes at the landscape level.

  6. Native Grass Community Management Plan for the Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Ryon, Michael G [ORNL; Parr, Patricia Dreyer [ORNL; Cohen, Kari [ORNL

    2007-06-01

    Land managers at the Department of Energy's Oak Ridge National Laboratory in East Tennessee are restoring native warm-season grasses and wildflowers to various sites across the Oak Ridge Reservation (ORR). Some of the numerous benefits to planting native grasses and forbs include improved habitat quality for wildlife, improved aesthetic values, lower long-term maintenance costs, and compliance with Executive Order 13112 (Clinton 1999). Challenges to restoring native plants on the ORR include the need to gain experience in establishing and maintaining these communities and the potentially greater up-front costs of getting native grasses established. The goals of the native grass program are generally outlined on a fiscal-year basis. An overview of some of the issues associated with the successful and cost-effective establishment and maintenance of native grass and wildflower stands on the ORR is presented in this report.

  7. Community-Based Native Teacher Education Programs.

    Science.gov (United States)

    Heimbecker, Connie; Minner, Sam; Prater, Greg

    This paper describes two exemplary school-based Native teacher education programs offered by Northern Arizona University (NAU) to serve Navajo students and by Lakehead University (Ontario) to serve members of the Nishnabe Nation of northern Ontario. The Reaching American Indian Special/Elementary Educators (RAISE) program is located in Kayenta,…

  8. Predicting establishment of non-native fishes in Greece: identifying key features

    Directory of Open Access Journals (Sweden)

    Christos Gkenas

    2015-11-01

    Full Text Available Non-native fishes are known to cause economic damage to human society and are considered a major threat to biodiversity loss in freshwater ecosystems. The growing concern about these impacts has driven to an investigation of the biological traits that facilitate the establishment of non-native fish. However, invalid assessment in choosing the appropriate statistical model can lead researchers to ambiguous conclusions. Here, we present a comprehensive comparison of traditional and alternative statistical methods for predicting fish invasions using logistic regression, classification trees, multicorrespondence analysis and random forest analysis to determine characteristics of successful and failed non-native fishes in Hellenic Peninsula through establishment. We defined fifteen categorical predictor variables with biological relevance and measures of human interest. Our study showed that accuracy differed according to the model and the number of factors considered. Among all the models tested, random forest and logistic regression performed best, although all approaches predicted non-native fish establishment with moderate to excellent results. Detailed evaluation among the models corresponded with differences in variables importance, with three biological variables (parental care, distance from nearest native source and maximum size and two variables of human interest (prior invasion success and propagule pressure being important in predicting establishment. The analyzed statistical methods presented have a high predictive power and can be used as a risk assessment tool to prevent future freshwater fish invasions in this region with an imperiled fish fauna.

  9. Community-level plant-soil feedbacks explain landscape distribution of native and non-native plants.

    Science.gov (United States)

    Kulmatiski, Andrew

    2018-02-01

    Plant-soil feedbacks (PSFs) have gained attention for their potential role in explaining plant growth and invasion. While promising, most PSF research has measured plant monoculture growth on different soils in short-term, greenhouse experiments. Here, five soil types were conditioned by growing one native species, three non-native species, or a mixed plant community in different plots in a common-garden experiment. After 4 years, plants were removed and one native and one non-native plant community were planted into replicate plots of each soil type. After three additional years, the percentage cover of each of the three target species in each community was measured. These data were used to parameterize a plant community growth model. Model predictions were compared to native and non-native abundance on the landscape. Native community cover was lowest on soil conditioned by the dominant non-native, Centaurea diffusa , and non-native community cover was lowest on soil cultivated by the dominant native, Pseudoroegneria spicata . Consistent with plant growth on the landscape, the plant growth model predicted that the positive PSFs observed in the common-garden experiment would result in two distinct communities on the landscape: a native plant community on native soils and a non-native plant community on non-native soils. In contrast, when PSF effects were removed, the model predicted that non-native plants would dominate all soils, which was not consistent with plant growth on the landscape. Results provide an example where PSF effects were large enough to change the rank-order abundance of native and non-native plant communities and to explain plant distributions on the landscape. The positive PSFs that contributed to this effect reflected the ability of the two dominant plant species to suppress each other's growth. Results suggest that plant dominance, at least in this system, reflects the ability of a species to suppress the growth of dominant competitors

  10. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Science.gov (United States)

    Moyle, Peter B; Kiernan, Joseph D; Crain, Patrick K; Quiñones, Rebecca M

    2013-01-01

    Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1) current status of each species (baseline vulnerability to extinction) and (2) likely future impacts of climate change (vulnerability to extinction). Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish species. It should be useful for setting conservation

  11. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Directory of Open Access Journals (Sweden)

    Peter B Moyle

    Full Text Available Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1 current status of each species (baseline vulnerability to extinction and (2 likely future impacts of climate change (vulnerability to extinction. Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (<22°C are particularly likely to go extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish

  12. Fish farming of native species in Colombia: current situation and perspectives

    DEFF Research Database (Denmark)

    Cruz-Casallas, P. E.; Medina-Robles, V. M.; Velasco-Santamaria, Y. M.

    2011-01-01

    . The Colombian pisciculture is based on red Tilapia Oreochromis sp. (Linnaeus), Rainbow trout Oncorhynchus mykiss (Walbaum) and cachama blanca Piaractus brachypomus (Cuvier), which currently represent around 96% of the total national production. The remaining 4% comes from other farmed species such as bocachico......In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities...... Prochilodus magdalenae (Steindachner), carp Cyprinus carpio (Linnaeus) and yamu Brycon amazonicus (Spix & Agassiz). From the three main fish species, cachama blanca is the only native species, which has shown excellent performance in pond farming due to its rusticity, omnivorous habits, docility, meat quality...

  13. Does functional redundancy stabilize fish communities?

    DEFF Research Database (Denmark)

    Rice, Jake; Daan, Niels; Gislason, Henrik

    2013-01-01

    in abundance or biomass could be accounted for by the Law of Large Numbers, providing no evidence that specific ecological processes or co-adaptations are necessary to produce this effect. This implies that successful conservation policies to maintain the resilience of a marine fish community could be based......Functional redundancy of species sharing a feeding strategy and/or maximum size has been hypothesized to contribute to increased resilience of marine fish communities (the “portfolio effect”). A consistent time-series of survey data of fish in the North Sea was used to examine if trophic functional...... groups or maximum length of species (Lmax) groups with larger numbers of species had lower coefficients of variation in abundance and biomass over time than did groupings with fewer species. Results supported this hypothesis. However, the stabilizing effect of numbers of species in a group on variation...

  14. Mining and Environmental Health Disparities in Native American Communities.

    Science.gov (United States)

    Lewis, Johnnye; Hoover, Joseph; MacKenzie, Debra

    2017-06-01

    More than a century of hard rock mining has left a legacy of >160,000 abandoned mines in the Western USA that are home to the majority of Native American lands. This article describes how abrogation of treaty rights, ineffective policies, lack of infrastructure, and a lack of research in Native communities converge to create chronic exposure, ill-defined risks, and tribal health concerns. Recent results show that Native Americans living near abandoned uranium mines have an increased likelihood for kidney disease and hypertension, and an increased likelihood of developing multiple chronic diseases linked to their proximity to the mine waste and activities bringing them in contact with the waste. Biomonitoring confirms higher than expected exposure to uranium and associated metals in the waste in adults, neonates, and children in these communities. These sites will not be cleaned up for many generations making it critical to understand and prioritize exposure-toxicity relationships in Native populations to appropriately allocate limited resources to protect health. Recent initiatives, in partnership with Native communities, recognize these needs and support development of tribal research capacity to ensure that research respectful of tribal culture and policies can address concerns in the future. In addition, recognition of the risks posed by these abandoned sites should inform policy change to protect community health in the future.

  15. Fish consumption behavior and rates in native and non-native people in Saudi Arabia

    KAUST Repository

    Burger, Joanna

    2014-08-01

    Fish are a healthy source of protein and nutrients, but contaminants in fish may provide health risks. Determining the risk from contaminants in fish requires site-specific information on consumption patterns. We examine consumption rates for resident and expatriates in the Jeddah region of Saudi Arabia, by species of fish and fishing location. For Saudis, 3.7% of males and 4.3% of females do not eat fish; for expatriates, the percent not eating fish is 6.6% and 6.1% respectively. Most people eat fish at home (over 90%), and many eat fish at restaurants (65% and 48%, respectively for Saudis and expatriates). Fish eaten at home comes from local fish markets, followed by supermarkets. Saudis included fish in their diets at an average of 1.4±1.2 meals/week at home and 0.8±0.7 meals/week at restaurants, while expats ate 2.0±1.7 meals/week at home and 1.1±1.1 meals/week in restaurants. Overall, Saudis ate 2.2 fish meals/week, while expats ate 3.1 meals/week. Grouper (Epinephelus and Cephalopholis) were eaten by 72% and 60% respectively. Plectropomus pessuliferus was the second favorite for both groups and Hipposcarus harid and Lethrinus lentjan were in 3rd and 4th place in terms of consumption. Average meal size was 68. g for Saudis and 128. g for expatriates. These data can be used by health professionals, risk assessors, and environmental regulators to examine potential risk from contaminants in fish, and to compare consumption rates with other sites. © 2014 Elsevier Inc.

  16. Native plant community response to alien plant invasion and removal

    Directory of Open Access Journals (Sweden)

    Jara ANDREU

    2011-01-01

    Full Text Available Given the potential ecological impacts of invasive species, removal of alien plants has become an important management challenge and a high priority for environmental managers. To consider that a removal effort has been successful requires both, the effective elimination of alien plants and the restoration of the native plant community back to its historical composition and function. We present a conceptual framework based on observational and experimental data that compares invaded, non-invaded and removal sites to quantify invaders’ impacts and native plant recover after their removal. We also conduct a meta-analysis to quantitatively evaluate the impacts of plant invaders and the consequences of their removal on the native plant community, across a variety of ecosystems around the world. Our results that invasion by alien plants is responsible for a local decline in native species richness and abundance. Our analysis also provides evidence that after removal, the native vegetation has the potential to recover to a pre-invasion target state. Our review reveal that observational and experimental approaches are rarely used in concert, and that reference sites are scarcely employed to assess native species recovery after removal. However, we believe that comparing invaded, non-invaded and removal sites offer the opportunity to obtain scientific information with relevance for management.

  17. Changes in the North Sea fish community: evidence of indirect effects of fishing?

    DEFF Research Database (Denmark)

    Daan, N.; Gislason, Henrik; Pope, J.

    2005-01-01

    , but such changes may simply reflect the cumulative, direct effects of fishing through selective removal of large individuals. If there is resilience in a fish community towards fishing, we may expect increases in specific components, for instance as a consequence of an associated reduction in predation and....... Taking average fishing mortality of assessed commercial species as an index of exploitation rate of the fish community, it appears that fishing effort reached its maximum in the mid-1980s and has declined slightly since. If the observed changes in the community are caused by indirect effects of fishing...

  18. Current status of non-native fish species in the St. Louis River estuary

    Science.gov (United States)

    The fish community of the St. Louis River estuary is well characterized, thanks to fishery assessment and invasive species early detection monitoring by federal, state, and tribal agencies. This sampling includes long-standing adult/juvenile fish surveys, larval fish surveys beg...

  19. Consumption of freshwater fish by recreational and native freshwater anglers in the upper St-Maurice (Quebec, Canada) and estimation of the intake of methylmercury in humans

    International Nuclear Information System (INIS)

    Loranger, S.; Houde, L.; Schetagne, R.

    1995-01-01

    Hydro-Quebec is planning to build two hydroelectric reservoirs in the upper Saint-Maurice River, which would flood about 80% of the surrounding area. The methylmercury (MeHg) content in freshwater fish will therefore tend to increase during the first few years. This development will have a direct impact on the amount of MeHg that the actual users of this river section are exposed to. The objective of this study is to assess the consumption of local fish of these target groups using a Monte-Carlo approach. This study is part of a larger research project aimed at assessing human exposure and the health risks related to MeHg contamination in local fish. The fish consumption rate for recreational freshwater anglers was calculated using the duration of the average annual fishing trip, the average number of catches per species, the average fish weight per species exceeding a specific length of fish usually caught, and the edible portion of fish consumed. This rate was calculated for the native communities based on the total number of meals per year per species, the average fish weight per species, and the edible portion. Based on these calculations, average intake for sport fishermen is estimated at 6.9 g/day (sd = 6.4). This value is 5 to 25 times lower on average than for other North American native communities. However, it must be pointed out that the food habits of the native population were very similar to those of non-native populations; less than 30% of the food comes from traditional sources

  20. Native and exotic fishes in a Patagonian reservoir with rainbow trout cage culture: spatial and trophic resource use

    Directory of Open Access Journals (Sweden)

    Nabaes Jodar Diego N.

    2017-01-01

    Full Text Available Although the interactions of exotic salmonids with native Patagonian fishes are well known, little is known about the ecology and impact of farmed fish escapees. Salmonid production in Argentina is largely concentrated in the Alicurá reservoir in north Patagonia, where fish community studies have been scarce. Here, we assess and compare the spatial distribution, body size–condition and diet of the different fish species in this reservoir. Strong vertical segregation was observed between exotic rainbow trout Oncorhynchus mykiss (both escapees and wild, dominating the littoral zone, and native Percichthys trucha which dominate the medium and deep strata. Low piscivory–benthivory and high zooplanktivory were observed for rainbow trout, both traits being uncommon at a regional scale. Escaped farmed rainbow trout (ERT diet included abundant indigestible items along with wild prey. Higher body condition of P. trucha close to farms, as well as the regionally unprecedented high incidence of Daphnia sp. in the guts of all the species suggest that farm nutrient discharges have had significant impacts. Finally, the high body condition of ERT, together with their wild food diet and the long dispersal distance observed, demonstrate post-escape success, drawing our attention to potential upstream dispersion affecting the biodiversity and fisheries of Patagonian rivers and lakes.

  1. Relative and combined effects of habitat and fishing on reef fish communities across a limited fishing gradient at Ningaloo.

    Science.gov (United States)

    Wilson, Shaun K; Babcock, Russ C; Fisher, Rebecca; Holmes, Thomas H; Moore, James A Y; Thomson, Damian P

    2012-10-01

    Habitat degradation and fishing are major drivers of temporal and spatial changes in fish communities. The independent effects of these drivers are well documented, but the relative importance and interaction between fishing and habitat shifts is poorly understood, particularly in complex systems such as coral reefs. To assess the combined and relative effects of fishing and habitat we examined the composition of fish communities on patch reefs across a gradient of high to low structural complexity in fished and unfished areas of the Ningaloo Marine Park, Western Australia. Biomass and species richness of fish were positively correlated with structural complexity of reefs and negatively related to macroalgal cover. Total abundance of fish was also positively related to structural complexity, however this relationship was stronger on fished reefs than those where fishing is prohibited. The interaction between habitat condition and fishing pressure is primarily due to the high abundance of small bodied planktivorous fish on fished reefs. However, the influence of management zones on the abundance and biomass of predators and target species is small, implying spatial differences in fishing pressure are low and unlikely to be driving this interaction. Our results emphasise the importance of habitat in structuring reef fish communities on coral reefs especially when gradients in fishing pressure are low. The influence of fishing effort on this relationship may however become more important as fishing pressure increases. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Patterns in the Use of a Restored California Floodplain by Native and Alien Fishes

    Directory of Open Access Journals (Sweden)

    Peter B Moyle

    2007-07-01

    Full Text Available Fishes were sampled on the restored floodplain of the Cosumnes River in Central California in order to determine patterns of floodplain use. The floodplain was sampled for seven years (1998-2002, 2004-2005 during the winter-spring flooding season. The fishes fell into five groups: (1 floodplain spawners, (2 river spawners, (3 floodplain foragers, (4 floodplain pond fishes, and (5 inadvertent users. Eight of the 18 abundant species were natives, while the rest were aliens. There was a consistent pattern of floodplain use, modified by timing and extent of flooding. The first fishes to appear were floodplain foragers, inadvertent users, and juvenile Chinook salmon (river spawners. Next were floodplain spawners, principally Sacramento splittail and common carp. At the end of the season, in ponds of residual water, non-native annual fishes, mainly inland silverside and western mosquitofish, became abundant. Adult spawners left when inflow decreased; their juveniles persisted as long as flood pulses kept water levels up and temperatures low. Juvenile splittail and carp quickly grew large enough to dominate floodplain fish samples, along with smaller numbers of juvenile Sacramento sucker and pikeminnow (river spawners. Such juveniles left the Relatively few fishes that used the floodplain for spawning or rearing became stranded, except late season alien fishes. Most alien fishes had resident populations in adjacent river, sloughs, and ditches and were not dependent on the floodplain for persistence. This indicates that Central Valley floodplains managed to favor native fishes should have the following char- acteristics: (1 extensive early season flooding, (2 complete drainage by the end of the flooding season, (3 few areas with permanent water, (4 a mosaic of physical habitats, (5 regular annual flooding but with high variability in flood regime.

  3. Invasive predator tips the balance of symmetrical competition between native coral-reef fishes.

    Science.gov (United States)

    Kindinger, Tye L

    2018-04-01

    The importance of competition and predation in structuring ecological communities is typically examined separately such that interactions between these processes are seldom understood. By causing large reductions in native prey, invasive predators may modify native species interactions. I conducted a manipulative field experiment in The Bahamas to investigate the possibility that the invasive Pacific red lionfish (Pterois volitans) alters competition between planktivorous fairy and blackcap basslets (Gramma loreto and Gramma melacara, respectively). Competition between these coral-reef fishes is known to have symmetrical effects on the juveniles of both species, whereby the feeding positions under reef ledges and growth rates of these individuals are hindered. Following baseline censuses of local populations of competing basslets, I simultaneously manipulated the abundance of lionfish on entire reefs, and the abundance of basslets in local populations under isolated ledges within each reef, resulting in three treatments: unmanipulated control populations of both basslets, reduced abundance of fairy basslet, and reduced abundance of blackcap basslet. For eight weeks, I measured the change in biomass and feeding position of 2-5 cm size classes of each basslet species and calculated the growth rates of ~2 cm individuals using a standard mark-and-recapture method. Experimental populations were filmed at dusk using automated video cameras to quantify the behavior of lionfish overlapping with basslets. Video playback revealed lionfish hunted across all ledge positions, regardless of which basslet species were present, yet lionfish differentially reduced the biomass of only juvenile (2 cm) fairy basslet. Predation reduced the effects of interspecific competition on juvenile blackcap basslet as evidenced by corresponding shifts in feeding position toward coveted front edges of ledges and increases in growth rates that were comparable to the response of these fish in

  4. Comparison of fish-community size spectra based on length ...

    African Journals Online (AJOL)

    Estimates of fish-community size spectra are promising indicators of the impact of fishing on fish assemblages. Size spectra consist of logarithmic graphs of abundance plotted against fish body size. Size spectra may either be constructed from length frequency data or estimated from the mean sizes and abundances of the ...

  5. Tropical fish community does not recover 45 years after predator introduction.

    Science.gov (United States)

    Sharpe, D M T; De León, L F; González, R; Torchin, M E

    2017-02-01

    Predation is considered to be an important factor structuring natural communities. However, it is often difficult to determine how it may influence long-term, broad-scale, diversity patterns, particularly in diverse tropical systems. Biological introductions can provide powerful insight to test the sustained consequences of predation in natural communities, if pre-introduction data are available. Half a century ago, Zaret and Paine demonstrated strong and immediate community-level effects following the introduction of a novel apex predator (peacock bass, Cichla monoculus) into Lake Gatun, Panama. To test for long-term changes associated with this predator introduction, we followed up on their classic study by replicating historical sampling methods and examining changes in the littoral fish community at two sites in Lake Gatun 45 years post-introduction. To broaden our inference, we complemented this temporal comparison with a spatial analysis, wherein we compared the fish communities from two lakes with and one lake without peacock bass. Comparisons with historical data revealed that the peacock bass remains the most abundant predator in Lake Gatun. Furthermore, the collapse of the littoral prey community observed immediately following the invasion has been sustained over the past 45 years. The mean abundance of native littoral fish is now 96% lower than it was prior to the introduction. Diversity (rarefied species richness) declined by 64% post-introduction, and some native species appear to have been locally extirpated. We observed a similar pattern across invaded and uninvaded lakes: the mean abundance of native fishes was 5-40 times lower in lakes with (Gatun, Alajuela) relative to the lake without peacock bass (Bayano). In particular, small-bodied native fishes (Characidae, Peociliidae), which are common prey of the peacock bass, were more than two orders of magnitude (307 times) less abundant in Gatun and one order of magnitude (28 times) less abundant in

  6. Synergistic impacts by an invasive amphipod and an invasive fish explain native gammarid extinction.

    Science.gov (United States)

    Beggel, S; Brandner, J; Cerwenka, A F; Geist, J

    2016-07-14

    Worldwide freshwater ecosystems are increasingly affected by invasive alien species. In particular, Ponto-Caspian gobiid fishes and amphipods are suspected to have pronounced effects on aquatic food webs. However, there is a lack of systematic studies mechanistically testing the potential synergistic effects of invasive species on native fauna. In this study we investigated the interrelations between the invasive amphipod Dikerogammarus villosus and the invasive fish species Neogobius melanostomus in their effects on the native amphipod Gammarus pulex. We hypothesized selective predation by the fish as a driver for displacement of native species resulting in potential extinction of G. pulex. The survival of G. pulex in the presence of N. melanostomus in relation to the presence of D. villosus and availability of shelter was analyzed in the context of behavioural differences between the amphipod species. Gammarus pulex had a significantly higher susceptibility to predation by N. melanostomus compared to D. villosus in all experiments, suggesting preferential predation by this fish on native gammarids. Furthermore, the presence of D. villosus significantly increased the vulnerability of G. pulex to fish predation. Habitat structure was an important factor for swimming activity of amphipods and their mortality, resulting in a threefold decrease in amphipods consumed with shelter habitat structures provided. Behavioral differences in swimming activity were additionally responsible for higher predation rates on G. pulex. Intraguild predation could be neglected within short experimental durations. The results of this study provide evidence for synergistic effects of the two invasive Ponto-Caspian species on the native amphipod as an underlying process of species displacements during invasion processes. Prey behaviour and monotonous habitat structures additionally contribute to the decline of the native gammarid fauna in the upper Danube River and elsewhere.

  7. Prey utilisation and trophic overlap between the non native mosquitofish and a native fish in two Mediterranean rivers

    Directory of Open Access Journals (Sweden)

    E. KALOGIANNI

    2014-04-01

    Full Text Available Non native freshwater fish species have been long implicated in the decline of native Mediterranean ichthyofauna, through hybridization, disease transmission, competition for food and habitat, predation and/or ecosystem alteration; our knowledge, however, on the underlying mechanisms of these ecological impacts remains very limited. To explore the potential for trophic competition between the widespread Eastern mosquitofish Gambusia holbrooki and its co-occurring native toothcarp Valencia letourneuxi we compared resource use, feeding strategies, trophic selectivities and diet niche overlap. For this purpose, we studied two populations of the two species from a freshwater and a brackish habitat respectively, characterized by different food resource availabilities. In both habitats, the mosquitofish consumed a greater diversity of invertebrates and preyed on terrestrial invertebrates more frequently than the native toothcarp. Furthermore, in the less diverse and less rich brackish habitat, the non native relied heavily on plant material to balance a decrease in animal prey consumption and modified its individual feeding strategy, whereas these adaptive changes were not apparent in the native species. Their diet overlapped, indicating trophic competition, but this overlap was affected by resource availability variation; in the freshwater habitat, there was limited overlap in their diet, whereas in the brackish habitat, their diets and prey selectivities converged and there was high overlap in resource use, indicative of intense interspecific trophic competition. Overall, it appears that the underlying mechanism of the putative negative impacts of the mosquitofish on the declining Corfu toothcarp is mainly trophic competition, regulated by resource variability, though there is also evidence of larvae predation by the mosquitofish.

  8. Women finding the way: American Indian women leading intervention research in Native communities.

    Science.gov (United States)

    Brave Heart, Maria Yellow Horse; Chase, Josephine; Elkins, Jennifer; Martin, Jennifer; Nanez, Jennifer; Mootz, Jennifer

    2016-01-01

    Although there is literature concentrating on cross-cultural approaches to academic and community partnerships with Native communities, few address the process and experiences of American Indian women leading federally funded and culturally grounded behavioral health intervention research in Native communities. This paper summarizes relevant literature on community-engaged research with Native communities, examines traditional roles and modern challenges for American Indian women, describes the culturally grounded collaborative process for the authors' behavioral health intervention development with Native communities, and considers emergent themes from our own research experiences navigating competing demands from mainstream and Native communities. It concludes with recommendations for supporting and enhancing resilience.

  9. Critical Contexts for Biomedical Research in a Native American Community: Health Care, History, and Community Survival

    Science.gov (United States)

    Sahota, Puneet Chawla

    2012-01-01

    Native Americans have been underrepresented in previous studies of biomedical research participants. This paper reports a qualitative interview study of Native Americans' perspectives on biomedical research. In-depth interviews were conducted with 53 members of a Southwest tribal community. Many interviewees viewed biomedical research studies as a…

  10. An assessment of a proposal to eradicate non-native fish from ...

    African Journals Online (AJOL)

    African Journal of Aquatic Science ... A pilot project to evaluate the use of the piscicide rotenone to eradicate non-native fish from selected reaches in four rivers has been proposed by CapeNature, the conservation ... It is expected that the project will be successful while having minimal impact on other aquatic fauna.

  11. Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

    Science.gov (United States)

    Rosen, Barry H.; St. Amand, Ann

    2015-09-14

    Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

  12. Interaction of historical and nonhistorical disturbances maintains native plant communities.

    Science.gov (United States)

    Davies, K W; Svejcar, T J; Bates, J D

    2009-09-01

    Historical disturbance regimes are often considered a critical element in maintaining native plant communities. However, the response of plant communities to disturbance may be fundamentally altered as a consequence of invasive plants, climate change, or prior disturbances. The appropriateness of historical disturbance patterns under modern conditions and the interactions among disturbances are issues that ecologists must address to protect and restore native plant communities. We evaluated the response of Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh plant communities to their historical disturbance regime compared to other disturbance regimes. The historical disturbance regime of these plant communities was periodic fires with minimal grazing by large herbivores. We also investigated the influence of prior disturbance (grazing) on the response of these communities to subsequent disturbance (burning). Treatments were: (1) ungrazed (livestock grazing excluded since 1936) and unburned, (2) grazed and unburned, (3) ungrazed and burned (burned in 1993), and (4) grazed and burned. The ungrazed-burned treatment emulated the historical disturbance regime. Vegetation cover, density, and biomass production were measured the 12th, 13th, and 14th year post-burning. Prior to burning the presence of Bromus tectorum L., an exotic annual grass, was minimal (resilience to more severe disturbances. Modern deviations from historical conditions can alter ecosystem response to disturbances, thus restoring the historical disturbance regime may not be an appropriate strategy for all ecosystems.

  13. Water guns affect abundance and behavior of bigheaded carp and native fish differently

    Science.gov (United States)

    Rivera, Jose; Glover, David C.; Kocovsky, Patrick; Garvey, James E.; Gaikowski, Mark; Jensen, Nathan R.; Adams, Ryan F.

    2017-01-01

    Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

  14. Status of native fishes in the western United States and issues for fire and fuels management

    Science.gov (United States)

    Rieman, B.; Lee, D.; Burns, D.; Gresswell, Robert E.; Young, M.; Stowell, R.; Rinne, J.; Howell, P.

    2003-01-01

    Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been viewed as one cause of this problem. Fires also can have substantial effects on streams and riparian systems and may threaten the persistence of some populations of fish, particularly those that are small and isolated. Despite that, major new efforts to actively manage fires and fuels in forests throughout the region may be perceived as a threat rather than a benefit to conservation of native fishes and their habitats. The management of terrestrial and aquatic resources has often been contentious, divided among a variety of agencies with different goals and mandates. Management of forests, for example, has generally been viewed as an impact on aquatic systems. Implementation of the management-regulatory process has reinforced a uniform approach to mitigate the threats to aquatic species and habitats that may be influenced by management activities. The problems and opportunities, however, are not the same across the landscapes of interest. Attempts to streamline the regulatory process often search for generalized solutions that may oversimplify the complexity of natural systems. Significant questions regarding the influence of fire on aquatic ecosystems, changing fire regimes, and the effects of fire-related management remain unresolved and contribute to the uncertainty. We argue that management of forests and fishes can be viewed as part of the same problem, that of conservation and restoration of the natural processes that create diverse and productive ecosystems. We suggest that progress toward more integrated management of forests and native fishes will require at least three steps: (1) better

  15. Water guns affect abundance and behavior of bigheaded carp and native fish differently

    Science.gov (United States)

    Rivera, Jose; Glover, David C.; Kocovsky, Patrick; Garvey, James E.; Gaikowski, Mark; Jensen, Nathan R.; Adams, Ryan F.

    2018-01-01

    Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

  16. Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

    Directory of Open Access Journals (Sweden)

    Alejandra F. G. N. Santos

    Full Text Available We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and channel catfish Ictalurus punctatus and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered. Prey survival was variable through time and among species (C. piquiti < O. niloticus < A. altiparanae < P. lineatus < I. punctatus, depending largely on species-specific prey behavior but also on prey size and morphological defenses. Habitat complexity did not directly affect P. corruscans piscivory but some prey species changed their microhabitat use and shoaling behavior among habitat treatments in predator's presence. Pseudoplatystoma corruscans preyed preferentially on smaller individuals of those invasive species with weak morphological defensive features that persisted in a non-shoaling behavior. Overall, our results contrast with those in a companion experiment using a diurnal predator, suggesting that nocturnal piscivores preferentially prey on different (rather diurnal fish species and are less affected by habitat complexity. Our findings suggest that recovering the native populations of P. corruscans might help controling some fish species introduced to the Paraná River basin, particularly C. piquiti and O. niloticus, whose parental care is expected to be weak or null at night.

  17. Comparison of root-associated communities of native and non-native ectomycorrhizal hosts in an urban landscape.

    Science.gov (United States)

    Lothamer, K; Brown, S P; Mattox, J D; Jumpponen, A

    2014-05-01

    Non-native tree species are often used as ornamentals in urban landscapes. However, their root-associated fungal communities remain yet to be examined in detail. Here, we compared richness, diversity and community composition of ectomycorrhizosphere fungi in general and ectomycorrhizal (EcM) fungi in particular between a non-native Pinus nigra and a native Quercus macrocarpa across a growing season in urban parks using 454-pyrosequencing. Our data show that, while the ectomycorrhizosphere community richness and diversity did not differ between the two host, the EcM communities associated with the native host were often more species rich and included more exclusive members than those of the non-native hosts. In contrast, the ectomycorrhizosphere communities of the two hosts were compositionally clearly distinct in nonmetric multidimensional ordination analyses, whereas the EcM communities were only marginally so. Taken together, our data suggest EcM communities with broad host compatibilities and with a limited numbers of taxa with preference to the non-native host. Furthermore, many common fungi in the non-native Pinus were not EcM taxa, suggesting that the fungal communities of the non-native host may be enriched in non-mycorrhizal fungi at the cost of the EcM taxa. Finally, while our colonization estimates did not suggest a shortage in EcM inoculum for either host in urban parks, the differences in the fungi associated with the two hosts emphasize the importance of using native hosts in urban environments as a tool to conserve endemic fungal diversity and richness in man-made systems.

  18. Mentoring in Native American Communities using STEM Concepts

    Science.gov (United States)

    Angrum, A.; Alexander, C. J.; Martin, M.

    2011-12-01

    In this paper we will present a concept for mentoring built on STEM principles, and applied to the Native American community in Chinle, AZ. Effective mentoring includes being sensitive, listening to, and advising mentees based upon a 'correct' appreciation not only of their needs but also of the desires of the community they come from. Our project is an outreach effort on the part of NASA's contribution to the International Rosetta mission. Our initial program design incorporated ambitious STEM materials developed by NASA/JPL for other communities that excite and engage future generations in geoscience careers, to be re-packaged and brought to the Navajo community in Chinle. We were cognizant of the communities' emphasis on the need to know themselves and their own culture when teaching their students. Recognizing that one of the most important near-term problems in Native American communities across the country is preservation of aboriginal language, a first step in our program involved defining STEM vocabulary. Community participation was required to identify existing words, write a STEM thesaurus, and also define contemporary words (what we called 'NASA words') that have no equivalent in the native tongue. This step critically involved obtaining approval of new words from tribal Elders. Finally, our objective was to put this newly defined STEM vocabulary to work, helping the kids to learn STEM curriculum in their own language. The communities' response to our approach was guarded interest, an invitation to return for further work, and finally a request that we co-sponsor a Summer Science Academy that was not focused on the subjects of space exploration originally envisioned by the project. Thus a first lesson learned was that ambitious material might not be the first step to a sustained educational program on the reservation. Understanding the end-users' environment, requirements and constraints is a major component to sustainability. After several months of

  19. Changes in the North Sea fish community: evidence of indirect effects of fishing?

    NARCIS (Netherlands)

    Daan, N.; Gislason, H.; Pope, J.G.; Rice, J.C.

    2005-01-01

    We investigate changes in the North Sea fish community with particular reference to possible indirect effects of fishing, mediated through the ecosystem. In the past, long-term changes in the slope of size spectra of research vessel catches have been related to changes in fishing effort, but such

  20. Invasibility of Mediterranean-climate rivers by non-native fish: the importance of environmental drivers and human pressures.

    Directory of Open Access Journals (Sweden)

    Maria Ilhéu

    Full Text Available Invasive species are regarded as a biological pressure to natural aquatic communities. Understanding the factors promoting successful invasions is of great conceptual and practical importance. From a practical point of view, it should help to prevent future invasions and to mitigate the effects of recent invaders through early detection and prioritization of management measures. This study aims to identify the environmental determinants of fish invasions in Mediterranean-climate rivers and evaluate the relative importance of natural and human drivers. Fish communities were sampled in 182 undisturbed and 198 disturbed sites by human activities, belonging to 12 river types defined for continental Portugal within the implementation of the European Union's Water Framework Directive. Pumpkinseed sunfish, Lepomis gibbosus (L., and mosquitofish, Gambusia holbrooki (Girard, were the most abundant non-native species (NNS in the southern river types whereas the Iberian gudgeon, Gobio lozanoi Doadrio and Madeira, was the dominant NNS in the north/centre. Small northern mountain streams showed null or low frequency of occurrence and abundance of NNS, while southern lowland river types with medium and large drainage areas presented the highest values. The occurrence of NNS was significantly lower in undisturbed sites and the highest density of NNS was associated with high human pressure. Results from variance partitioning showed that natural environmental factors determine the distribution of the most abundant NNS while the increase in their abundance and success is explained mainly by human-induced disturbance factors. This study stresses the high vulnerability of the warm water lowland river types to non-native fish invasions, which is amplified by human-induced degradation.

  1. Effect of Recreational Fish Feeding on Reef Fish Community ...

    African Journals Online (AJOL)

    ... that the reaction to bread at feeding sites was quicker than at control sites, which indicates that some species learn to feed on this novel source of food. Keywords:human-animal interactions, reef fish, recreational fish feeding, tourism impacts, MPAs, coral reefs, Kenya West Indian Ocean Journal of Marine Science Vol.

  2. Healthy Native Community Fellowship: An Indigenous Leadership Program to Enhance Community Wellness

    Directory of Open Access Journals (Sweden)

    Rebecca Rae

    2016-11-01

    Full Text Available The Healthy Native Communities Fellowship (HNCF is a grassroots evidence-based mentorship and leadership program that develops the skills and community-building capacities of leaders and community teams to improve health status through several intermediate social and cultural mechanisms: (a strengthening social participation (also known as social capital or cohesion; (b strengthening cultural connectedness and revitalization of cultural identity; and (c advocating for health-enhancing policies, practices, and programs that strengthen systems of prevention and care, as well as address the structural social determinants of health. This leadership program uses a community-based participatory research (CBPR approach and participatory evaluation to investigate how the work of local American Indian and Alaska Native leaders (fellows and their community coalitions contributes to individual, family, and community level health outcomes.

  3. Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.

    Science.gov (United States)

    Poosakkannu, Anbu; Nissinen, Riitta; Kytöviita, Minna-Maarit

    2017-11-01

    The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculation did not affect microbial species richness or diversity indices in leaves or roots, but the AM fungus inoculation significantly affected bacterial community composition in leaves. A total of three OTUs in leaves belonging to the phylum Firmicutes positively responded to the presence of the AM fungus in roots. Another six OTUs belonging to the Proteobacteria (Alpha, Beta, and Gamma) and Bacteroidetes were significantly more abundant in NM plants when compared to AM fungus-inoculated plants. Further, there was a significant correlation between plant dry weight and leaf microbial community compositional shift. Also, there was a significant correlation between leaf bacterial community compositional shift and foliar nitrogen content changes due to AM fungus inoculation. The results suggest that AM fungus colonization in roots has a profound effect on plant physiology that is reflected in leaf bacterial community composition.

  4. Predation on exotic zebra mussels by native fishes: Effects on predator and prey

    Science.gov (United States)

    Magoulick, D.D.; Lewis, L.C.

    2002-01-01

    1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

  5. Phytophagous insects on native and non-native host plants: combining the community approach and the biogeographical approach.

    Directory of Open Access Journals (Sweden)

    Kim Meijer

    Full Text Available During the past centuries, humans have introduced many plant species in areas where they do not naturally occur. Some of these species establish populations and in some cases become invasive, causing economic and ecological damage. Which factors determine the success of non-native plants is still incompletely understood, but the absence of natural enemies in the invaded area (Enemy Release Hypothesis; ERH is one of the most popular explanations. One of the predictions of the ERH, a reduced herbivore load on non-native plants compared with native ones, has been repeatedly tested. However, many studies have either used a community approach (sampling from native and non-native species in the same community or a biogeographical approach (sampling from the same plant species in areas where it is native and where it is non-native. Either method can sometimes lead to inconclusive results. To resolve this, we here add to the small number of studies that combine both approaches. We do so in a single study of insect herbivory on 47 woody plant species (trees, shrubs, and vines in the Netherlands and Japan. We find higher herbivore diversity, higher herbivore load and more herbivory on native plants than on non-native plants, generating support for the enemy release hypothesis.

  6. Hierarchical faunal filters: An approach to assessing effects of habitat and nonnative species on native fishes

    Science.gov (United States)

    Quist, M.C.; Rahel, F.J.; Hubert, W.A.

    2005-01-01

    Understanding factors related to the occurrence of species across multiple spatial and temporal scales is critical to the conservation and management of native fishes, especially for those species at the edge of their natural distribution. We used the concept of hierarchical faunal filters to provide a framework for investigating the influence of habitat characteristics and normative piscivores on the occurrence of 10 native fishes in streams of the North Platte River watershed in Wyoming. Three faunal filters were developed for each species: (i) large-scale biogeographic, (ii) local abiotic, and (iii) biotic. The large-scale biogeographic filter, composed of elevation and stream-size thresholds, was used to determine the boundaries within which each species might be expected to occur. Then, a local abiotic filter (i.e., habitat associations), developed using binary logistic-regression analysis, estimated the probability of occurrence of each species from features such as maximum depth, substrate composition, submergent aquatic vegetation, woody debris, and channel morphology (e.g., amount of pool habitat). Lastly, a biotic faunal filter was developed using binary logistic regression to estimate the probability of occurrence of each species relative to the abundance of nonnative piscivores in a reach. Conceptualising fish assemblages within a framework of hierarchical faunal filters is simple and logical, helps direct conservation and management activities, and provides important information on the ecology of fishes in the western Great Plains of North America. ?? Blackwell Munksgaard, 2004.

  7. Habitat preferences of common native fishes in a tropical river in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Marcus Rodrigues da Costa

    Full Text Available We determined in this study the habitat preferences of seven native fish species in a regulated river in Southeastern Brazil. We tested the hypothesis that fishes differ in habitat preference and that they use stretches of the river differing in hydraulic characteristics and substrate type. We surveyed fishes in four 1-km long river stretches encompassing different habitat traits, where we also measured water depth, velocity, and substrate type. We investigated preference patterns of four Siluriformes (Loricariichthys castaneus, Hoplosternum littorale, Pimelodus maculatus, and Trachelyopterus striatulus and three Characiformes (Astyanax aff. bimaculatus, Oligosarcus hepsetus, and Hoplias malabaricus, representing approximately 70% of the total number of fishes and 64% of the total biomass. We classified fishes into four habitat guilds: (1 a slow-flowing water guild that occupied mud-sand substrate, composed of two Siluriformes in either shallow ( 8 m, L. castaneus waters; (2 a run-dwelling guild that occurs in deep backwaters with clay-mud substrate, composed of the Characiformes A. aff. bimaculatus and O. hepsetus; (3 a run-dwelling guild that occurs in sandy and shallow substrate, composed of T. striatulus; and (4 a fast-flowing guild that occurs primarily along shorelines with shallow mud bottoms, composed of H. malabaricus and P. maculatus. Our hypothesis was confirmed, as different habitat preferences by fishes appear to occur in this regulated river.

  8. The consequences of balanced harvesting of fish communities

    DEFF Research Database (Denmark)

    Jacobsen, Nis Sand; Gislason, Henrik; Andersen, Ken Haste

    2014-01-01

    community structure and yield. We use a size- and trait-based model that resolves individual interactions through competition and predation to compare balanced harvesting with traditional selective harvesting, which protects juvenile fish from fishing. Four different exploitation patterns, generated......Balanced harvesting, where species or individuals are exploited in accordance with their productivity, has been proposed as a way to minimize the effects of fishing on marine fish communities and ecosystems. This calls for a thorough examination of the consequences balanced harvesting has on fish...... by combining selective or unselective harvesting with balanced or unbalanced fishing, are compared. We find that unselective balanced fishing, where individuals are exploited in proportion to their productivity, produces a slightly larger total maximum sustainable yield than the other exploitation patterns and...

  9. A synthesis of ecological and fish-community changes in Lake Ontario, 1970-2000

    Science.gov (United States)

    Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

    2005-01-01

    We assessed stressors associated with ecological and fishcommunity changes in Lake Ontario since 1970, when the first symposium on Salmonid Communities in Oligotrophic Lakes (SCOL I) was held (J. Fish. Res. Board Can. 29: 613-616). Phosphorus controls implemented in the early 1970s were undeniably successful; lower food-web studies showed declines in algal abundance and epilimnetic zooplankton production and a shift in pelagic primary productivity toward smaller organisms. Stressors on the fish community prior to 1970 such as exploitation, sea lamprey (Petromyzon marinus) predation, and effects of nuisance populations of alewife (Alosa pseudoharengus) were largely ameliorated by the 1990s. The alewife became a pivotal species supporting a multi-million-dollar salmonid sport fishery, but alewife-induced thiamine deficiency continued to hamper restoration and sustainability of native lake trout (Salvelinus namaycush). Expanding salmonine populations dependent on alewife raised concerns about predator demand and prey supply, leading to reductions in salmonine stocking in the early 1990s. Relaxation of the predation impact by alewives and their shift to deeper water allowed recovery of native fishes such as threespine stickleback (Gasterosteus aculeatus) and emerald shiner (Notropis atherinoides). The return of the Lake Ontario ecosystem to historical conditions has been impeded by unplanned introductions. Establishment of Dreissena spp. led to increased water clarity and increased vectoring of lower trophic-level production to benthic habitats and contributed to the collapse of Diporeia spp. populations, behavioral modifications of key fish species, and the decline of native lake whitefish (Coregonus clupeaformis). Despite reduced productivity, exotic-species introductions, and changes in the fish community, offshore Mysis relicta populations remained relatively stable. The effects of climate and climate change on the population abundance and dynamics of Lake Ontario

  10. The Arsenite Oxidation Potential of Native Microbial Communities from Arsenic-Rich Freshwaters.

    Science.gov (United States)

    Fazi, Stefano; Crognale, Simona; Casentini, Barbara; Amalfitano, Stefano; Lotti, Francesca; Rossetti, Simona

    2016-07-01

    Microorganisms play an important role in speciation and mobility of arsenic in the environment, by mediating redox transformations of both inorganic and organic species. Since arsenite [As(III)] is more toxic than arsenate [As(V)] to the biota, the microbial driven processes of As(V) reduction and As(III) oxidation may play a prominent role in mediating the environmental impact of arsenic contamination. However, little is known about the ecology and dynamics of As(III)-oxidizing populations within native microbial communities exposed to natural high levels of As. In this study, two techniques for single cell quantification (i.e., flow cytometry, CARD-FISH) were used to analyze the structure of aquatic microbial communities across a gradient of arsenic (As) contamination in different freshwater environments (i.e., groundwaters, surface and thermal waters). Moreover, we followed the structural evolution of these communities and their capacity to oxidize arsenite, when experimentally exposed to high As(III) concentrations in experimental microcosms. Betaproteobacteria and Deltaproteobacteria were the main groups retrieved in groundwaters and surface waters, while Beta and Gammaproteobacteria dominated the bacteria community in thermal waters. At the end of microcosm incubations, the communities were able to oxidize up to 95 % of arsenite, with an increase of Alphaproteobacteria in most of the experimental conditions. Finally, heterotrophic As(III)-oxidizing strains (one Alphaproteobacteria and two Gammaproteobacteria) were isolated from As rich waters. Our findings underlined that native microbial communities from different arsenic-contaminated freshwaters can efficiently perform arsenite oxidation, thus contributing to reduce the overall As toxicity to the aquatic biota.

  11. Species succession and sustainability of the Great Lakes fish community

    Science.gov (United States)

    Eshenroder, Randy L.; Burnham-Curtis, Mary K.; Taylor, William W.; Ferreri, C. Paola

    1999-01-01

    This article concentrates on the sustainability of the offshore pelagic and deepwater fish communities that were historically dominated by lake trout (Salvelinus namaycush). The causes of alteration in these fish communities (i.e., overfishing, introductions, and cultural eutrophication) were identified by Loftus and Regier (1972). Here we look at the ecology of these altered communities in relation to sustainability and discuss the need for restoration.

  12. Change in fish community structure in the Barents Sea.

    Directory of Open Access Journals (Sweden)

    Michaela Aschan

    Full Text Available Change in oceanographic conditions causes structural alterations in marine fish communities, but this effect may go undetected as most monitoring programs until recently mainly have focused on oceanography and commercial species rather than on whole ecosystems. In this paper, the objective is to describe the spatial and temporal changes in the Barents Sea fish community in the period 1992-2004 while taking into consideration the observed abundance and biodiversity patterns for all 82 observed fish species. We found that the spatial structure of the Barents Sea fish community was determined by abiotic factors such as temperature and depth. The observed species clustered into a deep assemblage, a warm water southern assemblage, both associated with Atlantic water, and a cold water north-eastern assemblage associated with mixed water. The latitude of the cold water NE and warm water S assemblages varied from year to year, but no obvious northward migration was observed over time. In the period 1996-1999 we observed a significant reduction in total fish biomass, abundance, mean fish weight, and a change in community structure including an increase in the pelagic/demersal ratio. This change in community structure is probably due to extremely cold conditions in 1996 impacting on a fish community exposed to historically high fishing rates. After 1999 the fish community variables such as biomass, abundance, mean weight, P/D ratio as well as community composition did not return to levels of the early 90s, although fishing pressure and climatic conditions returned to earlier levels.

  13. Pollution Problem in River Kabul: Accumulation Estimates of Heavy Metals in Native Fish Species.

    Science.gov (United States)

    Ahmad, Habib; Yousafzai, Ali Muhammad; Siraj, Muhammad; Ahmad, Rashid; Ahmad, Israr; Nadeem, Muhammad Shahid; Ahmad, Waqar; Akbar, Nazia; Muhammad, Khushi

    2015-01-01

    The contamination of aquatic systems with heavy metals is affecting the fish population and hence results in a decline of productivity rate. River Kabul is a transcountry river originating at Paghman province in Afghanistan and inters in Khyber Pakhtunkhwa province of Pakistan and it is the major source of irrigation and more than 54 fish species have been reported in the river. Present study aimed at the estimation of heavy metals load in the fish living in River Kabul. Heavy metals including chromium, nickel, copper, zinc, cadmium, and lead were determined through atomic absorption spectrophotometer after tissue digestion by adopting standard procedures. Concentrations of these metals were recorded in muscles and liver of five native fish species, namely, Wallago attu, Aorichthys seenghala, Cyprinus carpio, Labeo dyocheilus, and Ompok bimaculatus. The concentrations of chromium, nickel, copper, zinc, and lead were higher in both of the tissues, whereas the concentration of cadmium was comparatively low. However, the concentration of metals was exceeding the RDA (Recommended Dietary Allowance of USA) limits. Hence, continuous fish consumption may create health problems for the consumers. The results of the present study are alarming and suggest implementing environmental laws and initiation of a biomonitoring program of the river.

  14. Listening to the Community: Guidance from Native Community Members for Emerging Culturally Responsive Educators

    Science.gov (United States)

    Rogers, Christine A.; Jaime, Angela M.

    2010-01-01

    Critical race theory (CRT) emphasizes the importance of listening to the counter-narratives of people from marginalized groups. However, the applicability of CRT in practical settings often remains unclear for educators and scholars. This project offers not only a place for Native community members to share their experiences and ideas, it also…

  15. Reproduction of the non-native fish Lepomis gibbosus (Perciformes: Centrarchidae in Brazil

    Directory of Open Access Journals (Sweden)

    Rangel E. Santos

    2012-09-01

    Full Text Available Minas Gerais is the fourth largest Brazilian state, and has an estimate of 354 native fish species. However, these fish species may be threatened, as this state has the highest rank of fish introductions reported for Brazil and South America. As one from the total of 85 non-native species detected, Lepomis gibbosus was introduced in the 60s to serve both as foragefish and to improve sport fishing. In this study, we evaluated the establishment of L. gibbosus in a shallow lake in the city of Ouro Preto, Doce River basin, state of Minas Gerais, Southeastern Brazil. We collected fish with fishing rods every two months from March 2002-February 2003. Fragments of gonads from a total of 226 females and 226 males were obtained and processed following standard histological techniques; then 5-7μm thickness sections were taken and stained in hematoxylin-eosin. Besides, for each specimen, the biometric measurements included the standard length (SL and body weight (BW; and the sex ratio was obtained. The reproductive cycle stages were confirmed by the distribution of oocytes and spermatogenic cells. The type of spawning was determined by the frequency distribution of the reproductive cycle stages and ovarian histology. Based on the microscopic characteristics of the gonads, the following stages of the reproductive cycle were determined: one=Rest, two=Mature, three=Spawned for females or Spent for males; males and females in reproduction were found throughout the study period. Post-spawned ovaries containing oocytes in stages one (initial perinucleolar, two (advanced perinucleolar, three (pre-vitellogenic, four (vitellogenic and post-ovulatory follicles indicated fractionated-type spawning in this species. The smallest breeding male and female measured were 4.6 and 4.9cm standard length, respectively, suggesting stunting. The sex ratio did not vary between males and females along the year and bimonthly, being 1:1. Moreover, L. gibbosus appears to be at stage

  16. Status and future of Lake Huron fish communities

    Science.gov (United States)

    Ebener, M.P.; Johnson, J.E.; Reid, D.M.; Payne, N.P.; Argyle, R.L.; Wright, G.M.; Krueger, K.; Baker, J.P.; Morse, T.; Weise, J.; Munawar, M.; Edsall, T.; Leach, J.

    1995-01-01

    In 1993, fishery management agencies with jurisdiction over Lake Huron fish populations developed draft fish community objectives in response to the Joint Strategic Plan for Management of Great Lakes Fisheries. The Joint Strategic Plan charged the Great Lakes Fishery Commission sponsored Lake Huron Committee to define objectives for what the fish community of Lake Huron should look like in the future, and to develop means for measuring progress toward the objectives. The overall management objective for Lake Huron is to 'over the next two decades restore an ecologically balanced fish community dominated by top predators and consisting largely of self-sustaining, indigenous and naturalized species and capable of sustaining annual harvests of 8.9 million kg'. This paper represents the first attempt at consolidating current biological information from different management agencies on a lake-wide basis for the purpose of assessing the current status and dynamics of Lake Huron fishes.

  17. Transactional sex in the fishing communities along Lake Victoria ...

    African Journals Online (AJOL)

    The study describes the nature, context and implications of a unique form of transactional sexual relationships in the fishing communities along Lake Victoria in Kisumu County, Kenya. We conducted 12 focus group discussions and 17 key informant interviews among fishermen, fishmongers and fish transporters in Kisumu.

  18. Baseline assessment of fish communities of the Flower Garden Banks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The work developed baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys employed diving,...

  19. Radiological risk from consuming fish and wildlife to Native Americans on the Hanford Site (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Delistraty, Damon, E-mail: DDEL461@ecy.wa.gov [Washington State Department of Ecology, N. 4601 Monroe, Spokane, WA 99205-1295 (United States); Verst, Scott Van [Washington State Department of Health, Olympia, WA (United States); Rochette, Elizabeth A. [Washington State Department of Ecology, Richland, WA (United States)

    2010-02-15

    Historical operations at the Hanford Site (Washington State, USA) have released a wide array of non-radionuclide and radionuclide contaminants into the environment. As a result of stakeholder concerns, Native American exposure scenarios have been integrated into Hanford risk assessments. Because its contribution to radiological risk to Native Americans is culturally and geographically specific but quantitatively uncertain, a fish and wildlife ingestion pathway was examined in this study. Adult consumption rates were derived from 20 Native American scenarios (based on 12 studies) at Hanford, and tissue concentrations of key radionuclides in fish, game birds, and game mammals were compiled from the Hanford Environmental Information System (HEIS) database for a recent time interval (1995-2007) during the post-operational period. It was assumed that skeletal muscle comprised 90% of intake, while other tissues accounted for the remainder. Acknowledging data gaps, median concentrations of eight radionuclides (i.e., Co-60, Cs-137, Sr-90, Tc-99, U-234, U-238, Pu-238, and Pu-239/240) in skeletal muscle and other tissues were below 0.01 and 1 pCi/g wet wt, respectively. These radionuclide concentrations were not significantly different (Bonferroni P>0.05) on and off the Hanford Site. Despite no observed difference between onsite and offsite tissue concentrations, radiation dose and risk were calculated for the fish and wildlife ingestion pathway using onsite data. With median consumption rates and radionuclide tissue concentrations, skeletal muscle provided 42% of the dose, while other tissues (primarily bone and carcass) accounted for 58%. In terms of biota, fish ingestion was the largest contributor to dose (64%). Among radionuclides, Sr-90 was dominant, accounting for 47% of the dose. At median intake and radionuclide levels, estimated annual dose (0.36 mrem/yr) was below a dose limit of 15 mrem/yr recommended by the United States Environmental Protection Agency (USEPA

  20. Habitat degradation and fishing effects on the size structure of coral reef fish communities.

    Science.gov (United States)

    Wilson, S K; Fisher, R; Pratchett, M S; Graham, N A J; Dulvy, N K; Turner, R A; Cakacaka, A; Polunin, N V C

    2010-03-01

    Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

  1. Interactions between fishes and the structure of fish communities in Dutch shallow, eutrophic lakes

    NARCIS (Netherlands)

    Lammens, E.

    1986-01-01

    This thesis describes the structure of fish communities in Tjeukemeer (21 km 2) and some other surrounding very eutrophic lakes and emphasizes the interactions of the fishes with each other and their food organisms (predation and (exploitative) competition). It is a compilation of seven

  2. Preliminary assessment of factors influencing riverine fish communities in Massachusetts.

    Science.gov (United States)

    Armstrong, David S.; Richards, Todd A.; Brandt, Sara L.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Massachusetts Department of Conservation and Recreation (MDCR), Massachusetts Department of Environmental Protection (MDEP), and the Massachusetts Department of Fish and Game (MDFG), conducted a preliminary investigation of fish communities in small- to medium-sized Massachusetts streams. The objective of this investigation was to determine relations between fish-community characteristics and anthropogenic alteration, including flow alteration and impervious cover, relative to the effect of physical basin and land-cover (environmental) characteristics. Fish data were obtained for 756 fish-sampling sites from the Massachusetts Division of Fisheries and Wildlife fish-community database. A review of the literature was used to select a set of fish metrics responsive to flow alteration. Fish metrics tested include two fish-community metrics (fluvial-fish relative abundance and fluvial-fish species richness), and five indicator species metrics (relative abundance of brook trout, blacknose dace, fallfish, white sucker, and redfin pickerel). Streamflows were simulated for each fish-sampling site using the Sustainable Yield Estimator application (SYE). Daily streamflows and the SYE water-use database were used to determine a set of indicators of flow alteration, including percent alteration of August median flow, water-use intensity, and withdrawal and return-flow fraction. The contributing areas to the fish-sampling sites were delineated and used with a Geographic Information System (GIS) to determine a set of environmental characteristics, including elevation, basin slope, percent sand and gravel, percent wetland, and percent open water, and a set of anthropogenic-alteration variables, including impervious cover and dam density. Two analytical techniques, quantile regression and generalized linear modeling, were applied to determine the association between fish-response variables and the selected environmental and

  3. Assessing historical fish community composition using surveys, historical collection data, and species distribution models.

    Science.gov (United States)

    Labay, Ben; Cohen, Adam E; Sissel, Blake; Hendrickson, Dean A; Martin, F Douglas; Sarkar, Sahotra

    2011-01-01

    Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of

  4. Metal concentrations and pathological responses of wild native fish exposed to sewage discharge in a Mediterranean river

    Energy Technology Data Exchange (ETDEWEB)

    Maceda-Veiga, Alberto, E-mail: albertomaceda@gmail.com [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain); Monroy, Mario; Navarro, Elisenda [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain); Viscor, Ginés [Department of Animal Physiology (Faculty of Biology), University of Barcelona, E-08028 Barcelona (Spain); Sostoa, Adolfo de [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain)

    2013-04-01

    The requirements of the Water Framework Directive suggest the need for further research to test and develop sensitive tools that will allow freshwater managers to detect impacts on fish communities. Diagnostic refinement often encompasses the use of lethal diagnostic tools that are incompatible with the conservation of native ichthyofauna. Here we determine the metal concentration and the pathological response of Squalius laietanus exposed to sewage discharges in the Ripoll river (north-eastern Spain), and compare these findings with our previous studies on Barbus meridionalis using lethal and non-lethal diagnostic tools. Metals concentrations (Zn, Cu, Pb, Hg, Fe, Cd and Ni) were determined in liver and muscle. A complete blood cell profile (haematocrit, haemoglobin, differential leukocyte count, erythrocytic nuclear abnormalities, erythrocytes in division and the development stage of erythrocytes) was used as a non-lethal diagnostic tool to determine early warning signs of disease in these two fish species. As the reference range for these haematological variables is lacking, liver histology, calculation of body condition (CF) and organosomatic indices (HSI and GSI) were employed to support the findings of the blood analyses. Compared to our previous results on B. meridionalis, S. laietanus appeared to have fewer pathological responses than B. meridionalis under the environmental conditions measured and the fish size range examined in this study. Both species showed a similar bioaccumulation pattern, but B. meridionalis stored high Hg and Cu concentrations in muscle and liver, respectively. Hg, Cu and Pb concentrations in fish tissues exceeded the thresholds of European and Spanish legislation. Our findings pinpoint the potential suitability of the blood variables determined in the health diagnoses of these species. Further research will be necessary to establish the natural variability of these and other haematological variables to convert haematology into a

  5. Metal concentrations and pathological responses of wild native fish exposed to sewage discharge in a Mediterranean river

    International Nuclear Information System (INIS)

    Maceda-Veiga, Alberto; Monroy, Mario; Navarro, Elisenda; Viscor, Ginés; Sostoa, Adolfo de

    2013-01-01

    The requirements of the Water Framework Directive suggest the need for further research to test and develop sensitive tools that will allow freshwater managers to detect impacts on fish communities. Diagnostic refinement often encompasses the use of lethal diagnostic tools that are incompatible with the conservation of native ichthyofauna. Here we determine the metal concentration and the pathological response of Squalius laietanus exposed to sewage discharges in the Ripoll river (north-eastern Spain), and compare these findings with our previous studies on Barbus meridionalis using lethal and non-lethal diagnostic tools. Metals concentrations (Zn, Cu, Pb, Hg, Fe, Cd and Ni) were determined in liver and muscle. A complete blood cell profile (haematocrit, haemoglobin, differential leukocyte count, erythrocytic nuclear abnormalities, erythrocytes in division and the development stage of erythrocytes) was used as a non-lethal diagnostic tool to determine early warning signs of disease in these two fish species. As the reference range for these haematological variables is lacking, liver histology, calculation of body condition (CF) and organosomatic indices (HSI and GSI) were employed to support the findings of the blood analyses. Compared to our previous results on B. meridionalis, S. laietanus appeared to have fewer pathological responses than B. meridionalis under the environmental conditions measured and the fish size range examined in this study. Both species showed a similar bioaccumulation pattern, but B. meridionalis stored high Hg and Cu concentrations in muscle and liver, respectively. Hg, Cu and Pb concentrations in fish tissues exceeded the thresholds of European and Spanish legislation. Our findings pinpoint the potential suitability of the blood variables determined in the health diagnoses of these species. Further research will be necessary to establish the natural variability of these and other haematological variables to convert haematology into a

  6. Governance and Welfare of Fishing Communities of Lake Victoria ...

    African Journals Online (AJOL)

    These include the introduction of a co-management system of Beach Management units (BMUs) which are elected by the fishing communities and will work with the ... Educational standards remain low and many communities lack proper sanitation, and are therefore at risk of disease, while most basic facilities such as ...

  7. Fragmentation alters stream fish community structure in dendritic ecological networks.

    Science.gov (United States)

    Perkin, Joshuah S; Gido, Keith B

    2012-12-01

    Effects of fragmentation on the ecology of organisms occupying dendritic ecological networks (DENs) have recently been described through both conceptual and mathematical models, but few hypotheses have been tested in complex, real-world ecosystems. Stream fishes provide a model system for assessing effects of fragmentation on the structure of communities occurring within DENs, including how fragmentation alters metacommunity dynamics and biodiversity. A recently developed habitat-availability measure, the "dendritic connectivity index" (DCI), allows for assigning quantitative measures of connectivity in DENs regardless of network extent or complexity, and might be used to predict fish community response to fragmentation. We characterized stream fish community structure in 12 DENs in the Great Plains, USA, during periods of dynamic (summer) and muted (fall) discharge regimes to test the DCI as a predictive model of fish community response to fragmentation imposed by road crossings. Results indicated that fish communities in stream segments isolated by road crossings had reduced species richness (alpha diversity) relative to communities that maintained connectivity with the surrounding DEN during summer and fall. Furthermore, isolated communities had greater dissimilarity (beta diversity) to downstream sites notisolated by road crossings during summer and fall. Finally, dissimilarity among communities within DENs decreased as a function of increased habitat connectivity (measured using the DCI) for summer and fall, suggesting that communities within highly connected DENs tend to be more homogeneous. Our results indicate that the DCI is sensitive to community effects of fragmentation in riverscapes and might be used by managers to predict ecological responses to changes in habitat connectivity. Moreover, our findings illustrate that relating structural connectivity of riverscapes to functional connectivity among communities might aid in maintaining metacommunity

  8. Effects of fishing disturbance on benthic communities and secondary production within an intensively fished area

    NARCIS (Netherlands)

    Reiss, H.; Greenstreet, S.P.R.; Sieben, K.; Ehrich, S.; Piet, G.J.; Quirijns, F.; Wolff, W.J.; Kroncke, I.

    2009-01-01

    Demersal fishing alters seabed habitats and affects the structure and functioning of benthic invertebrate communities. At a critical level of disturbance, such communities may approach an equilibrium disturbed state in which a further increase in disturbance has little additional impact. Such

  9. Socioeconomic profiles of native American communities: Duckwater Shoshone Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Hamby, M. [Cultural Resources Consultants Ltd., Reno, NV (United States)

    1991-10-01

    This report presents socioeconomic aspects of Native Americans of the Duckwater Shoshone Reservation. A survey is included concerning their views on the proposed Yucca Mountain waste repository. (CBS)

  10. Factors affecting the quality of fish caught by Native Americans in the Zone 6 fishery 1991 through 1993

    Energy Technology Data Exchange (ETDEWEB)

    Abernethy, C.S.

    1994-09-01

    A program to monitor the salmon and steelhead (Oncorhynchus spp.) fishery in the lower Columbia River (Zone 6 fishery) was initiated in 1991 to respond to questions and comments frequently made by Native Americans at public meetings. Native Americans were concerned that the quality of the Columbia River had deteriorated and that the poor environmental conditions had affected the health and quality of fish they relied on for subsistence, ceremonial, religious, and commercial purposes. They also feared that eating contaminated fish might endanger the health of their children and future generations. Operations at the Hanford Site were listed as one of many causes of the deteriorating environment. Fisheries pathologists concluded that most of the external symptoms on fish were related to bacterial infection of gill net abrasions and pre-spawning trauma, and were not caused by pollution or contamination of the Columbia River. The pathologists also stated that consumption of the fish posed no threat to human consumers.

  11. Deep UV Native Fluorescence Imaging of Antarctic Cryptoendolithic Communities

    Science.gov (United States)

    Storrie-Lombardi, M. C.; Douglas, S.; Sun, H.; McDonald, G. D.; Bhartia, R.; Nealson, K. H.; Hug, W. F.

    2001-01-01

    An interdisciplinary team at the Jet Propulsion Laboratory Center for Life Detection has embarked on a project to provide in situ chemical and morphological characterization of Antarctic cryptoendolithic microbial communities. We present here in situ deep ultraviolet (UV) native fluorescence and environmental scanning electron microscopy images transiting 8.5 mm into a sandstone sample from the Antarctic Dry Valleys. The deep ultraviolet imaging system employs 224.3, 248.6, and 325 nm lasers to elicit differential fluorescence and resonance Raman responses from biomolecules and minerals. The 224.3 and 248.6 nm lasers elicit a fluorescence response from the aromatic amino and nucleic acids. Excitation at 325 nm may elicit activity from a variety of biomolecules, but is more likely to elicit mineral fluorescence. The resultant fluorescence images provide in situ chemical and morphological maps of microorganisms and the associated organic matrix. Visible broadband reflectance images provide orientation against the mineral background. Environmental scanning electron micrographs provided detailed morphological information. The technique has made possible the construction of detailed fluorescent maps extending from the surface of an Antarctic sandstone sample to a depth of 8.5 mm. The images detect no evidence of microbial life in the superficial 0.2 mm crustal layer. The black lichen component between 0.3 and 0.5 mm deep absorbs all wavelengths of both laser and broadband illumination. Filamentous deep ultraviolet native fluorescent activity dominates in the white layer between 0.6 mm and 5.0 mm from the surface. These filamentous forms are fungi that continue into the red (iron-rich) region of the sample extending from 5.0 to 8.5 mm. Using differential image subtraction techniques it is possible to identify fungal nuclei. The ultraviolet response is markedly attenuated in this region, apparently from the absorption of ultraviolet light by iron-rich particles coating

  12. Impact of native ungulates and beaver on riparian communities in the intermountain west

    OpenAIRE

    Kay, Charles E.

    1994-01-01

    This paper reviews the impact native ungulates, primarily elk and moose, and beaver can have on riparian communities in the Western United States. In Yellowstone National Park and in other areas where ungulates are not managed, repeated browsing has reduced tall willow, aspen, and cottonwood communities by approximately 95 percent since the late 1800's. Native ungulates can also severely reduce or eliminate palatable grasses and forbs from herbaceous riparian communities. By eliminating woody...

  13. Seasonal variation and community structure of fishes in the Mahananda River with special reference to conservation issues

    Directory of Open Access Journals (Sweden)

    Shams Muhammad Galib

    2016-04-01

    Full Text Available This study was carried out in the Mahananda River from January to December 2013 with a view to determining the seasonal variation and community structure of fishes along with some conservation issues. Monthly sampling was carried out using traditional fishing gears and fishes were identified based on morphometric and meristic characters. A total of 4082 individuals of native fish species were captured, analyzed and classified into 62 species belonging to 46 genera, 25 families and 9 orders. Cypriniformes and Siluriformes were the dominant fish orders represented by 19 species each and the most abundant family was Cyprinidae (14 species. In addition to indigenous individuals, 9 individuals of 2 exotic fish species (Hypophthalmichthys molitrix and Pangasius hypophthalmus were also recorded. Among three sampling sites, S-1 was the most diversified in terms of not only the number of individual fish but also the number of species present represented by mean (±SE individuals of 151.50±25.22 and species of 25.58±3.91. Three distinct fish groups of fish families were revealed from the cluster analysis of similarity. To improve the situation, control of illegal fishing gears, establishment of sanctuaries and legal protection for threatened species are recommended.

  14. Importance of Natural and Anthropogenic Environmental Factors to Fish Communities of the Fox River in Illinois

    Science.gov (United States)

    Schnier, Spencer; Cai, Ximing; Cao, Yong

    2016-02-01

    The dominant environmental determinants of aquatic communities have been a persistent topic for many years. Interactions between natural and anthropogenic characteristics within the aquatic environment influence fish communities in complex ways that make the effect of a single characteristic difficult to ascertain. Researchers are faced with the question of how to deal with a large number of variables and complex interrelationships. This study utilized multiple approaches to identify key environmental variables to fish communities of the Fox River Basin in Illinois: Pearson and Spearman correlations, an algorithm based on information theory called mutual information, and a measure of variable importance built into the machine learning algorithm Random Forest. The results are based on a dataset developed for this study, which uses a fish index of biological integrity (IBI) and its ten component metrics as response variables and a range of environmental variables describing geomorphology, stream flow statistics, climate, and both reach-scale and watershed-scale land use as independent variables. Agricultural land use and the magnitude and duration of low flow events were ranked by the algorithms as key factors for the study area. Reach-scale characteristics were dominant for native sunfish, and stream flow metrics were rated highly for native suckers. Regression tree analyses of environmental variables on fish IBI identified breakpoints in percent agricultural land in the watershed (~64 %), duration of low flow pulses (~12 days), and 90-day minimum flow (~0.13 cms). The findings should be useful for building predictive models and design of more effective monitoring systems and restoration plans.

  15. Impact of fishing on size composition and diversity of demersal fish communities

    DEFF Research Database (Denmark)

    Bianchi, G.; Gislason, Henrik; Graham, K.

    2000-01-01

    . but particularly in high-latitude regions, we observe a decreasing trend in the slope, reflecting changes in size composition toward a relative decline in larger fish. The results from tropical regions are less conclusive, partly owing to the difficulty in obtaining consistent data series, but probably also......By analysing data sets from different world regions we add evidence to documented changes in demersal fish community structure that may be related to fishing. Changes are analysed by community properties that might be expected to capture relevant overall changes - size spectra slopes and intercepts...... because the generally higher growth rates of the constituent species make the slope less sensitive to changes in fishing. No evidence was found of any decline in species richness, while changes in diversity (richness and evenness) were caused either by changes in patterns of dominance or by changes...

  16. Introduction of non-native marine fish species to the Canary Islands waters through oil platforms as vectors

    Science.gov (United States)

    Pajuelo, José G.; González, José A.; Triay-Portella, Raül; Martín, José A.; Ruiz-Díaz, Raquel; Lorenzo, José M.; Luque, Ángel

    2016-11-01

    This work documents the introduction of non-native fish species to the Canary Islands (central-eastern Atlantic) through oil rigs. Methodological approaches have included surveys by underwater visual censuses around and under oil platforms and along the docking area of rigs at the Port of Las Palmas. Eleven non-native fish species were registered. Paranthias furcifer, Abudefduf hoefleri, Acanthurus bahianus, Acanthurus chirurgus, and Acanthurus coeruleus are first recorded from the Canaries herein. Other three species could not be identified, although they have never been observed in the Canaries. Cephalopholis taeniops, Abudefduf saxatilis, and Acanthurus monroviae had been previously recorded. Native areas of these species coincide with the areas of origin and the scale of oil rigs with destination the Port of Las Palmas. The absence of native species in the censuses at rigs and their presence at rigs docking area, together with the observation of non-native species after the departure of platforms, reject the possibility that these non-native species were already present in the area introduced by another vector. C. taeniops, A. hoefleri, A. saxatilis, A. chirurgus, A. coeruleus and A. monroviae are clearly seafarer species. A. bahianus seems to be a potential seafarer species. P. furcifer is a castaway species. For the moment, the number of individuals of the non-native species in marine ecosystems of the Canaries seems to be low, and more investigation is needed for controlling these translocations.

  17. Fish-derived nutrient hotspots shape coral reef benthic communities.

    Science.gov (United States)

    Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

    2015-12-01

    Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

  18. Performance and lipid profiles of native chickens fed diet containing skipjack fish oil as by-product of fish canning factory

    Science.gov (United States)

    Leke, J. R.; Mandey, J. S.; Laihad, J. T.; Tinangon, R. M.; Tangkau, L.; Junus, C.

    2018-01-01

    The study was conducted to determine the use of fish oil as by-product of fish canning factory in diet on the performance and lipid profiles of native chickens. The experiment used 100 native chicken with an average initial body weight of 48,9 gram (sd + 9.9), was used in this study for 8 weeks experiment. These were arranged by a completely randomized design with 5 treatments, 5 replications and 4 hens in replication each. The diets were: R0 = 100% Based Diet (BD) + 0% Fish Oil (FO); R1 = 98.5% BD + 1.5% FO; R2 = 98% BD + 2% FO; R3 = 97.5% BD + 2.5% FO; R4 = 97 % BD + 3% FO. Feed and water were provided ad libitum. Variables were performance parameters and lipid profiles. Results showed that fish oil inclusion in diets were significantly increased feed intake, body weight gain, carcass percentage, liver, breast and thigh weight, and decreased blood cholesterol, carbohydrate and meat cholesterol, and also tended to decrease abdominal fat. However, there were no affected on feed conversion, water, protein, fat and ash of breast meat. It can be concluded that the use of fish oil in diet up to 3% could improved performance parameters of native chickens.

  19. Community Structure Of Reef Fish In Eastern Luwu Water Territory

    Directory of Open Access Journals (Sweden)

    Henny Tribuana Cinnawara

    2015-01-01

    Full Text Available Abstract One bio-indicators the condition of coral reefs is a presence of reef fish. The purpose of research is to determine species composition abundance distribution and structure of reef fish communities in these waters. Data collection was conducted in April at six locations in the north and the south eastern Luwu. Mechanical Underwater Visual Cencus UVC and transect method Line intercept Transec LIT with SCUBA equipment used for research data collection. Total reef fish species collected as many as 366 species belonging to 31 families consisting of 150 species of fish target fish consumption 10 species of indicator fish indicator species 206 types of major fissh. The most dominant indicator type of fish is Chaetodon octofasciatus while the major dominant family Pomacentridae Labridae and Apogonidae. Diversity index values ranged from 2.145 to 3.408. Dominance index C is in the range of 0.056 to 0.298. The result is expected to be a reference literature as basic data for the management of reef fish especially in the waters of eastern Luwu.

  20. Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions

    Science.gov (United States)

    Lawson, Katelyn M.; Tuckett, Quenton M.; Ritch, Jared L.; Nico, Leo; Fuller, Pam; Matheson, Richard E.; Hill, Jeffrey E.

    2017-01-01

    The Tampa Bay region of Florida (USA) is a hot spot for non-native freshwater fishes. However, published information on most non-native fishes in the basin is not current. Systematic sampling efforts targeting non-native fishes in the region were conducted from 2013–2015 by the University of Florida Tropical Aquaculture Laboratory. Data from these recent surveys were analyzed, along with historic and new data from published and unpublished sources, to assess current fish distributions and determine status. We focus on five of the non-native species sampled: pike killifish Belonesox belizanus Kner, 1860, green swordtail Xiphophorus hellerii Heckel, 1848, southern platyfish Xiphophorus maculatus (Günther, 1866), Mayan cichlid Mayaheros urophthalmus (Günther, 1862), and Jack Dempsey Rocio octofasciata (Regan, 1903). All five were found to have reproducing populations in the basin, each showing broader distributions than previously indicated. Non-native populations of four of the species have persisted in the Tampa Bay region since at least the 1990s. In contrast, the presence of Mayan cichlid in the basin was not confirmed until 2004. Based on numbers, distributions, and years of persistence, these five species all maintain established populations. Pike killifish and Mayan cichlid are established and spreading throughout multiple habitat types, while green swordtail, southern platyfish, and Jack Dempsey are localized and found primarily in more marginal habitats (e.g., small ditches and first order tributary streams). Factors affecting continued existence and distributions likely include aquaculture, biotic resistance, and thermal and salinity tolerances. We also clarify non-native species status determination using a multi-agency collaborative approach, and reconcile differences in terminology usage and interpretation.

  1. Ecohydrological Index, Native Fish, and Climate Trends and Relationships in the Kansas River Basin.

    Science.gov (United States)

    Sinnathamby, Sumathy; Douglas-Mankin, Kyle R; Muche, Muluken E; Hutchinson, Stacy L; Anandhi, Aavudai

    2018-01-01

    This study quantified climatological and hydrological trends and relationships to presence and distribution of two native aquatic species in the Kansas River Basin over the past half-century. Trend analyses were applied to indicators of hydrologic alteration (IHAs) at 34 streamgages over a 50-year period (1962-2012). Results showed a significant negative trend in annual streamflow for 10 of 12 western streamgages (up to -7.65 mm/50 yr) and smaller negative trends for most other streamgages. Significant negative trends in western Basin streamflow were more widespread in summer (12 stations) than winter or spring (6 stations). The negative-trend magnitude and significance decreased from west to east for maximum-flow IHAs. Minimum- flow IHAs, however, significantly decreased at High Plains streamgages but significantly increased at Central Great Plains streamgages. Number of zero-flow days showed positive trends in the High Plains. Most streamgages showed negative trends in low- and high-flow pulse frequency and high-flow pulse duration, and positive trends in low-flow pulse duration. These results were consistent with increasing occurrence of drought. Shift in occurrence from present (1860-1950) to absent (2000-2012) was significantly related (pBasin sites and had different responses to hydrological index trends at eastern Basin sites. These results demonstrate ecohydrological index changes impact distributions of native fish and suggest target factors for assessment or restoration activities.

  2. Non-native fish introductions and the decline of the mountain yellow-legged frog from within protected areas

    Science.gov (United States)

    R.A. Knapp; K.R. Matthews

    2000-01-01

    Abstract: One of the most puzzling aspects of the worldwide decline of amphibians is their disappearance from within protected areas. Because these areas are ostensibly undisturbed, habitat alterations are generally perceived as unlikely causes. The introduction of non-native fishes into protected areas, however, is a common practice throughout the world and may exert...

  3. Enhancing Cancer Education through the Arts: Building Connections with Alaska Native People, Cultures and Communities

    Science.gov (United States)

    Cueva, Melany; Kuhnley, Regina; Cueva, Katie

    2012-01-01

    Building upon the dynamic traditions of Alaska Native people, which include the arts as a viable way of knowing, the expressive arts were woven into a five-day cancer education course for Alaska village-based Community Health Workers (CHWs). Cancer is the leading cause of mortality for Alaska Native people. Course learning modalities included…

  4. Start with the seed: Native crops, indigenous knowledge, and community seed systems prerequisites for food sovereignty

    Science.gov (United States)

    The dynamic conservation and sustainable utilization of native crop genetic resources are crucial for food sovereignty of Native American communities. Indigenous knowledge of crop diversity when linked to food traditions, local practices and social norms provide the basis for building sovereign comm...

  5. Distribution and habitat use of the Missouri River and Lower Yellowstone River benthic fishes from 1996 to 1998: A baseline for fish community recovery

    Science.gov (United States)

    Wildhaber, M.L.; Gladish, D.W.; Arab, A.

    2011-01-01

    Past and present Missouri River management practices have resulted in native fishes being identified as in jeopardy. In 1995, the Missouri River Benthic Fishes Study was initiated to provide improved information on Missouri River fish populations and how alterations might affect them. The study produced a baseline against which to evaluate future changes in Missouri River operating criteria. The objective was to evaluate population structure and habitat use of benthic fishes along the entire mainstem Missouri River, exclusive of reservoirs. Here we use the data from this study to provide a recent-past baseline for on-going Missouri River fish population monitoring programmes along with a more powerful method for analysing data containing large percentages of zero values. This is carried out by describing the distribution and habitat use of 21 species of Missouri River benthic fishes based on catch-per-unit area data from multiple gears. We employ a Bayesian zero-inflated Poisson model expanded to include continuous measures of habitat quality (i.e. substrate composition, depth, velocity, temperature, turbidity and conductivity). Along with presenting the method, we provide a relatively complete picture of the Missouri River benthic fish community and the relationship between their relative population numbers and habitat conditions. We demonstrate that our single model provides all the information that is often obtained by a myriad of analytical techniques. An important advantage of the present approach is reliable inference for patterns of relative abundance using multiple gears without using gear efficiencies.

  6. Do Mangroves Subsidize Carbon to Adjacent Mudflat Fish Communities?

    Science.gov (United States)

    Henkel, S.; Kasten, S.; Hartmann, J.; Staubwasser, M.; Hernandez, M. F.; West, L.; Midway, S. R.; Polito, M. J.

    2017-12-01

    Mangroves are often implicated as energetic sources for fisheries productivity. However, the validity of this connection still remains in contention. Stable isotopes may provide answers by tracking the use of specific basal carbon sources in fish and invertebrates living in mangrove-mudflat habitat mosaics. We analyzed 307 consumer samples representing n=44 fish and invertebrate species collected from mangrove forest creeks and adjacent mudflats in coastal Tanzania using bulk carbon and nitrogen stable isotope analysis. Given the proposed high productivity of mangrove habitats, we hypothesize that mudflat communities will have carbon stable isotope values similar to mangrove communities either through the flux of mangrove carbon into adjacent mudflats and/or via the movement of mudflat fish communities into and out of mangrove habitats. Alternatively, mangrove carbon is often refractory, which may result in mudflat communities with isotopic values that differ from those found in adjacent mangrove communities. This scenario would suggest limited carbon flow between mudflat and mangrove food webs and that the movement of fish into and out of mangrove habitats is related to shelter from predation more than feeding. Data analysis is ongoing to test these competing hypotheses. By understanding the contribution of mangrove carbon to adjacent habitats, managers in Tanzania can make better informed decisions regarding the protection of mangroves and the local fisheries, which are a crucial source of income and food.

  7. Projected risk of population declines for native fish species in the Upper Mississippi River

    Science.gov (United States)

    Crimmins, S.M.; Boma, P.; Thogmartin, W.E.

    2015-01-01

    Conservationists are in need of objective metrics for prioritizing the management of habitats. For individual species, the threat of extinction is often used to prioritize what species are in need of conservation action. Using long-term monitoring data, we applied a Bayesian diffusion approximation to estimate quasi-extinction risk for 54 native fish species within six commercial navigation reaches along a 1350-km gradient of the upper Mississippi River system. We found a strong negative linear relationship between quasi-extinction risk and distance upstream. For some species, quasi-extinction estimates ranged from nearly zero in some reaches to one in others, suggesting substantial variability in threats facing individual river reaches. We found no evidence that species traits affected quasi-extinction risk across the entire system. Our results indicate that fishes within the upper Mississippi River system face localized threats that vary across river impact gradients. This suggests that conservation actions should be focused on local habitat scales but should also consider the additive effects on downstream conditions. We also emphasize the need for identification of proximate mechanisms behind observed and predicted population declines, as conservation actions will require mitigation of such mechanisms. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  8. Reef fish communities in the central Red Sea show evidence of asymmetrical fishing pressure

    KAUST Repository

    Kattan, Alexander; Coker, Darren James; Berumen, Michael L.

    2017-01-01

    In order to assess human impacts and develop rational restoration goals for corals reefs, baseline estimates of fish communities are required. In Saudi Arabian waters of the Red Sea, widespread unregulated fishing is thought to have been ongoing for decades, but there is little direct evidence of the impact on reef communities. To contextualize this human influence, reef-associated fish assemblages on offshore reefs in Saudi Arabia and Sudan in the central Red Sea were investigated. These reefs have comparable benthic environments, experience similar oceanographic influences, and are separated by less than 300 km, offering an ideal comparison for identifying potential anthropogenic impacts such as fishing pressure. This is the first study to assess reef fish biomass in both these regions, providing important baselines estimates. We found that biomass of top predators on offshore Sudanese reefs was on average almost three times that measured on comparable reefs in Saudi Arabia. Biomass values from some of the most remote reefs surveyed in Sudan’s far southern region even approach those previously reported in the Northwestern Hawaiian Islands, northern Line Islands, Pitcairn Islands, and other isolated Pacific islands and atolls. The findings suggest that fishing pressure has significantly altered the fish community structure of Saudi Arabian Red Sea reefs, most conspicuously in the form of top predator removal. The results point towards the urgent need for enhanced regulation and enforcement of fishing practices in Saudi Arabia, while making a strong case for protection in the form of no-take marine protected areas to maintain preservation of the relatively intact southern Sudanese Red Sea.

  9. Reef fish communities in the central Red Sea show evidence of asymmetrical fishing pressure

    KAUST Repository

    Kattan, Alexander

    2017-03-09

    In order to assess human impacts and develop rational restoration goals for corals reefs, baseline estimates of fish communities are required. In Saudi Arabian waters of the Red Sea, widespread unregulated fishing is thought to have been ongoing for decades, but there is little direct evidence of the impact on reef communities. To contextualize this human influence, reef-associated fish assemblages on offshore reefs in Saudi Arabia and Sudan in the central Red Sea were investigated. These reefs have comparable benthic environments, experience similar oceanographic influences, and are separated by less than 300 km, offering an ideal comparison for identifying potential anthropogenic impacts such as fishing pressure. This is the first study to assess reef fish biomass in both these regions, providing important baselines estimates. We found that biomass of top predators on offshore Sudanese reefs was on average almost three times that measured on comparable reefs in Saudi Arabia. Biomass values from some of the most remote reefs surveyed in Sudan’s far southern region even approach those previously reported in the Northwestern Hawaiian Islands, northern Line Islands, Pitcairn Islands, and other isolated Pacific islands and atolls. The findings suggest that fishing pressure has significantly altered the fish community structure of Saudi Arabian Red Sea reefs, most conspicuously in the form of top predator removal. The results point towards the urgent need for enhanced regulation and enforcement of fishing practices in Saudi Arabia, while making a strong case for protection in the form of no-take marine protected areas to maintain preservation of the relatively intact southern Sudanese Red Sea.

  10. Restoration of a temperate reef: Effects on the fish community

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Stenberg, Claus; Dahl, Karsten

    2014-01-01

    Trindel in Kattegat, Denmark, has now been re-established with the aim of restoring the reef’s historical structure and function. The effects of the restoration on the local fish community are reported here. Fishing surveys using gillnets and fyke nets were conducted before the restoration (2007) and four...... years after the restoration of the reef (2012). Species of the family Labridae, which have a high affinity for rocky reefs, dominated both before and after the restoration. Commercially important species such as cod Gadus morhua, and saithe Pollachius virens, occurred infrequently in the catches in 2007....... The findings highlight the importance of reef habitats for fish communities and the need for their protection...

  11. CHARACTERISTICS OFBENTHIC FISH COMMUNITY OF DNIEPER STORAGE POOL LITTORAL ZONE

    Directory of Open Access Journals (Sweden)

    Novitskiy R. A.

    2011-11-01

    Full Text Available Specific composition of bull-calves is analyzed together with their quantitative and quality parameters in the littoral zone of the Dnepr storage pool. The structural-functional features of organization of littoral communities of bull-calves were studied. The patterns of spatial distribution of Bull-calf (Gobiidae representatives were analyzed for the storage pool; their role in the littoral fish communities was clarified.

  12. Ectomycorrhizal fungal communities of native and non-native Pinus and Quercus species in a common garden of 35-year-old trees.

    Science.gov (United States)

    Trocha, Lidia K; Kałucka, Izabela; Stasińska, Małgorzata; Nowak, Witold; Dabert, Mirosława; Leski, Tomasz; Rudawska, Maria; Oleksyn, Jacek

    2012-02-01

    Non-native tree species have been widely planted or have become naturalized in most forested landscapes. It is not clear if native trees species collectively differ in ectomycorrhizal fungal (EMF) diversity and communities from that of non-native tree species. Alternatively, EMF species community similarity may be more determined by host plant phylogeny than by whether the plant is native or non-native. We examined these unknowns by comparing two genera, native and non-native Quercus robur and Quercus rubra and native and non-native Pinus sylvestris and Pinus nigra in a 35-year-old common garden in Poland. Using molecular and morphological approaches, we identified EMF species from ectomycorrhizal root tips and sporocarps collected in the monoculture tree plots. A total of 69 EMF species were found, with 38 species collected only as sporocarps, 18 only as ectomycorrhizas, and 13 both as ectomycorrhizas and sporocarps. The EMF species observed were all native and commonly associated with a Holarctic range in distribution. We found that native Q. robur had ca. 120% higher total EMF species richness than the non-native Q. rubra, while native P. sylvestris had ca. 25% lower total EMF species richness than non-native P. nigra. Thus, across genera, there was no evidence that native species have higher EMF species diversity than exotic species. In addition, we found a higher similarity in EMF communities between the two Pinus species than between the two Quercus species. These results support the naturalization of non-native trees by means of mutualistic associations with cosmopolitan and novel fungi.

  13. Recruitment and retention of women in fishing communities in HIV ...

    African Journals Online (AJOL)

    ... complete all study visits. Conclusion: Women had better retention rates than men at 18 months. Strategies for recruiting and retaining younger women and those who have stayed for less than 5 years need to be developed for improved retention of women in fishing communities in HIV prevention and research Programs.

  14. Comparison of bacterial communities of tilapia fish from Cameroon ...

    African Journals Online (AJOL)

    Comparison of bacterial communities of tilapia fish from Cameroon and Vietnam using PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) ... The different PCR-DGGE 16S rDNA banding profiles obtained were analysed and results showed that there were specific bands for each geographical ...

  15. A description of the nearshore fish communities in the Huron-Erie Corridor using multiple gear types

    Science.gov (United States)

    Francis, James T.; Chiotti, Justin A.; Boase, James C.; Thomas, Mike V.; Manny, Bruce A.; Roseman, Edward F.

    2013-01-01

    Great Lakes coastal wetlands provide a critical habitat for many fish species throughout their life cycles. Once home to one of the largest wetland complexes in the Great Lakes, coastal wetlands in the Huron–Erie Corridor (HEC) have decreased dramatically since the early 1900s. We characterized the nearshore fish communities at three different wetland complexes in the HEC using electrofishing, seines, and fyke nets. Species richness was highest in the Detroit River (63), followed by the St. Clair Delta (56), and Western Lake Erie (47). The nearshore fish communities in the Detroit River and St. Clair Delta consisted primarily of shiners, bluntnose minnow, centrarchids, and brook silverside, while the Western Lake Erie sites consisted of high proportions of non-native taxa including common carp, gizzard shad, goldfish, and white perch. Species richness estimates using individual-based rarefaction curves were higher when using electrofishing data compared to fyke nets or seine hauls at each wetland. Twelve fish species were captured exclusively during electrofishing assessments, while one species was captured exclusively in fyke nets, and none exclusively during seine hauls. Western Lake Erie wetlands were more indicative of degraded systems with lower species richness, lower proportion of turbidity intolerant species, and increased abundance of non-native taxa. This work highlights the importance of coastal wetlands in the HEC by capturing 69 different fish species utilizing these wetlands to fulfill life history requirements and provides insight when selecting gears to sample nearshore littoral areas.

  16. Trophic analysis of the fish community in the Ciénega Churince, Cuatro Ciénegas, Coahuila

    Directory of Open Access Journals (Sweden)

    Ariana Hernández

    2017-09-01

    Full Text Available Fish diets were analyzed to evaluate the dynamic trophs of the fish community in the Churince wetland system of the Cuatro Ciénegas, where the fauna consists of nine species: endemic, native and introduced. In nine sampling events (between February 2011 and May 2014 556 specimens of all nine species were collected. Stomach contents were analyzed and the Relative Importance Index (IRI was calculated. The feed coefficient (Q of the diets and the accumulated trophic diversity (Hk, as well as the amplitude of the trophic niche were evaluated. Feeding strategies in the fish community were found to be eurifagic. The main foods in general were insects, crustaceans, gastropods, plants and teleosts. According to the average linkage method, four functional trophic groups were defined, with no higher consumption species; nevertheless all were regulators, mainly invertebrates. Therefore, the chain reaction in food control was higher from top to bottom, meaning a downwards dietary control.

  17. Exploring fish microbial communities to mitigate emerging diseases in aquaculture.

    Science.gov (United States)

    de Bruijn, Irene; Liu, Yiying; Wiegertjes, Geert F; Raaijmakers, Jos M

    2018-01-01

    Aquaculture is the fastest growing animal food sector worldwide and expected to further increase to feed the growing human population. However, existing and (re-)emerging diseases are hampering fish and shellfish cultivation and yield. For many diseases, vaccination protocols are not in place and the excessive use of antibiotics and other chemicals is of substantial concern. A more sustainable disease control strategy to protect fish and shellfish from (re-)emerging diseases could be achieved by introduction or augmentation of beneficial microbes. To establish and maintain a 'healthy' fish microbiome, a fundamental understanding of the diversity and temporal-spatial dynamics of fish-associated microbial communities and their impact on growth and health of their aquatic hosts is required. This review describes insights in the diversity and functions of the fish bacterial communities elucidated with next-generation sequencing and discusses the potential of the microbes to mitigate (re-)emerging diseases in aquaculture. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Does functional redundancy stabilize fish communities?

    DEFF Research Database (Denmark)

    Rice, Jake; Daan, Niels; Gislason, Henrik

    2012-01-01

    Functional redundancy is a community property thought to contribute to ecosystem resilience. It is argued that trophic (or other) functional groups with more species have more linkages and opportunities to buffer variation in abundance of individual species. We explored this concept with a 30‐year...... time‐series of data on 83 species sampled in the International Bottom Trawl Survey. Our results were consistent with the hypothesis that functional redundancy leads to more stable (and by inference more resilient) communities. Over the time‐series trophic groups (assigned by diet, size (Lmax) group......, or both factors) with more species had lower coefficients of variation (CVs) in abundance and biomass than did trophic groups with fewer species. These findings are also consistent with Bernoulli’s Law of Large Numbers, a rule that does not require complex ecological and evolutionary processes to produce...

  19. Separate and combined effects of habitat-specific fish predation on the survival of invasive and native gammarids

    Science.gov (United States)

    Kotta, Jonne; Orav-Kotta, Helen; Herkül, Kristjan

    2010-10-01

    The North-American amphipod Gammarus tigrinus was observed for the first time in the northern Baltic Sea in 2003. The invasive amphipod has been particularly successful in some habitats (e.g. on pebbles) where it has become one of the most abundant gammarid species. We studied experimentally if the dominant fish Gasterosteus aculeatus preyed differentially on the exotic G. tigrinus and the native Gammarus salinus, if predation differed among habitats, and if one gammarid species facilitated predation on the other. The experiment demonstrated that (1) fish preyed more on the exotic G. tigrinus than the native G. salinus. (2) Predation did not differ among habitats. (3) Gammarus tigrinus facilitated the predation on G. salinus and this facilitation varied among habitats with significant effects on pebbles. Thus, the combined effect of habitat-specific fish predation and competition between gammarid amphipods is a possible explanation of the current range of G. tigrinus in the northern Baltic Sea. G. tigrinus seems to establish in habitats where it can significantly increase fish predation on the native gammarids.

  20. Seventy years of stream‐fish collections reveal invasions and native range contractions in an Appalachian (USA) watershed

    Science.gov (United States)

    Buckwalter, Joseph D.; Frimpong, Emmanuel A.; Angermeier, Paul L.; Barney, Jacob N.

    2018-01-01

    AimKnowledge of expanding and contracting ranges is critical for monitoring invasions and assessing conservation status, yet reliable data on distributional trends are lacking for most freshwater species. We developed a quantitative technique to detect the sign (expansion or contraction) and functional form of range‐size changes for freshwater species based on collections data, while accounting for possible biases due to variable collection effort. We applied this technique to quantify stream‐fish range expansions and contractions in a highly invaded river system.LocationUpper and middle New River (UMNR) basin, Appalachian Mountains, USA.MethodsWe compiled a 77‐year stream‐fish collections dataset partitioned into ten time periods. To account for variable collection effort among time periods, we aggregated the collections into 100 watersheds and expressed a species’ range size as detections per watershed (HUC) sampled (DPHS). We regressed DPHS against time by species and used an information‐theoretic approach to compare linear and nonlinear functional forms fitted to the data points and to classify each species as spreader, stable or decliner.ResultsWe analysed changes in range size for 74 UMNR fishes, including 35 native and 39 established introduced species. We classified the majority (51%) of introduced species as spreaders, compared to 31% of natives. An exponential functional form fits best for 84% of spreaders. Three natives were among the most rapid spreaders. All four decliners were New River natives.Main conclusionsOur DPHS‐based approach facilitated quantitative analyses of distributional trends for stream fishes based on collections data. Partitioning the dataset into multiple time periods allowed us to distinguish long‐term trends from population fluctuations and to examine nonlinear forms of spread. Our framework sets the stage for further study of drivers of stream‐fish invasions and declines in the UMNR and is widely transferable to

  1. Turbidity alters pre-mating social interactions between native and invasive stream fishes

    Science.gov (United States)

    Glotzbecker, Gregory J.; Ward, Jessica L.; Walters, David M.; Blum, Michael J.

    2015-01-01

    Environmental degradation can result in the loss of aquatic biodiversity if impairment promotes hybridisation between non-native and native species. Although aquatic biological invasions involving hybridisation have been attributed to elevated water turbidity, the extent to which impaired clarity influences reproductive isolation among non-native and native species is poorly understood.

  2. Water clarity of the Colorado River—Implications for food webs and fish communities

    Science.gov (United States)

    Voichick, Nicholas; Kennedy, Theodore A.; Topping, David; Griffiths, Ronald; Fry, Kyrie

    2016-11-01

    The closure of Glen Canyon Dam in 1963 resulted in drastic changes to water clarity, temperature, and flow of the Colorado River in Glen, Marble, and Grand Canyons. The Colorado River is now much clearer, water temperature is less variable throughout the year, and the river is much colder in the summer months. The flow—regulated by the dam—is now less variable annually, but has larger daily fluctuations than during pre-dam times. All of these changes have resulted in a different fish community and different food resources for fish than existed before the dam was built. Recent monitoring of water clarity, by measuring turbidity, has helped scientists and river managers understand modern water-clarity patterns in the dam-regulated Colorado River. These data were then used to estimate pre-dam turbidity in the Colorado River in order to make comparisons of pre-dam and dam-regulated conditions, which are useful for assessing biological changes in the river over time. Prior to dam construction, the large sediment load resulted in low water clarity almost all of the time, a condition which was more favorable for the native fish community.

  3. Fishing top predators indirectly affects condition and reproduction in a reef-fish community.

    Science.gov (United States)

    Walsh, S M; Hamilton, S L; Ruttenberg, B I; Donovan, M K; Sandin, S A

    2012-03-01

    To examine the indirect effects of fishing on energy allocation in non-target prey species, condition and reproductive potential were measured for five representative species (two-spot red snapper Lutjanus bohar, arc-eye hawkfish Paracirrhites arcatus, blackbar devil Plectroglyphidodon dickii, bicolour chromis Chromis margaritifer and whitecheek surgeonfish Acanthurus nigricans) from three reef-fish communities with different levels of fishing and predator abundance in the northern Line Islands, central Pacific Ocean. Predator abundance differed by five to seven-fold among islands, and despite no clear differences in prey abundance, differences in prey condition and reproductive potential among islands were found. Body condition (mean body mass adjusted for length) was consistently lower at sites with higher predator abundance for three of the four prey species. Mean liver mass (adjusted for total body mass), an indicator of energy reserves, was also lower at sites with higher predator abundance for three of the prey species and the predator. Trends in reproductive potential were less clear. Mean gonad mass (adjusted for total body mass) was high where predator abundance was high for only one of the three species in which it was measured. Evidence of consistently low prey body condition and energy reserves in a diverse suite of species at reefs with high predator abundance suggests that fishing may indirectly affect non-target prey-fish populations through changes in predation and predation risk. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  4. Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach.

    Science.gov (United States)

    Tummers, Jeroen S; Hudson, Steve; Lucas, Martyn C

    2016-11-01

    A more holistic approach towards testing longitudinal connectivity restoration is needed in order to establish that intended ecological functions of such restoration are achieved. We illustrate the use of a multi-method scheme to evaluate the effectiveness of 'nature-like' connectivity restoration for stream fish communities in the River Deerness, NE England. Electric-fishing, capture-mark-recapture, PIT telemetry and radio-telemetry were used to measure fish community composition, dispersal, fishway efficiency and upstream migration respectively. For measuring passage and dispersal, our rationale was to evaluate a wide size range of strong swimmers (exemplified by brown trout Salmo trutta) and weak swimmers (exemplified by bullhead Cottus perifretum) in situ in the stream ecosystem. Radio-tracking of adult trout during the spawning migration showed that passage efficiency at each of five connectivity-restored sites was 81.3-100%. Unaltered (experimental control) structures on the migration route had a bottle-neck effect on upstream migration, especially during low flows. However, even during low flows, displaced PIT tagged juvenile trout (total n=153) exhibited a passage efficiency of 70.1-93.1% at two nature-like passes. In mark-recapture experiments juvenile brown trout and bullhead tagged (total n=5303) succeeded in dispersing upstream more often at most structures following obstacle modification, but not at the two control sites, based on a Laplace kernel modelling approach of observed dispersal distance and barrier traverses. Medium-term post-restoration data (2-3years) showed that the fish assemblage remained similar at five of six connectivity-restored sites and two control sites, but at one connectivity-restored headwater site previously inhabited by trout only, three native non-salmonid species colonized. We conclude that stream habitat reconnection should support free movement of a wide range of species and life stages, wherever retention of such

  5. A NASA Community of Practice for Scientists and Educators Working with American Indians and Alaskan Natives

    Science.gov (United States)

    Scalice, D.; Sparrow, E. B.; Johnson, T. A.; Allen, J. E.; Gho, C. L.

    2016-12-01

    One size does not fit all. This is especially true in education, where each learner meets new information from a unique standpoint, bringing prior experiences and understandings to the learning space. It is the job of the educator to be sensitive to these unique perspectives, and work with them to bring learners to new levels of knowledge. This principle is foundational to conducting science education with Native American communities, as they have a distinct history in the US, especially where education is concerned. Many scientists and educators at agencies like NASA are engaging in science education with Native communities across the US, and are approaching the work from varied prior experiences, levels of knowledge of the history of Native America, and desired outcomes. Subsequently, there are varied levels of success, and in some cases, oppressive patterns may be perpetuated. It is therefore the responsibility of the science educator to become informed and sensitized to the unique situation of Native Americans and their history with education and science. It is incumbent on science educators to ensure that the goals they have for Native youth are derived from the goals Native leaders have for their youth, and programming is co-created with Native partners. Toward supporting its science education community to do this, NASA's Science Mission Directorate has initiated a Working Group of individuals, teams, and organizations that are involved in science education with Native American communities via K-12 and/or tribal college programming, and/or grant-making. The purpose is to cultivate a Community of Practice through the sharing of information, knowledge, wisdom, ideas, experience, and best practices, and through the leveraging of resources, assets, and networks. The ultimate goal is the improvement and increased cultural competence of the programs implemented and managed by the group's members.

  6. Herbivory and dominance shifts among exotic and congeneric native plant species during plant community establishment

    DEFF Research Database (Denmark)

    Engelkes, Tim; Meisner, Annelein; Morriën, Elly

    2016-01-01

    in a riparian ecosystem during early establishment of invaded communities. We planted ten plant communities each consisting of three individuals of each of six exotic plant species as well as six phylogenetically related natives. Exotic plant species were selected based on a rapid recent increase in regional...... abundance, the presence of a congeneric native species, and their co-occurrence in the riparian ecosystem. All plant communities were covered by tents with insect mesh. Five tents were open on the leeward side to allow herbivory. The other five tents were completely closed in order to exclude insects...... and vertebrates. Herbivory reduced aboveground biomass by half and influenced which of the plant species dominated the establishing communities. Exposure to herbivory did not reduce the total biomass of natives more than that of exotics, so aboveground herbivory did not selectively enhance exotics during...

  7. Is 30 years enough time to niche segregation between a non-native and a native congeneric fish species? Evidences from stable isotopes

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Zaia Alves

    2015-12-01

    Full Text Available The invasion of non-native species that are phylogenetically similar to native species was observed in the Upper Paraná River following the construction of the Itaipu hydroelectric plant and subsequent removal of a natural geographic barrier (Sete Quedas Falls. Endemic fish species from the Lower Paraná River, such as the piranha Serrasalmus marginatus, successfully colonized the new environment. A few years later, S. marginatus had become the dominant species, while the prevalence of the congeneric species, Serrasalmus maculatus, had declined. Considering that the two piranha species naturally coexist in the Pantanal and that S. marginatus is a non-native species in the Upper Paraná River floodplain, we hypothesized that trophic niche overlap between Serrasalmus species only occurred in the Upper Paraná River floodplain due to short-term co-existence. The study area in which the isotopic niche overlap between S. maculatus and S. marginatus was evaluated consisted of two ponds located in different floodplains, the Pantanal and the Upper Paraná River. We used carbon and nitrogen stable isotope analysis to elucidate the differences in the energy intake by the native and non-native species. We used mixing models and calculated the isotopic niche area and niche overlap to infer the nature of the trophic interactions between the species in both habitats. According to the mixing model, the predominant source of carbon for both species was terrestrial. Nevertheless, in Upper Paraná River, the δ13C signature of the two species differed significantly and the non-native species had a greater niche width than the native species. In the Pantanal, there were no differences in δ13C, but the species differed with respect to δ 15N, and the niche widths were narrow for both species.Based on these results, it can be inferred that the species depend on different food sources. Piranhas obtain energy from distinct prey species, which probably consume

  8. Functionally diverse reef-fish communities ameliorate coral disease.

    Science.gov (United States)

    Raymundo, Laurie J; Halford, Andrew R; Maypa, Aileen P; Kerr, Alexander M

    2009-10-06

    Coral reefs, the most diverse of marine ecosystems, currently experience unprecedented levels of degradation. Diseases are now recognized as a major cause of mortality in reef-forming corals and are complicit in phase shifts of reef ecosystems to algal-dominated states worldwide. Even so, factors contributing to disease occurrence, spread, and impact remain poorly understood. Ecosystem resilience has been linked to the conservation of functional diversity, whereas overfishing reduces functional diversity through cascading, top-down effects. Hence, we tested the hypothesis that reefs with trophically diverse reef fish communities have less coral disease than overfished reefs. We surveyed reefs across the central Philippines, including well-managed marine protected areas (MPAs), and found that disease prevalence was significantly negatively correlated with fish taxonomic diversity. Further, MPAs had significantly higher fish diversity and less disease than unprotected areas. We subsequently investigated potential links between coral disease and the trophic components of fish diversity, finding that only the density of coral-feeding chaetodontid butterflyfishes, seldom targeted by fishers, was positively associated with disease prevalence. These previously uncharacterized results are supported by a second large-scale dataset from the Great Barrier Reef. We hypothesize that members of the charismatic reef-fish family Chaetodontidae are major vectors of coral disease by virtue of their trophic specialization on hard corals and their ecological release in overfished areas, particularly outside MPAs.

  9. A framework for assessing the feasibility of native fish conservation translocations: Applications to threatened bull trout

    Science.gov (United States)

    Galloway, Benjamin T.; Muhlfeld, Clint C.; Guy, Christopher S.; Downs, Christopher C.; Fredenberg, Wade A.

    2016-01-01

    There is an urgent need to consider more aggressive and direct interventions for the conservation of freshwater fishes that are threatened by invasive species, habitat loss, and climate change. Conservation introduction (moving a species outside its indigenous range to other areas where conditions are predicted to be more suitable) is one type of translocation strategy that fisheries managers can use to establish new conservation populations in areas of refugia. To date, however, there are few examples of successful conservation-based introductions. Many attempts fail to establish new populations—in part because environmental factors that might influence success are inadequately evaluated before the translocation is implemented. We developed a framework to assess the feasibility of rescuing threatened fish populations through translocation into historically unoccupied stream and lake habitats. The suitability of potential introduction sites was evaluated based on four major components: the recipient habitat, recipient community, donor population, and future threats. Specific questions were then developed to evaluate each major component. The final assessment was based on a scoring system that addressed each question by using criteria developed from characteristics representative of highly suitable habitats and populations. This framework was used to evaluate the proposed within-drainage translocation of three Bull Trout Salvelinus confluentus populations in Glacier National Park, Montana. Our results indicated that within-drainage translocation is a feasible strategy for conserving locally adapted populations of Bull Trout through the creation of new areas of refugia in Glacier National Park. The framework provides a flexible platform that can help managers make informed decisions for moving threatened fishes into new areas of refugia for conservation and recovery programs.

  10. Observations on the seasonal distribution of native fish in a 10-kilometer reach of San Bernardino Creek, Sonora, Mexico

    Science.gov (United States)

    C. O. Minckley

    2013-01-01

    San Bernardino Creek is a northern tributary of the Río Yaqui that originates in the United States and crosses the International Border just east of Douglas, Arizona/Agua Prieta, Sonora and immediately south of San Bernardino/Leslie Canyon National Wildlife Refuge. Six of eight Río Yaqui native fishes occur in this reach:four minnows, a sucker, and a poeciliid....

  11. Detection of iron-depositing Pedomicrobium species in native biofilms from the Odertal National Park by a new, specific FISH probe.

    Science.gov (United States)

    Braun, Burga; Richert, Inga; Szewzyk, Ulrich

    2009-10-01

    Iron-depositing bacteria play an important role in technical water systems (water wells, distribution systems) due to their intense deposition of iron oxides and resulting clogging effects. Pedomicrobium is known as iron- and manganese-oxidizing and accumulating bacterium. The ability to detect and quantify members of this species in biofilm communities is therefore desirable. In this study the fluorescence in situ hybridization (FISH) method was used to detect Pedomicrobium in iron and manganese incrusted biofilms. Based on comparative sequence analysis, we designed and evaluated a specific oligonucleotide probe (Pedo 1250) complementary to the hypervariable region 8 of the 16S rRNA gene for Pedomicrobium. Probe specificities were tested against 3 different strains of Pedomicrobium and Sphingobium yanoikuyae as non-target organism. Using optimized conditions the probe hybridized with all tested strains of Pedomicrobium with an efficiency of 80%. The non-target organism showed no hybridization signals. The new FISH probe was applied successfully for the in situ detection of Pedomicrobium in different native, iron-depositing biofilms. The hybridization results of native bioflims using probe Pedo_1250 agreed with the results of the morphological structure of Pedomicrobium bioflims based on scanning electron microscopy.

  12. Suppression of invasive topmouth gudgeon Pseudorasbora parva by native pike Esox lucius in ponds

    NARCIS (Netherlands)

    Lemmens, P.; Mergeay, J.; Vanhove, T.; De Meester, L.; Declerck, S.A.J.

    2015-01-01

    1. Asian topmouth gudgeon Pseudorasbora parva has been recognized as a highly invasive cyprinid fish species in Europe that can present risk to native fish communities. 2. The present study aimed to investigate whether a native piscivorous fish, pike Esox lucius, is able to reduce the establishment

  13. Small size today, aquarium dumping tomorrow: sales of juvenile non-native large fish as an important threat in Brazil

    Directory of Open Access Journals (Sweden)

    André L. B. Magalhães

    2017-12-01

    Full Text Available ABSTRACT Informal sales of large-bodied non-native aquarium fishes (known as “tankbusters” is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST. We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm, and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.

  14. Microscopic examination of skin in native and nonnative fish from Lake Tahoe exposed to ultraviolet radiation and fluoranthene

    Energy Technology Data Exchange (ETDEWEB)

    Gevertz, Amanda K., E-mail: agevertz@geiconsultants.com [Miami University, Department of Zoology, 212 Pearson Hall, Oxford 45056, Ohio (United States); GEI Consultants, Inc. , 4601 DTC Blvd, Suite 900, Denver 80237, Colorado (United States); Oris, James T., E-mail: orisjt@miamioh.edu [Miami University, Department of Zoology, 212 Pearson Hall, Oxford 45056, Ohio (United States)

    2014-02-15

    Highlights: •PAH cause photo-induced toxicity in aquatic organisms in the natural environment. •Montane lakes like Lake Tahoe receive PAH exposure from recreational watercraft. •These lakes are susceptible to invasion and establishment of non-native species. •Non-natives were less tolerant to photo-toxicity compared to native species. •Sensitivity differences were related to levels of oxidative damage in epidermis. -- Abstract: The presence of nonnative species in Lake Tahoe (CA/NV), USA has been an ongoing concern for many decades, and the management of these species calls for an understanding of their ability to cope with the Lake's stressors and for an understanding of their potential to out-compete and reduce the populations of native species. Decreasing levels of ultraviolet radiation (UVR) due to eutrophication and increasing levels of phototoxic polycyclic aromatic hydrocarbons (PAHs) due to recreational activities may combine to affect the relative ability of native versus nonnative fish species to survive in the lake. Following a series of toxicity tests which exposed larvae of the native Lahontan redside minnow (Richardsonius egregius) and the nonnative warm-water bluegill sunfish (Lepomis macrochirus) to UVR and FLU, the occurrence of skin damage and/or physiologic defense mechanisms were studied using multiple microscopic techniques. The native minnow appeared to exhibit fewer instances of skin damage and increased instances of cellular coping mechanisms. This study supports the results of previous work conducted by the authors, who determined that the native redside minnow is the more tolerant of the two species, and that setting and adhering to a water quality standard for UVR transparency may aid in preventing the spread of the less tolerant nonnative bluegill and similar warm-water species.

  15. [Effects of submarine topography and water depth on distribution of pelagic fish community in minnan-taiwan bank fishing ground].

    Science.gov (United States)

    Fang, Shuimei; Yang, Shengyun; Zhang, Chengmao; Zhu, Jinfu

    2002-11-01

    According to the fishing record of the light-seine information vessel in Minnan-Taiwan bank ground during 1989 to 1999, the effects of submarine topography and water depth on distribution of pelagic fish community in Minnan-Taiwan bank fishing ground was studied. The results showed that the pelagic fish distributed concentratively, while the submarine topography and water depth varied widely, but in different fishing regions, the distribution of pelagic fishes was uneven. The distribution of fishing yield increased from north to south, and closed up from sides of the bank to south or north in the regions. Pelagic fish distributed mainly in mixed water in the southern Taiwan Strait, and in warm water in the Taiwan Strait. The central fishing grounds were at high salt regions. Close gathering regions of pelagic fish or central fishing ground would be varied with the seasonal variation of mixed water in the southern Taiwan Strait and warm water in the Taiwan Strait. Central fishing ground was not only related to submarine topography and water depth, but also related to wind direction, wind-power and various water systems. In the fishing ground, the gathering depth of pelagic fish was 30-60 m in spring and summer, and 40-80 m in autumn and winter.

  16. Present status and approaches for the sustainable development of community based fish culture in seasonal floodplains of Bangladesh.

    Science.gov (United States)

    Rahman, M F; Jalal, K C A; Jahan, Nasrin; Kamaruzzaman, B Y; Ara, R; Arshad, A

    2012-06-15

    Coordination among the different stakeholders at policy planning, implementation and target beneficiary level, particularly among the agencies responsible for development and management of water resources, agriculture and fisheries, is essential for overall sustainable development. Stocking of larger fingerlings at suitable stocking densities of endemic (rohu, catla, mrigal) and exotic (silver carp, bighead carp, common carp/mirror carp) species should be stocked at varying proportion. Floodplain fish production depends only on the natural fertility of the water bodies. Technological interventions should include the installation of low cost bamboo fencing at water inlet and outlet points and setting of ring culverts for maintaining suitable levels of water for fish culture without hampering the production of rice and other crops in the intervention areas, selective stocking with native and exotic carps, restricted fishing for certain period of time and guarding. It is expected to exert positive influences in enhancing the standing crop and biodiversity of non-stocked species of fishes in the intervention seasonal floodplain. Entry of fish larvae, hatchlings and young fry of wild non-stocked fishes into the seasonal floodplains because of large fence spacing (approximately 1.0 cm), could restrict fishing for certain period, undisturbed habitat and guarding could contribute to higher productivity and enhancement of fish biodiversity in the seasonal floodplains. Proper motivation and effective cooperation of the beneficiaries are extremely important to culture fish in the seasonal floodplains under community based management system. Institutional support and constant vigilance from the Department of Fisheries (DoF) and local administrations are indispensable to ensure the sustainability of fish culture initiatives in the seasonal floodplains. Active participation and involvement of the local community people in all stages of fish culture operation beginning from

  17. Alien fish species in reservoir systems in Turkey: a review

    OpenAIRE

    Deniz Innal

    2012-01-01

    Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distributio...

  18. Accounting for Incomplete Species Detection in Fish Community Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University; Jager, Yetta [ORNL

    2013-01-01

    Riverine fish assemblages are heterogeneous and very difficult to characterize with a one-size-fits-all approach to sampling. Furthermore, detecting changes in fish assemblages over time requires accounting for variation in sampling designs. We present a modeling approach that permits heterogeneous sampling by accounting for site and sampling covariates (including method) in a model-based framework for estimation (versus a sampling-based framework). We snorkeled during three surveys and electrofished during a single survey in suite of delineated habitats stratified by reach types. We developed single-species occupancy models to determine covariates influencing patch occupancy and species detection probabilities whereas community occupancy models estimated species richness in light of incomplete detections. For most species, information-theoretic criteria showed higher support for models that included patch size and reach as covariates of occupancy. In addition, models including patch size and sampling method as covariates of detection probabilities also had higher support. Detection probability estimates for snorkeling surveys were higher for larger non-benthic species whereas electrofishing was more effective at detecting smaller benthic species. The number of sites and sampling occasions required to accurately estimate occupancy varied among fish species. For rare benthic species, our results suggested that higher number of occasions, and especially the addition of electrofishing, may be required to improve detection probabilities and obtain accurate occupancy estimates. Community models suggested that richness was 41% higher than the number of species actually observed and the addition of an electrofishing survey increased estimated richness by 13%. These results can be useful to future fish assemblage monitoring efforts by informing sampling designs, such as site selection (e.g. stratifying based on patch size) and determining effort required (e.g. number of

  19. Assessment of the pelagic fish populations using CEN multi-mesh gillnets: consequences for the characterization of the fish communities

    Directory of Open Access Journals (Sweden)

    C. Deceliere-Vergès

    2008-01-01

    Full Text Available The contribution of CEN standard pelagic nets to the assessment of fish communities is tested by comparing three metrics (species composition, species abundance, and size structures measured in accordance with the standard (i.e. using benthic nets only to those calculated from the total effort (i.e. including pelagic nets. Hydroacoustic surveys were used simultaneously to assess fish densities in the pelagic habitat. The results show that in most cases the pelagic nets did not provide any extra information about these three metrics. However, their inclusion in the calculation of CPUE and size structures may affect the picture of the fish communities, especially in lakes containing salmonid populations. This study highlights the need to sample pelagic fish when assessing fish communities in order to determine lake quality.

  20. Granivory of invasive, naturalized, and native plants in communities differentially susceptible to invasion

    Science.gov (United States)

    B. M. Connolly; D. E. Pearson; R. N. Mack

    2014-01-01

    Seed predation is an important biotic filter that can influence abundance and spatial distributions of native species through differential effects on recruitment. This filter may also influence the relative abundance of nonnative plants within habitats and the communities' susceptibility to invasion via differences in granivore identity, abundance, and food...

  1. Properties of native plant communities do not determine exotic success during early forest succession

    Science.gov (United States)

    Aldo Compagnoni; Charles B. Halpern

    2009-01-01

    Considerable research has been devoted to understanding how plant invasions are influenced by properties of the native community and to the traits of exotic species that contribute to successful invasion. Studies of invasibility are common in successionally stable grasslands, but rare in recently disturbed or seral forests. We used 16 years of species richness and...

  2. Microbial Communities in Cerrado Soils under Native Vegetation Subjected to Prescribed Fires and Under Pasture

    Science.gov (United States)

    The objective of this work was to evaluate the effects of fire regimes and vegetation cover on the structure and dynamics of soil microbial communities, through phospholipid fatty acid (PLFA) analysis. Comparisons were made between native areas with different woody covers ("cerra...

  3. Distance from a fishing community explains fish abundance in a no-take zone with weak compliance.

    Science.gov (United States)

    Advani, Sahir; Rix, Laura N; Aherne, Danielle M; Alwany, Magdy A; Bailey, David M

    2015-01-01

    There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into 'paper parks' through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community.

  4. Distance from a fishing community explains fish abundance in a no-take zone with weak compliance.

    Directory of Open Access Journals (Sweden)

    Sahir Advani

    Full Text Available There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into 'paper parks' through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community.

  5. When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs

    NARCIS (Netherlands)

    Denderen, van P.D.; Kooten, van T.; Rijnsdorp, A.D.

    2013-01-01

    Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and

  6. Marine protected areas increase temporal stability of community structure, but not density or diversity, of tropical seagrass fish communities.

    Directory of Open Access Journals (Sweden)

    Elisa Alonso Aller

    Full Text Available Marine protected areas (MPAs have been shown to increase long-term temporal stability of fish communities and enhance ecosystem resilience to anthropogenic disturbance. Yet, the potential ability of MPAs to buffer effects of environmental variability at shorter time scales remains widely unknown. In the tropics, the yearly monsoon cycle is a major natural force affecting marine organisms in tropical regions, and its timing and severity are predicted to change over the coming century, with potentially severe effects on marine organisms, ecosystems and ecosystem services. Here, we assessed the ability of MPAs to buffer effects of monsoon seasonality on seagrass-associated fish communities, using a field survey in two MPAs (no-take zones and two unprotected (open-access sites around Zanzibar (Tanzania. We assessed the temporal stability of fish density and community structure within and outside MPAs during three monsoon seasons in 2014-2015, and investigated several possible mechanisms that could regulate temporal stability. Our results show that MPAs did not affect fish density and diversity, but that juvenile fish densities were temporally more stable within MPAs. Second, fish community structure was more stable within MPAs for juvenile and adult fish, but not for subadult fish or the total fish community. Third, the observed effects may be due to a combination of direct and indirect (seagrass-mediated effects of seasonality and, potentially, fluctuating fishing pressure outside MPAs. In summary, these MPAs may not have the ability to enhance fish density and diversity and to buffer effects of monsoon seasonality on the whole fish community. However, they may increase the temporal stability of certain groups, such as juvenile fish. Consequently, our results question whether MPAs play a general role in the maintenance of biodiversity and ecosystem functioning under changing environmental conditions in tropical seagrass fish communities.

  7. Modification of a Community Garden to Attract Native Bee Pollinators in Urban San Luis Obispo, California

    Directory of Open Access Journals (Sweden)

    Robbin W. Thorp

    2009-01-01

    Full Text Available Gardens have become increasingly important places for growing nutritional food, for conserving biodiversity, for biological and ecological research and education, and for community gathering. Gardens can also be designed with the goal of attracting specific wildlife, like birds and butterflies, but pollinators, like bees, can also be drawn to specially planned and modified gardens. A community garden in San Luis Obispo, California provided the setting for modification with the goal of attracting native bee pollinators by planting known bee-attractive plants. The local gardeners participated in a survey questionnaire and focused interviews to provide their input and interest in such a project. Presentations on our work with native bees in urban environments and gardening to attract bees were also given to interested gardeners. Work of this type also benefited from a lead gardener who managed donated bee plants and kept up momentum of the project. Modification of the garden and monitoring of native bees started in 2007 and continued through the growing season of 2009. Diversity of collected and observed native bees has increased each year since 2007. To date, 40 species in 17 genera of mostly native bees has been recorded from the garden, and this number is expected to increase through time.

  8. The effect of native and introduced biofuel crops on the composition of soil biota communities

    Science.gov (United States)

    Frouz, Jan; Hedenec, Petr

    2016-04-01

    Biofuel crops are an accepted alternative to fossil fuels, but little is known about the ecological impact of their production. The aim of this contribution is to study the effect of native (Salix viminalis and Phalaris arundinacea) and introduced (Helianthus tuberosus, Reynoutria sachalinensis and Silphium perfoliatum) biofuel crop plantations on the soil biota in comparison with cultural meadow vegetation used as control. The study was performed as part of a split plot field experiment of the Crop Research Institute in the city of Chomutov (Czech Republic). The composition of the soil meso- and macrofauna community, composition of the cultivable fraction of the soil fungal community, cellulose decomposition (using litter bags), microbial biomass, basal soil respiration and PLFA composition (incl. F/B ratio) were studied in each site. The C:N ratio and content of polyphenols differed among plant species, but these results could not be considered significant between introduced and native plant species. Abundance of the soil meso- and macrofauna was higher in field sites planted with S. viminalis and P. arundinacea than those planted with S. perfoliatum, H. tuberosus and R. sachalinensis. RDA and Monte Carlo Permutation Test showed that the composition of the faunal community differed significantly between various native and introduced plants. Significantly different basal soil respiration was found in sites planted with various energy crops; however, this difference was not significant between native and introduced species. Microbial biomass carbon and cellulose decomposition did not exhibit any statistical differences among the biofuel crops. The largest statistically significant difference we found was in the content of actinobacterial and bacterial (bacteria, G+ bacteria and G- bacteria) PLFA in sites overgrown by P. arundinacea compared to introduced as well as native biofuel crops. In conclusion, certain parameters significantly differ between various native

  9. Preliminary Insight into Winter Native Fish Assemblages in Guadiana Estuary Salt Marshes Coping with Environmental Variability and Non-Indigenous Fish Introduction

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves

    2017-10-01

    Full Text Available This work aims to undertake a preliminary characterization of winter fish assemblages in the salt marsh areas of Guadiana lower estuary (South-East Portugal and discusses the potential risks of habitat dominance by a non-indigenous species (NIS. To this effect, six field campaigns were carried out in four sampling sites during winter season targeting the collection of fish species. A total of 48 samples were collected. Individuals from seven different taxa (marine and estuarine were collected, although the assemblage was dominated by two estuarine species—the native Pomatoschistus sp. (goby and the NIS Fundulus heteroclitus (mummichog. Goby was the most abundant taxa in the majority of salt marsh habitats, except for one specific, marsh pool, where extreme environmental conditions were registered, namely high temperature and salinity. Such conditions may have boosted the intrusion of mummichog in this area. This species is well adapted to a wide range of abiotic factors enabling them to colonize habitats where no predators inhabit. Impacts of mummichog introduction in the Guadiana salt marsh area are still unpredictable since this is the first time they have been recorded in such high density. Nevertheless, in scenarios of increased anthropogenic pressure and, consequently, habitat degradation, there is a potential risk of mummichog spreading to other habitats and therefore competing for space and food resources with native species.

  10. Language Preservation: the Language of Science as a bridge to the Native American Community

    Science.gov (United States)

    Alexander, C. J.; Martin, M.; Grant, G.

    2009-12-01

    Many Native American communities recognize that the retention of their language, and the need to make the language relevant to the technological age we live in, represents one of their largest and most urgent challenges. Almost 70 percent of Navajos speak their tribal language in the home, and 25 per cent do not know English very well. In contrast, only 30 percent of Native Americans as a whole speak their own tribal language in the home. For the Cherokee and the Chippewa, less than 10 percent speak the native language in the home. And for the Navajo, the number of first graders who solely speak English is almost four times higher than it was in 1970. The U.S. Rosetta Project is the NASA contribution to the International Rosetta Mission. The Rosetta stone is the inspiration for the mission’s name. As outlined by the European Space Agency, Rosetta is expected to provide the keys to the primordial solar system the way the original Rosetta Stone provided a key to ancient language. The concept of ancient language as a key provides a theme for this NASA project’s outreach to Native American communities anxious for ways to enhance and improve the numbers of native speakers. In this talk we will present a concept for building on native language as it relates to STEM concepts. In 2009, a student from the Dine Nation interpreted 28 NASA terms for his senior project at Chinle High School in Chinle, AZ. These terms included such words as space telescope, weather satellite, space suit, and the planets including Neptune and Uranus. This work represents a foundation for continued work between NASA and the Navajo Nation. Following approval by the tribal elders, the U.S. Rosetta project would host the newly translated Navajo words on a web-site, and provide translation into both Navajo and English. A clickable map would allow the user to move through all the words, see Native artwork related to the word, and hear audio translation. Extension to very remote teachers in the

  11. A new freshwater biodiversity indicator based on fish community assemblages.

    Directory of Open Access Journals (Sweden)

    Joanne Clavel

    Full Text Available Biodiversity has reached a critical state. In this context, stakeholders need indicators that both provide a synthetic view of the state of biodiversity and can be used as communication tools. Using river fishes as model, we developed community indicators that aim at integrating various components of biodiversity including interactions between species and ultimately the processes influencing ecosystem functions. We developed indices at the species level based on (i the concept of specialization directly linked to the niche theory and (ii the concept of originality measuring the overall degree of differences between a species and all other species in the same clade. Five major types of originality indices, based on phylogeny, habitat-linked and diet-linked morphology, life history traits, and ecological niche were analyzed. In a second step, we tested the relationship between all biodiversity indices and land use as a proxy of human pressures. Fish communities showed no significant temporal trend for most of these indices, but both originality indices based on diet- and habitat- linked morphology showed a significant increase through time. From a spatial point of view, all indices clearly singled out Corsica Island as having higher average originality and specialization. Finally, we observed that the originality index based on niche traits might be used as an informative biodiversity indicator because we showed it is sensitive to different land use classes along a landscape artificialization gradient. Moreover, its response remained unchanged over two other land use classifications at the global scale and also at the regional scale.

  12. Spatial Structure and Temporal Variation of Fish Communities in the Upper Mississippi River System

    National Research Council Canada - National Science Library

    Chick, John H; Ickes, Brian S; Pegg, Mark A; Barko, Valerie A; Hrabik, Robert A; Herzog, David P

    2005-01-01

    Variation in community composition (presence/absence data) and structure (relative abundance) of Upper Mississippi River fishes was assessed using data from the Long Term Resource Monitoring Program...

  13. 'Snag bags': adapting condoms to community values in Native American communities.

    Science.gov (United States)

    Gilley, Brian Joseph

    2006-01-01

    HIV/AIDS researchers working among Native Americans have consistently noted resistance to discussions of sexuality and the distribution of condoms. This resistance is inspired by long held values about shame and public discussions of sexuality. Also, American Indians have been reluctant to welcome public discussions of HIV/AIDS and sexuality from external entities, such as governmental agencies. As a result, Native peoples have some of the lowest documented condom use rates. However, innovations in culturally integrating condoms and safe sex messages into Native cultural ideals are proving beneficial. One such innovation is the snag bag, which incorporates popular Native sexual ideology while working within local ideals of shame to distribute condoms and safe sex materials to sexually active young people and adults. Using snag bags as an example, this research proposes that an effective approach to HIV prevention among Native peoples is not cultural sensitivity but cultural integration. That is, HIV prevention strategies must move beyond the empty promise of merely culturally-sensitizing ideas about disease cause. Instead of simply 'translating' HIV/AIDS programming into Native culture, prevention strategies must be integrated by Native peoples into their own disease theories and contemporary culture.

  14. Recreational freshwater fishing drives non-native aquatic species richness patterns at a continental scale

    Data.gov (United States)

    U.S. Environmental Protection Agency — Aim. Mapping the geographic distribution of non-native aquatic species is a critically important precursor to understanding the anthropogenic and environmental...

  15. Changes in the fish community and water quality during seven years of stocking piscivorous fish in a shallow lake

    DEFF Research Database (Denmark)

    Skov, Christian; Perrow, M.R.; Berg, Søren

    2002-01-01

    evaluated between predatory fish and potential prey and between zooplanktivorous or benthivorous fish and water quality parameters. In addition, potential consumption of piscivorous fishes was calculated. 3. The density of fish feeding on larger zooplankton or benthos (roach >15 cm, crucian carp >15 cm......1. Piscivores (annual stocking of 1000 individuals ha(-1) of 0+ pike and a single stocking of 30 kg ha(-1) of large 20-30 cm perch) were stocked in seven consecutive years in a shallow eutrophic lake in Denmark. The stocking programme aimed at changing food-web structure by reducing...... zooplanktivorous and benthivorous fish, with resultant effects on lower trophic levels and ultimately water quality. 2. The fish community and water quality parameters (Secchi depth, concentrations of total phosphorus, chlorophyll a and suspended solids) were monitored between 1996 and 2000 and relationships were...

  16. Spatio-temporal segregation and size distribution of fish assemblages as related to non-native species occurrence in the middle rio Doce Valley, MG, Brazil

    Directory of Open Access Journals (Sweden)

    Henrique Corrêa Giacomini

    Full Text Available The lakes in the middle rio Doce Valley (MG are suffering impacts due to the introduction of invasive fish species, mainly piscivorous species like red piranha Pygocentrus nattereri and peacock bass Cichla kelberi. Fishes were collected in bimonthly samples conducted at ten lakes along a year. The present study showed that the composition of native fish assemblages is significantly related to the presence and type of non-native species. Fish species distribution among lakes can be explained by differences in species body size: smaller native species are less concentrated in lakes with invasive piscivores, which is in accordance with the hypothesis that they have greater susceptibility to predation by invaders. Another probable cause for this correlation is the proximity of lakes to the drainage system, which could explain both the non-native incidence and the turnover of native species composition. Furthermore, temporal variability in species composition was significantly higher in invaded lakes. This last factor may be linked to seasonal flood pulses, which carry immigrant fishes from streams in the vicinity. The metacommunity framework can bring insights for future studies in such spatially structured systems, and the approach should improve our understanding of processes underlying species composition as well as help direct conservation-focused management plans.

  17. Rebuilding fish communities: the ghost of fisheries past and the virtue of patience.

    Science.gov (United States)

    Collie, Jeremy; Rochet, Marie-Joëlle; Bell, Richard

    2013-03-01

    The ecosystem approach to management requires the status of individual species to be considered in a community context. We conducted a comparative ecosystem analysis of the Georges Bank and North Sea fish communities to determine the extent to which biological diversity is restored when fishing pressure is reduced. First, fishing mortality estimates were combined to quantify the community-level intensity and selectivity of fishing pressure. Second, standardized bottom-trawl survey data were used to investigate the temporal trends in community metrics. Third, a size-based, multispecies model (LeMans) was simulated to test the response of community metrics to both hypothetical and observed changes in fishing pressure in the two communities. These temperate North Atlantic fish communities have much in common, including a history of overfishing. In recent decades fishing pressure has been reduced, and some species have started to rebuild. The Georges Bank fishery has been more selective, and fishing pressure was reduced sooner. The two communities have similar levels of size diversity and biomass per unit area, but fundamentally different community structure. The North Sea is dominated by smaller species and has lower evenness than Georges Bank. These fundamental differences in community structure are not explained by recent fishing patterns. The multispecies model was able to predict the observed changes in community metrics better on Georges Bank, where rebuilding is more apparent than in the North Sea. Model simulations predicted hysteresis in rebuilding community metrics toward their unfished levels, particularly in the North Sea. Species in the community rebuild at different rates, with smaller prey species outpacing their large predators and overshooting their pre-exploitation abundances. This indirect effect of predator release delays the rebuilding of community structure and biodiversity. Therefore community rebuilding is not just the sum of single

  18. How Are Fishing Patterns and Fishing Communities Responding to Climate Change? A Test Case from the Northwest Atlantic

    Science.gov (United States)

    Young, T.; Fuller, E.; Coleman, K.; Provost, M.; Pinsky, M. L.; St Martin, K.

    2016-02-01

    We know climate is changing and fish are moving in response to those changes. But we understand less about how harvesters are responding to these changes in fish distribution and the ramifications of those changes for fishing communities. Ecological and evolutionary theory suggests that organisms must move, adapt, or die in response to environmental changes, and a related frame may be relevant for human harvesters in the face of climate change. Furthermore, research suggests that there may be a portfolio effect: a wider diversity of catch may buffer harvesters from some effects of climate change. To get at these questions, we explored changes in fishing patterns among commercial fishing communities in the northeast US from 1997-2014 using NOAA-collected logbook data. We found that communities using more mobile gear (large trawl vessels) demonstrated a greater range of latitudinal shift than communities using any other gear. Latitudinal shift was also inversely related to species diversity of catch and port latitude in those communities: southern communities that caught few species shifted dramatically northward, and northern communities that caught many species did not demonstrate marked latitudinal shifts. Those communities that demonstrated larger latitudinal shifts also demonstrated smaller changes in catch composition than their more stationary counterparts. We also found that vessels are indeed leaving many, but not all, fisheries in this region. These results suggest that harvesters are moving, adapting, and leaving fisheries, and that there does appear to be a portfolio effect, with catch diversity mediating some of these responses. While these changes in fishing patterns cannot all be directly attributed to climate change per se, marine fishes in this region are shifting north rapidly, as is expected under climate change. This study provides a valuable test case for exploring the potential ramifications of climate change on coastal socio-ecological systems.

  19. Seasonal changes in the assembly mechanisms structuring tropical fish communities.

    Science.gov (United States)

    Fitzgerald, Daniel B; Winemiller, Kirk O; Sabaj Pérez, Mark H; Sousa, Leandro M

    2017-01-01

    Despite growing interest in trait-based approaches to community assembly, little attention has been given to seasonal variation in trait distribution patterns. Mobile animals can rapidly mediate influences of environmental factors and species interactions through dispersal, suggesting that the relative importance of different assembly mechanisms can vary over short time scales. This study analyzes seasonal changes in functional trait distributions of tropical fishes in the Xingu River, a major tributary of the Amazon with large predictable temporal variation in hydrologic conditions and species density. Comparison of observed functional diversity revealed that species within wet-season assemblages were more functionally similar than those in dry-season assemblages. Further, species within wet-season assemblages were more similar than random expectations based on null model predictions. Higher functional richness within dry season communities is consistent with increased niche complementarity during the period when fish densities are highest and biotic interactions should be stronger; however, null model tests suggest that stochastic factors or a combination of assembly mechanisms influence dry-season assemblages. These results demonstrate that the relative influence of community assembly mechanisms can vary seasonally in response to changing abiotic conditions, and suggest that studies attempting to infer a single dominant mechanism from functional patterns may overlook important aspects of the assembly process. During the prolonged flood pulse of the wet season, expanded habitat and lower densities of aquatic organisms likely reduce the influence of competition and predation. This temporal shift in the influence of different assembly mechanisms, rather than any single mechanism, may play a large role in maintaining the structure and diversity of tropical rivers and perhaps other dynamic and biodiverse systems. © 2016 by the Ecological Society of America.

  20. Community-based native seed production for restoration in Brazil - the role of science and policy.

    Science.gov (United States)

    Schmidt, I B; de Urzedo, D I; Piña-Rodrigues, F C M; Vieira, D L M; de Rezende, G M; Sampaio, A B; Junqueira, R G P

    2018-05-20

    Large-scale restoration programmes in the tropics require large volumes of high quality, genetically diverse and locally adapted seeds from a large number of species. However, scarcity of native seeds is a critical restriction to achieve restoration targets. In this paper, we analyse three successful community-based networks that supply native seeds and seedlings for Brazilian Amazon and Cerrado restoration projects. In addition, we propose directions to promote local participation, legal, technical and commercialisation issues for up-scaling the market of native seeds for restoration with high quality and social justice. We argue that effective community-based restoration arrangements should follow some principles: (i) seed production must be based on real market demand; (ii) non-governmental and governmental organisations have a key role in supporting local organisation, legal requirements and selling processes; (iii) local ecological knowledge and labour should be valued, enabling local communities to promote large-scale seed production; (iv) applied research can help develop appropriate techniques and solve technical issues. The case studies from Brazil and principles presented here can be useful for the up-scaling restoration ecology efforts in many other parts of the world and especially in tropical countries where improving rural community income is a strategy for biodiversity conservation and restoration. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  1. Community-Based Research as a Mechanism to Reduce Environmental Health Disparities in American Indian and Alaska Native Communities

    Directory of Open Access Journals (Sweden)

    Cynthia Agumanu McOliver

    2015-04-01

    Full Text Available Racial and ethnic minority communities, including American Indian and Alaska Natives, have been disproportionately impacted by environmental pollution and contamination. This includes siting and location of point sources of pollution, legacies of contamination of drinking and recreational water, and mining, military and agricultural impacts. As a result, both quantity and quality of culturally important subsistence resources are diminished, contributing to poor nutrition and obesity, and overall reductions in quality of life and life expectancy. Climate change is adding to these impacts on Native American communities, variably causing drought, increased flooding and forced relocation affecting tribal water resources, traditional foods, forests and forest resources, and tribal health. This article will highlight several extramural research projects supported by the United States Environmental Protection Agency (USEPA Science to Achieve Results (STAR tribal environmental research grants as a mechanism to address the environmental health inequities and disparities faced by tribal communities. The tribal research portfolio has focused on addressing tribal environmental health risks through community based participatory research. Specifically, the STAR research program was developed under the premise that tribal populations may be at an increased risk for environmentally-induced diseases as a result of unique subsistence and traditional practices of the tribes and Alaska Native villages, community activities, occupations and customs, and/or environmental releases that significantly and disproportionately impact tribal lands. Through a series of case studies, this article will demonstrate how grantees—tribal community leaders and members and academic collaborators—have been addressing these complex environmental concerns by developing capacity, expertise and tools through community-engaged research.

  2. Community-Based Research as a Mechanism to Reduce Environmental Health Disparities in American Indian and Alaska Native Communities

    Science.gov (United States)

    McOliver, Cynthia Agumanu; Camper, Anne K.; Doyle, John T.; Eggers, Margaret J.; Ford, Tim E.; Lila, Mary Ann; Berner, James; Campbell, Larry; Donatuto, Jamie

    2015-01-01

    Racial and ethnic minority communities, including American Indian and Alaska Natives, have been disproportionately impacted by environmental pollution and contamination. This includes siting and location of point sources of pollution, legacies of contamination of drinking and recreational water, and mining, military and agricultural impacts. As a result, both quantity and quality of culturally important subsistence resources are diminished, contributing to poor nutrition and obesity, and overall reductions in quality of life and life expectancy. Climate change is adding to these impacts on Native American communities, variably causing drought, increased flooding and forced relocation affecting tribal water resources, traditional foods, forests and forest resources, and tribal health. This article will highlight several extramural research projects supported by the United States Environmental Protection Agency (USEPA) Science to Achieve Results (STAR) tribal environmental research grants as a mechanism to address the environmental health inequities and disparities faced by tribal communities. The tribal research portfolio has focused on addressing tribal environmental health risks through community based participatory research. Specifically, the STAR research program was developed under the premise that tribal populations may be at an increased risk for environmentally-induced diseases as a result of unique subsistence and traditional practices of the tribes and Alaska Native villages, community activities, occupations and customs, and/or environmental releases that significantly and disproportionately impact tribal lands. Through a series of case studies, this article will demonstrate how grantees—tribal community leaders and members and academic collaborators—have been addressing these complex environmental concerns by developing capacity, expertise and tools through community-engaged research. PMID:25872019

  3. Effects of hay management and native species sowing on grassland community structure, biomass, and restoration.

    Science.gov (United States)

    Foster, Bryan L; Kindscher, Kelly; Houseman, Greg R; Murphy, Cheryl A

    2009-10-01

    Prairie hay meadows are important reservoirs of grassland biodiversity in the tallgrass prairie regions of the central United States and are the object of increasing attention for conservation and restoration. In addition, there is growing interest in the potential use of such low-input, high-diversity (LIHD) native grasslands for biofuel production. The uplands of eastern Kansas, USA, which prior to European settlement were dominated by tallgrass prairie, are currently utilized for intensive agriculture or exist in a state of abandonment from agriculture. The dominant grasslands in the region are currently high-input, low-diversity (HILD) hay fields seeded to introduced C3 hay grasses. We present results from a long-term experiment conducted in a recently abandoned HILD hay field in eastern Kansas to evaluate effects of fertilization, haying, and native species sowing on community dynamics, biomass, and potential for restoration to native LIHD hay meadow. Fertilized plots maintained dominance by introduced grasses, maintained low diversity, and were largely resistant to colonization throughout the study. Non-fertilized plots exhibited rapid successional turnover, increased diversity, and increased abundance of C4 grasses over time. Haying led to modest changes in species composition and lessened the negative impact of fertilization on diversity. In non-fertilized plots, sowing increased representation by native species and increased diversity, successional turnover, and biomass production. Our results support the shifting limitations hypothesis of community organization and highlight the importance of species pools and seed limitations in constraining successional turnover, community structure, and ecosystem productivity under conditions of low fertility. Our findings also indicate that several biological and functional aspects of LIHD hay meadows can be restored from abandoned HILD hay fields by ceasing fertilization and reintroducing native species through

  4. Genetic ancestry and indigenous heritage in a Native American descendant community in Bermuda.

    Science.gov (United States)

    Gaieski, Jill B; Owings, Amanda C; Vilar, Miguel G; Dulik, Matthew C; Gaieski, David F; Gittelman, Rachel M; Lindo, John; Gau, Lydia; Schurr, Theodore G

    2011-11-01

    Discovered in the early 16th century by European colonists, Bermuda is an isolated set of islands located in the mid-Atlantic. Shortly after its discovery, Bermuda became the first English colony to forcibly import its labor by trafficking in enslaved Africans, white ethnic minorities, and indigenous Americans. Oral traditions circulating today among contemporary tribes from the northeastern United States recount these same events, while, in Bermuda, St. David's Islanders consider their histories to be linked to a complex Native American, European, and African past. To investigate the influence of historical events on biological ancestry and native cultural identity, we analyzed genetic variation in 111 members of Bermuda's self-proclaimed St. David's Island Native Community. Our results reveal that the majority of mitochondrial DNA (mtDNA) and Y-chromosome haplotypes are of African and West Eurasian origin. However, unlike other English-speaking New World colonies, most African mtDNA haplotypes appear to derive from central and southeast Africa, reflecting the extent of maritime activities in the region. In light of genealogical and oral historical data from the St. David's community, the low frequency of Native American mtDNA and NRY lineages may reflect the influence of genetic drift, the demographic impact of European colonization, and historical admixture with persons of non-native backgrounds, which began with the settlement of the islands. By comparing the genetic data with genealogical and historical information, we are able to reconstruct the complex history of this Bermudian community, which is unique among New World populations. Copyright © 2011 Wiley-Liss, Inc.

  5. Granivory of invasive, naturalized, and native plants in communities differentially susceptible to invasion.

    Science.gov (United States)

    Connolly, B M; Pearson, D E; Mack, R N

    2014-07-01

    Seed predation is an important biotic filter that can influence abundance and spatial distributions of native species through differential effects on recruitment. This filter may also influence the relative abundance of nonnative plants within habitats and the communities' susceptibility to invasion via differences in granivore identity, abundance, and food preference. We evaluated the effect of postdispersal seed predators on the establishment of invasive, naturalized, and native species within and between adjacent forest and steppe communities of eastern Washington, USA that differ in severity of plant invasion. Seed removal from trays placed within guild-specific exclosures revealed that small mammals were the dominant seed predators in both forest and steppe. Seeds of invasive species (Bromus tectorum, Cirsium arvense) were removed significantly less than the seeds of native (Pseudoroegneria spicata, Balsamorhiza sagittata) and naturalized (Secale cereale, Centaurea cyanus) species. Seed predation limited seedling emergence and establishment in both communities in the absence of competition in a pattern reflecting natural plant abundance: S. cereale was most suppressed, B. tectorum was least suppressed, and P. spicata was suppressed at an intermediate level. Furthermore, seed predation reduced the residual seed bank for all species. Seed mass correlated with seed removal rates in the forest and their subsequent effects on plant recruitment; larger seeds were removed at higher rates than smaller seeds. Our vegetation surveys indicate higher densities and canopy cover of nonnative species occur in the steppe compared with the forest understory, suggesting the steppe may be more susceptible to invasion. Seed predation alone, however, did not result in significant differences in establishment for any species between these communities, presumably due to similar total small-mammal abundance between communities. Consequently, preferential seed predation by small

  6. Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

    Science.gov (United States)

    Martin, Charles W.; Valentine, Marla M.; Valentine, John F.

    2010-01-01

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important. PMID:21200433

  7. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs.

    Directory of Open Access Journals (Sweden)

    Charles W Martin

    2010-12-01

    Full Text Available Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus, in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus. Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important.

  8. [Phytoplankton community in a recreational fishing lake, Brazil].

    Science.gov (United States)

    Matsuzaki, Mayla; Mucci, José Luiz Negrão; Rocha, Aristides Almeida

    2004-10-01

    The assessment of water quality and phytoplankton community in recreational environments allows to setting management programs aiming at preventing potential harm to human health. The purpose of the present study was to describe phytoplankton seasonal changes in a freshwater system and their relation to water quality. The recreational fishing lake is located in the southern area of the city of São Paulo, Brazil. Water samples were collected in three previously selected sites in the lake throughout a year and analyzed regarding floristic composition and physical and chemical parameters. The phytoplankton qualitative analysis revealed 91 taxa distributed among eight classes: Chlorophyceae, Cyanophyceae, Euglenophyceae, Zygnemaphyceae, Bacillariophyceae, Xantophyceae, Dinophyceae, and Chrysophyceae. Some physical and chemical parameters seemed to influence phytoplankton community behavior. Chlorophyceae development was favored by local conditions. Among the species of cyanobacteria identified, Microcystis paniformis, Cylindrospermopsis raciborskii, and Anabaena species were the most important due to their ability to produce toxins, posing a high risk to public health. Some physical and chemical parameters had an impact on the structure of phytoplankton community. The presence of Microcystis paniformis, Cylindrospermopsis raciborskii and Anabaena species indicates toxic potential and likelihood of public health problems unless there is constant monitoring. Further studies are recommended to prevent hazardous effects to the environment and public health.

  9. Arbuscular mycorrhizal fungal community composition associated with Juniperus brevifolia in native Azorean forest

    Science.gov (United States)

    Melo, Catarina Drumonde; Luna, Sara; Krüger, Claudia; Walker, Christopher; Mendonça, Duarte; Fonseca, Henrique M. A. C.; Jaizme-Vega, Maria; da Câmara Machado, Artur

    2017-02-01

    The communities of glomeromycotan fungi (arbuscular mycorrhizal fungi, AMF) under native Juniperus brevifolia forest from two Azorean islands, Terceira and São Miguel, were compared, mainly by spore morphology, and when possible, by molecular analysis. Thirty-nine morphotypes were detected from 12 genera. Glomeromycotan fungal richness was similar in Terceira and São Miguel, but significantly different among the four fragments of native forest. Spore diversity and community composition differed significantly between the two islands. The less degraded island, Terceira, showed 10 exclusive morphotypes including more rare types, whereas the more disturbed forest on São Miguel showed 13 morphs, mostly of common types. Forests from Terceira were dominated by Acaulosporaceae and Glomeraceae. Whereas members of Acaulosporaceae, Glomeraceae and Ambisporaceae were most frequent and abundant in those from São Miguel. Spore abundance was greatest on Terceira, and correlated with soil chemical properties (pH), average monthly temperature and relative humidity.

  10. Invasion of a dominant floral resource: effects on the floral community and pollination of native plants.

    Science.gov (United States)

    Goodell, Karen; Parker, Ingrid M

    2017-01-01

    Through competition for pollinators, invasive plants may suppress native flora. Community-level studies provide an integrative assessment of invasion impacts and insights into factors that influence the vulnerability of different native species. We investigated effects of the nonnative herb Lythrum salicaria on pollination of native species in 14 fens of the eastern United States. We compared visitors per flower for 122 native plant species in invaded and uninvaded fens and incorporated a landscape-scale experiment, removing L. salicaria flowers from three of the invaded fens. Total flower densities were more than three times higher in invaded than uninvaded or removal sites when L. salicaria was blooming. Despite an increase in number of visitors with number of flowers per area, visitors per native flower declined with increasing numbers of flowers. Therefore, L. salicaria invasion depressed visitation to native flowers. In removal sites, visitation to native flowers was similar to uninvaded sites, confirming the observational results and also suggesting that invasion had not generated a persistent build-up of visitor populations. To study species-level impacts, we examined effects of invasion on visitors per flower for the 36 plant species flowering in both invaded and uninvaded fens. On average, the effect of invasion represented about a 20% reduction in visits per flower. We measured the influence of plant traits on vulnerability to L. salicaria invasion using meta-analysis. Bilaterally symmetrical flowers experienced stronger impacts on visitation, and similarity in flower color to L. salicaria weakly intensified competition with the invader for visitors. Finally, we assessed the reproductive consequences of competition with the invader in a dominant flowering shrub, Dasiphora fruticosa. Despite the negative effect of invasion on pollinator visitation in this species, pollen limitation of seed production was not stronger in invaded than in uninvaded

  11. The assessment of radiation exposures in native American communities from nuclear weapons testing in Nevada

    International Nuclear Information System (INIS)

    Frohmberg, E.; Goble, R.; Sanchez, V.; Quigley, D.

    2000-01-01

    Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from eating small game. The dose reconstruction model assumptions about cattle feeding practices across a year are unlikely to apply to the native communities as are other model assumptions about diet. Thus exposures from drinking milk and eating vegetables have not yet been properly estimated for these communities. Through consultations with members of the affected communities, these deficiencies could be corrected and the dose reconstruction extended to Native Americans. An illustration of the feasibility of extending the dose reconstruction is provided by a sample calculation to estimate radiation exposures to the thyroid from eating radio-iodine-contaminated rabbit thyroids after the Dedan test. The illustration is continued with a discussion of how the calculation results may be used to make estimates for other tests and other locations

  12. Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species

    Directory of Open Access Journals (Sweden)

    E. N. Fragoso-Moura

    Full Text Available Abstract The introduction of species has become an important problem for biodiversity and natural ecosystem conservation. The lake system of the middle Rio Doce (MG, Brazil comprises c. 200 lakes at various conservation states, of which 50 are located within the Rio Doce State Park (PERD. Previous studies had verified several of these lakes suffered non-native fishes introductions and the presence of these species needs for the implementation of actions aiming at not only their control but also the preservation of the native species. This study discusses the effects of non-native fish species in the largest conservation unit of Atlantic Forest in Minas Gerais, southeast of Brazil, using data from 1983 to 2010 distributed as follow: data prior to 2006 were obtained from previous studies, and data from September 2006 to July 2010 were obtained in Lake Carioca at four sampling stations using gillnets, seine nets and sieve. A total of 17 fish species was collected (2006-2010 of which five were introduced species. Among the small to medium size native species (30 to 2000 mm standard length seven had disappeared, two are new records and one was recaptured. The non-native species Cichla kelberi (peacock bass and Pygocentrus nattereri (red piranha are within the most abundant captured species. Integrated with other actions, such as those preventing new introductions, a selective fishing schedule is proposed as an alternative approach to improve the conservation management actions and the local and regional biodiversity maintenance.

  13. Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species.

    Science.gov (United States)

    Fragoso-Moura, E N; Oporto, L T; Maia-Barbosa, P M; Barbosa, F A R

    2016-02-01

    The introduction of species has become an important problem for biodiversity and natural ecosystem conservation. The lake system of the middle Rio Doce (MG, Brazil) comprises c. 200 lakes at various conservation states, of which 50 are located within the Rio Doce State Park (PERD). Previous studies had verified several of these lakes suffered non-native fishes introductions and the presence of these species needs for the implementation of actions aiming at not only their control but also the preservation of the native species. This study discusses the effects of non-native fish species in the largest conservation unit of Atlantic Forest in Minas Gerais, southeast of Brazil, using data from 1983 to 2010 distributed as follow: data prior to 2006 were obtained from previous studies, and data from September 2006 to July 2010 were obtained in Lake Carioca at four sampling stations using gillnets, seine nets and sieve. A total of 17 fish species was collected (2006-2010) of which five were introduced species. Among the small to medium size native species (30 to 2000 mm standard length) seven had disappeared, two are new records and one was recaptured. The non-native species Cichla kelberi (peacock bass) and Pygocentrus nattereri (red piranha) are within the most abundant captured species. Integrated with other actions, such as those preventing new introductions, a selective fishing schedule is proposed as an alternative approach to improve the conservation management actions and the local and regional biodiversity maintenance.

  14. Native Prairie Adaptive Management: a multi region adaptive approach to invasive plant management on Fish and Wildlife Service owned native prairies

    Science.gov (United States)

    Gannon, Jill J.; Shaffer, Terry L.; Moore, Clinton T.

    2013-01-01

    Much of the native prairie managed by the U.S. Fish and Wildlife Service (FWS) in the Prairie Pothole Region (PPR) of the northern Great Plains is extensively invaded by the introduced cool-season grasses, smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). Management to suppress these invasive plants has had poor to inconsistent success. The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. In partnership with the FWS, the U.S. Geological Survey (USGS) developed an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. This joint partnership is known as the Native Prairie Adaptive Management (NPAM) initiative. The NPAM decision framework is built around practical constraints faced by FWS refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen FWS field stations, spanning four states of the PPR, have participated in the initiative. These FWS cooperators share a common management objective, available management strategies, and biological uncertainties. Though the scope is broad, the initiative interfaces with individual land managers who provide site-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators. We describe the technical components of this approach, how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. During an initial scoping workshop, FWS cooperators developed a consensus management objective

  15. Native-likeness in second language lexical categorization reflects individual language history and linguistic community norms.

    Science.gov (United States)

    Zinszer, Benjamin D; Malt, Barbara C; Ameel, Eef; Li, Ping

    2014-01-01

    SECOND LANGUAGE LEARNERS FACE A DUAL CHALLENGE IN VOCABULARY LEARNING: First, they must learn new names for the 100s of common objects that they encounter every day. Second, after some time, they discover that these names do not generalize according to the same rules used in their first language. Lexical categories frequently differ between languages (Malt et al., 1999), and successful language learning requires that bilinguals learn not just new words but new patterns for labeling objects. In the present study, Chinese learners of English with varying language histories and resident in two different language settings (Beijing, China and State College, PA, USA) named 67 photographs of common serving dishes (e.g., cups, plates, and bowls) in both Chinese and English. Participants' response patterns were quantified in terms of similarity to the responses of functionally monolingual native speakers of Chinese and English and showed the cross-language convergence previously observed in simultaneous bilinguals (Ameel et al., 2005). For English, bilinguals' names for each individual stimulus were also compared to the dominant name generated by the native speakers for the object. Using two statistical models, we disentangle the effects of several highly interactive variables from bilinguals' language histories and the naming norms of the native speaker community to predict inter-personal and inter-item variation in L2 (English) native-likeness. We find only a modest age of earliest exposure effect on L2 category native-likeness, but importantly, we find that classroom instruction in L2 negatively impacts L2 category native-likeness, even after significant immersion experience. We also identify a significant role of both L1 and L2 norms in bilinguals' L2 picture naming responses.

  16. Native-Likeness in Second Language Lexical Categorization Reflects Individual Language History and Linguistic Community Norms

    Directory of Open Access Journals (Sweden)

    Benjamin D Zinszer

    2014-10-01

    Full Text Available Second language learners face a dual challenge in vocabulary learning: First, they must learn new names for the hundreds of common objects that they encounter every day. Second, after some time, they discover that these names do not generalize according to the same rules used in their first language. Lexical categories frequently differ between languages (Malt et al., 1999, and successful language learning requires that bilinguals learn not just new words but new patterns for labeling objects. In the present study, Chinese learners of English with varying language histories and resident in two different language settings (Beijing, China and State College, PA, USA named 67 photographs of common serving dishes (e.g., cups, plates, and bowls in both Chinese and English. Participants’ response patterns were quantified in terms of similarity to the responses of functionally monolingual native speakers of Chinese and English and showed the cross-language convergence previously observed in simultaneous bilinguals (Ameel et al., 2005. For English, bilinguals’ names for each individual stimulus were also compared to the dominant name generated by the native speakers for the object. Using two statistical models, we disentangle the effects of several highly interactive variables from bilinguals' language histories and the naming norms of the native speaker community to predict inter-personal and inter-item variation in L2 (English native-likeness. We find only a modest age of earliest exposure effect on L2 category native-likeness, but importantly, we find that classroom instruction in L2 negatively impacts L2 category native-likeness, even after significant immersion experience. We also identify a significant role of both L1 and L2 norms in bilinguals’ L2 picture naming responses.

  17. Recreational freshwater fishing drives non-native aquatic species richness patterns at a continental scale.

    Science.gov (United States)

    Mapping the geographic distribution of non-native aquatic species is a critically important precursor to understanding the anthropogenic and environmental factors that drive freshwater biological invasions. Such efforts are often limited to local scales and/or to single species, ...

  18. Non-native fish introductions and the reversibility of amphibian declines in the Sierra Nevada

    Science.gov (United States)

    Roland A. Knapp

    2004-01-01

    Amphibians are declining worldwide for a variety of reasons, including habitat alteration, introduction of non-native species, disease, climate change, and environmental contaminants. Amphibians often play important roles in structuring ecosystems, and, as a result, amphibian population declines or extinctions are likely to affect other trophic levels (Matthews and...

  19. Ecohydrological index, native fish, and climate trends and relationships in the Kansas River basin

    Science.gov (United States)

    This study sought to quantify climatological and hydrological trends and their relationship to presence and distribution of two native aquatic species in the Kansas River Basin over the past half century. Trend analyses were applied to indicators of hydrologic alteration (IHAs) ...

  20. Discharge, water quality, and native fish abundance in the Virgin River, Utah, Nevada, and Arizona, in support of Pah Tempe Springs discharge remediation efforts

    Science.gov (United States)

    Miller, Matthew P.; Lambert, Patrick M.; Hardy, Thomas B.

    2014-01-01

    Pah Tempe Springs discharge hot, saline, low dissolved-oxygen water to the Virgin River in southwestern Utah, which is transported downstream to Lake Mead and the Colorado River. The dissolved salts in the Virgin River negatively influence the suitability of this water for downstream agricultural, municipal, and industrial use. Therefore, various remediation scenarios to remove the salt load discharged from Pah Tempe Springs to the Virgin River are being considered. One concern about this load removal is the potential to impact the ecology of the Virgin River. Specifically, information is needed regarding possible impacts of Pah Tempe Springs remediation scenarios on the abundance, distribution, and survival of native fish in the Virgin River. Future efforts that aim to quantitatively assess how various remediation scenarios to reduce the load of dissolved salts from Pah Tempe Springs into the Virgin River may influence the abundance, distribution, and survival of native fish will require data on discharge, water quality, and native fish abundance. This report contains organized accessible discharge, water quality, and native fish abundance data sets from the Virgin River, documents the compilation of these data, and discusses approaches for quantifying relations between abiotic physical and chemical conditions, and fish abundance.

  1. Investigating the link between fish community structure and environmental state in deep-time

    Science.gov (United States)

    Sibert, E. C.

    2017-12-01

    In the modern ocean, a bottom-up ecological viewpoint posits that the composition of plankton communities is often a function of ambient oceanographic conditions, including nutrient concentrations and water temperature. Thus, certain plankton species or communities can be associated with specific oceanographic conditions, giving them potential as carriers of paleoceanographic information. Furthermore, consumer groups, such as fish, depend on the structure and composition of these plankton, and therefore different plankton communities will support different types of fish. In addition, fish have their own physiological constraints for surviving in particular environments, such as oxygen demand, and metabolic rate, causing certain clades to be selectively associated with different water mass characteristics. Thus, the relative or absolute abundances of different fish species or groups could shed light on shifting oxygen concentrations, temperature, or primary productivity in the past. To assess whether fish communities have sufficient environmental control to provide paleoceanographic insights, I use a variety of morphological, phylogenetic, and ecological statistical approaches, to correlate modern fish communities from around the world with environmental variables. I then apply these principles to a series of ichthyolith assemblages from the Cretaceous and Cenozoic, across both space and time, to assess whether fish community composition, abundance, or other characteristics can be predictive of ocean temperature or export productivity. I find that while the abundance of fish fossils in deep-sea cores is often, though not always, correlated with certain export production and temperature proxies, community composition appears to vary independently of these variables on long timescales, driven more by evolutionary processes. However, there are distinct differences in contemporary communities in different locations, suggesting that there is potential in using fish

  2. Fish community status in Norwegian lakes in relation to acidification: a comparison between interviews and actual catches by test fishing

    Energy Technology Data Exchange (ETDEWEB)

    Hesthagen, T.; Berger, H.M.; Larsen, B.M. (Norwegian Inst. for Nature Research, Trondheim (Norway)); Rosseland, B.O. (Norwegian Inst. for Water Research, Oslo (Norway))

    1993-01-01

    Inquiries are used to obtain information on fish community status in terms of unchanged, reduced and lost communities, to assess the effects of acidification in lakes. The aim of this paper was to investigate the validity of this method by comparing fish status with actual catches on standard gill net series (CPUE). Data from 230 test fishing incidents comprising 357 stocks of 7 different fish species are presented. We found significant differences in CPUE between perceived fish status categories for brown trout (Salmo trutta), arctic char (Salvelinus alpinus) and perch (Perca fluviatilis), for which sufficient data were available. A discriminant analysis revealed that for stocks reported as unchanged and lost, the predicted membership ranged between 60.0-72.1 % respectively. However, a dominant fraction (50.0-66.7 %) of stocks reported as reduced were assigned as lost. Stocks which have been declining for less than 10 years, had a significantly higher CPUE than stocks which have declined for a longer period of time. Another apparent change in population characteristics was an acidification induced increase in mean weight for fish affected stocks. It is suggested that interviews tend to overestimate the current fish status. This is discussed in relation to a time lag between the damage and the time when it became apparent to fishermen, and rapid decline in population numbers. 26 refs, 2 figs, 4 tabs

  3. Competitive effects of non-native plants are lowest in native plant communities that are most vulnerable to invasion

    Science.gov (United States)

    J.Stephen Brewer; W. Chase Bailey

    2014-01-01

    Despite widespread acknowledgment that disturbance favors invasion, a hypothesis that has received little attention is whether non-native invaders have greater competitive effects on native plants in undisturbed habitats than in disturbed habitats. This hypothesis derives from the assumption that competitive interactions are more persistent in habitats that have not...

  4. Impacts of species introductions on the health of fish communities receiving chronic radionuclide exposures

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

    2006-01-01

    A study was conducted to evaluate the potential impacts of a northern pike introduction on the health of a fish community receiving chronic radionuclide exposure, primarily from 90 Sr. Overall, although significant changes occurred in the community composition and the health of fish populations following the pike introduction, these were not linked to radionuclide dose to fishes. This finding was further supported by assessing the health of forage fishes, which did not significantly change in the pre-versus post-pike fish communities and were comparable in condition to forage fishes inhabiting lakes with background radionuclide levels. Application of such resilient species as 'baseline organisms' can provide a useful tool in the routine monitoring of ecosystems affected by multiple stressors. (author)

  5. NATIVE AND INTRODUCED LARVAL FISHES IN SUISAN MARSH, CALIFORNIA,: THE EFFECTS OF FRESHWATER FLOW

    Science.gov (United States)

    We sampled ichthyoplankton weekly in Suisun Marsh in the San Francisco Estuary from February to June each year from 1994 to 1999. We collected approximately 227,900 fish, predominantly shimofuri goby Tridentiger bifasciatus (60%) and prickly sculpin Cottus asper (33%). Principal ...

  6. Hexavalent chromium reduction under fermentative conditions with lactate stimulated native microbial communities.

    Science.gov (United States)

    Somenahally, Anil C; Mosher, Jennifer J; Yuan, Tong; Podar, Mircea; Phelps, Tommy J; Brown, Steven D; Yang, Zamin K; Hazen, Terry C; Arkin, Adam P; Palumbo, Anthony V; Van Nostrand, Joy D; Zhou, Jizhong; Elias, Dwayne A

    2013-01-01

    Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure and on the Cr(VI)-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM) and continuously amended with Cr(VI) at 0.0 (No-Cr), 0.1 (Low-Cr) and 3.0 (High-Cr) mg/L. Microbial growth, metabolites, Cr(VI), 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI) levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%), Methanosarcina (17%) and others, to mostly Methanosarcina spp. (95%). Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI) reduction, and as a result 3.0 mg/L Cr(VI) did not impact the overall bacterial community structure.

  7. Hexavalent chromium reduction under fermentative conditions with lactate stimulated native microbial communities.

    Directory of Open Access Journals (Sweden)

    Anil C Somenahally

    Full Text Available Microbial reduction of toxic hexavalent chromium (Cr(VI in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI concentrations on community structure and on the Cr(VI-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM and continuously amended with Cr(VI at 0.0 (No-Cr, 0.1 (Low-Cr and 3.0 (High-Cr mg/L. Microbial growth, metabolites, Cr(VI, 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%, Methanosarcina (17% and others, to mostly Methanosarcina spp. (95%. Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI reduction, and as a result 3.0 mg/L Cr(VI did not impact the overall bacterial community structure.

  8. Hexavalent Chromium Reduction under Fermentative Conditions with Lactate Stimulated Native Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    Somenahally, Anil C [ORNL; Mosher, Jennifer J [ORNL; Yuan, Tong [University of Oklahoma; Phelps, Tommy Joe [ORNL; Brown, Steven D [ORNL; Yang, Zamin Koo [ORNL; Hazen, Terry C [ORNL; Arkin, Adam [Lawrence Berkeley National Laboratory (LBNL); Palumbo, Anthony Vito [ORNL; Van Nostrand, Dr. Joy D. [Oklahoma University; Zhou, Jizhong [University of Oklahoma; Elias, Dwayne A [ORNL

    2013-01-01

    Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure and on the Cr(VI)-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM) and continuously amended with Cr(VI) at 0.0 (No-Cr), 0.1 (Low-Cr) and 3.0 (High-Cr) mg/L. Microbial growth, metabolites, Cr(VI), 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI) levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%), Methanosarcina (17%) and others, to mostly Methanosarcina spp. (95%). Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI) reduction, and as a result 3.0 mg/L Cr(VI) did not impact the overall bacterial community structure.

  9. Structure of Caribbean coral reef communities across a large gradient of fish biomass.

    Science.gov (United States)

    Newman, Marah J H; Paredes, Gustavo A; Sala, Enric; Jackson, Jeremy B C

    2006-11-01

    The collapse of Caribbean coral reefs has been attributed in part to historic overfishing, but whether fish assemblages can recover and how such recovery might affect the benthic reef community has not been tested across appropriate scales. We surveyed the biomass of reef communities across a range in fish abundance from 14 to 593 g m(-2), a gradient exceeding that of any previously reported for coral reefs. Increased fish biomass was correlated with an increased proportion of apex predators, which were abundant only inside large marine reserves. Increased herbivorous fish biomass was correlated with a decrease in fleshy algal biomass but corals have not yet recovered.

  10. Exploring relationships among land ownership, agricultural land use, and native fish species richness in the Upper Mississippi River Basin

    Science.gov (United States)

    DeJager, Nathan R.; Rohweder, Jason J.

    2012-01-01

    The general effects of agriculture on in-stream fish communities in the Upper Midwestern United States have been well studied for nearly three decades (Karr et al. 1985; Nerbonne and Vondracek 1991; Zimmerman et al. 2001; Goldstein and Meador 2005). Specific impacts include: lowered water levels, sediment loading and nutrient enrichment, loss of riparian habitat, changes to channel morphometry and physical habitat, and changes to the forage base. As part of the National Fish Habitat Action Plan (NFHAP), an initiative to protect, restore, and enhance the nation's fish and aquatic communities, the Fishers and Farmers Partnership specifically focuses on working with agricultural producers to help protect and restore aquatic resources in the Upper Mississippi River Basin (UMRB) (Fig. 1). Successful protection and/or restoration will require the partnership and local conservation agencies to effectively communicate and work with local landowners. However, roughly 43% of the agricultural lands in the UMRB are not operated by those who own the land (National Agricultural Statistics Service 2009) and this is expected to increase as heirs of farm estates now reside greater distances from their home farms than ever before (Arbuckle 2010).

  11. Investigating temporal patterns of a native bee community in a remnant North American bunchgrass prairie using blue vane traps.

    Science.gov (United States)

    Kimoto, Chiho; Debano, Sandra J; Thorp, Robbin W; Rao, Sujaya; Stephen, William P

    2012-01-01

    Native bees are important ecologically and economically because their role as pollinators fulfills a vital ecosystem service. Pollinators are declining due to various factors, including habitat degradation and destruction. Grasslands, an important habitat for native bees, are particularly vulnerable. One highly imperiled and understudied grassland type in the United States is the Pacific Northwest Bunchgrass Prairie. No studies have examined native bee communities in this prairie type. To fill this gap, the bee fauna of the Zumwalt Prairie, a large, relatively intact remnant of the Pacific Northwest Bunchgrass Prairie, was examined. Native bees were sampled during the summers of 2007 and 2008 in sixteen 40-ha study pastures on a plateau in northeastern Oregon, using a sampling method not previously used in grassland studies-blue vane traps. This grassland habitat contained an abundant and diverse community of native bees that experienced marked seasonal and inter-annual variation, which appears to be related to weather and plant phenology. Temporal variability evident over the entire study area was also reflected at the individual trap level, indicating a consistent response across the spatial scale of the study. These results demonstrate that temporal variability in bee communities can have important implications for long-term monitoring protocols. In addition, the blue vane trap method appears to be well-suited for studies of native bees in large expanses of grasslands or other open habitats, and may be a useful tool for monitoring native bee communities in these systems.

  12. Non-native fish introductions in the Czech Republic – species inventory, facts and future perspectives

    Czech Academy of Sciences Publication Activity Database

    Musil, J.; Jurajda, Pavel; Adámek, Z.; Horký, P.; Slavík, O.

    2010-01-01

    Roč. 26, Suppl. 2 (2010), s. 38-45 ISSN 0175-8659. [International Conference and Workshop on Managing Alien Species for Sustainable Development of Aquaculture and Fisheries. Florence, 05.11.2008-07.11.2008] Institutional research plan: CEZ:AV0Z60930519 Keywords : freshwater fish * fisheries management * invasion success Subject RIV: EH - Ecology, Behaviour Impact factor: 0.945, year: 2010

  13. The red road to wellness: cultural reclamation in a Native First Nations community treatment center.

    Science.gov (United States)

    Gone, Joseph P

    2011-03-01

    This article explores how Native American cultural practices were incorporated into the therapeutic activities of a community-controlled substance abuse treatment center on a "First Nations" reserve in the Canadian north. Analysis of open-ended interviews with nineteen staff and clients-as contextualized by participant observation, program records, and existing ethnographic resources-yielded insights concerning local therapeutic practice with outpatients and other community members. Specifically, program staff adopted and promoted a diverse array of both western and Aboriginal approaches that were formally integrated with reference to the Aboriginal symbol of the medicine wheel. Although incorporations of indigenous culture marked Lodge programs as distinctively Aboriginal in character, the subtle but profound influence of western "therapy culture" was centrally evident in healing activities as well. Nuanced explication of these activities illustrated four contributions of cultural analysis for community psychology.

  14. Impacts of species introductions on the health of fish communities receiving chronic radionuclide inputs

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

    2004-01-01

    There is widespread interest in gaining further understanding of the relative influences of multiple stressors on aquatic ecosystem structure and function. To address this, work has been done to evaluate the effects of the introduction of an efficient predator (northern pike) on a fish community in a small lake (Perch Lake, Chalk River, Ontario) receiving chronic inputs of radionuclides over a 50-year period. In general, large changes in fish community structure, with corresponding changes in fish health, occurred following the pike introduction. For example, several forage fish species were extirpated from the lake and densities of the past top predator, yellow perch, became greatly reduced, likely due to predation by northern pike and/or other species in the lake. The reduced perch numbers appeared to alleviate an ecological bottleneck, which resulted in significant increases in brown bullhead densities to levels that were much higher than observed in other water bodies under typical conditions. Corresponding changes in the health of the Perch Lake fish community could also be detected, and included decreased fish diversity, shifts in fish community size structure to smaller body sizes, significant reductions in fish condition factors, reduced hepato-somatic indices, depletion of fish internal fat reserves, hardening of the gastrointestinal tract, resorption of gonadal material, degradation of muscle tissue, emaciation and ultimately, mortality of northern pike and brown bullheads. Evaluation of data indicated that female fishes responded more quickly than did males in terms of condition loss, likely due to their higher energetic requirements. In addition, although pike and bullheads were detrimentally affected by the pike introduction, health of forage fish species, such as pumpkinseeds, did not appear to be greatly influenced. No clear relationships existed between fish community health and exposure to radionuclides in the lake. (author)

  15. Genetic Diversity and Hybridisation between Native and Introduced Salmonidae Fishes in a Swedish Alpine Lake.

    Directory of Open Access Journals (Sweden)

    Leanne Faulks

    Full Text Available Understanding the processes underlying diversification can aid in formulating appropriate conservation management plans that help maintain the evolutionary potential of taxa, particularly under human-induced activities and climate change. Here we assessed the microsatellite genetic diversity and structure of three salmonid species, two native (Arctic charr, Salvelinus alpinus and brown trout, Salmo trutta and one introduced (brook charr, Salvelinus fontinalis, from an alpine lake in sub-arctic Sweden, Lake Ånn. The genetic diversity of the three species was similar and sufficiently high from a conservation genetics perspective: corrected total heterozygosity, H'T = 0.54, 0.66, 0.60 and allelic richness, AR = 4.93, 5.53 and 5.26 for Arctic charr, brown trout and brook charr, respectively. There were indications of elevated inbreeding coefficients in brown trout (GIS = 0.144 and brook charr (GIS = 0.129 although sibling relationships were likely a confounding factor, as a high proportion of siblings were observed in all species within and among sampling locations. Overall genetic structure differed between species, Fst = 0.01, 0.02 and 0.04 in Arctic charr, brown trout and brook charr respectively, and there was differentiation at only a few specific locations. There was clear evidence of hybridisation between the native Arctic charr and the introduced brook charr, with 6% of individuals being hybrids, all of which were sampled in tributary streams. The ecological and evolutionary consequences of the observed hybridisation are priorities for further research and the conservation of the evolutionary potential of native salmonid species.

  16. Defining fish community structure in Lake Winnipeg using stable isotopes (δ{sup 13}C, δ{sup 15}N, δ{sup 34}S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

    Energy Technology Data Exchange (ETDEWEB)

    Ofukany, Amy F.A. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Wassenaar, Leonard I. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Bond, Alexander L., E-mail: alex.bond@rspb.org.uk [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Hobson, Keith A. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada)

    2014-11-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km{sup 2} watershed and the arrival of non-native zooplankters and fishes. We measured δ{sup 13}C, δ{sup 15}N, and δ{sup 34}S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ{sup 13}C and δ{sup 34}S, and lower δ{sup 15}N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels.

  17. Defining fish community structure in Lake Winnipeg using stable isotopes (δ13C, δ15N, δ34S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

    International Nuclear Information System (INIS)

    Ofukany, Amy F.A.; Wassenaar, Leonard I.; Bond, Alexander L.; Hobson, Keith A.

    2014-01-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km 2 watershed and the arrival of non-native zooplankters and fishes. We measured δ 13 C, δ 15 N, and δ 34 S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ 13 C and δ 34 S, and lower δ 15 N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels

  18. Using Storytelling to Address Oral Health Knowledge in American Indian and Alaska Native Communities.

    Science.gov (United States)

    Heaton, Brenda; Gebel, Christina; Crawford, Andrew; Barker, Judith C; Henshaw, Michelle; Garcia, Raul I; Riedy, Christine; Wimsatt, Maureen A

    2018-05-24

    We conducted a qualitative analysis to evaluate the acceptability of using storytelling as a way to communicate oral health messages regarding early childhood caries (ECC) prevention in the American Indian and Alaska Native (AIAN) population. A traditional story was developed and pilot tested among AIAN mothers residing in 3 tribal locations in northern California. Evaluations of the story content and acceptability followed a multistep process consisting of initial feedback from 4 key informants, a focus group of 7 AIAN mothers, and feedback from the Community Advisory Board. Upon story approval, 9 additional focus group sessions (N = 53 participants) were held with AIAN mothers following an oral telling of the story. Participants reported that the story was culturally appropriate and used relatable characters. Messages about oral health were considered to be valuable. Concerns arose about the oral-only delivery of the story, story content, length, story messages that conflicted with normative community values, and the intent to target audiences. Feedback by focus group participants raised some doubts about the relevance and frequency of storytelling in AIAN communities today. AIAN communities value the need for oral health messaging for community members. However, the acceptability of storytelling as a method for the messaging raises concerns, because the influence of modern technology and digital communications may weaken the acceptability of the oral tradition. Careful attention must be made to the delivery mode, content, and targeting with continual iterative feedback from community members to make these messages engaging, appropriate, relatable, and inclusive.

  19. Ethnotaxonomical considerations and usage of ichthyofauna in a fishing community in Cear? State, Northeast Brazil

    OpenAIRE

    Pinto, M?rcia Freire; Mour?o, Jos? da Silva; Alves, R?mulo Romeu N?brega

    2013-01-01

    Background Artisanal fishery is one of the most important economic activities for human populations living in coastal areas. The traditional knowledge that fishermen have of fishes is of utmost importance for the establishment of conservation strategies for many species. This study aimed to analyse the knowledge of and utilization of fishes by the artisanal fishermen in a fishing community on the coast of Cear? State (Northeast Brazil). Methods In 2011, a number of semi-structured interviews ...

  20. Reef fish community in presence of the lionfish (Pterois volitans) in Santa Marta, Colombian Caribbean

    OpenAIRE

    García-Urueña, Rocío; Acero P, Arturo; Coronado-Carrascal, Víctor

    2015-01-01

    ABSTRACT Objective. Fish species community structure and benthic organisms coverage were studied in five localities in Santa Marta where the lionfish is present. Materials and methods. Abundance of fish species, including lion fish, was established using 30 m random visual censuses and video transects; trophic guilds were established according to available references. On the other hand benthic coverage was evaluated using the software Coral Point Count (CPCe) 4.0. Results. Families with highe...

  1. Fish Community Structure and Diet Responses to Newbury Weirs in a Low-Gradient River

    Science.gov (United States)

    Bonjour, Sophia M.; Rantala, Heidi M.; Bennett, Micah G.; Whiles, Matt R.

    2018-06-01

    Restoration projects are often implemented to address specific issues in the environment. Consequences of a restoration project, if any are measured, typically focus on direct changes to the projects focus. However, changing habitat structure likely results in changes to the environment that affect the communities living there. Rock weirs have been used for channel stabilization in many midwestern rivers. Previous research in a southern Illinois river found that weirs benefitted aquatic macroinvertebrate and riparian bird communities by enhancing habitat heterogeneity and insect emergence production. We hypothesized that fishes would also benefit from weirs through enhanced habitat and food availability. We collected fishes in the Cache River in southern Illinois using hand nets, seines, and electroshocking at sites where weirs had been installed and at non-weir sites. Gut contents were identified and individual food items measured. Fish species richness, but not diversity, was higher at weir sites. Fish communities also differed between site types, with benthic feeders characterizing weir sites. Gut content biomass and abundance differed among fish guilds but not between weir and non-weir sites. Fishes from both site types selected for prey taxa predominately found at weirs. Differences between site types were not always captured by univariate metrics, but connecting fish prey to habitat suggests a reach-scale benefit for fishes through increased abundance of favored prey and enhanced prey diversity. Additionally, given the paucity of rocky substrata in the river as a whole, rock weirs enhance fish species richness by providing habitat for less common benthic species.

  2. Establishment of a fish community in the hayden-rhodes and salt-gila aqueducts, Arizona

    Science.gov (United States)

    Mueller, G.

    1996-01-01

    Fish populations were studied in the Central Arizona Project's canal system during the first 4 years of aqueduct operation (1986-1989). Ichthyoplankton entering the canal from Lake Havasu averaged 1 larva/m3 during April-June 1987 and 1988. Larval fish densities increased significantly in downstream samples, substantiating diver observations that fish were spawning in the canal system. Of the 16 fish species collected, 14 were assumed to have originated from Lake Havasu and 2 were introduced by anglers from their bait buckets. Initially, the fish community was dominated numerically by threadfin shad Dorosoma petenense (>88%), centrarchids (< 10%), cyprinids (<2%), and striped bass Morone saxatilis (<1%). However, as annual water diversions increased from 13 x 108 m3 in 1986 to 9.4 x 108 m3 in 1989, community composition shifted from clupeids to centrarchids (70%). Fish densities dropped from an estimated 1,260 fish/ha in 1986 to 17 fish/ha in 1989, and biomass dropped from 116 to 73 kg/ha. Declines were attributed to higher operational velocities, associated scour, deprivation, and predation. Although initial populations adjusted downward to planned operational conditions, the fish community continued to represent a potentially valuable, but as yet unused, resource.

  3. Diversity and community structure of epibenthic invertebrates and fish in the North Sea

    DEFF Research Database (Denmark)

    Callaway, R.; Alsväg, J.; de Boois, I.

    2002-01-01

    The structure of North Sea benthic invertebrate and fish communities is an important indicator of anthropogenic and environmental impacts. Although North Sea fish stocks are monitored regularly, benthic fauna are not. Here, we report the results of a survey carried out in 2000, in which five...

  4. Community based fish culture in the public and private floodplains of Bangladesh

    NARCIS (Netherlands)

    Mahfuzul Haque, A.B.

    2015-01-01

    Seasonal floodplains are water bodies that retain water for 5-6 months during which they are suitable to grow fish and other aquatic animals. Out of 2.8 million ha of medium and deep-flooded areas, about 1.5 million ha are estimated to be suitable for Community-Based Fish Culture (CBFC).

  5. Spatial and temporal repeatability in parasite community structure of tropical fish hosts.

    Science.gov (United States)

    Vidal-Martínez, V M; Poulin, R

    2003-10-01

    An assessment is made of the repeatability of parasite community structure in space for a marine fish, and in space and time for a freshwater fish from south-eastern Mexico. The marine fish species was the red grouper, Epinephelus morio (collected from 9 localities), and the freshwater species was the cichlid, Cichlasoma urophthalmus (collected from 6 localities: including monthly at 2 localities for 1 year, and bimonthly at 1 locality in 1990 and 1999). Pairwise interspecific associations and analyses of nested patterns in the distributions of parasite species among hosts were used in both fish species, with comparisons over time made only with the cichlid. Positive interspecific associations, and nested patterns were noted in some localities for both fish species, and/or at some sampling times for the cichlid fish. However, non-random patterns in the structure of parasite communities in these 2 host species only were observed sporadically. When present, nestedness in both fish species was apparently linked with a positive association between total infection intensities and fish size. Additionally, adjacent localities were more likely to display similar parasite community structure than distant ones. This preliminary result suggests that distance between localities is an important determinant of predictability in parasite community structure.

  6. The importance of surrogate habitats in lowland river floodplains for fish community composition

    Czech Academy of Sciences Publication Activity Database

    Ryšavá-Nováková, Michaela; Ondračková, Markéta; Jurajda, Pavel

    2009-01-01

    Roč. 16, č. 6 (2009), s. 468-477 ISSN 0969-997X R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish community * fish recruitment * flood * rehabilitation * substitute habitats Subject RIV: EH - Ecology, Behaviour Impact factor: 1.264, year: 2009

  7. Impacts of climate warming on lake fish community structure and potential effects on ecosystem function

    NARCIS (Netherlands)

    Jeppesen, E.; Meerhoff, M.; Holmgren, K.; González-Bergonzoni, I.; Teixeira-de Mello, F.; Declerck, Steven A.J.; De Meester, L.; Søndergaard, M.; Lauridsen, T.; Bjerring, R.; Conde-Porcuna, J-M.; Mazzeo, N.; Iglesias, C.; Reizenstein, M.; Malmquist, H.J.; Liu, Z.; Balayla, D.; Lazzaro, X.

    2010-01-01

    Fish play a key role in the trophic dynamics of lakes, not least in shallow systems. With climate warming, complex changes in fish community structure may be expected owing to the direct and indirect effects of temperature, and indirect effects of eutrophication, water-level changes and salinisation

  8. PISCATOR, an individual-based model to analyze the dynamics of lake fish communities

    NARCIS (Netherlands)

    Nes, van E.H.; Lammens, E.H.R.R.; Scheffer, M.

    2002-01-01

    Unraveling the mechanisms that drive dynamics of multi-species fish communities is notoriously difficult. Not only are the interactions between fish populations complex, but also the functional niche of individual animals changes profoundly as they grow, making variation in size within populations

  9. Spearfishing data reveals the littoral fish communities' association to coastal configuration

    Science.gov (United States)

    Boada, Jordi; Sagué, Oscar; Gordoa, Ana

    2017-12-01

    Increasing the knowledge about littoral fish communities is important for ecological sciences, fisheries and the sustainability of human communities. The scarcity of baseline data at large spatial scales in a fast-changing world makes it necessary to implement special programs to monitor natural ecosystems. In the present study, we evaluate littoral fish communities using data from spearfishing contests. The Catalan Federation of Underwater Activities (FECDAS) regularly organizes fishing contests across ca. 600 km of coast. Catch records made over the last sixteen years were used to study the fish communities along the coastline. We found two different communities that are closely related to the habitat configuration at a regional level. Interestingly, contests held on the northern coast were mainly grouped together and were characterized by species that inhabit complex rocky habitats, and contests held on the southern coast were grouped together and were mainly determined by soft bottoms species (i.e. mugilids and Sarpa salpa). In the south group the white sea bream was also very abundant compared to the north group. No significant changes in the community composition were found in the studied period and we successfully set descriptive baselines. Finally, based on these results we propose that studying the data from fishing contest records can be used to complement the available tools for monitoring fish communities.

  10. Alien fish species in reservoir systems in Turkey: a review

    Directory of Open Access Journals (Sweden)

    Deniz Innal

    2012-12-01

    Full Text Available Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distribution. The present paper reviews fish stocking studies in Turkey’s reservoirs.

  11. Baseline assessment of the fish and benthic communities of the Flower Garden Banks (NODC Accession 0118358)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The proposed work develop baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys will employ...

  12. Baseline assessment of fish and benthic communities of the Flower Garden Banks (NODC Accession 0118358)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The proposed work develop baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys will employ...

  13. Baseline assessment of fish and benthic communities of the Flower Garden Banks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The work developed baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys employed diving,...

  14. Spatial patterns of infauna, epifauna and demersal fish communities in the North Sea.

    NARCIS (Netherlands)

    Reiss, H.; Degraer, S.; Duineveld, G.C.A.; Craeymeersch, J.A.M.

    2010-01-01

    Understanding the structure and interrelationships of North Sea benthic invertebrate and fish communities and their underlying environmental drivers is an important prerequisite for conservation and spatial ecosystem management on scales relevant to ecological processes. Datasets of North Sea

  15. Baseline assessment of fish communities of the Flower Garden Banks (2010 - present): 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The proposed work develop baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys will employ...

  16. Application of the target fish community model to an urban river system.

    Science.gov (United States)

    Meixler, Marcia S

    2011-04-01

    Several models have been developed to assess the biological integrity of aquatic systems using fish community data. One of these, the target fish community (TFC) model, has been used primarily to assess the biological integrity of larger, mainstem rivers in southern New England with basins characterized by dispersed human activities. We tested the efficacy of the TFC approach to specify the fish community in the highly urbanized Charles River watershed in eastern Massachusetts. To create a TFC for the Charles River we assembled a list of fish species that historically inhabited the Charles River watershed, identified geomorphically and zoogeographically similar reference rivers regarded as being in high quality condition, amassed fish survey data for the reference rivers, and extracted from the collections the information needed to define a TFC. We used a similarity measurement method to assess the extent to which the study river community complies with the TFC and an inference approach to summarize the manner in which the existing fish community differed from target conditions. The five most abundant species in the TFC were common shiners (34%), fallfish (17%) redbreast sunfish (11%), white suckers (8%), and American eel (7%). Three of the five species predicted to be most abundant in the TFC were scarce or absent in the existing river community. Further, the river was dominated by macrohabitat generalists (99%) while the TFC was predicted to contain 19% fluvial specialist species, 43% fluvial dependent species, and 38% macrohabitat generalist species. In addition, while the target community was dominated by fish intolerant (37%) and moderately tolerant (39%) of water quality degradation, the existing community was dominated by tolerant individuals (59%) and lacked intolerant species expected in the TFC. Similarity scores for species, habitat use specialization, and water quality degradation tolerance categories were 28%, 35% and 66%, respectively. The clear

  17. Status of Coral Reef Fish Communities within the Mombasa Marine ...

    African Journals Online (AJOL)

    The abundance, trophic composition and diversity of fish were investigated in the Mombasa Marine Protected Area (MPA) on the Kenya coast over a period of four years (2004-2007) sixteen years after its establishment to determine its effectiveness. Fish monitoring data collected using belt transects revealed significant ...

  18. Effects of marine reserves versus nursery habitat availability on structure of reef fish communities.

    Science.gov (United States)

    Nagelkerken, Ivan; Grol, Monique G G; Mumby, Peter J

    2012-01-01

    No-take marine fishery reserves sustain commercial stocks by acting as buffers against overexploitation and enhancing fishery catches in adjacent areas through spillover. Likewise, nursery habitats such as mangroves enhance populations of some species in adjacent habitats. However, there is lack of understanding of the magnitude of stock enhancement and the effects on community structure when both protection from fishing and access to nurseries concurrently act as drivers of fish population dynamics. In this study we test the separate as well as interactive effects of marine reserves and nursery habitat proximity on structure and abundance of coral reef fish communities. Reserves had no effect on fish community composition, while proximity to nursery habitat only had a significant effect on community structure of species that use mangroves or seagrass beds as nurseries. In terms of reef fish biomass, proximity to nursery habitat by far outweighed (biomass 249% higher than that in areas with no nursery access) the effects of protection from fishing in reserves (biomass 21% lower than non-reserve areas) for small nursery fish (≤ 25 cm total length). For large-bodied individuals of nursery species (>25 cm total length), an additive effect was present for these two factors, although fish benefited more from fishing protection (203% higher biomass) than from proximity to nurseries (139% higher). The magnitude of elevated biomass for small fish on coral reefs due to proximity to nurseries was such that nursery habitats seem able to overrule the usually positive effects on fish biomass by reef reserves. As a result, conservation of nursery habitats gains importance and more consideration should be given to the ecological processes that occur along nursery-reef boundaries that connect neighboring ecosystems.

  19. Effects of marine reserves versus nursery habitat availability on structure of reef fish communities.

    Directory of Open Access Journals (Sweden)

    Ivan Nagelkerken

    Full Text Available No-take marine fishery reserves sustain commercial stocks by acting as buffers against overexploitation and enhancing fishery catches in adjacent areas through spillover. Likewise, nursery habitats such as mangroves enhance populations of some species in adjacent habitats. However, there is lack of understanding of the magnitude of stock enhancement and the effects on community structure when both protection from fishing and access to nurseries concurrently act as drivers of fish population dynamics. In this study we test the separate as well as interactive effects of marine reserves and nursery habitat proximity on structure and abundance of coral reef fish communities. Reserves had no effect on fish community composition, while proximity to nursery habitat only had a significant effect on community structure of species that use mangroves or seagrass beds as nurseries. In terms of reef fish biomass, proximity to nursery habitat by far outweighed (biomass 249% higher than that in areas with no nursery access the effects of protection from fishing in reserves (biomass 21% lower than non-reserve areas for small nursery fish (≤ 25 cm total length. For large-bodied individuals of nursery species (>25 cm total length, an additive effect was present for these two factors, although fish benefited more from fishing protection (203% higher biomass than from proximity to nurseries (139% higher. The magnitude of elevated biomass for small fish on coral reefs due to proximity to nurseries was such that nursery habitats seem able to overrule the usually positive effects on fish biomass by reef reserves. As a result, conservation of nursery habitats gains importance and more consideration should be given to the ecological processes that occur along nursery-reef boundaries that connect neighboring ecosystems.

  20. Non-native fish control below Glen Canyon Dam - Report from a structured decision-making project

    Science.gov (United States)

    Runge, Michael C.; Bean, Ellen; Smith, David; Kokos, Sonja

    2011-01-01

    This report describes the results of a structured decision-making project by the U.S. Geological Survey to provide substantive input to the Bureau of Reclamation (Reclamation) for use in the preparation of an Environmental Assessment concerning control of non-native fish below Glen Canyon Dam. A forum was created to allow the diverse cooperating agencies and Tribes to discuss, expand, and articulate their respective values; to develop and evaluate a broad set of potential control alternatives using the best available science; and to define individual preferences of each group on how to manage the inherent trade-offs in this non-native fish control problem. This project consisted of two face-to-face workshops, held in Mesa, Arizona, October 18-20 and November 8-10, 2010. At the first workshop, a diverse set of objectives was discussed, which represented the range of concerns of those agencies and Tribes present. A set of non-native fish control alternatives ('hybrid portfolios') was also developed. Over the 2-week period between the two workshops, four assessment teams worked to evaluate the control alternatives against the array of objectives. At the second workshop, the results of the assessment teams were presented. Multi-criteria decision analysis methods were used to examine the trade-offs inherent in the problem, and allowed the participating agencies and Tribes to express their individual judgments about how those trade-offs should best be managed in Reclamation`s selection of a preferred alternative. A broad array of objectives was identified and defined, and an effort was made to understand how these objectives are likely to be achieved by a variety of strategies. In general, the objectives reflected desired future conditions over 30 years. A rich set of alternative approaches was developed, and the complex structure of those alternatives was documented. Multi-criteria decision analysis methods allowed the evaluation of those alternatives against the array

  1. Effects of climate change on native fish and other aquatic species [Chapter 5

    Science.gov (United States)

    Daniel J. Isaak; Michael K. Young; Cynthia Tait; Daniel Duffield; Dona L. Horan; David E. Nagel; Matthew C. Groce

    2018-01-01

    The diverse landscapes of the Intermountain Adaptation Partnership (IAP) region contain a broad range of aquatic habitats and biological communities. A number of aquatic species are regional endemics, several are threatened or endangered under the U.S. Endangered Species Act (ESA), and many have declined because of the introduction of nonnative aquatic species, habitat...

  2. The role of culture in substance abuse treatment programs for American Indian and Alaska Native communities.

    Science.gov (United States)

    Legha, Rupinder Kaur; Novins, Douglas

    2012-07-01

    Culture figures prominently in discussions regarding the etiology of alcohol and substance abuse in American Indian and Alaska Native (AI/AN) communities, and a substantial body of literature suggests that it is critical to developing meaningful treatment interventions. However, no study has characterized how programs integrate culture into their services. Furthermore, reports regarding the associated challenges are limited. Twenty key informant interviews with administrators and 15 focus groups with clinicians were conducted in 18 alcohol and substance abuse treatment programs serving AI/AN communities. Transcripts were coded to identify relevant themes. Substance abuse treatment programs for AI/AN communities are integrating culture into their services in two discrete ways: by implementing specific cultural practices and by adapting Western treatment models. More important, however, are the fundamental principles that shape these programs and their interactions with the people and communities they serve. These foundational beliefs and values, defined in this study as the core cultural constructs that validate and incorporate AI/AN experience and world view, include an emphasis on community and family, meaningful relationships with and respect for clients, a homelike atmosphere within the program setting, and an “open door” policy for clients. The primary challenges for integrating these cultural practices include AI/AN communities' cultural diversity and limited socioeconomic resources to design and implement these practices. The prominence of foundational beliefs and values is striking and suggests a broader definition of culture when designing services. This definition of foundational beliefs and values should help other diverse communities culturally adapt their substance abuse interventions in more meaningful ways.

  3. Suppression of invasive topmouth gudgeon Pseudorasbora parva by native pike Esox lucius in ponds

    OpenAIRE

    Lemmens, Pieter; Mergeay, Joachim; Vanhove, Tom; De Meester, Luc; Declerck, Steven A. J

    2015-01-01

    1. Asian topmouth gudgeon Pseudorasbora parva has been recognized as a highly invasive cyprinid fish species in Europe that can present risk to native fish communities. 2. The present study aimed to investigate whether a native piscivorous fish, pike Esox lucius, is able to reduce the establishment success and invasiveness of topmouth gudgeon Pseudorasbora parva in shallow ponds. We performed a large scale, replicated whole-pond experiment in which ponds were spontaneously colonized by to...

  4. Satellite lakes as reservoirs of fish species diversity

    OpenAIRE

    Nkalubo, W.; Wandera, S.B.; Namulemo, G.

    2010-01-01

    Satellite lakes and rivers in the Victoria and Kyoga basins provide a sanctuary for endangered native fish species. The structural heterogeneity of macrophyte covering these lakes has made it possible for most of the biodiversity to be kept intact. The Kyoga minor lakes have the highest fish species diversity especially of the haplochromines. Most fish communities of these satellite lakes are composed of native species.

  5. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities

    Science.gov (United States)

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-01-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery. PMID:24634720

  6. Impact of 21st century climate change on the Baltic Sea fish community and fisheries

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Gislason, Henrik; Möllmann, C.

    2007-01-01

    reviewed. We then use recent regional - scale climate - ocean modelling results to consider how climate change during this century will affect the fish community of the Baltic and fisheries management. Expected climate changes in northern Europe will likely affect both the temperature and salinity...... some of the uncertainties and complexities associated with forecasting how fish populations, communities and industries dependent on an estuarine ecosystem might respond to future climate change.......The Baltic Sea is a large brackish semienclosed sea whose species-poor fish community supports important commercial and recreational fisheries. Both the fish species and the fisheries are strongly affected by climate variations. These climatic effects and the underlying mechanisms are briefly...

  7. Food resource partitioning in a fish community of the central Amazon floodplain

    Directory of Open Access Journals (Sweden)

    Bernard de Mérona

    Full Text Available Diets of most of fish species inhabiting a floodplain lake in central Amazonia were studied over a two years and half period. Based on the percentage of relative occurrence of 11 major food categories a classification of species in 11 feeding guilds is proposed. Many species were found to be specialized feeders. Fish, detritus and insects were the most important food resources supporting the fish community in both seasons, but the proportions of fruits, invertebrates and fish were reduced during the low water season. At the community level mean diet overlap between species was low, suggesting efficient resource partitioning within the community. However mean overlap between unspecialized feeders was high. Based on the 23 most abundant species belonging to the different feeding guilds, there was no difference in mean overlap between seasons. Whereas individual species exhibited diet changes between high water and low water seasons, there was no general pattern of seasonal change within feeding guilds.

  8. IMPACT OF JUTE RETTING ON NATIVE FISH DIVERSITY AND AQUATIC HEALTH OF ROADSIDE TRANSITORY WATER BODIES: AN ASSESSMENT IN EASTERN INDIA

    Directory of Open Access Journals (Sweden)

    Dipankar Ghosh

    2015-09-01

    Full Text Available Roadside transitory water bodies being manmade depressions have a great ecological and socio-economic importance from years. The effects of agricultural runoffs, jute retting, macro-phytes infestations and inadequate rainfall in changed climate often degrade transitory water bodies’ environment while the biodiversity have impacted severely because of population pressure, over exploitation and indiscriminate use of fine meshed fishing gears as a whole. Physico-chemical and biological analysis with fish species composition, relative abundance, diversity indices like species richness, evenness and Shannon-Wiener index were carried out for pre-, during and post-jute retting season and for year mean as a whole to assess impact of jute retting on the roadside transitory water body’s environmental health and indigenous fish diversity at Sahebnagar village in Nadia District, India. All the physico-chemical parameters barring biochemical oxygen demand and water transparency remained more or less same or marginally got little changed during those three seasons. As much as 19 native fish species with varied relative abundances and dominances were identified. Jute retting impacted lower native fish diversity indices like Shannon-Wiener index values (1.94 to 2.68 clearly indicated poor to moderate pollution status of the transitory water body in that area during monsoon in particular and throughout the year in general. So we opined there should be some control over the intense jute retting in the road side transitory water bodies for sustainable management of these manmade resources.

  9. Long-term trends in the St. Marys River open water fish community

    Science.gov (United States)

    Schaeffer, Jeffrey S.; Fielder, David G.; Godby, Neal; Bowen, Anjanette; O'Connor, Lisa; Parrish, Josh; Greenwood, Susan; Chong, Stephen; Wright, Greg

    2011-01-01

    We examined trends in species composition and abundance of the St. Marys River fish community. Abundance data were available approximately once every six years from 1975 through 2006, and size and age data were available from 1995 through 2006. We also compared survey data in 2006 with results of a concurrent creel survey that year, as well as data from prior surveys spanning a 69 year time frame. The St. Marys River fish community was best characterized as a coolwater fish community with apparent little variation in species composition, and only slight variation in overall fish abundance since 1975. However, we did find recent trends in abundance among target species sought by anglers: centrarchids increased, percids appeared stable, and both northern pike Esox lucius and cisco Coregonus artedii declined. Survey results suggested that walleye (Sander vitreus) and yellow perch (Perca flavescens) experienced moderate exploitation but benefited from recent strong recruitment and faster growth. Mechanisms underlying declines of northern pike and cisco were not clear; reduced abundance could have resulted from high exploitation, variation in recruitment, or a combination of both factors. Despite these challenges, the St. Marys River fish community appears remarkably stable. We suggest that managers insure that creel surveys occur simultaneously with assessments, but periodic gill net surveys may no longer provide adequate data in support of recent, more complex management objectives. While additional surveys would add costs, more frequent data might ensure sustainability of a unique fish community that supports a large proportion of angler effort on Lake Huron.

  10. Fish community composition, seasonality and abundance in Fortaleza Lagoon, cidreira

    Directory of Open Access Journals (Sweden)

    Lúcia Cabral Schifino

    2004-09-01

    Full Text Available The Fortaleza Lagoon belongs to the Southern Tramandaí subsystem, formed by lagoons disposed linearly on the north-south direction (30º 08’S, 50º 13’W. The objective of this study was to describe some aspects related to the composition of the fish community of Fortaleza Lagoon. Samples were collected monthly from November 1998 to October 1999. The specimens were captured at four previously determined points in the lagoon, and classified in five orders, 12 families and 22 species. Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus and Loricariichthys anus were more abundant species. Amongst the sampled species only two could not be characterised as freshwater species: Centropomus sp (marine and Lycengraulius grossidens (estuarine. The ichthyofauna of the lagoon was predominantly composed by constant species.A Planície Costeira do Rio Grande do Sul é formada por uma série de corpos d’água, dispostos em seqüência ao longo da costa. A lagoa da Fortaleza pertence ao subsistema lagunar Tramandaí-Sul que é composto por lagoas, dispostas linearmente no sentido norte-sul. O do presente estudo teve como objetivo descrever alguns aspectos relacionados à composição da comunidade de peixes da Lagoa da Fortaleza. As amostragens foram realizadas, mensalmente, no período de novembro de 1998 a outubro de 1999. Os exemplares foram capturados em 4 pontos da lagoa previamente determinados e classificados em 5 ordens, 11 famílias e 22 espécies. As espécies Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus e Loricariichthys anus mostraram-se as mais abundantes. Entre as espécies coletadas apenas duas não caracterizam espécies de água doce: Centropomus sp (marinha and Lycengraulius grossidens (estuarina. A ictiofauna da lagoa caracterizou-se por uma predominância de espécies constantes.

  11. [Fish community structure and its seasonal change in subtidal sandy beach habitat off southern Gouqi Island].

    Science.gov (United States)

    Wang, Zhen-Hua; Wang, Kai; Zhao, Jing; Zhang, Shou-Yu

    2011-05-01

    To understand the characteristics of fish community structure in sandy beach habitats of island reef water areas, and to evaluate the potential capacity of these habitats in local fish stock maintenance, fishes were monthly collected with multi-mesh trammel nets in 2009 from the subtidal sandy beach habitat off southern Gouqi Island, taking the adjacent rocky reef habitat as the control. alpha and beta species diversity indices, index of relative importance (IRI), relative catch rate, and dominance curve for abundance and biomass (ABC curve) were adopted to compare the fish species composition, diversity, and community pattern between the two habitats, and multivariate statistical analyses such as non-metric multidimensional scaling (nMDS) and cluster were conducted to discuss the fish assemblage patterns. A total of 63 fish species belonging to 11 orders, 38 families, and 56 genera were collected, of which, 46 fish species were appeared in the two habitats. Due to the appearance of more warm water species in sandy bottom, the fishes in subtidal sandy beach habitat showed much higher richness, and the abundance catch rate (ACR) from May to July was higher than that in rocky reef habitat. In most rest months, the ACR in subtidal sandy beach habitat also showed the similar trend. However, the species richness and diversity in spring and summer were significantly lower in subtidal sandy beach habitat than in rocky reef habitat, because of the high species dominance and low evenness in the sandy beach habitat. Japanese tonguefish (Paraplagusia japonica) was the indicator species in the sandy beach habitat, and dominated in early spring, later summer, autumn, and winter when the fishing pressure was not strong. In sandy bottom, a unique community structure was formed and kept in dynamic, due to the nursery use of sandy beach by Japanese anchovy (Engraulis japonicus) from May to July, the gathering of gray mullet (Mugil cephalus) in most months for feeding, and the large

  12. Defining thresholds of sustainable impact on benthic communities in relation to fishing disturbance.

    Science.gov (United States)

    Lambert, G I; Murray, L G; Hiddink, J G; Hinz, H; Lincoln, H; Hold, N; Cambiè, G; Kaiser, M J

    2017-07-14

    While the direct physical impact on seabed biota is well understood, no studies have defined thresholds to inform an ecosystem-based approach to managing fishing impacts. We addressed this knowledge gap using a large-scale experiment that created a controlled gradient of fishing intensity and assessed the immediate impacts and short-term recovery. We observed a mosaic of taxon-specific responses at various thresholds. The lowest threshold of significant lasting impact occurred between 1 and 3 times fished and elicited a decrease in abundance of 39 to 70% for some sessile epifaunal organisms (cnidarians, bryozoans). This contrasted with significant increases in abundance and/or biomass of scavenging species (epifaunal echinoderms, infaunal crustaceans) by two to four-fold in areas fished twice and more. In spite of these significant specific responses, the benthic community structure, biomass and abundance at the population level appeared resilient to fishing. Overall, natural temporal variation in community metrics exceeded the effects of fishing in this highly dynamic study site, suggesting that an acute level of disturbance (fished over six times) would match the level of natural variation. We discuss the implications of our findings for natural resources management with respect to context-specific human disturbance and provide guidance for best fishing practices.

  13. Ecophysiological Responses of Invasive and Native Grass Communities with Simulated Warming

    Science.gov (United States)

    Quade, B.; Ravi, S.; Huxman, T. E.

    2010-12-01

    William Quade1, Sujith Ravi2, Ashley Weide2, Greg Barron-Gafford2, Katerina Dontsova2 and Travis E Huxman2 1Carthage College, WI 2 B2 Earthscience & UA Biosphere 2, University of Arizona, Tucson. Abstract Climate change, anthropogenic disturbances and lack of proper management practices have rendered many arid regions susceptible to invasions by exotic grasses with consequent ecohydrological, biogeochemical and socio economic implications. Thus, understanding the ecophysiological processes driving these large-scale vegetation shifts in drylands, in the context of rising temperatures and recurrent droughts is fundamental to global change research. Using the Biosphere 2 facility to maintain distinct temperature treatments of ambient and predicted warmer conditions (+ 4o C) inside, we compared the physiological (e.g. photosynthesis, stomatal conductance, biomass) responses of a native grass - Heteropogan contortus (Tanglehead) and an invasive grass - Pennisetum ciliare (Buffelgrass) growing in single and mixed communities. The results indicate that Buffelgrass can assimilate more CO2 per unit leaf area under current conditions, though warming seems to inhibit the performance when looking at biomass, photosynthesis and stomatal conductance. Under similar moisture regimes Buffelgrass performed better than Tangle head in mixed communities regardless of the temperature. Both grasses had decrease in stomatal conductance with warmer conditions, however the Buffel grass did not have the same decrease of conductance when planted in a mixed communities. Key words: Buffelgrass, Tanglehead, Biosphere 2, stomatal conductance, climate change

  14. Marine fish community structure and habitat associations on the Canadian Beaufort shelf and slope

    Science.gov (United States)

    Majewski, Andrew R.; Atchison, Sheila; MacPhee, Shannon; Eert, Jane; Niemi, Andrea; Michel, Christine; Reist, James D.

    2017-03-01

    Marine fishes in the Canadian Beaufort Sea have complex interactions with habitats and prey, and occupy a pivotal position in the food web by transferring energy between lower- and upper-trophic levels, and also within and among habitats (e.g., benthic-pelagic coupling). The distributions, habitat associations, and community structure of most Beaufort Sea marine fishes, however, are unknown thus precluding effective regulatory management of emerging offshore industries in the region (e.g., hydrocarbon development, shipping, and fisheries). Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. Benthic trawling was conducted at 45 stations spanning 18-1001 m depths across shelf and slope habitats. Physical oceanographic variables (depth, salinity, temperature, oxygen), biological variables (benthic chlorophyll and integrated water-column chlorophyll) and sediment composition (grain size) were assessed as potential explanatory variables for fish community structure using a non-parametric statistical approach. Selected stations were re-sampled in 2013 and 2014 for a preliminary assessment of inter-annual variability in the fish community. Four distinct fish assemblages were delineated on the Canadian Beaufort Shelf and slope: 1) Nearshore-shelf: 50 and ≤200 m depths, 3) Upper-slope: ≥200 and ≤500 m depths, and 4) Lower-slope: ≥500 m depths. Depth was the environmental variable that best explained fish community structure, and each species assemblage was spatially associated with distinct aspects of the vertical water mass profile. Significant differences in the fish community from east to west were not detected, and the species composition of the assemblages on the Canadian Beaufort Shelf have not changed substantially over the past decade. This community analysis provides a framework for testing hypotheses regarding the trophic

  15. Responses of epibenthic and nektonic macroinvertebrate communities to a gradient of fish size in ponds

    Directory of Open Access Journals (Sweden)

    Marek Nieoczym

    2014-07-01

    Full Text Available Size relationships between fish and organisms from adjacent trophic levels are crucial for predicting the structure and dynamics of aquatic ecosystems. We compared macroinvertebrate communities along a fish-size gradient created by separate stocking of three age cohorts of common carp Cyprinus carpio in semi-natural ponds. The specific size range of fish (small, medium and large corresponding to fish age in ponds was the factor most strongly associated with macroinvertebrate composition. The other significant habitat variables were dissolved oxygen concentration in the water and submerged vegetation abundance in the open-water zone. Among the most numerous taxa in the ponds, relative abundances of Hirudinea, Gastropoda, Odonata and Coleoptera were larger in the presence of small-sized than of larger-sized carp. However, fish size effect was not linear, in that macroinvertebrate assemblages were less similar between ponds containing medium- vs large-sized fish than between ponds with small- vs large-sized fish. The dissimilarity patterns were mainly determined by disparities in abundance of Corixidae, which unlike other taxa common in the ponds occurred in the greatest numbers in the presence of large-sized carp. Macroinvertebrate diversity was greatest in ponds with small-sized fish and was positively related to emergent macrophyte cover. Enhancement of emergent vegetation is recommended as the most effective management strategy to buffer adverse impacts of fish on macroinvertebrates. If fish are present in the system, assessment of the size structure of fish populations can be advantageous in unravelling the essential processes driving the variation in pond communities.

  16. Consistent nutrient storage and supply mediated by diverse fish communities in coral reef ecosystems.

    Science.gov (United States)

    Allgeier, Jacob E; Layman, Craig A; Mumby, Peter J; Rosemond, Amy D

    2014-08-01

    Corals thrive in low nutrient environments and the conservation of these globally imperiled ecosystems is largely dependent on mitigating the effects of anthropogenic nutrient enrichment. However, to better understand the implications of anthropogenic nutrients requires a heightened understanding of baseline nutrient dynamics within these ecosystems. Here, we provide a novel perspective on coral reef nutrient dynamics by examining the role of fish communities in the supply and storage of nitrogen (N) and phosphorus (P). We quantified fish-mediated nutrient storage and supply for 144 species and modeled these data onto 172 fish communities (71 729 individual fish), in four types of coral reefs, as well as seagrass and mangrove ecosystems, throughout the Northern Antilles. Fish communities supplied and stored large quantities of nutrients, with rates varying among ecosystem types. The size structure and diversity of the fish communities best predicted N and P supply and storage and N : P supply, suggesting that alterations to fish communities (e.g., overfishing) will have important implications for nutrient dynamics in these systems. The stoichiometric ratio (N : P) for storage in fish mass (~8 : 1) and supply (~20 : 1) was notably consistent across the four coral reef types (but not seagrass or mangrove ecosystems). Published nutrient enrichment studies on corals show that deviations from this N : P supply ratio may be associated with poor coral fitness, providing qualitative support for the hypothesis that corals and their symbionts may be adapted to specific ratios of nutrient supply. Consumer nutrient stoichiometry provides a baseline from which to better understand nutrient dynamics in coral reef and other coastal ecosystems, information that is greatly needed if we are to implement more effective measures to ensure the future health of the world's oceans. © 2014 John Wiley & Sons Ltd.

  17. Fish community-based measures of estuarine ecological quality and pressure-impact relationships

    Science.gov (United States)

    Fonseca, Vanessa F.; Vasconcelos, Rita P.; Gamito, Rita; Pasquaud, Stéphanie; Gonçalves, Catarina I.; Costa, José L.; Costa, Maria J.; Cabral, Henrique N.

    2013-12-01

    Community-based responses of fish fauna to anthropogenic pressures have been extensively used to assess the ecological quality of estuarine ecosystems. Several methodologies have been developed recently combining metrics reflecting community structure and function. A fish community facing significant environmental disturbances will be characterized by a simplified structure, with lower diversity and complexity. However, estuaries are naturally dynamic ecosystems exposed to numerous human pressures, making it difficult to distinguish between natural and anthropogenic-induced changes to the biological community. In the present work, the variability of several fish metrics was assessed in relation to different pressures in estuarine sites. The response of a multimetric index (Estuarine Fish Assessment Index) was also analysed. Overall, fish metrics and the multimetric index signalled anthropogenic stress, particularly environmental chemical pollution. The fish assemblage associated with this type of pressure was characterized by lower species diversity, lower number of functional guilds, lower abundance of marine migrants and of piscivorous individuals, and higher abundance of estuarine resident species. A decreased ecological quality status, based on the EFAI, was also determined for sites associated with this pressure group. Ultimately, the definition of each pressure groups favoured a stressor-specific analysis, evidencing pressure patterns and accounting for multiple factors in a highly dynamic environment.

  18. Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

    International Nuclear Information System (INIS)

    Besser, J.; Giesy, J.; Brown, R.; Herdt, T.; Dawson, G.

    1995-01-01

    Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 microg/g (wet wt.). The top predator in the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife

  19. Helminth communities of the exotic introduced turtle, Trachemys scripta elegans in southwestern Spain: Transmission from native turtles.

    Science.gov (United States)

    Hidalgo-Vila, J; Díaz-Paniagua, C; Ribas, A; Florencio, M; Pérez-Santigosa, N; Casanova, J C

    2009-06-01

    We report the prevalence and diversity of helminth parasites found in native turtles Mauremys leprosa and Emys orbicularis from three localities in southwestern Spain and we describe the helminth communities of exotic turtles Trachemys scripta elegans coexisting in the wild with both native turtle species. Five nematodes species were identified, of which Serpinema microcephalus was the only species common between two localities, although infection parameters were different between them. This is the first report of cross transmission of S. microcephalus and Falcaustra donanaensis from native to exotic turtles and the first report of genus Physaloptera in turtles of the Palearctic Region. Continuous releasing of exotic pet turtles in wildlife ecosystems increases the risk of parasite introductions and, consequently, potential transmission to native species, and highlights the impending need for regulation of pet turtle trade in Europe.

  20. Taxonomy of USA east coast fishing communities in terms of social vulnerability and resilience

    Energy Technology Data Exchange (ETDEWEB)

    Pollnac, Richard B., E-mail: pollnac3@gmail.com [Department of Marine Affairs, University of Rhode Island, 1 Greenhouse Rd., Kingston, RI 02881 (United States); Seara, Tarsila, E-mail: tarsila.seara@noaa.gov [National Marine Fisheries Service, NOAA, Northeast Fisheries Science Center, Social Sciences Branch, 28 Tarzwell Dr., Narragansett, RI 02882 (United States); Colburn, Lisa L., E-mail: lisa.l.colburn@noaa.gov [National Marine Fisheries Service, NOAA, Northeast Fisheries Science Center, Social Sciences Branch, 28 Tarzwell Dr., Narragansett, RI 02882 (United States); Jepson, Michael, E-mail: michael.jepson@noaa.gov [National Marine Fisheries Service, NOAA, Southeast Fisheries Science Center, Social Sciences Branch, 263 13th Avenue South, Saint Petersburg, FL 33701 (United States)

    2015-11-15

    Increased concern with the impacts that changing coastal environments can have on coastal fishing communities led to a recent effort by NOAA Fisheries social scientists to develop a set of indicators of social vulnerability and resilience for the U.S. Southeast and Northeast coastal communities. A goal of the NOAA Fisheries social vulnerability and resilience indicator program is to support time and cost effective use of readily available data in furtherance of both social impact assessments of proposed changes to fishery management regulations and climate change adaptation planning. The use of the indicators to predict the response to change in coastal communities would be enhanced if community level analyses could be grouped effectively. This study examines the usefulness of combining 1130 communities into 35 relevant subgroups by comparing results of a numerical taxonomy with data collected by interview methods, a process herein referred to as “ground-truthing.” The validation of the taxonomic method by the method of ground-truthing indicates that the clusters are adequate to be used to select communities for in-depth research. - Highlights: • We develop a taxonomy of fishing communities based on vulnerability indicators. • We validate the community clusters through the use of surveys (“ground-truthing”). • Clusters differ along important aspects of fishing community vulnerability. • Clustering communities allows for accurate and timely social impact assessments.

  1. Taxonomy of USA east coast fishing communities in terms of social vulnerability and resilience

    International Nuclear Information System (INIS)

    Pollnac, Richard B.; Seara, Tarsila; Colburn, Lisa L.; Jepson, Michael

    2015-01-01

    Increased concern with the impacts that changing coastal environments can have on coastal fishing communities led to a recent effort by NOAA Fisheries social scientists to develop a set of indicators of social vulnerability and resilience for the U.S. Southeast and Northeast coastal communities. A goal of the NOAA Fisheries social vulnerability and resilience indicator program is to support time and cost effective use of readily available data in furtherance of both social impact assessments of proposed changes to fishery management regulations and climate change adaptation planning. The use of the indicators to predict the response to change in coastal communities would be enhanced if community level analyses could be grouped effectively. This study examines the usefulness of combining 1130 communities into 35 relevant subgroups by comparing results of a numerical taxonomy with data collected by interview methods, a process herein referred to as “ground-truthing.” The validation of the taxonomic method by the method of ground-truthing indicates that the clusters are adequate to be used to select communities for in-depth research. - Highlights: • We develop a taxonomy of fishing communities based on vulnerability indicators. • We validate the community clusters through the use of surveys (“ground-truthing”). • Clusters differ along important aspects of fishing community vulnerability. • Clustering communities allows for accurate and timely social impact assessments

  2. Challenges in using fish communities for assessing the ecological ...

    African Journals Online (AJOL)

    2009-10-02

    Oct 2, 2009 ... context of a Reserve determination process, in order to comply ... natural conditions and a Category F represents a critically- ... Define ecological categories and recommend one ... that the Seekoei River experiences surface flow for approxi- ... To apply the FRAI model to the acquired fish data, the 8 steps.

  3. Exploring fish microbial communities to mitigate emerging diseases in aquaculture

    NARCIS (Netherlands)

    Bruijn, de Irene; Liu, Yiying; Wiegertjes, Geert F.; Raaijmakers, Jos M.

    2018-01-01

    Aquaculture is the fastest growing animal food sector worldwide and expected to further increase to feed the growing human population. However, existing and (re-)emerging diseases are hampering fish and shellfish cultivation and yield. For many diseases, vaccination protocols are not in place and

  4. Women fishing activities in rural communities of Epe Local ...

    African Journals Online (AJOL)

    Women are not aware of fishery extension activities in the area and the fisherwomen faced different types of problems in their fishery activities. However, to improve fishery activities by women in the area, extension agents should organize training workshops for the women on how to construct and mend fishing nets and ...

  5. Seasonal fish and invertebrate communities in three northern California estuaries

    OpenAIRE

    Osborn, Katherine

    2017-01-01

    The majority of Northern California estuaries are small, flooded, river valleys that are largely unstudied due to their small sizes and remote locations. Yet these estuaries serve as important nursery areas for many marine fish species including rockfish, flatfish, smelt, and herring, and they are vital to anadromous species such as Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead (O. mykiss). I sampled the summer and winter fish and invertebrate communities of the Big, Mad, and Ten Mi...

  6. Report of the Workshop on Population Characteristics and Change in Coastal Fishing Communities: Madras, India, 10-14 March 1997

    National Research Council Canada - National Science Library

    1997-01-01

    This workshop brought together 23 fisheries scientists/socio-economists and population experts with experience in demographic and population research on fishing communities and in fisheries management...

  7. Relationship of dietary intake of fish and non-fish selenium to serum lipids in Japanese rural coastal community.

    Science.gov (United States)

    Miyazaki, Yukiko; Koyama, Hiroshi; Nojiri, Masami; Suzuki, Shosuke

    2002-01-01

    Several studies have suggested that dietary selenium deficiency may be associated with an increased risk of coronary heart disease (CHD). In the present study, 55 men and 71 women were selected from participants in a health examination in a rural coastal community in Japan. The mean dietary selenium intake calculated from the simple food frequency questionnaire (SFFQ) was 127.5 micrograms/day. Fish was the major source of dietary selenium and it contributed to 68.7% of the daily total. HDL cholesterol was higher in the middle selenium intake group and in the high selenium intake group than in the low selenium intake group in all subjects and for males, and a significant difference was found between the middle selenium intake group and the low selenium intake group. The atherogenic index was significantly higher in the low selenium intake group than in the middle selenium intake group and in the high selenium intake group in males. GPx activity, total cholesterol and triacylglycerols did not show any significant differences among the three different selenium intake groups. Dietary intake of non-fish Se had a positive correlation with HDL cholesterol, and an inverse correlation with the atherogenic index in all subjects and for females. On the other hand, dietary intake of fish-Se had no relationship with any serum lipids. Non-fish Se is an important factor in selenium status for the prevention of CHD.

  8. Darwin's naturalization hypothesis up-close: Intermountain grassland invaders differ morphologically and phenologically from native community dominants

    Science.gov (United States)

    Dean E. Pearson; Yvette K. Ortega; Samantha J. Sears

    2012-01-01

    Darwin's naturalization hypothesis predicts that successful invaders will tend to differ taxonomically from native species in recipient communities because less related species exhibit lower niche overlap and experience reduced biotic resistance. This hypothesis has garnered substantial support at coarse scales. However, at finer scales, the influence of traits...

  9. Influence of Remedial Education Policies: Experiences of Low-Income Native American Women at a Midwestern Community College

    Science.gov (United States)

    Wilson-Armour, Carole Cristine

    2017-01-01

    The purpose of this study was to determine how policies regarding remedial education can influence the experiences of students who identify as low socioeconomic (SES) Native American women at a Midwestern community college. This study proposed to use interpretive policy analysis and phenomenological qualitative research to learn more about how low…

  10. Household reporting of childhood respiratory health and air pollution in rural Alaska Native communities.

    Science.gov (United States)

    Ware, Desirae N; Lewis, Johnnye; Hopkins, Scarlett; Boyer, Bert; Montrose, Luke; Noonan, Curtis W; Semmens, Erin O; Ward, Tony J

    2014-01-01

    Air pollution is an important contributor to respiratory disease in children. To examine associations between household reporting of childhood respiratory conditions and household characteristics related to air pollution in Alaska Native communities. In-home surveys were administered in 2 rural regions of Alaska. The 12-month prevalence of respiratory conditions was summarized by region and age. Odds ratios (ORs) were calculated to describe associations between respiratory health and household and air quality characteristics. Household-reported respiratory health data were collected for 561 children in 328 households. In 1 region, 33.6% of children aged respiratory infections in children (ORs 1.6-2.5), while reported wheezing was associated with 1 or more smokers living in the household. Reported asthma in 1 region (7.6%) was lower than national prevalence estimates. Findings suggest that there may be preventable exposures, including wood smoke and mould that affect childhood respiratory disease in these rural areas. Additional research is needed to quantify particulate matter 2.5 microns in aerodynamic diameter or less and mould exposures in these communities, and to objectively evaluate childhood respiratory health.

  11. Household reporting of childhood respiratory health and air pollution in rural Alaska Native communities

    Directory of Open Access Journals (Sweden)

    Desirae N. Ware

    2014-05-01

    Full Text Available Background: Air pollution is an important contributor to respiratory disease in children. Objective: To examine associations between household reporting of childhood respiratory conditions and household characteristics related to air pollution in Alaska Native communities. Design: In-home surveys were administered in 2 rural regions of Alaska. The 12-month prevalence of respiratory conditions was summarized by region and age. Odds ratios (ORs were calculated to describe associations between respiratory health and household and air quality characteristics. Results: Household-reported respiratory health data were collected for 561 children in 328 households. In 1 region, 33.6% of children aged <5 years had a recent history of pneumonia and/or bronchitis. Children with these conditions were 2 times more likely to live in a wood-heated home, but these findings were imprecise. Resident concern with mould was associated with elevated prevalence of respiratory infections in children (ORs 1.6–2.5, while reported wheezing was associated with 1 or more smokers living in the household. Reported asthma in 1 region (7.6% was lower than national prevalence estimates. Conclusions: Findings suggest that there may be preventable exposures, including wood smoke and mould that affect childhood respiratory disease in these rural areas. Additional research is needed to quantify particulate matter 2.5 microns in aerodynamic diameter or less and mould exposures in these communities, and to objectively evaluate childhood respiratory health.

  12. Does human pressure affect the community structure of surf zone fish in sandy beaches?

    Science.gov (United States)

    Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

    2017-01-01

    Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

  13. PCDD and PCDF exposures among fishing community through intake of fish and shellfish from the Straits of Malacca.

    Science.gov (United States)

    Azlan, Azrina; Nasir, Nurul Nadiah Mohamad; Shamsudin, Norashikin; Rahman, Hejar Abdul; Khoo, Hock Eng; Razman, Muhammad Rizal

    2015-07-21

    Exposure to PCDD/PCDF (dioxin and furan) through consumption of fish and shellfish is closely related to the occurrence of skin diseases, such as chloracne and hyperpigmentation. This study aimed to determine the exposure of PCDD/PCDF and its congeners in fish and shellfish obtained from different regions of the Straits of Malacca among the fishing community. The risk of fish and shellfish consumption and exposure to PCDD/PCDF among fishermen living in coastal areas of the Straits were evaluated based on a cross-sectional study involving face to face interviews, blood pressure and anthropometric measurements, and administration of food frequency questionnaires (FFQ). Skin examination was done by a dermatologist after the interview session. Determination of 17 congeners of PCDD/PCDF in 48 composite samples of fish and shellfish was performed based on HRGC/HRMS analysis. The total PCDD/PCDF in the seafood samples ranged from 0.12 to 1.24 pg WHO-TEQ/g fresh weight (4.6-21.8 pg WHO-TEQ/g fat). No significant difference found for the concentrations of PCDD/PCDF between the same types of seafood samples obtained from the three different regions. The concentrations of the most potent congener, 2,3,7,8-TCDD in the seafood samples ranged from 0.01 to 0.11 pg WHO-TEQ/g FW (1.9 pg WHO-TEQ/g fat). A positive moderate correlation was found between the fat contents and concentrations of PCDD/PCDF determined in the seafood samples. The total PCDD/PCDF in all seafood samples were below the 1 pg WHO-TEQ/g fresh weight, with the exception of grey eel-catfish. The respondents had consumed fish and shellfish with the amounts ranging between 2.02 g and 44.06 g per person per day. The total PCDD/PCDF exposures through consumption of fish and shellfish among the respondents were between 0.01 and 0.16 pg WHO-TEQ/kg BW/day. With regard to the two PCDD/PCDF-related skin diseases, no chloracne case was found among the respondents, but 2.2% of the respondents were diagnosed to have

  14. Modeling the fish community population dynamics and forecasting the eradication success of an exotic fish from an alpine stream

    Science.gov (United States)

    Laplanche, Christophe; Elger, Arnaud; Santoul, Frédéric; Thiede, Gary P.; Budy, Phaedra

    2018-01-01

    Management actions aimed at eradicating exotic fish species from riverine ecosystems can be better informed by forecasting abilities of mechanistic models. We illustrate this point with an example of the Logan River, Utah, originally populated with endemic cutthroat trout (Oncorhynchus clarkii utah), which compete with exotic brown trout (Salmo trutta). The coexistence equilibrium was disrupted by a large scale, experimental removal of the exotic species in 2009–2011 (on average, 8.2% of the stock each year), followed by an increase in the density of the native species. We built a spatially-explicit, reaction-diffusion model encompassing four key processes: population growth in heterogeneous habitat, competition, dispersal, and a management action. We calibrated the model with detailed long-term monitoring data (2001–2016) collected along the 35.4-km long river main channel. Our model, although simple, did a remarkable job reproducing the system steady state prior to the management action. Insights gained from the model independent predictions are consistent with available knowledge and indicate that the exotic species is more competitive; however, the native species still occupies more favorable habitat upstream. Dynamic runs of the model also recreated the observed increase of the native species following the management action. The model can simulate two possible distinct long-term outcomes: recovery or eradication of the exotic species. The processing of available knowledge using Bayesian methods allowed us to conclude that the chance for eradication of the invader was low at the beginning of the experimental removal (0.7% in 2009) and increased (20.5% in 2016) by using more recent monitoring data. We show that accessible mathematical and numerical tools can provide highly informative insights for managers (e.g., outcome of their conservation actions), identify knowledge gaps, and provide testable theory for researchers.

  15. Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

    Science.gov (United States)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

    2017-10-01

    Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of

  16. Community structure and seasonal variation of an inshore demersal fish community at Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Chatterji, A.; Ingole, B.S.; Sreepada, R.A.; Rivonker, C.U.; Parulekar, A.H.

    as an environment for nekton. Fish Community Ecology in Estuaries aud Coastal Lagoons: Towards an Ecosystem Integration (Yanez-Arancibia, A., ed.). DR(R) UNAM Press Mexico, Mexico City, pp. 17-34. Fisher, W. & Biachi, G. 1984 FAO Species Indenttjkation Sheets...

  17. Temporal dynamics of fish communities on an exposed shoreline in Hawaii

    Science.gov (United States)

    Friedlander, A.M.; Parrish, J.D.

    1998-01-01

    Environmental conditions on higher latitude coral reefs can be extremely variable, and may structure fish communities in ways not previously observed in the more stable, low latitude locations where communities have usually been studied. Temporal changes in fish community structure were examined in an intensive two-year study of the reef fishes of Hanalei Bay, Kauai, Hawaii. Hanalei Bay is directly exposed to winter swells with high surf, as well as frequent heavy winter rainfall and high river discharge. Twenty-two transects (25 x 5 m) were established in a wide variety of habitats and censused monthly (N = 1052 censuses). Over 121 000 sightings of individuals from 150 species were made during the study. Seasonal patterns in number of species, number of individuals, species diversity, and evenness were observed, with winter values usually lowest. Values of these ensemble variables tended to be higher at deeper sites and at sites with greater habitat complexity. Surf height and degree of wave exposure were negatively correlated with several measures of community organization. Groups of fishes with different levels of spatial mobility tended to occupy depths consistent with their various abilities to respond to events of heavy weather. The rank abundance of fish taxa tended to be more stable seasonally at sites with less exposure to high wave energy. These seasonal effects may suggest some type of short-range movement from more exposed and monotypic habitats to locations that are deeper or otherwise provide refuge from seasonally heavy seas.

  18. Fish community in the chronically polluted middle Elbe River

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Janáč, Michal; Valová, Zdenka; Streck, G.

    2010-01-01

    Roč. 59, č. 2 (2010), s. 157-168 ISSN 0139-7893 R&D Projects: GA MŠk LC522 Grant - others:6th Framework Programme EC(XE) MODELKEY (511237-GOCE) Institutional research plan: CEZ:AV0Z60930519 Keywords : fish * bioindicators * pollution * channelization Subject RIV: EG - Zoology Impact factor: 0.548, year: 2010 http://www.ivb.cz/folia/59/2/9_ms_1491_jurajda.pdf

  19. Phylogenetic community structure: temporal variation in fish assemblage

    OpenAIRE

    Santorelli, Sergio; Magnusson, William; Ferreira, Efrem; Caramaschi, Erica; Zuanon, Jansen; Amadio, Sidnéia

    2014-01-01

    Hypotheses about phylogenetic relationships among species allow inferences about the mechanisms that affect species coexistence. Nevertheless, most studies assume that phylogenetic patterns identified are stable over time. We used data on monthly samples of fish from a single lake over 10 years to show that the structure in phylogenetic assemblages varies over time and conclusions depend heavily on the time scale investigated. The data set was organized in guild structures and temporal scales...

  20. Longitudinal structure in temperate stream fish communities: evaluating conceptual models with temporal data

    Science.gov (United States)

    Roberts, James H.; Hitt, Nathaniel P.

    2010-01-01

    Five conceptual models of longitudinal fish community organization in streams were examined: (1) niche diversity model (NDM), (2) stream continuum model (SCM), (3) immigrant accessibility model (IAM), (4) environmental stability model (ESM), and (5) adventitious stream model (ASM). We used differences among models in their predictions about temporal species turnover, along with five spatiotemporal fish community data sets, to evaluate model applicability. Models were similar in predicting a positive species richness–stream size relationship and longitudinal species nestedness, but differed in predicting either similar temporal species turnover throughout the stream continuum (NDM, SCM), higher turnover upstream (IAM, ESM), or higher turnover downstream (ASM). We calculated measures of spatial and temporal variation from spatiotemporal fish data in five wadeable streams in central and eastern North America spanning 34–68 years (French Creek [New York], Piasa Creek [Illinois], Spruce Run [Virginia], Little Stony Creek [Virginia], and Sinking Creek [Virginia]). All streams exhibited substantial species turnover (i.e., at least 27% turnover in stream-scale species pools), in contrast to the predictions of the SCM. Furthermore, community change was greater in downstream than upstream reaches in four of five streams. This result is most consistent with the ASM and suggests that downstream communities are strongly influenced by migrants to and from species pools outside the focal stream. In Sinking Creek, which is isolated from external species pools, temporal species turnover (via increased richness) was higher upstream than downstream, which is a pattern most consistent with the IAM or ESM. These results corroborate the hypothesis that temperate stream habitats and fish communities are temporally dynamic and that fish migration and environmental disturbances play fundamental roles in stream fish community organization.

  1. Contested Domains of Science and Science Learning in Contemporary Native American Communities: Three Case Studies from a National Science Foundation grant titled, "Archaeology Pathways for Native Learners"

    Science.gov (United States)

    Parent, Nancy Brossard

    This dissertation provides a critical analysis of three informal science education partnerships that resulted from a 2003-2006 National Science Foundation grant titled, "Archaeology Pathways for Native Learners" (ESI-0307858), hosted by the Mashantucket Pequot Museum and Research Center. This dissertation is designed to contribute to understandings of learning processes that occur within and at the intersection of diverse worldviews and knowledge systems, by drawing upon experiences derived from three disparate contexts: 1) The Navajo Nation Museum in Window Rock, Arizona; 2) The A:shiwi A:wan Museum and Heritage Center on the Zuni Reservation in Zuni, New Mexico; and 3) Science learning camps at the Mashantucket Pequot Museum and Research Center for Native youth of southern New England. While informal science education is increasingly moving toward decolonizing and cross-cutting institutional boundaries of learning through critical thinking and real-world applications, the construction of "science" (even within diverse contexts) continues to be framed within a homogenous, predominantly Euro-American perspective. This study analyzes the language of Western science employed in these partnerships, with particular attention to the use of Western/Native binaries that shape perceptions of Native peoples and communities, real or imagined. Connections are drawn to broader nation-state interests in education, science, and the global economy. The role of educational evaluation in these case studies is also critically analyzed, by questioning the ways in which it is constructed, conducted, and evaluated for the purposes of informing future projects and subsequent funding. This study unpacks problems of the dominant language of "expert" knowledge embedded in Western science discourse, and highlights the possibilities of indigenous knowledge systems that can inform Western science frameworks of education and evaluation. Ultimately, this study suggests that research

  2. Modelling an exploited marine fish community with 15 parameters - results from a simple size-based model

    NARCIS (Netherlands)

    Pope, J.G.; Rice, J.C.; Daan, N.; Jennings, S.; Gislason, H.

    2006-01-01

    To measure and predict the response of fish communities to exploitation, it is necessary to understand how the direct and indirect effects of fishing interact. Because fishing and predation are size-selective processes, the potential response can be explored with size-based models. We use a

  3. Impact of habitat diversity on the sampling effort required for the assessment of river fish communities and IBI

    NARCIS (Netherlands)

    Van Liefferinge, C.; Simoens, I.; Vogt, C.; Cox, T.J.S.; Breine, J.; Ercken, D.; Goethals, P.; Belpaire, C.; Meire, P.

    2010-01-01

    The spatial variation in the fish communities of four small Belgian rivers with variable habitat diversity was investigated by electric fishing to define the minimum sampling distance required for optimal fish stock assessment and determination of the Index of Biotic Integrity. This study shows that

  4. Trait-based approaches in the analysis of stream fish communities

    Science.gov (United States)

    Frimpong, Emmanuel; Angermeier, Paul

    2010-01-01

    Species traits are used to study the functional organization of fish communities for a range of reasons, from simply reducing data dimensionality to providing mechanistic explanations for observed variation in communities. Ecological and life history traits have been used to understand the basic ecology of fishes and predict (1) species and community responses to habitat and climate alteration, and (2) species extinction, species invasion, and community homogenization. Many approaches in this arena have been developed during the past three decades, but they often have not been integrated with related ecological concepts or subdisciplines, which has led to confusion in terminology. We review 102 studies of species traits and then summarize patterns in traits being used and questions being addressed with trait-based approaches. Overall, studies of fish–habitat relationships that apply habitat templates and hierarchical filters dominate our sample; the most frequently used traits are related to feeding. We define and show the relationships among key terms such as fundamental and realized niches; functional traits, performance, and fitness; tactic, trait-state, syndromes, and strategies; and guilds and functional groups. We propose accelerating research to (1) quantify trait plasticity, (2) identify traits useful for testing ecological hypotheses, (3) model habitat and biotic interactions in communities while explicitly accounting for phylogenetic relationships, (4) explore how traits control community assembly, and (5) document the importance of traits in fish– community responses to anthropogenic change and in delivering ecosystem services. Further synthesis of these topics is still needed to develop concepts, models, and principles that can unify the disparate approaches taken in trait-based analysis of fish communities, link fish community ecology to general community ecology, and inform sustainable management of ecosystems.

  5. The importance of sponges and mangroves in supporting fish communities on degraded coral reefs in Caribbean Panama.

    Science.gov (United States)

    Seemann, Janina; Yingst, Alexandra; Stuart-Smith, Rick D; Edgar, Graham J; Altieri, Andrew H

    2018-01-01

    Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfish Scarus iseri comprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.

  6. Overestimating fish counts by non-instantaneous visual censuses: consequences for population and community descriptions.

    Directory of Open Access Journals (Sweden)

    Christine Ward-Paige

    Full Text Available BACKGROUND: Increasingly, underwater visual censuses (UVC are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into the natural abundance and structure of reef fish communities in remote areas. Recently, high apex predator densities (>100,000 individuals x km(-2 and biomasses (>4 tonnes x ha(-1 have been reported for some remote islands suggesting the occurrence of inverted trophic biomass pyramids. However, few studies have critically evaluated the methods used for sampling conspicuous and highly mobile fish such as sharks. Ideally, UVC are done instantaneously, however, researchers often count animals that enter the survey area after the survey has started, thus performing non-instantaneous UVC. METHODOLOGY/PRINCIPAL FINDINGS: We developed a simulation model to evaluate counts obtained by divers deploying non-instantaneous belt-transect and stationary-point-count techniques. We assessed how fish speed and survey procedure (visibility, diver speed, survey time and dimensions affect observed fish counts. Results indicate that the bias caused by fish speed alone is huge, while survey procedures had varying effects. Because the fastest fishes tend to be the largest, the bias would have significant implications on their biomass contribution. Therefore, caution is needed when describing abundance, biomass, and community structure based on non-instantaneous UVC, especially for highly mobile species such as sharks. CONCLUSIONS/SIGNIFICANCE: Based on our results, we urge that published literature state explicitly whether instantaneous counts were made and that survey procedures be accounted for when non-instantaneous counts are used. Using published density and biomass values of communities that include sharks we explore the effect of this bias and suggest that further investigation may be needed to determine pristine shark abundances and the

  7. Is Fish Farming an Illusion for Lake Malawi Riparian Communities under Environmental Changes?

    Directory of Open Access Journals (Sweden)

    Moses Majid Limuwa

    2018-05-01

    Full Text Available Global environmental changes have negatively affected many food systems while the demand for food has continued to rise. An urgent need exists to identify other sustainable means of producing food. This is a case in Malawi, where capture fisheries and agriculture are not supplying sufficient food. Fish farming food systems by communities who rely on inland fisheries have not been evaluated. Therefore, a study was conducted in two phases: January 2016 to May 2016 and in July 2017 to evaluate if fish farming could sustainably support livelihoods of Lake Malawi riparian communities. We used mixed methods to collect and analyze data. The data collection methods included explorative surveys, household survey interviews, focus group discussion and key informant interviews. Qualitative data was analyzed using content analysis for themes. This identified themes that were quantitatively analyzed using descriptive and inferential statistics. We observed that fish farming was dominated by men and also not the main occupation for the respondents despite owning fishponds. The respondents have water and land, which are prerequisite for any farming. The study also observed fish farming production challenges related to quality fingerlings, formulated diets, and extension services. Cases of food insecurity amongst the respondents were also prevalent due to lack of food to cover the entire year. Weak synergies existed between fish farming and agriculture restricting bio-resource flow and water usage between these two food systems, meaning the outcomes of the food systems provide unsustainable diets. Furthermore, water availability, money spent on food, and cassava cropping increased fish farming participation. Whereas operating a bicycle taxi, casual labor, former fish farming, as well as application of agricultural wastes negatively affected fish farming. On the other hand, extreme weather events (increased incidences of droughts and floods attributed to inter

  8. Spatial patterns of fish communities along two estuarine gradients in southern Florida

    Science.gov (United States)

    Green, D.P.J.; Trexler, J.C.; Lorenz, J.J.; McIvor, C.C.; Philippi, T.

    2006-01-01

    In tropical and subtropical estuaries, gradients of primary productivity and salinity are generally invoked to explain patterns in community structure and standing crops of fishes. We documented spatial and temporal patterns in fish community structure and standing crops along salinity and nutrient gradients in two subtropical drainages of Everglades National Park, USA. The Shark River drains into the Gulf of Mexico and experiences diurnal tides carrying relatively nutrient enriched waters, while Taylor River is more hydrologically isolated by the oligohaline Florida Bay and experiences no discernable lunar tides. We hypothesized that the more nutrient enriched system would support higher standing crops of fishes in its mangrove zone. We collected 50 species of fish from January 2000 to April 2004 at six sampling sites spanning fresh to brackish salinities in both the Shark and Taylor River drainages. Contrary to expectations, we observed lower standing crops and density of fishes in the more nutrient rich tidal mangrove forest of the Shark River than in the less nutrient rich mangrove habitats bordering the Taylor River. Tidal mangrove habitats in the Shark River were dominated by salt-tolerant fish and displayed lower species richness than mangrove communities in the Taylor River, which included more freshwater taxa and yielded relatively higher richness. These differences were maintained even after controlling for salinity at the time of sampling. Small-scale topographic relief differs between these two systems, possibly created by tidal action in the Shark River. We propose that this difference in topography limits movement of fishes from upstream marshes into the fringing mangrove forest in the Shark River system, but not the Taylor River system. Understanding the influence of habitat structure, including connectivity, on aquatic communities is important to anticipate effects of construction and operational alternatives associated with restoration of the

  9. Fish communities associated with cold-water corals vary with depth and substratum type

    Science.gov (United States)

    Milligan, Rosanna J.; Spence, Gemma; Roberts, J. Murray; Bailey, David M.

    2016-08-01

    Understanding the processes that drive the distribution patterns of organisms and the scales over which these processes operate are vital when considering the effective management of species with high commercial or conservation value. In the deep sea, the importance of scleractinian cold-water corals (CWCs) to fish has been the focus of several studies but their role remains unclear. We propose this may be due to the confounding effects of multiple drivers operating over multiple spatial scales. The aims of this study were to investigate the role of CWCs in shaping fish community structure and individual species-habitat associations across four spatial scales in the NE Atlantic ranging from "regions" (separated by >500 km) to "substratum types" (contiguous). Demersal fish and substratum types were quantified from three regions: Logachev Mounds, Rockall Bank and Hebrides Terrace Seamount (HTS). PERMANOVA analyses showed significant differences in community composition between all regions which were most likely caused by differences in depths. Within regions, significant variation in community composition was recorded at scales of c. 20-3500 m. CWCs supported significantly different fish communities to non-CWC substrata at Rockall Bank, Logachev and the HTS. Single-species analyses using generalised linear mixed models showed that Sebastes sp. was strongly associated with CWCs at Rockall Bank and that Neocyttus helgae was more likely to occur in CWCs at the HTS. Depth had a significant effect on several other fish species. The results of this study suggest that the importance of CWCs to fish is species-specific and depends on the broader spatial context in which the substratum is found. The precautionary approach would be to assume that CWCs are important for associated fish, but must acknowledge that CWCs in different depths will not provide redundancy or replication within spatially-managed conservation networks.

  10. Effect of multiple electro-fishing on determining the structure of fish communities in small streams

    Czech Academy of Sciences Publication Activity Database

    Humpl, Martin; Lusk, Stanislav

    2006-01-01

    Roč. 55, č. 3 (2006), s. 315-322 ISSN 0139-7893 R&D Projects: GA MŽP SM/6/3/05 Institutional research plan: CEZ:AV0Z60930519 Keywords : electro- fishing efficacy * repeated sampling * probability of detection * species richness Subject RIV: EH - Ecology, Behaviour Impact factor: 0.529, year: 2006 http://www.ivb.cz/folia/55/3/315-322.pdf

  11. Boys Go Fishing, Girls Work at Home: Gender Roles, Poverty and Unequal School Access among Semi-Nomadic Fishing Communities in South Western Madagascar

    Science.gov (United States)

    Nascimento Moreira, Catarina; Rabenevanana, Man Wai; Picard, David

    2017-01-01

    Drawing from data gathered in South Western Madagascar in 2011, the work explores the combination of poverty and traditional gender roles as a critical factor in determining unequal school access among young people from semi-nomadic fishing communities. It demonstrates that from the age of early puberty, most boys go fishing with their fathers and…

  12. Biogeographic Patterns of Reef Fish Communities in the Saudi Arabian Red Sea

    KAUST Repository

    Roberts, May B.

    2014-12-01

    As a region renowned for high biodiversity, endemism and extreme temperature and salinity levels, the Red Sea is of high ecological interest. Despite this, there is relatively little literature on basic broad scale characteristics of the biodiversity or overall reef fish communities and how they change across latitude. We conducted visual transects recording the abundance of over 200 species of fish from 45 reefs spanning over 1000 km of Saudi Arabian coastline and used hierarchical cluster analysis to find that for combined depths from 0m-10m across this geographical range, the reef fish communities are relatively similar. However we find some interesting patterns both at the community level across depth and latitude as well as in endemic community distributions. We find that the communities, much like the environmental factors, shift gradually along latitude but do not show distinct clusters within the range we surveyed (from Al-Wajh in the north to the Farasan Banks in the south). Numbers of endemic species tend to be higher in the Thuwal region and further south. This type of baseline data on reef fish distribution and possible factors that may influence their ranges in the Red Sea are critical for future scientific studies as well as effective monitoring and in the face of the persistent anthropogenic influences such as coastal development, overfishing and climate change.

  13. Sheep response to fish meal supplements for diets based on industrial by-products or native pastures of the Peruvian High Andes

    International Nuclear Information System (INIS)

    Talavera, V.

    1987-01-01

    Rumen degradabilities were determined for various proteins by incubation for 48 h in nylon bags. Values obtained were 37.3% for corn grain and feather meal, 59.6% for alfalfa meal, 63.4% for cottonseed meal, 66.8% for soybean meal and 68.0% for rice polishings. Fish meal protein degradability was less than 45%. Sheep given either cottonseed meal or fish meal as sources of 'bypass' protein did not show differences in daily gain or intake. Fish meal diets gave better feed/gain ratios. Fish meal or urea supplementation of a basal diet containing 4.6% crude protein increased feed intake, daily gain, the feed/gain ratio and wool staple length. Castrated sheep grazing native pastures of the Peruvian Andes (altitude approximately 3800 m) during either the rainy or dry season did not show significant improvement in growth rate with fish meal supplementation. Supplementation of ewes at first mating produced higher weights at the end of gestation, as well as an increase in the number and weight of lambs born, in the weaning rate and in wool weight from the ewes. (author)

  14. Temporal and geographic variation in fish communities of lower Cook Inlet, Alaska

    Science.gov (United States)

    Robards, Martin D.; Piatt, John F.; Kettle, Arthur B.; Abookire, Alisa A.

    1999-01-01

    Nearshore and shelf fish communities were studied in three areas of lower Cook Inlet, Alaska: the Barren Islands (oceanic and well-mixed waters), Kachemak Bay (mixed oceanic waters with significant freshwater runoff), and Chisik Island (estuarine waters). Fish were sampled with beach seines (n=413 sets) and midwater trawls (n=39 sets). We found that lower Cook Inlet supported a diverse nearshore fish community of at least 52 species. Fifty of these species were caught in Kachemak Bay, 24 at Chisik Island, and 12 at the Barren Islands. Pacific sand lance dominated Barren Islands and Kachemak Bay nearshore habitats, comprising 99% and 71% of total individuals, respectively. The nearshore Chisik Island fish community was not dominated by any one species; instead it exhibited higher diversity. These spatial differences appeared linked to local oceanographic regimes and sediment influx. Analysis of historical data revealed that the nearshore Kachemak Bay fish community changed significantly between 1976 and 1996, showing increased diversity and abundance in several taxa, notably gadids, salmonids, pleuronectids, and sculpins. Decadal differences appeared to be related to large-scale climate changes in the North Pacific. Catches of most taxa peaked in May-August, and were low during other months of the year. Several species were present for only part of the summer. Species composition of seine catches differed significantly between consecutive high and low tides, but not between consecutive sets or years. Midwater trawls took 26 species, 14 of which were present in Kachemak Bay, 19 near Chisik Island, and 7 at the Barren Islands. Community structures in shelf and nearshore waters were similar: diversity was high and abundance low at Chisik Island, whereas a few abundant species dominated at both Kachemak Bay and the Barren Islands. In addition, the low fish abundance near Chisik Island appeared to be related to declining seabird numbers at this colony.

  15. Non-Random Variability in Functional Composition of Coral Reef Fish Communities along an Environmental Gradient.

    Science.gov (United States)

    Plass-Johnson, Jeremiah G; Taylor, Marc H; Husain, Aidah A A; Teichberg, Mirta C; Ferse, Sebastian C A

    2016-01-01

    Changes in the coral reef complex can affect predator-prey relationships, resource availability and niche utilisation in the associated fish community, which may be reflected in decreased stability of the functional traits present in a community. This is because particular traits may be favoured by a changing environment, or by habitat degradation. Furthermore, other traits can be selected against because degradation can relax the association between fishes and benthic habitat. We characterised six important ecological traits for fish species occurring at seven sites across a disturbed coral reef archipelago in Indonesia, where reefs have been exposed to eutrophication and destructive fishing practices for decades. Functional diversity was assessed using two complementary indices (FRic and RaoQ) and correlated to important environmental factors (live coral cover and rugosity, representing local reef health, and distance from shore, representing a cross-shelf environmental gradient). Indices were examined for both a change in their mean, as well as temporal (short-term; hours) and spatial (cross-shelf) variability, to assess whether fish-habitat association became relaxed along with habitat degradation. Furthermore, variability in individual traits was examined to identify the traits that are most affected by habitat change. Increases in the general reef health indicators, live coral cover and rugosity (correlated with distance from the mainland), were associated with decreases in the variability of functional diversity and with community-level changes in the abundance of several traits (notably home range size, maximum length, microalgae, detritus and small invertebrate feeding and reproductive turnover). A decrease in coral cover increased variability of RaoQ while rugosity and distance both inversely affected variability of FRic; however, averages for these indices did not reveal patterns associated with the environment. These results suggest that increased

  16. Mercury exposure as a function of fish consumption in two Asian communities in coastal Virginia, USA.

    Science.gov (United States)

    Xu, Xiaoyu; Newman, Michael C

    2015-04-01

    Fish consumption and associated mercury exposure were explored for two Asian-dominated church communities in coastal Virginia and compared with that of two non-Asian church communities. Seafood-consumption rates for the Chinese (36.9 g/person/day) and Vietnamese (52.7 g/person/day) church communities were greater than the general United States fish-consumption rate (12.8 g/person/day). Correspondingly, hair mercury concentrations for people from the Chinese (0.52 µg/g) and the Vietnamese church (1.46 µg/g) were greater than the overall level for United States women (0.20 µg/g) but lower than the published World Health Organization exposure threshold (14 µg/g). A conventional regression model indicated a positive relationship between seafood consumption rates and hair mercury concentrations suggesting the importance of mercury exposure through seafood consumption. The annual-average daily methylmercury intake rate for the studied communities calculated by Monte Carlo simulations followed the sequence: Vietnamese community > Chinese community > non-Asian communities. Regardless, their daily methylmercury intake rates were all lower than the United States Environmental Protection Agency reference dose of 0.1 µg/kg body weight-day. In conclusion, fish-consumption patterns differed among communities, which resulted in different levels of mercury exposure. The greater seafood and mercury ingestion rates of studied Asian groups compared with non-Asian groups suggest the need for specific seafood consumption advice for ethnic communities in the United States. Otherwise the health benefits from fish consumption could be perceived as trivial compared with the ill-defined risk of mercury exposure.

  17. Conversion of sulfur compounds and microbial community in anaerobic treatment of fish and pork waste.

    Science.gov (United States)

    He, Ruo; Yao, Xing-Zhi; Chen, Min; Ma, Ruo-Chan; Li, Hua-Jun; Wang, Chen; Ding, Shen-Hua

    2018-04-07

    Volatile sulfur compounds (VSCs) are not only the main source of malodor in anaerobic treatment of organic waste, but also pose a threat to human health. In this study, VSCs production and microbial community was investigated during the anaerobic degradation of fish and pork waste. The results showed that after the operation of 245 days, 94.5% and 76.2% of sulfur compounds in the fish and pork waste was converted into VSCs. Among the detected VSCs including H 2 S, carbon disulfide, methanethiol, ethanethiol, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide, methanethiol was the major component with the maximum concentration of 4.54% and 3.28% in the fish and pork waste, respectively. The conversion of sulfur compounds including total sulfur, SO 4 2- -S, S 2- , methionine and cysteine followed the first-order kinetics. Miseq sequencing analysis showed that Acinetobacter, Clostridium, Proteus, Thiobacillus, Hyphomicrobium and Pseudomonas were the main known sulfur-metabolizing microorganisms in the fish and pork waste. The C/N value had most significant influence on the microbial community in the fish and pork waste. A main conversion of sulfur compounds with CH 3 SH as the key intermediate was firstly hypothesized during the anaerobic degradation of fish and pork waste. These findings are helpful to understand the conversion of sulfur compounds and to develop techniques to control ordor pollution in the anaerobic treatment of organic waste. Copyright © 2018. Published by Elsevier Ltd.

  18. The distribution and abundance of the Neogobius fishes in their native range (Bulgaria) with notes on the non-native range in the Danube River

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Janáč, Michal; Trichkova, T.; Vassilev, M.; Keckeis, H.; Jurajda, Pavel

    2008-01-01

    Roč. 18, 1-2 (2008), s. 193-208 ISSN 0945-3784 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Neogobius fishes * Danube River Subject RIV: EH - Ecology, Behaviour

  19. Ecomorphology of a size-structured tropical freshwater fish community

    NARCIS (Netherlands)

    Piet, G.J.

    1998-01-01

    Among nine species of a tropical community ecomorphological correlates were sought throughout ontogeny. Ontogenetic changes were distinguished by establishing six pre-defined size- classes. Morphometric data associated with feeding were compared by canonical correspondence analysis to dietary data.

  20. Trophic structure of a coastal fish community determined with diet and stable isotope analyses.

    Science.gov (United States)

    Malek, A J; Collie, J S; Taylor, D L

    2016-09-01

    A combination of dietary guild analysis and nitrogen (δ(15) N) and carbon (δ(13) C) stable-isotope analysis was used to assess the trophic structure of the fish community in Rhode Island and Block Island Sounds, an area off southern New England identified for offshore wind energy development. In the autumn of 2009, 2010 and 2011, stomach and tissue samples were taken from 20 fish and invertebrate species for analysis of diet composition and δ(15) N and δ(13) C signatures. The food chain in Rhode Island and Block Island Sounds comprises approximately four trophic levels within which the fish community is divided into distinct dietary guilds, including planktivores, benthivores, crustacivores and piscivores. Within these guilds, inter-species isotopic and dietary overlap is high, suggesting that resource partitioning or competitive interactions play a major role in structuring the fish community. Carbon isotopes indicate that most fishes are supported by pelagic phytoplankton, although there is evidence that benthic production also plays a role, particularly for obligate benthivores such as skates Leucoraja spp. This type of analysis is useful for developing an ecosystem-based approach to management, as it identifies species that act as direct links to basal resources as well as species groups that share trophic roles. © 2016 The Fisheries Society of the British Isles.

  1. The offshore fish community in southern Lake Ontario, 1972-1998

    Science.gov (United States)

    Owens, Randall W.; O'Gorman, Robert; Eckert, Thomas H.; Lantry, Brian F.; Munawar, M.

    2003-01-01

    The authors document the status of Lake Ontario's open-water fish community in 1972, near the beginning of an era of massive fish stocking and when phosphorus levels in the lake from anthropogenic inputs, were near their peak. They then describe changes that occurred in the fish community in 1978-98. This was a period when large numbers of young salmonid piscivores were released annually, sea lamprey control continued to improve, and phosphorus levels were declining due to successful nutrient abatement programs. Coincident with the above, the lower food web was changed by the addition of new exotic invertebrates, the zooplankter Bythotrephes cederstroemi and particularly the zebra mussel, Dreissena polymorpha, and quagga mussel, D. bugensis. The picture of the fish community structure is drawn from records of catches in bottom trawls and gill nets during surveys of southern Lake Ontario conducted the the U.S. Geological Survey (USGS) and the New York Department of Environmental Conservation (NYDEC), from records of fish stocked in Lake Ontario by the NYDEC, and from a creel census of boat anglers returning to southern Lake Ontario ports conducted by the NYDEC.

  2. A hierarchical community occurrence model for North Carolina stream fish

    Science.gov (United States)

    Midway, S.R.; Wagner, Tyler; Tracy, B.H.

    2016-01-01

    The southeastern USA is home to one of the richest—and most imperiled and threatened—freshwater fish assemblages in North America. For many of these rare and threatened species, conservation efforts are often limited by a lack of data. Drawing on a unique and extensive data set spanning over 20 years, we modeled occurrence probabilities of 126 stream fish species sampled throughout North Carolina, many of which occur more broadly in the southeastern USA. Specifically, we developed species-specific occurrence probabilities from hierarchical Bayesian multispecies models that were based on common land use and land cover covariates. We also used index of biotic integrity tolerance classifications as a second level in the model hierarchy; we identify this level as informative for our work, but it is flexible for future model applications. Based on the partial-pooling property of the models, we were able to generate occurrence probabilities for many imperiled and data-poor species in addition to highlighting a considerable amount of occurrence heterogeneity that supports species-specific investigations whenever possible. Our results provide critical species-level information on many threatened and imperiled species as well as information that may assist with re-evaluation of existing management strategies, such as the use of surrogate species. Finally, we highlight the use of a relatively simple hierarchical model that can easily be generalized for similar situations in which conventional models fail to provide reliable estimates for data-poor groups.

  3. Natural shorelines promote the stability of fish communities in an urbanized coastal system.

    Directory of Open Access Journals (Sweden)

    Steven B Scyphers

    Full Text Available Habitat loss and fragmentation are leading causes of species extinctions in terrestrial, aquatic and marine systems. Along coastlines, natural habitats support high biodiversity and valuable ecosystem services but are often replaced with engineered structures for coastal protection or erosion control. We coupled high-resolution shoreline condition data with an eleven-year time series of fish community structure to examine how coastal protection structures impact community stability. Our analyses revealed that the most stable fish communities were nearest natural shorelines. Structurally complex engineered shorelines appeared to promote greater stability than simpler alternatives as communities nearest vertical walls, which are among the most prevalent structures, were most dissimilar from natural shorelines and had the lowest stability. We conclude that conserving and restoring natural habitats is essential for promoting ecological stability. However, in scenarios when natural habitats are not viable, engineered landscapes designed to mimic the complexity of natural habitats may provide similar ecological functions.

  4. Habitat template approach for green roofs using a native rocky sea coast plant community in Japan.

    Science.gov (United States)

    Nagase, Ayako; Tashiro-Ishii, Yurika

    2018-01-15

    The present study examined whether it is possible to simulate a local herbaceous coastal plant community on a roof, by studying the natural habitats of rocky sea coast plants and their propagation and performance on a green roof. After studying the natural habitat of coastal areas in Izu peninsula, a germination and cutting transplant study was carried out using herbaceous plants from the Jogasaki sea coast. Many plant species did not germinate at all and the use of cuttings was a better method than direct seeding. The green roof was installed in the spring of 2012 in Chiba city. Thirteen plant species from the Jogasaki sea coast, which were successfully propagated, were planted in three kinds of substrate (15 cm depth): pumice, roof tile and commercial green roof substrate. The water drainage was restricted and a reservoir with 5 cm depth of water underlaid the substrate to simulate a similar growing environment to the sea coast. Volcanic rocks were placed as mulch to create a landscape similar to that on the Jogasaki sea coast. Plant coverage on the green roof was measured every month from June 2012 to October 2014. All plants were harvested and their dry shoot weight was measured in December 2014. The type of substrate did not cause significant differences in plant survival and dry shoot weight. Sea coast plant species were divided into four categories: vigorous growth; seasonal change; disappearing after a few years; limited growth. Understanding the ecology of natural habitats was important to simulating a local landscape using native plant communities on the green roof. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. PiSCES: Pi(scine) stream community estimation software: A tool for nationwide fish assemblage predictions

    Science.gov (United States)

    Background/Question/Methods What species of fish might someone find in a local stream? How might that community change as a result of changes to characteristics of the stream and its watershed? PiSCES is a browser-based toolkit developed to predict a fish community for any NHD-Pl...

  6. Effects of fish community on occurrences of Yangtze finless porpoise in confluence of the Yangtze and Wanhe Rivers.

    Science.gov (United States)

    Zhang, Xiaoke; Yu, Daoping; Wang, Huili; Wan, An; Chen, Minmin; Tao, Feng; Song, Zunrong

    2015-06-01

    The Yangtze finless porpoise is a subspecies of narrow-ridged finless porpoise endemic to the middle and lower reaches of the Yangtze River and the adjoining Poyang and Dongting Lakes. With the depletion of fish stocks in the Yangtze River in recent decades, food availability has become the most important factor affecting the survival of this subspecies. Despite this, the relationships between fish community and occurrences of porpoise are far from being fully understood. Therefore, during September 2013 to August 2014, the occurrences of porpoise were investigated in confluence of the Yangtze and Wanhe Rivers; fish community was also surveyed synchronously in confluence and two adjacent transects. The results showed that (1) the confluence had maximum fish species richness, and the main dominant species was upper fish, while the other two transects were mainly dominated by demersal fish. ANOVA analyses showed that individual number and yield of upper fish which can be eaten by porpoise (upper edible fish) in the confluence were significantly higher than other two transects. (2) Average group size of the porpoise was 3.7 ± 1.8 individuals. The occurrences of porpoise in different seasons had great differences, and the porpoise was more likely to be detected in autumn and winter. (3) Fish community had significant effects on occurrences of porpoise, and the main influencing factors were fish species richness, individual number, and yield of edible fish, especially the upper edible fish. The results of this study will have important implications for the conservation of porpoise.

  7. Estuarine fish communities respond to climate variability over both river and ocean basins.

    Science.gov (United States)

    Feyrer, Frederick; Cloern, James E; Brown, Larry R; Fish, Maxfield A; Hieb, Kathryn A; Baxter, Randall D

    2015-10-01

    Estuaries are dynamic environments at the land-sea interface that are strongly affected by interannual climate variability. Ocean-atmosphere processes propagate into estuaries from the sea, and atmospheric processes over land propagate into estuaries from watersheds. We examined the effects of these two separate climate-driven processes on pelagic and demersal fish community structure along the salinity gradient in the San Francisco Estuary, California, USA. A 33-year data set (1980-2012) on pelagic and demersal fishes spanning the freshwater to marine regions of the estuary suggested the existence of five estuarine salinity fish guilds: limnetic (salinity = 0-1), oligohaline (salinity = 1-12), mesohaline (salinity = 6-19), polyhaline (salinity = 19-28), and euhaline (salinity = 29-32). Climatic effects propagating from the adjacent Pacific Ocean, indexed by the North Pacific Gyre Oscillation (NPGO), affected demersal and pelagic fish community structure in the euhaline and polyhaline guilds. Climatic effects propagating over land, indexed as freshwater outflow from the watershed (OUT), affected demersal and pelagic fish community structure in the oligohaline, mesohaline, polyhaline, and euhaline guilds. The effects of OUT propagated further down the estuary salinity gradient than the effects of NPGO that propagated up the estuary salinity gradient, exemplifying the role of variable freshwater outflow as an important driver of biotic communities in river-dominated estuaries. These results illustrate how unique sources of climate variability interact to drive biotic communities and, therefore, that climate change is likely to be an important driver in shaping the future trajectory of biotic communities in estuaries and other transitional habitats. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  8. Assessing plant community composition fails to capture impacts of white-tailed deer on native and invasive plant species.

    Science.gov (United States)

    Nuzzo, Victoria; Dávalos, Andrea; Blossey, Bernd

    2017-07-01

    Excessive herbivory can have transformative effects on forest understory vegetation, converting diverse communities into depauperate ones, often with increased abundance of non-native plants. White-tailed deer are a problematic herbivore throughout much of eastern North America and alter forest understory community structure. Reducing (by culling) or eliminating (by fencing) deer herbivory is expected to return understory vegetation to a previously diverse condition. We examined this assumption from 1992 to 2006 at Fermilab (Batavia, IL) where a cull reduced white-tailed deer ( Odocoileus virginianus ) abundance in 1998/1999 by 90 % from 24.6 to 2.5/km 2 , and at West Point, NY, where we assessed interactive effects of deer, earthworms, and invasive plants using 30 × 30 m paired fenced and open plots in 12 different forests from 2009 to 2012. We recorded not only plant community responses (species presence and cover) within 1 m 2 quadrats, but also responses of select individual species (growth, reproduction). At Fermilab, introduced Alliaria petiolata abundance initially increased as deer density increased, but then declined after deer reduction. The understory community responded to the deer cull by increased cover, species richness and height, and community composition changed but was dominated by early successional native forbs. At West Point plant community composition was affected by introduced earthworm density but not deer exclusion. Native plant cover increased and non-native plant cover decreased in fenced plots, thus keeping overall plant cover similar. At both sites native forb cover increased in response to deer reduction, but the anticipated response of understory vegetation failed to materialize at the community level. Deer-favoured forbs ( Eurybia divaricata , Maianthemum racemosum , Polygonatum pubescens and Trillium recurvatum ) grew taller and flowering probability increased in the absence of deer. Plant community monitoring fails to capture

  9. Mathematics Funds of Knowledge: "Sotmaute" and "Sermaute" Fish in a Torres Strait Islander Community

    Science.gov (United States)

    Ewing, Bronwyn

    2012-01-01

    The purpose of this article is to describe a project with one Torres Strait Islander Community. It provides some insights into parents' funds of knowledge that are mathematical in nature, such as sorting shells and giving fish. The idea of funds of knowledge is based on the premise that people are competent and have knowledge that has been…

  10. Determinants of Selenium Intake in a High HIV Prevalence Fishing Community in Bondo District, Kenya

    OpenAIRE

    Samwel Boaz Otieno; Fred Were; Ephantus Kabiru; Kaunda Waza

    2016-01-01

    A study was done to establish determinants of selenium intake in a high HIV prevalence fishing community in the Pala Bondo district, Kenya. It was established that most of the respondents (61%) were small holder Farmers and Fishermen {χ2 (1, N=386) p

  11. Effects of fishing on a temperate reef community in South Africa 2 ...

    African Journals Online (AJOL)

    Crinoidea, the principal food source of roman Chrysoblephus laticeps, was scarce at protected sites where this species was most abundant. Low algal abundance at protected sites was negatively correlated with grazer abundance within the fish communities encountered there, suggesting a high potential for coexistence of ...

  12. The fish community of East Cape tidal pools and an assessment of ...

    African Journals Online (AJOL)

    Fish occurring in tidal pools in the lower balanoid zone near Port Elizabeth were examined by visual census and rotenone collections. Numerically, Clinidae constituted 28% of the community, Sparidae 23%, Gobiidae 17% and the Cheilodactylidae 12%, while eleven other families contributed to the remaining 20%. The 44 ...

  13. From traits to life-history strategies: Deconstructing fish community composition across European seas

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Lindegren, Martin; Hidalgo, Manuel

    2017-01-01

    The life history of a species is determined by trade-offs between growth, survival and reproduction to maximize fitness in a given environment. Following a theoretical model, we investigate whether the composition of marine fish communities can be understood in terms of a set of lifehistory...

  14. The subtidal gully fish community of the eastern Cape and the role of ...

    African Journals Online (AJOL)

    1988-02-25

    Feb 25, 1988 ... The subtidal gully fish community of the eastern Cape and the ... relation to previous studies of intertidal pools in the eastern and western Cape, ... transient species, particularly two species in the family ..... schooling species (27%) made up the balance. ..... consistent with other work that has shown greater.

  15. Nonrandom Composition of Flower Colors in a Plant Community: Mutually Different Co-Flowering Natives and Disturbance by Aliens

    Science.gov (United States)

    Makino, Takashi T.; Yokoyama, Jun

    2015-01-01

    When pollinators use flower color to locate food sources, a distinct color can serve as a reproductive barrier against co-flowering species. This anti-interference function of flower color may result in a community assembly of plant species displaying mutually different flower colors. However, such color dispersion is not ubiquitous, suggesting a variable selection across communities and existence of some opposing factors. We conducted a 30-week study in a plant community and measured the floral reflectances of 244 species. The reflectances were evaluated in insect color spaces (bees, swallowtails, and flies), and the dispersion was compared with random expectations. We found that co-existing colors were overdispersed for each analyzed pollinator type, and this overdispersion was statistically significant for bees. Furthermore, we showed that exclusion of 32 aliens from the analysis significantly increased the color dispersion of native flowers in every color space. This result indicated that aliens disturbed a native plant–pollinator network via similarly colored flowers. Our results demonstrate the masking effects of aliens in the detection of color dispersion of native flowers and that variations in pollinator vision yield different outcomes. Our results also support the hypothesis that co-flowering species are one of the drivers of color diversification and affect the community assembly. PMID:26650121

  16. Nonrandom Composition of Flower Colors in a Plant Community: Mutually Different Co-Flowering Natives and Disturbance by Aliens.

    Directory of Open Access Journals (Sweden)

    Takashi T Makino

    Full Text Available When pollinators use flower color to locate food sources, a distinct color can serve as a reproductive barrier against co-flowering species. This anti-interference function of flower color may result in a community assembly of plant species displaying mutually different flower colors. However, such color dispersion is not ubiquitous, suggesting a variable selection across communities and existence of some opposing factors. We conducted a 30-week study in a plant community and measured the floral reflectances of 244 species. The reflectances were evaluated in insect color spaces (bees, swallowtails, and flies, and the dispersion was compared with random expectations. We found that co-existing colors were overdispersed for each analyzed pollinator type, and this overdispersion was statistically significant for bees. Furthermore, we showed that exclusion of 32 aliens from the analysis significantly increased the color dispersion of native flowers in every color space. This result indicated that aliens disturbed a native plant-pollinator network via similarly colored flowers. Our results demonstrate the masking effects of aliens in the detection of color dispersion of native flowers and that variations in pollinator vision yield different outcomes. Our results also support the hypothesis that co-flowering species are one of the drivers of color diversification and affect the community assembly.

  17. Native excellence

    International Nuclear Information System (INIS)

    Bower, T.

    1992-01-01

    Syncrude Canada Ltd., operator of the oil sands mine and processing plant near Fort McMurray, Alberta, produces 11% of Canada's crude oil and is the country's largest private-sector employer of native Canadians. Syncrude has the goal of employing about 10% native Canadians, which is about the percentage of natives in the regional population. Examples are presented of successful native employment and entrepreneurship at Syncrude. Doreen Janvier, once employed at Syncrude's mine wash bays, was challenged to form her own company to contract out labor services. Her company, DJM Enterprises, now has a 2-year contract to operate three highly sophisticated wash bays used to clean mining equipment, and is looking to bid on other labor contracts. Mabel Laviolette serves as liaison between the oil containment and recovery team, who recover oil skimmed off Syncrude's tailings basin, and the area manager. The team approach and the seasonal nature of the employment fit in well with native cultural patterns. The excellence of native teamwork is also illustrated in the mine rescue team, one unit of which is entirely native Canadian. Part of Syncrude's aboriginal policy is to encourage development of aboriginal enterprises, such as native-owned Clearwater Welding and Fabricating Ltd., which has held welding and fabricating contracts with most major companies in the region and is a major supplier of skilled tradesmen to Syncrude. Syncrude also provides employment and training, encourages natives to continue their education, and promotes local community development. 4 figs

  18. The theoretical foundations for size spectrum models of fish communities

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Jacobsen, Nis Sand; Farnsworth, K.D.

    2016-01-01

    Size spectrum models have emerged from 40 years of basic research on how body size determines individual physiology and structures marine communities. They are based on commonly accepted assumptions and have a low parameter set, which make them easy to deploy for strategic ecosystem oriented impact...... assessment of fisheries. We describe the fundamental concepts in size-based models about food encounter and the bioenergetics budget of individuals. Within the general framework three model types have emerged that differs in their degree of complexity: the food-web, the trait-based and the community model...

  19. Confocal microscopy as a useful approach to describe gill rakers of Asian species of carp and native filter-feeding fishes of the upper Mississippi River system

    Science.gov (United States)

    Liza R. Walleser,; D.R. Howard,; Sandheinrich, Mark B.; Gaikowski, Mark P.; Amberg, Jon J.

    2014-01-01

    To better understand potential diet overlap among exotic Asian species of carp and native species of filter-feeding fishes of the upper Mississippi River system, microscopy was used to document morphological differences in the gill rakers. Analysing samples first with light microscopy and subsequently with confocal microscopy, the three-dimensional structure of gill rakers in Hypophthalmichthys molitrix,Hypophthalmichthys nobilis and Dorosoma cepedianum was more thoroughly described and illustrated than previous work with traditional microscopy techniques. The three-dimensional structure of gill rakers in Ictiobus cyprinellus was described and illustrated for the first time.

  20. Density-dependent effects of non-native brown trout Salmo trutta on the species-area relationship in stream fish assemblages.

    Science.gov (United States)

    Hasegawa, K; Mori, T; Yamazaki, C

    2017-01-01

    The spatial scale and density-dependent effects of non-native brown trout Salmo trutta on species richness of fish assemblages were examined at 48 study sites in Mamachi Stream, a tributary of Chitose River, Hokkaido, Japan. The density of age ≥1 year S. trutta was high in the upstream side of the main stem of Mamachi Stream. Fish species richness increased with increasing area of study sites (habitat size), but the increasing magnitude of the species richness with area decreased with increasing age of ≥1 year S. trutta density. The relationships between age ≥1 year S. trutta, however, and presence-absence of each species seemed to be different among species. Species richness was also determined by location and physical environmental variables, i.e. it was high on the downstream side and in structurally complex environments. © 2016 The Fisheries Society of the British Isles.

  1. Fish community response to increased river flow in the Kariega ...

    African Journals Online (AJOL)

    In the absence of freshwater inflow, the ichthyofaunal community in the littoral zone was numerically dominated by estuarine resident species, whilst after the freshwater pulse an increased contribution of marine migrant species was observed. Within the demersal zone, marine straggler species dominated during the dry ...

  2. Promoting Communities of Practice among Non-Native Speakers of English in Online Discussions

    Science.gov (United States)

    Kim, Hoe Kyeung

    2011-01-01

    An online discussion involving text-based computer-mediated communication has great potential for promoting equal participation among non-native speakers of English. Several studies claimed that online discussions could enhance the academic participation of non-native speakers of English. However, there is little research around participation…

  3. Status and use of important native grasses adapted to sagebrush communities

    Science.gov (United States)

    Thomas A. Jones; Steven R. Larson

    2005-01-01

    Due to the emphasis on restoration, native cool-season grass species are increasing in importance in the commercial seed trade in the Western U.S. Cultivated seed production of these native grasses has often been hampered by seed dormancy, seed shattering, and pernicious awns that are advantageous outside of cultivation. Relatively low seed yields and poor seedling...

  4. Soil nematode community under the non-native trees in the Botanic Garden of Petrozavodsk State University

    Directory of Open Access Journals (Sweden)

    Sushchuk Anna

    2016-12-01

    Full Text Available The particularities of soil nematode communities of the rhizosphere of non-native trees were studied in the Botanic Garden of Petrozavodsk State University (Republic of Karelia. Taxonomic diversity, abundance, community structure and ecological indices derived from nematode fauna analysis were used as the evaluation parameters. Nematode fauna included 51 genera, 6 of them were plant parasitic. The dominant eco-trophic group in the nematode community structure of coniferous trees was bacterial feeders; fungal feeders in most cases were observed in the second numbers. The contribution of bacterial feeders was decreased and plant parasites were increased in eco-trophic structure of nematode communities of deciduous trees in compared with coniferous trees. Analysis of ecological indices showed that the state of soil nematode communities reflects complex, structured (stable soil food web in the biocenoses with deciduous trees, and degraded (basal food web – under coniferous trees.

  5. Effectiveness of FISK, an invasiveness screening tool for non-native freshwater fishes, to perform risk identification assessments in the Iberian Peninsula.

    Science.gov (United States)

    Almeida, David; Ribeiro, Filipe; Leunda, Pedro M; Vilizzi, Lorenzo; Copp, Gordon H

    2013-08-01

    Risk assessments are crucial for identifying and mitigating impacts from biological invasions. The Fish Invasiveness Scoring Kit (FISK) is a risk identification (screening) tool for freshwater fishes consisting of two subject areas: biogeography/history and biology/ecology. According to the outcomes, species can be classified under particular risk categories. The aim of this study was to apply FISK to the Iberian Peninsula, a Mediterranean climate region highly important for freshwater fish conservation due to a high level of endemism. In total, 89 fish species were assessed by three independent assessors. Results from receiver operating characteristic analysis showed that FISK can discriminate reliably between noninvasive and invasive fishes for Iberia, with a threshold of 20.25, similar to those obtained in several regions around the world. Based on mean scores, no species was categorized as "low risk," 50 species as "medium risk," 17 as "moderately high risk," 11 as "high risk," and 11 as "very high risk." The highest scoring species was goldfish Carassius auratus. Mean certainty in response was above the category "mostly certain," ranging from tinfoil barb Barbonymus schwanenfeldii with the lowest certainty to eastern mosquitofish Gambusia holbrooki with the highest level. Pair-wise comparison showed significant differences between one assessor and the other two on mean certainty, with these two assessors showing a high coincidence rate for the species categorization. Overall, the results suggest that FISK is a useful and viable tool for assessing risks posed by non-native fish in the Iberian Peninsula and contributes to a "watch list" in this region. © 2013 Crown copyright This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  6. [Malocclusions in children and adolescents from villages and native communities in the Ucayali Amazon region in Peru].

    Science.gov (United States)

    Aliaga-Del Castillo, Arón; Mattos-Vela, Manuel Antonio; Aliaga-Del Castillo, Rosalinda; Del Castillo-Mendoza, Claudia

    2011-03-01

    We conducted a cross-sectional descriptive study to assess the prevalence of malocclusions in children and adolescents aged 2 to 18 years of villages and native communities of the Ucayali jungle of Peru. We assessed the presence of malocclusions using Angle's classification and orthodontic changes. We evaluated 201 individuals, 106 (52.7%) were women, most of them (54.7%) had between 6 and 12 years. The prevalence of malocclusions was 85.6%, the most prevalent according to Angle's classification was class I (59.6%). Orthodontic alterations were present in 67.2% of cases. The most frequent were dental crowding (28.4%), anterior crossbite (17.4%), exaggerated overjet (8.5%), excessive overbite (5.0%) and anterior open bite (5.0%). We found a high prevalence of malocclusion and orthodontic changes in the evaluated native communities, highlighting the need to implement preventive programs to improve the oral health of these neglected populations.

  7. Diet compositions and trophic guild structure of the eastern Chukchi Sea demersal fish community

    Science.gov (United States)

    Whitehouse, George A.; Buckley, Troy W.; Danielson, Seth L.

    2017-01-01

    Fishes are an important link in Arctic marine food webs, connecting production of lower trophic levels to apex predators. We analyzed 1773 stomach samples from 39 fish species collected during a bottom trawl survey of the eastern Chukchi Sea in the summer of 2012. We used hierarchical cluster analysis of diet dissimilarities on 21 of the most well sampled species to identify four distinct trophic guilds: gammarid amphipod consumers, benthic invertebrate generalists, fish and shrimp consumers, and zooplankton consumers. The trophic guilds reflect dominant prey types in predator diets. We used constrained analysis of principal coordinates (CAP) to determine if variation within the composite guild diets could be explained by a suite of non-diet variables. All CAP models explained a significant proportion of the variance in the diet matrices, ranging from 7% to 25% of the total variation. Explanatory variables tested included latitude, longitude, predator length, depth, and water mass. These results indicate a trophic guild structure is present amongst the demersal fish community during summer in the eastern Chukchi Sea. Regular monitoring of the food habits of the demersal fish community will be required to improve our understanding of the spatial, temporal, and interannual variation in diet composition, and to improve our ability to identify and predict the impacts of climate change and commercial development on the structure and functioning of the Chukchi Sea ecosystem.

  8. Methylmercury exposure in a subsistence fishing community in Lake Chapala, Mexico: an ecological approach

    Directory of Open Access Journals (Sweden)

    Abercrombie Mary I

    2010-01-01

    Full Text Available Abstract Background Elevated concentrations of mercury have been documented in fish in Lake Chapala in central Mexico, an area that is home to a large subsistence fishing community. However, neither the extent of human mercury exposure nor its sources and routes have been elucidated. Methods Total mercury concentrations were measured in samples of fish from Lake Chapala; in sections of sediment cores from the delta of Rio Lerma, the major tributary to the lake; and in a series of suspended-particle samples collected at sites from the mouth of the Lerma to mid-Lake. A cross-sectional survey of 92 women ranging in age from 18-45 years was conducted in three communities along the Lake to investigate the relationship between fish consumption and hair mercury concentrations among women of child-bearing age. Results Highest concentrations of mercury in fish samples were found in carp (mean 0.87 ppm. Sediment data suggest a pattern of moderate ongoing contamination. Analyses of particles filtered from the water column showed highest concentrations of mercury near the mouth of the Lerma. In the human study, 27.2% of women had >1 ppm hair mercury. On multivariable analysis, carp consumption and consumption of fish purchased or captured from Lake Chapala were both associated with significantly higher mean hair mercury concentrations. Conclusions Our preliminary data indicate that, despite a moderate level of contamination in recent sediments and suspended particulate matter, carp in Lake Chapala contain mercury concentrations of concern for local fish consumers. Consumption of carp appears to contribute significantly to body burden in this population. Further studies of the consequences of prenatal exposure for child neurodevelopment are being initiated.

  9. Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

    Directory of Open Access Journals (Sweden)

    Ana Paula Vidotto-Magnoni

    Full Text Available We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples and Bonito (two samples between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI. The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%, followed by crustaceans (AI = 7.1%. Four trophic guilds were identified according a cluster analysis (Pearson distance: insectivorous (10 species, omnivorous (4 species, detritivorous (3 species and piscivorous/carcinophagous (3 species. Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb. The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

  10. Reef fish community in presence of the lionfish (Pterois volitans in Santa Marta, Colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Rocío García-Urueña

    2015-11-01

    Full Text Available Objective. Fish species community structure and benthic organisms coverage were studied in five localities in Santa Marta where the lionfish is present. Materials and methods. Abundance of fish species, including lion fish, was established using 30 m random visual censuses and video transects; trophic guilds were established according to available references. On the other hand benthic coverage was evaluated using the software Coral Point Count (CPCe 4.0. Results. Families with higher species numbers were Serranidae, Labridae, and Pomacentridae. Lionfish abundances were low (2.6±2.1 ind/120 m2, but in any case Pterois volitans was observed as the eleventh more abundant species, surpassing species of commercial value such as Cephalopholis cruentata. Species that were found in larger numbers (>100, Thalassoma bifasciatum, Haemulon aurolineatum, Canthigaster rostrata, Abudefduf saxatilis, Chromis cyanea, and Stegastes partitus were mainly invertebrate eaters, planctivores, and territorial herbivores. Coral coverage showed higher coral percentages in Chengue (69.9% and Cinto (27.4%, larger sponge percentages in Morro (32.7%; Isla Aguja and Remanso showed the larger figures for abiotic substrate (41.6 and 37%, respectively; corals, sponges, and gorgonians were the components best explaining fish community, but not for the lion fish, which inhabit all studied reef formations. Conclusions. Lion fish is ranked between the 20 more abundant species, with none commercially important species larger, hence no species may qualify as a natural control. Lion fish has as well become a relatively abundant species in Santa Marta reefs, independent of benthic coverage.

  11. Patterns and drivers of fish community assembly in a large marine ecosystem

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Törnroos, Anna; Lindegren, Martin

    2016-01-01

    . To determine assembly rules, ecological similarities of co-occurring species are often investigated. This can be evaluated using trait-based indices summarizing the species’ niches in a given community. In order to investigate the underlying processes shaping community assembly in marine ecosystems, we...... investigated the patterns and drivers of fish community composition in the Baltic Sea, a semi-enclosed sea characterized by a pronounced environmental gradient. Our results showed a marked decline in species- and functional richness, largely explained by decreasing salinities. In addition, habitat complexity...

  12. Exploring the Potential for Technology-Based Nutrition Education Among WIC Recipients in Remote Alaska Native Communities.

    Science.gov (United States)

    Power, Julianne M; Braun, Kathryn L; Bersamin, Andrea

    Estimate media technology use in Alaska Native communities to inform the feasibility of technology-based nutrition education. A self-administered questionnaire was mailed to a random selection of about 50% of Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) authorized representatives in remote Alaska Native communities (n = 975). Media technology use, interest in media technology-based nutrition education, and potential barriers were assessed. Chi-square tests were used to investigate associations among technology use, age, and education. Technology use was common among respondents (n = 368); use was significantly more common among younger age groups and participants with a higher level of education. Smartphone (78.8%) and Facebook (95.8%) use was comparable to national averages, but having a computer at home (38.4%) was much less likely. Less than 50% of participants have Internet access at home. Findings shed light on new opportunities for WIC and other programs to deliver nutrition education to Alaska Native people in remote communities. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  13. Environmental factors predicting fish community structure in two neotropical rivers in Brazil

    Directory of Open Access Journals (Sweden)

    Yzel Rondon Súarez

    Full Text Available In order to assess the organization patterns of the fish communities in the Jogui and Iguatemi rivers, we collected fish with gill nets tri-monthly from November 1999 to August 2000. Hypostomus ancistroides and Parauchenipterus galeatus were the most abundant species in the Jogui and Iguatemi rivers, respectively. Longitudinal variation was more important than seasonal in determining the species composition in both rivers, and the difference between seasons was not statistically significant. Altitude was the most important factor determining species distribution.

  14. Low Functional β-Diversity Despite High Taxonomic β-Diversity among Tropical Estuarine Fish Communities

    Science.gov (United States)

    Villéger, Sébastien; Miranda, Julia Ramos; Hernandez, Domingo Flores; Mouillot, David

    2012-01-01

    The concept of β-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic β-diversity, due to marked environmental gradients, the level of functional β-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional β-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional β-diversity values among fish communities (diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional β-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules. PMID:22792395

  15. Characterization of water quality and biological communities, Fish Creek, Teton County, Wyoming, 2007-2011

    Science.gov (United States)

    Eddy-Miller, Cheryl A.; Peterson, David A.; Wheeler, Jerrod D.; Edmiston, C. Scott; Taylor, Michelle L.; Leemon, Daniel J.

    2013-01-01

    Fish Creek, an approximately 25-kilometer-long tributary to Snake River, is located in Teton County in western Wyoming near the town of Wilson. Fish Creek is an important water body because it is used for irrigation, fishing, and recreation and adds scenic value to the Jackson Hole properties it runs through. Public concern about nuisance growths of aquatic plants in Fish Creek has been increasing since the early 2000s. To address these concerns, the U.S. Geological Survey conducted a study in cooperation with the Teton Conservation District to characterize the hydrology, water quality, and biologic communities of Fish Creek during 2007–11. The hydrology of Fish Creek is strongly affected by groundwater contributions from the area known as the Snake River west bank, which lies east of Fish Creek and west of Snake River. Because of this continuous groundwater discharge to the creek, land-use activities in the west bank area can affect the groundwater quality. Evaluation of nitrate isotopes and dissolved-nitrate concentrations in groundwater during the study indicated that nitrate was entering Fish Creek from groundwater, and that the source of nitrate was commonly a septic/sewage effluent or manure source, or multiple sources, potentially including artificial nitrogen fertilizers, natural soil organic matter, and mixtures of sources. Concentrations of dissolved nitrate and orthophosphate, which are key nutrients for growth of aquatic plants, generally were low in Fish Creek and occasionally were less than reporting levels (not detected). One potential reason for the low nutrient concentrations is that nutrients were being consumed by aquatic plant life that increases during the summer growing season, as a result of the seasonal increase in temperature and larger number of daylight hours. Several aspects of Fish Creek’s hydrology contribute to higher productivity and biovolume of aquatic plants in Fish Creek than typically observed in streams of its size in

  16. Spatio-temporal segregation and size distribution of fish assemblages as related to non-native species occurrence in the middle rio Doce Valley, MG, Brazil

    Directory of Open Access Journals (Sweden)

    Henrique Corrêa Giacomini

    2011-03-01

    Full Text Available The lakes in the middle rio Doce Valley (MG are suffering impacts due to the introduction of invasive fish species, mainly piscivorous species like red piranha Pygocentrus nattereri and peacock bass Cichla kelberi. Fishes were collected in bimonthly samples conducted at ten lakes along a year. The present study showed that the composition of native fish assemblages is significantly related to the presence and type of non-native species. Fish species distribution among lakes can be explained by differences in species body size: smaller native species are less concentrated in lakes with invasive piscivores, which is in accordance with the hypothesis that they have greater susceptibility to predation by invaders. Another probable cause for this correlation is the proximity of lakes to the drainage system, which could explain both the non-native incidence and the turnover of native species composition. Furthermore, temporal variability in species composition was significantly higher in invaded lakes. This last factor may be linked to seasonal flood pulses, which carry immigrant fishes from streams in the vicinity. The metacommunity framework can bring insights for future studies in such spatially structured systems, and the approach should improve our understanding of processes underlying species composition as well as help direct conservation-focused management plans.Os lagos do Vale do médio rio Doce (MG têm sofrido impactos devido à introdução de espécies invasoras de peixes, principalmente de espécies piscívoras como a piranha Pygocentrus nattereri e o tucunaré Cichla kelberi. Peixes foram coletados em seis amostragens bimestrais durante um ano. O presente trabalho demonstrou que a composição das assembleias de peixes nativos está significativamente relacionada à presença e ao tipo de espécies não nativas. A distribuição de espécies entre os lagos pode ser explicada por diferenças no tamanho corporal: espécies nativas de

  17. Assessing the Impact of Spectral Resolution on Classification of Lowland Native Grassland Communities Based on Field Spectroscopy in Tasmania, Australia

    Directory of Open Access Journals (Sweden)

    Bethany Melville

    2018-02-01

    Full Text Available This paper presents a case study for the analysis of endangered lowland native grassland communities in the Tasmanian Midlands region using field spectroscopy and spectral convolution techniques. The aim of the study was to determine whether there was significant improvement in classification accuracy for lowland native grasslands and other vegetation communities based on hyperspectral resolution datasets over multispectral equivalents. A spectral dataset was collected using an ASD Handheld-2 spectroradiometer at Tunbridge Township Lagoon. The study then employed a k-fold cross-validation approach for repeated classification of a full hyperspectral dataset, a reduced hyperspectral dataset, and two convoluted multispectral datasets. Classification was performed on each of the four datasets a total of 30 times, based on two different class configurations. The classes analysed were Themeda triandra grassland, Danthonia/Poa grassland, Wilsonia rotundifolia/Selliera radicans, saltpan, and a simplified C3 vegetation class. The results of the classifications were then tested for statistically significant differences using ANOVA and Tukey’s post-hoc comparisons. The results of the study indicated that hyperspectral resolution provides small but statistically significant increases in classification accuracy for Themeda and Danthonia grasslands. For other classes, differences in classification accuracy for all datasets were not statistically significant. The results obtained here indicate that there is some potential for enhanced detection of major lowland native grassland community types using hyperspectral resolution datasets, and that future analysis should prioritise good performance in these classes over others. This study presents a method for identification of optimal spectral resolution across multiple datasets, and constitutes an important case study for lowland native grassland mapping in Tasmania.

  18. Fluctuating interaction network and time-varying stability of a natural fish community

    Science.gov (United States)

    Ushio, Masayuki; Hsieh, Chih-Hao; Masuda, Reiji; Deyle, Ethan R.; Ye, Hao; Chang, Chun-Wei; Sugihara, George; Kondoh, Michio

    2018-02-01

    Ecological theory suggests that large-scale patterns such as community stability can be influenced by changes in interspecific interactions that arise from the behavioural and/or physiological responses of individual species varying over time. Although this theory has experimental support, evidence from natural ecosystems is lacking owing to the challenges of tracking rapid changes in interspecific interactions (known to occur on timescales much shorter than a generation time) and then identifying the effect of such changes on large-scale community dynamics. Here, using tools for analysing nonlinear time series and a 12-year-long dataset of fortnightly collected observations on a natural marine fish community in Maizuru Bay, Japan, we show that short-term changes in interaction networks influence overall community dynamics. Among the 15 dominant species, we identify 14 interspecific interactions to construct a dynamic interaction network. We show that the strengths, and even types, of interactions change with time; we also develop a time-varying stability measure based on local Lyapunov stability for attractor dynamics in non-equilibrium nonlinear systems. We use this dynamic stability measure to examine the link between the time-varying interaction network and community stability. We find seasonal patterns in dynamic stability for this fish community that broadly support expectations of current ecological theory. Specifically, the dominance of weak interactions and higher species diversity during summer months are associated with higher dynamic stability and smaller population fluctuations. We suggest that interspecific interactions, community network structure and community stability are dynamic properties, and that linking fluctuating interaction networks to community-level dynamic properties is key to understanding the maintenance of ecological communities in nature.

  19. Fish community responses to submerged aquatic vegetation in Maumee Bay, Western Lake Erie

    Science.gov (United States)

    Miller, Jacob; Kocovsky, Patrick; Wiegmann, Daniel; Miner, Jeffery G.

    2018-01-01

    Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have experienced a decline of SAV and an increase in suspended solids (turbidity) over the last century due to numerous causes. To compare fish communities in open‐water (turbid) and in SAV (clearer water) habitats in this region, which is designated by the U.S. Environmental Protection Agency as an Area of Concern, and to indicate community changes that could occur with expansion of SAV habitat, we sampled a 300‐ha sector of northern Maumee Bay that contained both habitats. Using towed neuston nets through patches of each habitat, we determined that areas of SAV contained more species and a different species complex (based on the Jaccard index and the wetland fish index), than did the open‐water habitat (averaging 8.6 versus 5 species per net trawl). The SAV habitat was dominated by centrarchids, namely Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, and Black Crappie Pomoxis nigromaculatus. Open‐water habitat was dominated by Spottail Shiner Notropis hudsonius, Gizzard Shad Dorosoma cepedianum, and White Perch Morone americana, an invasive species. These results indicate that restoration efforts aimed at decreasing turbidity and increasing the distribution of SAV could cause substantive shifts in the fish community and address important metrics for assessing the beneficial use impairments in this Area of Concern.

  20. Patchiness in a large floodplain river: Associations among hydrology, nutrients, and fish communities

    Science.gov (United States)

    DeJager, Nathan R.; Houser, Jeff N.

    2016-01-01

    Large floodplain rivers have internal structures shaped by directions and rates of water movement. In a previous study, we showed that spatial variation in local current velocities and degrees of hydrological exchange creates a patch-work mosaic of nitrogen and phosphorus concentrations and ratios in the Upper Mississippi River. Here, we used long-term fish and limnological data sets to test the hypothesis that fish communities differ between the previously identified patches defined by high or low nitrogen to phosphorus ratios (TN:TP) and to determine the extent to which select limnological covariates might explain those differences. Species considered as habitat generalists were common in both patch types but were at least 2 times as abundant in low TN:TP patches. Dominance by these species resulted in lower diversity in low TN:TP patches, whereas an increased relative abundance of a number of rheophilic (flow-dependent) species resulted in higher diversity and a more even species distribution in high TN:TP patches. Of the limnological variables considered, the strongest predictor of fish species assemblage and diversity was water flow velocity, indicating that spatial patterns in water-mediated connectivity may act as the main driver of both local nutrient concentrations and fish community composition in these reaches. The coupling among hydrology, biogeochemistry, and biodiversity in these river reaches suggests that landscape-scale restoration projects that manipulate hydrogeomorphic patterns may also modify the spatial mosaic of nutrients and fish communities. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  1. Adirondack lakes survey: An interpretive analysis of fish communities and water chemistry, 1984--1987

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.P. (Baker (Joan P.), Raleigh, NC (USA)); Gherini, S.A.; Munson, R.K. (Tetra Tech, Inc., Pasadena, CA (USA)); Christensen, S.W. (Oak Ridge National Lab., TN (USA)); Driscoll, C.T. (Syracuse Univ., NY (USA)); Gallagher, J. (Adirondack Lakes Survey Corp., Ray Brook, NY (USA)); Newton, R.M. (Smith Coll., Northampton, MA (USA)); Reckhow, K.H. (Duke Univ., Durham, NC (USA)); Schofield, C.L. (Co

    1990-01-01

    The Adirondack Lakes Survey Corporation (ALSC) was formed as a cooperative effort of the New York State Department of Environmental Conservation and the Empire State Electric Energy Research Corporation to better characterize the chemical and biological status of Adirondack lakes. Between 1984 and 1987, the ALSC surveyed 1469 lakes within the Adirondack ecological zone. As a follow-up to the survey, the ALSC sponsored a series of interpretive analyses of the ALSC data base. The primary objectives of these analyses were as follows: Evaluate the influence of mineral acids (from acidic deposition) and nonmineral acids (natural organic acids) on lake pH levels; classify Adirondack lakes according to lake and watershed features expected to influence their responsiveness to changes in acidic deposition; evaluate the sensitivity of Adirondack lakes to changes in environmental conditions, such as changes in mineral acids or dissolved organic carbon concentrations; identify lake characteristics important in explaining the observed present-day status of fish communities in Adirondack lakes, in particular the relative importance of lake acidity; evaluate changes that have occurred over time in Adirondack fish communities and probable causes for these trends by using the available historical data on fish communities in the Adirondacks and the ALSC data base; and determine the degree to which the existing fish resource might be at risk from continued acidic deposition, or might recover if acidity levels were reduced. The basic approach examined relationships observed in the ALSC data base among watershed characteristics, lake chemistry, and fish status. Individual reports are processed separately for the data bases.

  2. Composition and temporal patterns of larval fish communities in Chesapeake and Delaware Bays

    Directory of Open Access Journals (Sweden)

    Filipe Ribeiro

    2015-11-01

    Full Text Available Comparing larval fish assemblages in different estuaries provides insights about the coastal distribution of larval populations, larval transport, and adult spawning locations (Ribeiro et al. 2015. We simultaneously compared the larval fish assemblages entering two Middle Atlantic Bight (MAB estuaries (Delaware Bay and Chesapeake Bay, USA through weekly sampling from 2007 to 2009. In total, 43 taxa (32 families and 36 taxa (24 families were collected in Delaware and Chesapeake Bays, respectively. Mean taxonomic diversity, mean richness, and evenness were generally lower in Delaware Bay. Communities of both bays were dominated by Anchoa spp., Gobiosoma spp., Micropogonias undulatus, and Brevoortia tyrannus; Paralichthys spp. was more abundant in Delaware Bay and Microgobius thalassinus was more abundant in Chesapeake Bay. Inter-annual variation in the larval fish communities was low at both sites, with a relatively consistent composition across years, but strong seasonal (intra-annual variation in species composition occurred in both bays. Two groups were identified in Chesapeake Bay: a ‘winter’ group dominated by shelf-spawned species (e.g. M. undulatus and a ‘summer’ group comprising obligate estuarine species and coastal species (e.g. Gobiosoma spp. and Cynoscion regalis, respectively. In Delaware Bay, 4 groups were identified: a ‘summer’ group of mainly obligate estuarine fishes (e.g. Menidia sp. being replaced by a ‘fall’ group (e.g. Ctenogobius boleosoma and Gobionellus oceanicus; ‘winter’ and ‘spring’ groups were dominated by shelf-spawned (e.g. M. undulatus and Paralichthys spp. and obligate estuarine species (e.g. Leiostomus xanthurus and Pseudopleuronectes americanus, respectively. This study demonstrates that inexpensive and simultaneous sampling in different estuaries provides important insights into the variability in community structure of fish assemblages at large spatial scales.

  3. Evidence for serial discontinuity in the fish community of a heavily impounded river

    Science.gov (United States)

    Miranda, Leandro E.; Dembkowski, D.J.

    2016-01-01

    In the Tennessee River, USA, we examined lengthwise patterns in fish community structure and species richness within and among nine reservoirs organized in sequence and connected through navigational locks. Within reservoirs, the riverine, transition and lacustrine zones supported distinct, although overlapping, nearshore fish assemblages; differences were also reflected in measures of species richness. Spatial patterns were most apparent for rheophilic species, which increased in species richness and representation upstream within each reservoir and downstream across the chain of reservoirs. This pattern resembled a sawtooth wave, with the amplitude of the wave peaking in the riverine zone below each dam, and progressively higher wave amplitude developing downstream in the reservoir chain. The observed sawtooth pattern supports the serial discontinuity concept in that the continuity of the riverine fish community is interrupted by the lacustrine conditions created behind each dam. Upstream within each reservoir, and downstream in the chain of reservoirs, habitat characteristics become more riverine. To promote sustainability of rheophilic fishes and maintain biodiversity in impounded rivers, conservation plans could emphasize maintenance and preservation of riverine environments of the reservoir's upper reaches, while remaining cognizant of the broader basin trends that provide opportunities for a lengthwise array of conservation and management policy. 

  4. Ecological risk assessment in a large river-reservoir. 2: Fish community

    International Nuclear Information System (INIS)

    Suter, G.W. II; Barnthouse, L.W.; Efroymson, R.A.; Jager, H.

    1999-01-01

    This paper summarizes the assessment of risks to fishes in the Clinch River Operable Unit due to contaminants released by the US Department of Energy's activities on its Oak Ridge Reservation in Tennessee. This paper focuses on the most contaminated area, the Poplar Creek (PC) embayment. The assessment is of interest because of its use of five distinct lines of evidence: fish community surveys, fish body burdens, toxicity tests of ambient waters, suborganismal bioindicators, and single chemical toxicity tests. None of these lines of evidence provided unambiguous evidence of a significant risk, but the surveys indicated that the fish community in PC was depauperate, polychlorinated biphenyl body burdens may have been at toxic levels in catfish, one of the three tests of ambient water showed clear toxicity, some of the indicators were indicative of toxic effects, and concentrations that have been toxic in the laboratory were detected periodically. Interpretation was further complicated by upstream contamination of both the Clinch River and PC. The risk characterization was performed by evaluating each line of evidence separately and then weighing the evidence using an ecoepidemiological approach

  5. Warming shelf seas drive the subtropicalization of European pelagic fish communities.

    Science.gov (United States)

    Montero-Serra, Ignasi; Edwards, Martin; Genner, Martin J

    2015-01-01

    Pelagic fishes are among the most ecologically and economically important fish species in European seas. In principle, these pelagic fishes have potential to demonstrate rapid abundance and distribution shifts in response to climatic variability due to their high adult motility, planktonic larval stages, and low dependence on benthic habitat for food or shelter during their life histories. Here, we provide evidence of substantial climate-driven changes to the structure of pelagic fish communities in European shelf seas. We investigated the patterns of species-level change using catch records from 57,870 fisheries-independent survey trawls from across European continental shelf region between 1965 and 2012. We analysed changes in the distribution and rate of occurrence of the six most common species, and observed a strong subtropicalization of the North Sea and Baltic Sea assemblages. These areas have shifted away from cold-water assemblages typically characterized by Atlantic herring and European sprat from the 1960s to 1980s, to warmer-water assemblages including Atlantic mackerel, Atlantic horse mackerel, European pilchard and European anchovy from the 1990s onwards. We next investigated if warming sea temperatures have forced these changes using temporally comprehensive data from the North Sea region. Our models indicated the primary driver of change in these species has been sea surface temperatures in all cases. Together, these analyses highlight how individual species responses have combined to result in a dramatic subtropicalization of the pelagic fish assemblage of the European continental shelf. © 2014 John Wiley & Sons Ltd.

  6. Perceptions of Obvious and Disruptive Climate Change: Community-Based Risk Assessment for Two Native Villages in Alaska

    Directory of Open Access Journals (Sweden)

    Jon Rosales

    2015-10-01

    Full Text Available This work operationalizes the determinants of climate change risk, exposure and vulnerability, through the perceptions held by Native hunters, fishers, and gatherers in Savoonga and Shaktoolik, Alaska. Informed by their skill, experience, and the traditional knowledge of their elders, hunters, fishers, and gatherers in these communities are astute observers of their environment and environmental change. A questionnaire is used to sort and rank their perceptions of the most obvious and disruptive elements of climate change as representations of exposure and vulnerability, respectively. Results represent the relative strength and significance of those perceptions of environmental change. In addition to other changes, storms are among the most obvious and disruptive impacts of climate change to respondents in both communities, while changes to sea ice tend to be more disruptive in Savoonga, a more ice-obligate culture, than Shaktoolik. Changes on the tundra are more obvious in Shaktoolik, but is the least disruptive category of change in both villages. Changes along the coast were both obvious and disruptive, albeit more so in Shaktoolik than Savoonga. The findings suggest that traditional ecological knowledge is a valuable source of information to access perceptions of risk, and develop climate risk management and adaptation plans. The questionnaire design and statistical methodology may be of interest to those working on community-based adaptation and risk assessment projects in high-risk, poor, and marginalized Native communities with small populations.

  7. Breaking the Bounds of Rationality: Values, Relationships, and Decision-making in Mexican Fishing Communities

    Directory of Open Access Journals (Sweden)

    Nicole D Peterson

    2014-01-01

    Full Text Available In fishing communities in Baja California Sur, Mexico, fisheries management is heavily influenced by models of individual economic rationality held by biologists and others involved in management, in which fishermen ′choose′ to overfish because they are motivated by selfish individual rationality. Yet there is much that is neglected by these models, including the pressures of economic markets, family and community expectations, and cultural and personal value systems. Actual decisions about fishing and resource management rarely match the expectations of classical or neoliberal economic models of individual behaviour. I argue here that rational choice theory is a historically and culturally constructed discourse that becomes a taken-for-granted lens for viewing behaviour around the world. The effects of this discourse can be seen in the policies that are derived from them, as shown through this case study.

  8. Persistence and stability of fish community structure in a southwest New York stream

    Science.gov (United States)

    Hansen, Michael J.; Ramm, Carl W.

    1994-01-01

    We used multivariate and nonparametric statistics to examine persistence and stability of fish species in the upper 43 km of French Creek, New York. Species occurred in upstream and downstream groups in 1937 that persisted in 1979. However, the downstream group expanded its range in the drainage from 1937 to 1979 at the expense of the upstream group. A dam prevented further upstream expansion of the downstream group. Ranks of species abundances were stable, as tests of group similarity were significant. The abundances and distributions of benthic species were stable across seven sampling dates in 1980 despite several floods and repeated removals by sampling that could have altered community structure. We conclude that the fish community in French Creek persisted and was stable over the 42-yr interval, 1937-1979, and that abundances of benthic species were stable in summer 1980.

  9. Fish communities in sandy pool of Magela Creek, Alligator Rivers Region

    International Nuclear Information System (INIS)

    Woodland, D.J.; Ward, P.J.

    1992-01-01

    Physico-chemical conditions, changes in fish communities and characteristics of species populations of eight permanent sandy pools along Magela Creek during the 1981 Dry season are described. Causes of mortality in each species, especially Craterocephalus marianae, were investigated. It is emphasised that in using baseline data to assess the impact of mining and animal communities, it may sometimes be difficult to differentiate natural mortality from mortality resulting from pollution. The aim of this study was to distinguish the most important environmental factors responsible for fish mortality. The study indicates that the mortality was low (<50% of the original population) in most pools. In populations that did suffer high mortality, anoxic conditions may have been an important cause. 67 refs., 36 tabs., 21 figs., ills

  10. Reconstructing riverine mesohabitat unit composition using fish community data and an autecology matrix.

    Science.gov (United States)

    Suen, J P; Su, W C

    2010-09-01

    This research proposes a simplified method for estimating the mesohabitat composition that would favour members of a given set of aquatic species. The simulated composition of four types of mesohabitat units (deep pool, shallow pool, deep riffle and shallow riffle) could guide the design of in-stream structures in creating pool-riffle systems with ecological reference. Fish community data and an autecology matrix are used to support the development of a stream mesohabitat simulation based on regression models for reaches in mid to upper-order streams. The fish community-mesohabitat model results constitute a reference condition that can be used to guide stream restoration and ecological engineering decisions aimed at maintaining the natural ecological integrity and diversity of rivers. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

  11. Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

    Directory of Open Access Journals (Sweden)

    Padanillay C. Prabu

    2008-05-01

    Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

  12. The importance of sponges and mangroves in supporting fish communities on degraded coral reefs in Caribbean Panama

    Directory of Open Access Journals (Sweden)

    Janina Seemann

    2018-03-01

    Full Text Available Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm, with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes and Gobiidae (gobies. Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfish Scarus iseri comprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.

  13. Fish communities in the Poodří Protected Landscape Area (the Odra River basin)

    Czech Academy of Sciences Publication Activity Database

    Lojkásek, B.; Lusk, Stanislav; Halačka, Karel; Lusková, Věra

    2004-01-01

    Roč. 49, č. 3 (2004), s. 121-130 ISSN 1212-1819 R&D Projects: GA AV ČR IAA6093105; GA ČR GA206/00/0824; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : fish communities * River Odra * floodplain Subject RIV: EH - Ecology, Behaviour Impact factor: 0.227, year: 2004 http://www.cazv.cz/attachments/5-Lojkásek.pdf

  14. Habitat fragmentation and extinction rates within freshwater fish communities : a faunal relaxation approach

    OpenAIRE

    Hugueny, Bernard; Movellan, A.; Belliard, J.

    2011-01-01

    Aim To estimate population extinction rates within freshwater fish communities since the fragmentation of palaeo-rivers due to sea level rise at the end of the Pleistocene; to combine this information with rates estimated by other approaches (population surveys, fossil records); and to build an empirical extinction-area relationship. Location Temperate rivers from the Northern Hemisphere, with a special focus on rivers discharging into the English Channel, in north-western France. Methods (1)...

  15. Invasion of top and intermediate consumers in a size structured fish community

    OpenAIRE

    Ask, Per

    2010-01-01

    In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was...

  16. Water quality improvements following political changes, enhanced fish communities, and fisheries in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Peňáz, Milan; Reichard, Martin; Bernardová, I.

    2008-01-01

    Roč. 49, - (2008), s. 845-850. ISBN 978-1-888569-80-3. ISSN 0892-2284. [World fisheries congress /4./. Vancouver, 02.05.2004-06.05.2004] R&D Projects: GA AV ČR(CZ) IA66902; GA AV ČR IAB6093106 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish communities * Morava River * water quality Subject RIV: EH - Ecology, Behaviour

  17. Status and trends in the fish community of Lake Superior, 2012

    Science.gov (United States)

    Gorman, Owen T.; Evrard, Lori M.; Cholwek, Gary A.; Vinson, Mark

    2012-01-01

    The Great Lakes Science Center has conducted daytime nearshore bottom trawl surveys of Lake Superior (15-80 m bathymetric depth zone) each spring since 1978 and an offshore survey (>80 m) since 2011 to provide long-term trends of relative abundance and biomass of the fish community. In 2012, 72 nearshore and 34 offshore stations were sampled with a 12-m Yankee bottom trawl.

  18. Effects of fish density and river fertilization on algal standing stocks, invertebrates communities, and fish production in an Arctic River

    Science.gov (United States)

    Deegan, Linda A.; Peterson, B.J.; Golden, H.; McIvor, C.C.; Miller, M.C.

    1997-01-01

    This study examined the relative importance of bottom-up and top-down controls of an arctic stream food web by simultaneous manipulation of the top predator and nutrient availability. We created a two-step trophic system (algae to insects) by removal of the top predator (Arctic grayling, Thymallus arcticus) in fertilized and control stream reaches. Fish abundance was also increased 10 times to examine the effect of high fish density on stream ecosystem dynamics and fish. We measured the response of epilithic algae, benthic and drifting insects, and fish to nutrient enrichment and to changes in fish density. Insect grazers had little effect on algae and fish had little effect on insects. In both the control and fertilized reaches, fish growth, energy storage, and reproductive response of females declined with increased fish density. Fish growth and energy storage were more closely correlated with per capita insect availability than with per capita algal standing stock

  19. Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea

    KAUST Repository

    Khalil, Maha T.

    2017-06-06

    Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3–24 km from shore) in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was generally low compared to reefs experiencing minimal human influence around the world. All reefs had a herbivore-dominated trophic structure and few top predators, such as sharks, jacks, or large groupers. Coral cover was considerably lower on inshore reefs, likely due to a 2010 bleaching event. Community analyses showed inshore reefs to be characterized by turf algae, slower-growing corals, lower herbivore diversity, and highly abundant turf-farming damselfishes. Offshore reefs had more planktivorous fishes, a more diverse herbivore assemblage, and faster-growing corals. All reefs appear to be impacted by overfishing, and inshore reefs seem more vulnerable to thermal bleaching. The study provides a description of the spatial variation in biomass and community structure in the central Saudi Arabian Red Sea and provides a basis for spatial prioritization and subsequent marine protected area design in Thuwal.

  20. Helminth communities of four commercially important fish species from Chetumal Bay, Mexico.

    Science.gov (United States)

    Aguirre-Macedo, M L; Vidal-Martínez, V M; González-Solís, D; Caballero, P I

    2007-03-01

    The relative importance of ecology and evolution as factors determining species richness and composition of the helminth communities of fish is a matter of current debate. Theoretical studies use host-parasite lists, but these do not include studies on a temporal or spatial scale. Local environmental conditions and host biological characteristics are shown to influence helminth species richness and composition in four fish species (Eugerres plumieri, Hexanematichthys assimilis, Oligoplites saurus, and Scomberomorus maculatus) in Chetumal Bay, Mexico. With the exception of H. assimilis, the helminth communities had not been previously studied and possible associations between environmental and host biological characteristics as factors determining helminth species richness and composition using redundancy analysis (RDA) are described. Thirty-four helminth species are identified, with the highest number of species (19 total (mean = 6.3 +/- 2.1)) and the lowest (9 (4.0 +/- 1.0)) occurring in H. assimilis and S. maculatus, respectively. The larval nematodes Contracaecum sp. and Pseudoterranova sp. were not only the helminth species shared by all four host species but also were the most prevalent and abundant. Statistical associations between helminth community parameters and local ecological variables such as host habitat use, feeding habits, mobility, and time of residence in coastal lagoons are identified. Phylogeny is important because it clearly separates all four host species by their specialist parasites, although specific habitat and feeding habits also significantly influence the differentiation between the four fish species.

  1. Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea.

    Science.gov (United States)

    Khalil, Maha T; Bouwmeester, Jessica; Berumen, Michael L

    2017-01-01

    Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3-24 km from shore) in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was generally low compared to reefs experiencing minimal human influence around the world. All reefs had a herbivore-dominated trophic structure and few top predators, such as sharks, jacks, or large groupers. Coral cover was considerably lower on inshore reefs, likely due to a 2010 bleaching event. Community analyses showed inshore reefs to be characterized by turf algae, slower-growing corals, lower herbivore diversity, and highly abundant turf-farming damselfishes. Offshore reefs had more planktivorous fishes, a more diverse herbivore assemblage, and faster-growing corals . All reefs appear to be impacted by overfishing, and inshore reefs seem more vulnerable to thermal bleaching. The study provides a description of the spatial variation in biomass and community structure in the central Saudi Arabian Red Sea and provides a basis for spatial prioritization and subsequent marine protected area design in Thuwal.

  2. Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea

    Directory of Open Access Journals (Sweden)

    Maha T. Khalil

    2017-06-01

    Full Text Available Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3–24 km from shore in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was generally low compared to reefs experiencing minimal human influence around the world. All reefs had a herbivore-dominated trophic structure and few top predators, such as sharks, jacks, or large groupers. Coral cover was considerably lower on inshore reefs, likely due to a 2010 bleaching event. Community analyses showed inshore reefs to be characterized by turf algae, slower-growing corals, lower herbivore diversity, and highly abundant turf-farming damselfishes. Offshore reefs had more planktivorous fishes, a more diverse herbivore assemblage, and faster-growing corals. All reefs appear to be impacted by overfishing, and inshore reefs seem more vulnerable to thermal bleaching. The study provides a description of the spatial variation in biomass and community structure in the central Saudi Arabian Red Sea and provides a basis for spatial prioritization and subsequent marine protected area design in Thuwal.

  3. Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea

    KAUST Repository

    Khalil, Maha T.; Bouwmeester, Jessica; Berumen, Michael L.

    2017-01-01

    Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3–24 km from shore) in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was generally low compared to reefs experiencing minimal human influence around the world. All reefs had a herbivore-dominated trophic structure and few top predators, such as sharks, jacks, or large groupers. Coral cover was considerably lower on inshore reefs, likely due to a 2010 bleaching event. Community analyses showed inshore reefs to be characterized by turf algae, slower-growing corals, lower herbivore diversity, and highly abundant turf-farming damselfishes. Offshore reefs had more planktivorous fishes, a more diverse herbivore assemblage, and faster-growing corals. All reefs appear to be impacted by overfishing, and inshore reefs seem more vulnerable to thermal bleaching. The study provides a description of the spatial variation in biomass and community structure in the central Saudi Arabian Red Sea and provides a basis for spatial prioritization and subsequent marine protected area design in Thuwal.

  4. Research Note: Yavirau: A traditional Fijian fish drive as an example of culturally embedded community development

    Directory of Open Access Journals (Sweden)

    Fink, Michael

    2012-09-01

    Full Text Available A yavirau (traditional Fijian fish drive is an ancient Fijian custom which has been adapted to today’s needs. Implemented and organised by a village community without external assistance, this highly this culturally specific custom is an example of development on a local level. According to theorists and practitioners working on development issues, such a strategy for Community Development (CD is promising because it seizes current approaches as it fosters local, decentralised, cultural specific development and aims at a high level of local participation. This research note analyses a yavirau as an example of CD, showing its advantages as well as its limitations.

  5. Assessing the state of pelagic fish communities within an ecosystem approach and the European Marine Strategy Framework Directive

    DEFF Research Database (Denmark)

    Shephard, Samuel; Rindorf, Anna; Dickey-Collas, Mark

    2014-01-01

    Pelagic fish are key elements in marine foodwebs and thus comprise an important part of overall ecosystem health. We develop a suite of ecological indicators that track pelagic fish community state and evaluate state of specific objectives against Good Environmental Status (GES) criteria. Indicator...

  6. The composition of fish communities of nine Ethiopian lakes along a north-south gradient: threats and possible solutions

    NARCIS (Netherlands)

    Vijverberg, J.; Dejen, E.; Getahun, A.; Nagelkerke, L.A.J.

    2012-01-01

    Fish populations of nine Ethiopian freshwater lakes were quantitatively sampled with a standardized protocol, using multi-mesh gill nets. In total, 27 species were identified, but only 14 species were common. Based on the common species, the fish communities showed large differences in their species

  7. Geological differentiation explains diversity and composition of fish communities in upland streams in the southern Amazon of Colombia

    NARCIS (Netherlands)

    Arbeláez, F.; Duivenvoorden, J.F.; Maldonado-Ocampo, J.A.

    2008-01-01

    Fish biomass, species richness and composition were compared between upland streams draining two contrasting geological units (Pebas and Tsa) in Colombian Amazonia. Because Pebas sediments reportedly show higher levels of base concentrations than Tsa sediments, we expected that the fish communities

  8. The gut microbial community of Midas cichlid fish in repeatedly evolved limnetic-benthic species pairs.

    Science.gov (United States)

    Franchini, Paolo; Fruciano, Carmelo; Frickey, Tancred; Jones, Julia C; Meyer, Axel

    2014-01-01

    Gut bacterial communities are now known to influence a range of fitness related aspects of organisms. But how different the microbial community is in closely related species, and if these differences can be interpreted as adaptive is still unclear. In this study we compared microbial communities in two sets of closely related sympatric crater lake cichlid fish species pairs that show similar adaptations along the limnetic-benthic axis. The gut microbial community composition differs in the species pair inhabiting the older of two crater lakes. One major difference, relative to other fish, is that in these cichlids that live in hypersaline crater lakes, the microbial community is largely made up of Oceanospirillales (52.28%) which are halotolerant or halophilic bacteria. This analysis opens up further avenues to identify candidate symbiotic or co-evolved bacteria playing a role in adaptation to similar diets and life-styles or even have a role in speciation. Future functional and phylosymbiotic analyses might help to address these issues.

  9. Baseline assessment of fish communities of the Flower Garden Banks (2010 - 2013) using technical diving operations: 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The proposed work develop baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys will employ...

  10. Red Lionfish (Pterois volitans Invade San Salvador, Bahamas: No Early Effects on Coral and Fish Communities

    Directory of Open Access Journals (Sweden)

    Alexander, Amanda K.

    2011-10-01

    Full Text Available Biological invaders are a leading contributor to global losses of biodiversity. A recent invader to the waters surrounding San Salvador, Bahamas, the red lionfish, Pterois volitans, was first reported in 2006; by 2009 they were common in waters 2-40 m deep around the island. Our study collected data on coral communities and fish assemblages at three patch reef complexes (Rice Bay, Rocky Point, Lindsay Reef in 2007, during the initial phase of the invasion, and compared the results to a nearly identical study done in 2001 before P. volitans colonized San Salvador. Prey selection and quantity of consumption by P. volitans were also examined. Coral and fish species richness, diversity, percent cover (corals and abundance (fish were similar in 2001 and 2007. Of the 5,078 fish recorded during our study on shallow patch reefs, only two were P. volitans, but they were more prevalent in deeper water along San Salvador’s “wall.” Captured P. volitans ranged in size from 19-32 cm, all longer than maturity length. Pallid goby (Coryphopterus eidolon, black cap basslet (Gramma melacara and red night shrimp (Rynchocienetes rigens were the most commonly identified stomach contents. The effects of the successful invasion and increasing population of P. volitans on San Salvador’s reef ecosystem are uncertain at this time; future monitoring of potential changes in coral and fish communities on the patch reefs of San Salvador is recommended to determine if population control measures need to be considered. Initial post-invasion data (2007, along with pre-invasion data (2001, are valuable benchmarks for future studies.

  11. Sub-indicator: Prey fish

    Science.gov (United States)

    Weidel, Brian C.; Dunlop, Erin

    2017-01-01

    Prey fish communities across the Great Lakes continue to change, although the direction and magnitude of those changes are not consistent across the lakes. The metrics used to categorize prey fish status in this and previous periods are based on elements that are common among each of the lake’s Fish Community Objectives and include diversity and the relative role of native species in the prey fish communities. The diversity index categorized three of lakes as ‘fair’, while Superior and Erie were ‘good’ (Table 1). The short term trend, from the previous period (2008-2010) to the current period (2011-2014) found diversity in Erie and Superior to be unchanging, but the other three lakes to be ‘deteriorating’, resulting in an overall trend categorization of ‘undetermined’ (Table 1). The long term diversity trend suggested Lakes Superior and Erie have the most diverse prey communities although the index for those prey fish have been quite variable over time (Figure 1). In Lake Huron, where non-native alewife have substantially declined, the diversity index has also declined. The continued dominance of alewife in Lake Ontario (96% of the prey fish biomass) resulted in the lowest diversity index value (Figure 1). The proportion of native species within the community was judged as ‘good’ in Lakes Superior and Huron, ‘fair’ in Michigan and Erie and ‘poor’ in Ontario (Table 2). The short term trend was improving in in all lakes except Michigan (‘deteriorating’) and Ontario (‘unchanging’), resulting in an overall short term trend of ‘undetermined’ (Table 2). Over the current period, Lake Superior consistently had the highest proportion native prey fish (87%) while Lake Ontario had the lowest (1%) (Figure 2). Lake Michigan’s percent native has declined as round goby increase and comprises a greater proportion of the community. Native prey fish make up 51% of Lake Erie, although basin-specific values differed (Figure 2). Most notably

  12. Stress tolerance of soil fungal communities from native Atlantic forests, reforestations, and a sand mining degraded area.

    Science.gov (United States)

    Ferreira, Paulo C; Pupin, Breno; Rangel, Drauzio E N

    2018-06-01

    Microorganisms are essential to the functionality of the soil, particularly in organic matter decomposition and nutrient cycling, which regulate plant productivity and shape the soil structure. However, biotic and abiotic stresses greatly disrupt soil fungal communities and, thereby, disturb the ecosystem. This study quantified seasonal tolerances to UV-B radiation and heat of fungal communities, which could be cultured, found in soil from two native Atlantic forest fragments called F1 and F2, five reforested areas (RA) planted in 1994, 1997, 2004, 2007, and 2009 with native species of the Atlantic forest, and one sand mining degraded soil (SMDS). The cold activity of the soil fungal communities (FC) from the eight different areas was also studied. Higher tolerance to UV-B radiation and heat was found in the FC from the SMDS and the 2009RA, where the incidence of heat and UV radiation from sun was more intense, which caused selection for fungal taxa that were more UV-B and heat tolerant in those areas. Conversely, the FC from the native forests and older reforested sites were very susceptible to heat and UV-B radiation. The cold activity of the soil FC from different areas of the study showed an erratic pattern of responses among the sampling sites. Little difference in tolerance to UV-B radiation and heat was found among the FC of soil samples collected in different seasons; in general soil FC collected in winter were less tolerant to UV-B radiation, but not for heat. In conclusion, FC from SMDS soil that receive intense heat and UV radiation, as well as with low nutrient availability, were more tolerant to both UV-B radiation and heat. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Community of Learning: Music Learning and Performance Practices among the Native Peoples of North America

    Science.gov (United States)

    Burton, J. Bryan

    2010-01-01

    Through descriptions drawn from interviews of Native American musicians and observations of tribal musical events, this paper presents a challenge to the "conservative educational practices" in public schools of the United States. In conclusion, the paper suggests that by more closely examining different cultural learning, values and traditions,…

  14. EFFECT OF MANAGEMENT PRACTICES ON THE SOIL MICROBIAL COMMUNITY IN AGRICULTURAL AND NATIVE SYSTEMS IN BRAZIL

    Science.gov (United States)

    Increase in agricultural practices in the Cerrado (tropical savannah) and Amazon regions in Brazil is causing drastic changes in the nutrient and carbon cycling of native areas. Because microorganisms play a key role in biogeochemical cycling, monitoring the shifts in the microb...

  15. Challenges to Evaluating Physical Activity Programs in American Indian/Alaska Native Communities

    Science.gov (United States)

    Roberts, Erica Blue; Butler, James; Green, Kerry M.

    2018-01-01

    Despite the importance of evaluation to successful programming, a lack of physical activity program (PAP) evaluation for American Indian/Alaska Native (AI/AN) programs exists, which is significant given the high rates of obesity and diabetes in this population. While evaluation barriers have been identified broadly among AI/AN programs, challenges…

  16. STRUCTURE OF MICROBIAL COMMUNITIES IN NATIVE AND CONVERTED SAVANNA AREAS OF CENTRAL BRAZIL

    Science.gov (United States)

    Brazilian savannas (Cerrado) have suffered drastic changes in land use with major conversion of native areas to agriculture since 1960. Burning, both due to natural conditions and as a human-induced practice, is a common event during the dry season (April to September) and plays ...

  17. Arbuscular mycorrhizal fungal community composition associated with Juniperus brevifolia in native Azorean forest

    Czech Academy of Sciences Publication Activity Database

    Drumonde Melo, C.; Luna, S.; Krüger, Claudia; Walker, C.; Mendonça, D.; Fonseca, H. M. A. C.; Jaizme-Vega, M.; da Camara Machado, A.

    2017-01-01

    Roč. 79, FEB 2017 (2017), s. 48-61 ISSN 1146-609X Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal fungi * Juniperus bravifolia * native forests Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.652, year: 2016

  18. The recent distribution and abundance of non-native Neogobius fishes in the Slovak section of the River Danube

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Černý, J.; Polačik, Matej; Valová, Zdenka; Janáč, Michal; Blažek, R.; Ondračková, Markéta

    2005-01-01

    Roč. 21, č. 4 (2005), s. 319-323 ISSN 0175-8659 R&D Projects: GA ČR GP524/05/P291 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish * River Danube Subject RIV: EG - Zoology Impact factor: 0.563, year: 2005

  19. Habitat relationships and larval drift of native and nonindigenous fishes in neighboring tributaries of a coastal California river

    Science.gov (United States)

    Bret C. Harvey; Jason L. White; Rodney J. Nakamoto

    2002-01-01

    Abstract - Motivated by a particular interest in the distribution of the nonindigenous, piscivorous Sacramento pikeminnow, Ptychocheilus grandis, we examined fish-habitat relationships in small tributaries (draining 20-200 km 2 )in the Eel River drainage of northwestern California.We sampled juvenile and adult fish in 15 tributaries in both the summer and...

  20. Ecomorphology as a predictor of fish diet: a case study on the North Sea benthic fish community

    NARCIS (Netherlands)

    Diderich, W.P.

    2006-01-01

    A methodological approach based on fish ecomorphology was chosen to predict potential fish diet. This study tests a method used in earlier research on a marine ecosystem containing phylogenetically diverse organisms: the North Sea. Fish feeding morphology imposes constraints on feeding options. A

  1. Speaking out about physical harms from tobacco use: response to graphic warning labels among American Indian/Alaska Native communities

    OpenAIRE

    Patterson Silver Wolf, David A; Tovar, Molly; Thompson, Kellie; Ishcomer, Jamie; Kreuter, Matthew W; Caburnay, Charlene; Boyum, Sonia

    2016-01-01

    Objective This study is the first to explore the impact of graphic cigarette labels with physical harm images on members of American Indian/Alaska Native (AI/AN) communities. The aim of this article is to investigate how AI/AN respond to particular graphic warning labels. Methods The parent study recruited smokers, at-risk smokers and non-smokers from three different age groups (youths aged 13?17?years, young adults aged 18?24?years and adults aged 25+ years) and five population subgroups wit...

  2. A Functional Approach to Zooplankton Communities in Mountain Lakes Stocked With Non-Native Sportfish Under a Changing Climate

    Science.gov (United States)

    Redmond, Laura E.; Loewen, Charlie J. G.; Vinebrooke, Rolf D.

    2018-03-01

    Cumulative impacts of multiple stressors on freshwater biodiversity and ecosystem function likely increase with elevation, thereby possibly placing alpine communities at greatest risk. Here, consideration of species traits enables stressor effects on taxonomic composition to be translated into potential functional impacts. We analyzed data for 47 taxa across 137 mountain lakes and ponds spanning large latitudinal (491 km) and elevational (1,399 m) gradients in western Canada, to assess regional and local factors of the taxonomic composition and functional structure of zooplankton communities. Multivariate community analyses revealed that small body size, clonal reproduction via parthenogenesis, and lack of pigmentation were species traits associated with both introduced non-native sportfish and also environmental conditions reflecting a warmer and drier climate—namely higher water temperatures, shallower water depths, and more chemically concentrated water. Thus, historical introductions of sportfish appear to have potentially induced greater tolerance in zooplankton communities of future climatic warming, especially in previously fishless alpine lakes. Although alpine lake communities occupied a relatively small functional space (i.e., low functional diversity), they were contained within the broader regional functional structure. Therefore, our findings point to the importance of dispersal by lower montane species to the future functional stability of alpine communities.

  3. What is the destiny of a threatened fish, Ptychobarbus chungtienensis, now that non-native weatherfishes have been introduced into Bita Lake, Shangri-La?

    Science.gov (United States)

    Jiang, Wan-Sheng; Qin, Tao; Wang, Wei-Ying; Zhao, Ya-Peng; Shu, Shu-Sen; Song, Wei-Hong; Chen, Xiao-Yong; Yang, Jun-Xing

    2016-09-18

    Biological invasion is a pervasive negative force of global change, especially in its effects on sensitive freshwater ecosystems. Even protected areas are usually not immune. Ptychobarbus chungtienensis is a threatened freshwater fish now almost confined to Bita Lake, in the Shangri-La region of Yunnan province, China. Its existence is threatened by the introduction of non-native weatherfishes (Misgurnus anguillicaudatus and Paramisgurnus dabryanus) by an unusual method known as 'prayer animal release'. Periodic surveys revealed the ratio of invasive weatherfishes to P. chungtienensis has been increasing since the former species was first recorded from the lake in August, 2009. Ptychobarbus chungtienensis shows low genetic diversity in the relict Lake Bita population. Weatherfishes, however, have highly successful survival strategies. The degree of dietary overlap between the species is alarming and perhaps critical if food is found to be a limiting factor.

  4. [Changes in fish communities of coral reefs at Sabana-Camagüey Archipelago, Cuba].

    Science.gov (United States)

    Claro, Rodolfo; Cantelar, Karel; Amargós, Fabián Pina; García-Arteaga, Juan P

    2007-06-01

    A comparison of fish community structure in the Sabana-Camagüey Archipelago (1988-1989 and 2000) using visual census surveys (eight belt transects 2x50 m in each site) suggests a notable decrease on species richness, and a two thirds reduction in fish density and biomass on coral reefs. This decrease in fish populations may be related to the alarming decrease of scleractinian coral cover, and an enormous proliferation of algae, which currently covers 70-80% of the hard substrate, impeding the recovery of corals and other benthic organisms. High coral mortalities occurred between the study periods, which correlate with the high temperatures caused by the ENSO events of 1995, 1997 and 1998. These events caused massive bleaching of corals and subsequent algae overgrowth. Evidence of nutrient enrichment from the inner lagoons and overfishing are also present. Collectively, these effects have provoked a marked degradation of reef habitats. These changes appear to have affected the availability of refuges and food for fishes, and may be constraining individual growth potential and population size.

  5. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    Directory of Open Access Journals (Sweden)

    Emily S Darling

    Full Text Available Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  6. On the structure of the inshore fish community of England and Wales

    International Nuclear Information System (INIS)

    Henderson, P.A.

    1988-12-01

    Records of fish captures on power station intake screens were used to analyse the structure of the English and Welsh inshore fish community. The study was undertaken as part of a programme to predict fish captures at future power station sites. It was found that 118 of the 122 fish species known to live inshore were recorded from the screens of only 12 coastal power stations. The minimum number of species at one site was about 80, found at fully marine localities along the English Channel coast. This number declined with increasing latitude and decreasing salinity. On average, 28 species were present simultaneously and these would include four pelagic, eight demersal and 16 benthic species. There was found to be 31 dominant species which comprised greater than 96% of the total catch by weight or number at all of the sites. These can be considered as the key species through which most of the energy and nutrients in the ecosystem must travel. The major factors determining the abundance of these species were salinity, degree of shelter, summer temperatures and winter temperatures. (author)

  7. Statistical power to detect change in a mangrove shoreline fish community adjacent to a nuclear power plant.

    Science.gov (United States)

    Dolan, T E; Lynch, P D; Karazsia, J L; Serafy, J E

    2016-03-01

    An expansion is underway of a nuclear power plant on the shoreline of Biscayne Bay, Florida, USA. While the precise effects of its construction and operation are unknown, impacts on surrounding marine habitats and biota are considered by experts to be likely. The objective of the present study was to determine the adequacy of an ongoing monitoring survey of fish communities associated with mangrove habitats directly adjacent to the power plant to detect fish community changes, should they occur, at three spatial scales. Using seasonally resolved data recorded during 532 fish surveys over an 8-year period, power analyses were performed for four mangrove fish metrics (fish diversity, fish density, and the occurrence of two ecologically important fish species: gray snapper (Lutjanus griseus) and goldspotted killifish (Floridichthys carpio). Results indicated that the monitoring program at current sampling intensity allows for detection of <33% changes in fish density and diversity metrics in both the wet and the dry season in the two larger study areas. Sampling effort was found to be insufficient in either season to detect changes at this level (<33%) in species-specific occurrence metrics for the two fish species examined. The option of supplementing ongoing, biological monitoring programs for improved, focused change detection deserves consideration from both ecological and cost-benefit perspectives.

  8. [The fish community in the Términos lagoon: compared current structure].

    Science.gov (United States)

    Amado Ayala-Pérez, Luis; Ramos Miranda, Julia; Flores Hernández, Domingo

    2003-01-01

    The structure of the fish community in Terminos Lagoon, Campeche, is analyzed on the base the description of the abundance, distribution, length composition and identification of the dominant species. The results are discussed and compared with the published information. 437 trawl tows were made in 19 monthly collection in 23 sites between September 1997 to March 1999. A total of 25,588 individual with a total weight of 601.5 kg were grouped in 107 species, 76 gender and 37 families. The abundance of the fish community showed the following intervals in temporal scale: 0.395 to 0.895 ind/m2; 8.637 to 18.316 g/m2 and 18.358 to 34.837 g/ind. The Shannon index oscillated between 1.875 and 3.995 and 4.94 and 7.88 respectively. 18 dominant species were identified. The most important species by its numerical abundance and appearance frequency is Arius melanopus that represents to the 26.5% of the total catch followed by Diapterus rhombeus with 18.9%. As dominant species, Bairdiella chrysura, B. ronchus, Archosargus rhomboidalis, Eugerres plumieri, Cynoscion arenarius and Chaetodipterus faber, are fishing resources with local and regional value.

  9. Phylogenetically poor plant communities receive more alien species, which more easily coexist with natives

    NARCIS (Netherlands)

    Gerhold, P.; Pärtel, M.; Tackenberg, O.; Hennekens, S.M.; Bartish, I.; Schaminee, J.H.J.; Fergus, A.J.F.; Ozinga, W.A.; Prinzing, A.

    2011-01-01

    Alien species can be a major threat to ecological communities, but we do not know why some community types allow the entry of many more alien species than do others. Here, for the first time, we suggest that evolutionary diversity inherent to the constituent species of a community may determine its

  10. Ecology of selected marine communities in Glacier Bay: Zooplankton, forage fish, seabirds and marine mammals

    Science.gov (United States)

    Robards, Martin D.; Drew, Gary S.; Piatt, John F.; Anson, Jennifer Marie; Abookire, Alisa A.; Bodkin, James L.; Hooge, Philip N.; Speckman, Suzann G.

    2003-01-01

    We studied oceanography (including primary production), secondary production, small schooling fish (SSF), and marine bird and mammal predators in Glacier Bay during 1999 and 2000. Results from these field efforts were combined with a review of current literature relating to the Glacier Bay environment. Since the conceptual model developed by Hale and Wright (1979) ‘changes and cycles’ continue to be the underlying theme of the Glacier Bay ecosystem. We found marked seasonality in many of the parameters that we investigated over the two years of research, and here we provide a comprehensive description of the distribution and relative abundance of a wide array of marine biota. Glacier Bay is a tidally mixed estuary that leads into basins, which stratify in summer, with the upper arms behaving as traditional estuaries. The Bay is characterized by renewal and mixing events throughout the year, and markedly higher primary production than in many neighboring southeast Alaska fjords (Hooge and Hooge, 2002). Zooplankton diversity and abundance within the upper 50 meters of the water column in Glacier Bay is similar to communities seen throughout the Gulf of Alaska. Zooplankton in the lower regions of Glacier Bay peak in abundance in late May or early June, as observed at Auke Bay and in the Gulf of Alaska. The key distinction between the lower Bay and other estuaries in the Gulf of Alaska is that a second smaller peak in densities occurs in August. The upper Bay behaved uniformly in temporal trends, peaking in July. Densities had begun to decline in August, but were still more than twice those observed in that region in May. The highest density of zooplankton observed was 17,870 organisms/m3 in Tarr Inlet during July. Trends in zooplankton community abundance and diversity within the lower Bay were distinct from upper-Glacier Bay trends. Whereas the lower Bay is strongly influenced by Gulf of Alaska processes, local processes are the strongest influence in the upper

  11. Hawaii ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, marine, estuarine, and native stream fish species in coastal Hawaii. Vector polygons in this data...

  12. Expanding perceptions of subsistence fish consumption: evidence of high commercial fish consumption and dietary mercury exposure in an urban coastal community.

    Science.gov (United States)

    Holloman, Erica L; Newman, Michael C

    2012-02-01

    Through collaborative partnerships established between current researchers and The Moton Community House (a local community center), African American women (ages 16-49yrs) from the Southeast Community of Newport News, Virginia, USA were surveyed to assess the reproducibility and consistency of fish consumption patterns (ingestion rates, exposure frequencies, weight, and fish consumption rates) derived from a community-specific fish consumption survey. Women were also surveyed to assess the reliability of the survey responses, and to estimate daily mercury intake. Fish consumption patterns were reproducible and the survey responses were reliable. Comparison between years revealed that fish consumption patterns remained consistent over time. In addition, the high fish consumption rate estimated in 2008 (147.8g/day; 95% CI: 117.6-185.8g/day) was confirmed with a rate (134.9g/day; 95% CI: 88-207g/day) not materially different and still considerably higher than mean fish consumption rates reported for U.S. women. Daily mercury intake rates were estimated using consumption data from 2008 and three consumption scenarios (canned white, canned light, and no tuna) due to confirmed differences in mercury concentration between canned white and light tuna. Arithmetic mean daily mercury intake rates were 0.284μg/kg bw/day (95% CI: 0.229-0.340μg/kg bw/day) using canned white tuna, 0.212μg/kg bw/day (95% CI: 0.165-0.259μg/kg bw/day) using light tuna, and 0.197μg/kg bw/day (95% CI: 0.151-0.243μg/kg bw/day) using no tuna. Approximately 58%-73% of the daily mercury intake rates for African American women in the Southeast Community exceeded US EPA's oral reference dose (RfD) of 0.10μg/kg bw/day for mercury. In addition, 2% of the rates exceeded a level (1.00μg/kg bw/day) documented to produce adverse health effects. Past and current investigations confirmed that even though women in this community were not subsistence fishers, they are subsistence fish consumers. Copyright

  13. Struktur Komunitas Ikan Karang di Perairan Kendari (Community Structure of Coral Reef Fishes at Kendari Waters

    Directory of Open Access Journals (Sweden)

    Muhammad Adrim

    2012-09-01

    Full Text Available Keberadaan ikan karang merupakan salah satu bioindikator terhadap kondisi terumbu karang yang baik. Penelitian ikan karang di perairan Kendari bertujuan untuk mengetahui komposisi jenis, kelimpahan, sebaran, dan struktur komunitas ikan karang di perairan tersebut. Pengumpulan data dilakukan bulan Juli 2011 pada lima lokasi di bagian utara dan selatan Kendari. Data dihimpun dengan menggunakan teknik Underwater Visual Census (UVC dan metode transek (Line Intersept Transect, LIT dengan peralatan SCUBA. Total jenis ikan karang terkumpul sebanyak 111 jenis yang mewakili 24 famili, terdiri dari 31 jenis ikan target (ikan konsumsi, 17 jenis ikan indikator (indicator species, dan kelompok major 63 jenis. Kelornpok ikan pangan (target yang dominan; Caesio cuning, Siganus vulpinus dan Ctenochaetus striatus. Jenis yang paling dominan dari ikan indikator adalah Chaetodon octofasciatus. Sedangkan kelompok lainnya (major yang dominan adalah Pomacentrus smithii, Chrysiptera rollandi, Chrysiptera springeri, dan Pomacentrus alexanderae. Nilai Indeks keanekaragaman berkisar 1,36– 3,23. Indeks dominasi Margalef (d berkisar 4,74–8,66. Indeks kemerataan Pielou (J’=H’/logeS diperololeh pada kisaran 0,38–0,81 . Hasil analisis kluster pada matrik kesamaan Bray-Curtis 37 % diperoleh dendrograrn yang menunjukkan dua pengelompokan stasiun. Berdasarkan ordinasi sampel dengan MDS diperoleh dari kesamaan (stress= 0 dengan jelas menunjukkan dua komunitas yang berbeda. Hasil penelitian ini diharapkan dapat menjadi masukan sebagai data dasar untuk pengelolaan daerah pesisir bagi pemerintahan daerah (PEMDA. Kata kunci: ikan karang, struktur komunitas, indeks ekologi, perairan Kendari. Coral reef Fishes is one of bio-indicators for good condition coral reef ecosystem. A study on coral reef fishes in the Kendari waters was aimed to find out species composition, abundance, distribution and community structure of coral reef fishes in that area. The study was conducted in

  14. Oxygen limitation and tissue metabolic potential of the African fish Barbus neumayeri: roles of native habitat and acclimatization

    Directory of Open Access Journals (Sweden)

    Rees Bernard B

    2011-01-01

    Full Text Available Abstract Background Oxygen availability in aquatic habitats is a major environmental factor influencing the ecology, behaviour, and physiology of fishes. This study evaluates the contribution of source population and hypoxic acclimatization of the African fish, Barbus neumayeri, in determining growth and tissue metabolic enzyme activities. Individuals were collected from two sites differing dramatically in concentration of dissolved oxygen (DO, Rwembaita Swamp (annual average DO 1.35 mgO2 L-1 and Inlet Stream West (annual average DO 5.58 mgO2 L-1 in Kibale National Park, Uganda, and reciprocally transplanted using a cage experiment in the field, allowing us to maintain individuals under natural conditions of oxygen, food availability, and flow. Fish were maintained under these conditions for four weeks and sampled for growth rate and the activities of phosphofructokinase (PFK, lactate dehydrogenase (LDH, citrate synthase (CS, and cytochrome c oxidase (CCO in four tissues, liver, heart, brain, and skeletal muscle. Results Acclimatization to the low DO site resulted in lower growth rates, lower activities of the aerobic enzyme CCO in heart, and higher activities of the glycolytic enzyme PFK in heart and skeletal muscle. The activity of LDH in liver tissue was correlated with site of origin, being higher in fish collected from a hypoxic habitat, regardless of acclimatization treatment. Conclusions Our results suggest that the influence of site of origin and hypoxic acclimatization in determining enzyme activity differs among enzymes and tissues, but both factors contribute to higher glycolytic capacity and lower aerobic capacity in B. neumayeri under naturally-occurring conditions of oxygen limitation.

  15. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    Directory of Open Access Journals (Sweden)

    Zach J Farris

    Full Text Available The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species and domestic dogs (Canis familiaris had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica. Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year, the ring-tailed vontsira (Galidia elegans (mean=58 consumed/year, and the fosa (Cryptoprocta ferox (mean=31 consumed/year. Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest

  16. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    Science.gov (United States)

    Farris, Zach J; Golden, Christopher D; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M; Kelly, Marcella J

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (mean=58 consumed/year), and the fosa (Cryptoprocta ferox) (mean=31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various

  17. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar

    OpenAIRE

    Farris, Zach J.; Golden, Christopher D.; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M.; Kelly, Marcella J.

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore c...

  18. Ethnotaxonomical considerations and usage of ichthyofauna in a fishing community in Ceará State, Northeast Brazil.

    Science.gov (United States)

    Pinto, Márcia Freire; Mourão, José da Silva; Alves, Rômulo Romeu Nóbrega

    2013-03-08

    Artisanal fishery is one of the most important economic activities for human populations living in coastal areas. The traditional knowledge that fishermen have of fishes is of utmost importance for the establishment of conservation strategies for many species. This study aimed to analyse the knowledge of and utilization of fishes by the artisanal fishermen in a fishing community on the coast of Ceará State (Northeast Brazil). In 2011, a number of semi-structured interviews were performed with fishermen with more than 20 years of fishery experience. The interviews were about fisheries (collecting spots, artefacts, etc.) and fish use. The fishes cited by the fishermen were identified scientifically and ethnotaxonomically. Considered masters of fishery, they cited 162 vernacular names of fishes, which corresponded to 290 different species, also including other animals such as dolphins, porpoises, whales and manatees. The criteria for the classification of the fishes were well known and utilised by the fishermen, and they were based on morphology, behaviour, habitat and the importance of commercial and fishing activities. Four hierarchical categories were identified in their classification system: kingdom, life-form, generic and specific. The fish nomenclature created by the fishermen was mostly composed of generic and monotypic names. The main uses of fish were for food and commercial purposes. The results stress the richness and complexity of the knowledge of the artisanal fishermen of Redonda Beach, and they provide support for the possibility of future studies and for the development of management plans and the management of wildlife resources.

  19. Survival of bacterial indicators and the functional diversity of native microbial communities in the Floridan aquifer system, south Florida

    Science.gov (United States)

    Lisle, John T.

    2014-01-01

    model than when exposed to groundwater from the APPZ (range: 0.540–0.684 h-1). The inactivation rates for the first phase of the models for P. aeruginosa were not significantly different between the UFA (range: 0.144–0.770 h-1) and APPZ (range: 0.159–0.772 h-1) aquifer zones. The inactivation rates for the second phase of the model for this P. aeruginosa were also similar between UFA (range: 0.003–0.008 h-1) and APPZ (0.004–0.005 h-1) zones, although significantly slower than the model’s first phase rates for this bacterial species. Geochemical data were used to determine which dissimilatory biogeochemical reactions were most likely to occur under the native conditions in the UFA and APPZ zones using thermodynamics principles to calculate free energy yields and other cell-related energetics data. The biogeochemical processes of acetotrophic and hydrogenotrophic sulfate reduction, methanogenesis and anaerobic oxidation of methane dominated in all six groundwater sites. A high throughput DNA microarray sequencing technology was used to characterize the diversity in the native aquifer bacterial communities (bacteria and archaea) and assign putative physiological capabilities to the members of those communities. The bacterial communities in both zones of the aquifer were shown to possess the capabilities for primary and secondary fermentation, acetogenesis, methanogenesis, anaerobic methane oxidation, syntrophy with methanogens, ammonification, and sulfate reduction. The data from this study provide the first determination of bacterial indicator survival during exposure to native geochemical conditions of the Floridan aquifer in south Florida. Additionally, the energetics and functional bacterial diversity characterizations are the first descriptions of native bacterial communities in this region of the Floridan aquifer and reveal how these communities persist under such extreme conditions. Collectively, these types of data can be used to develop and refine

  20. Response of fish communities to intense drought in Brazilian savanna streams

    Directory of Open Access Journals (Sweden)

    Dianne Michelle Alves da Silva

    2017-08-01

    Full Text Available The physical structures of streams are subjected to intense changes throughout the seasons. Intense drought in dry periods has been frequent and potentially harmful to aquatic species. In this study, we tested whether the changes in the habitat structure of the streams during the dry period determine the organization of fish communities. Five streams in the Upper Tocantins River were studied in the dry and rainy seasons. The species were characterized by 13 functional traits based on morphological measurements. The descriptors of functional diversity were: mean pairwise functional distance of species in the community (MPD and mean functionally nearest species distance (MNTD. We also calculated the standardized effect size for MPD and MNTD, an indicator of functional redundancy, and compared the observed patterns with those expected by chance. Streams differed between seasons with respect to environmental variables. Functional diversity in the rainy season did not differ from the pattern expected by chance for both metrics. While functional diversity in the dry season has not differed from the pattern expected by chance for SESMPD, a greater functional redundancy for SESMNTD was found in this season. These results indicate that environmental changes in the streams during the dry season are important constraints for fish occurrence, preventing the occurrence of functionally original species. Therefore, a prospective scenario of dry-period intensification could result in functionally redundant communities, with functional homogenization of the regional species pool.

  1. Focus groups to increase the cultural acceptability of a contingency management intervention for American Indian and Alaska Native Communities.

    Science.gov (United States)

    Hirchak, Katherine A; Leickly, Emily; Herron, Jalene; Shaw, Jennifer; Skalisky, Jordan; Dirks, Lisa G; Avey, Jaedon P; McPherson, Sterling; Nepom, Jenny; Donovan, Dennis; Buchwald, Dedra; McDonell, Michael G

    2018-07-01

    Many American Indian and Alaska Native (AI/AN) people seek evidence-based, cost-effective, and culturally acceptable solutions for treating alcohol use disorders. Contingency management (CM) is a feasible, low-cost approach to treating alcohol use disorders that uses "reinforcers" to promote and support alcohol abstinence. CM has not been evaluated among AI/AN communities. This study explored the cultural acceptability of CM and adapted it for use in diverse AI/AN communities. We conducted a total of nine focus groups in three AI/AN communities: a rural reservation, an urban health clinic, and a large Alaska Native healthcare system. Respondents included adults in recovery, adults with current drinking problems, service providers, and other interested community members (n = 61). Focus group questions centered on the cultural appropriateness of "reinforcers" used to incentivize abstinence and the cultural acceptability of the intervention. Focus groups were audio-recorded, transcribed, and coded independently by two study team members using both a priori and emergent codes. We then analyzed coded data. Across all three locations, focus group participants described the importance of providing both culturally specific (e.g., bead work and cultural art work supplies), as well as practical (e.g., gas cards and bus passes) reinforcers. Focus group participants underscored the importance of providing reinforcers for the children and family of intervention participants to assist with reengaging with family and rebuilding trust that may have been damaged during alcohol use. Respondents indicated that they believed CM was in alignment with AI/AN cultural values. There was consensus that Elders or a well-respected community member implementing this intervention would enhance participation. Focus group participants emphasized use of the local AI/AN language, in addition to the inclusion of appropriate cultural symbols and imagery in the delivery of the intervention. A CM

  2. Planktivory in the changing Lake Huron zooplankton community: Bythotrephes consumption exceeds that of Mysis and fish

    Science.gov (United States)

    Bunnell, D.B.; Hunter, R. Douglas; Warner, D.M.; Chriscinske, M.A.; Roseman, E.F.

    2011-01-01

    Oligotrophic lakes are generally dominated by calanoid copepods because of their competitive advantage over cladocerans at low prey densities. Planktivory also can alter zooplankton community structure. We sought to understand the role of planktivory in driving recent changes to the zooplankton community of Lake Huron, a large oligotrophic lake on the border of Canada and the United States. We tested the hypothesis that excessive predation by fish (rainbow smelt Osmerus mordax, bloater Coregonus hoyi) and invertebrates (Mysis relicta, Bythotrephes longimanus) had driven observed declines in cladoceran and cyclopoid copepod biomass between 2002 and 2007. We used a field sampling and bioenergetics modelling approach to generate estimates of daily consumption by planktivores at two 91-m depth sites in northern Lake Huron, U.S.A., for each month, May-October 2007. Daily consumption was compared to daily zooplankton production. Bythotrephes was the dominant planktivore and estimated to have eaten 78% of all zooplankton consumed. Bythotrephes consumption exceeded total zooplankton production between July and October. Mysis consumed 19% of all the zooplankton consumed and exceeded zooplankton production in October. Consumption by fish was relatively unimportant - eating only 3% of all zooplankton consumed. Because Bythotrephes was so important, we explored other consumption estimation methods that predict lower Bythotrephes consumption. Under this scenario, Mysis was the most important planktivore, and Bythotrephes consumption exceeded zooplankton production only in August. Our results provide no support for the hypothesis that excessive fish consumption directly contributed to the decline of cladocerans and cyclopoid copepods in Lake Huron. Rather, they highlight the importance of invertebrate planktivores in structuring zooplankton communities, especially for those foods webs that have both Bythotrephes and Mysis. Together, these species occupy the epi-, meta- and

  3. Climate-driven changes in functional biogeography of Arctic marine fish communities.

    Science.gov (United States)

    Frainer, André; Primicerio, Raul; Kortsch, Susanne; Aune, Magnus; Dolgov, Andrey V; Fossheim, Maria; Aschan, Michaela M

    2017-11-14

    Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions. Copyright © 2017 the Author(s). Published by PNAS.

  4. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar

    Science.gov (United States)

    Farris, Zach J.; Golden, Christopher D.; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M.; Kelly, Marcella J.

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar’s largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar’s largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (x¯ = 90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (x¯ = 58 consumed/year), and the fosa (Cryptoprocta ferox) (x¯ = 31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are

  5. The effects of tertiary treated municipal wastewater on fish communities of a small river tributary in Southern Ontario, Canada

    International Nuclear Information System (INIS)

    Brown, Carolyn J.M.; Knight, Brendan W.; McMaster, Mark E.; Munkittrick, Kelly R.; Oakes, Ken D.; Tetreault, Grald R.; Servos, Mark R.

    2011-01-01

    Fish community changes associated with a tertiary treated municipal wastewater effluent outfall in the Speed River, Ontario, Canada, were evaluated at nine sites over two seasons (2008) using standardized electrofishing. Habitat evaluations were conducted to ensure that the riffle sites selected were physically similar. The fish community was dominated by several species of darters that differed in their response to the effluent outfall. There was a significant decrease in Greenside Darter (Etheostoma blennioides) but an increase in Rainbow Darter (E. caeruleum) abundance directly downstream of the outfall. Stable isotope signatures (δ 13 C and δ 15 N), which indicate shifts in energy utilization and flow, increased in Rainbow Darter downstream, but showed no change in Greenside Darter. Rainbow Darter may be exploiting a food source that is not as available at upstream sites giving them a competitive advantage over the Greenside Darter immediately downstream of the outfall. - Highlights: → Fish communities are altered by tertiary treated municipal wastewater exposure. → Relative abundance of the two dominant fish (darter) species changed downstream. → Differing stable isotope signatures in fish suggests shifting energy flow and diet. → The altered environment may allow resilient species a competitive advantage. → The system recovers quickly downstream. - Tertiary treated effluent altered fish community composition in a small receiving stream possibly as a result of altered availability of resources (diet) as indicated by stable isotopes.

  6. Community Structure, Biodiversity, and Ecosystem Services in Treeline Whitebark Pine Communities: Potential Impacts from a Non-Native Pathogen

    Directory of Open Access Journals (Sweden)

    Diana F. Tomback

    2016-01-01

    Full Text Available Whitebark pine (Pinus albicaulis has the largest and most northerly distribution of any white pine (Subgenus Strobus in North America, encompassing 18° latitude and 21° longitude in western mountains. Within this broad range, however, whitebark pine occurs within a narrow elevational zone, including upper subalpine and treeline forests, and functions generally as an important keystone and foundation species. In the Rocky Mountains, whitebark pine facilitates the development of krummholz conifer communities in the alpine-treeline ecotone (ATE, and thus potentially provides capacity for critical ecosystem services such as snow retention and soil stabilization. The invasive, exotic pathogen Cronartium ribicola, which causes white pine blister rust, now occurs nearly rangewide in whitebark pine communities, to their northern limits. Here, we synthesize data from 10 studies to document geographic variation in structure, conifer species, and understory plants in whitebark pine treeline communities, and examine the potential role of these communities in snow retention and regulating downstream flows. Whitebark pine mortality is predicted to alter treeline community composition, structure, and function. Whitebark pine losses in the ATE may also alter response to climate warming. Efforts to restore whitebark pine have thus far been limited to subalpine communities, particularly through planting seedlings with potential blister rust resistance. We discuss whether restoration strategies might be appropriate for treeline communities.

  7. Linking hydrologic, physical and chemical habitat environments for the potential assessment of fish community rehabilitation in a developing city

    Science.gov (United States)

    Zhao, C. S.; Yang, S. T.; Liu, C. M.; Dou, T. W.; Yang, Z. L.; Yang, Z. Y.; Liu, X. L.; Xiang, H.; Nie, S. Y.; Zhang, J. L.; Mitrovic, S. M.; Yu, Q.; Lim, R. P.

    2015-04-01

    Aquatic ecological rehabilitation is increasingly attracting considerable public and research attention. An effective method that requires less data and expertise would help in the assessment of rehabilitation potential and in the monitoring of rehabilitation activities as complicated theories and excessive data requirements on assemblage information make many current assessment models expensive and limit their wide use. This paper presents an assessment model for restoration potential which successfully links hydrologic, physical and chemical habitat factors to fish assemblage attributes drawn from monitoring datasets on hydrology, water quality and fish assemblages at a total of 144 sites, where 5084 fish were sampled and tested. In this model three newly developed sub-models, integrated habitat index (IHSI), integrated ecological niche breadth (INB) and integrated ecological niche overlap (INO), are established to study spatial heterogeneity of the restoration potential of fish assemblages based on gradient methods of habitat suitability index and ecological niche models. To reduce uncertainties in the model, as many fish species as possible, including important native fish, were selected as dominant species with monitoring occurring over several seasons to comprehensively select key habitat factors. Furthermore, a detrended correspondence analysis (DCA) was employed prior to a canonical correspondence analysis (CCA) of the data to avoid the "arc effect" in the selection of key habitat factors. Application of the model to data collected at Jinan City, China proved effective reveals that three lower potential regions that should be targeted in future aquatic ecosystem rehabilitation programs. They were well validated by the distribution of two habitat parameters: river width and transparency. River width positively influenced and transparency negatively influenced fish assemblages. The model can be applied for monitoring the effects of fish assemblage restoration

  8. Morphological divergence and flow-induced phenotypic plasticity in a native fish from anthropogenically altered stream habitats.

    Science.gov (United States)

    Franssen, Nathan R; Stewart, Laura K; Schaefer, Jacob F

    2013-11-01

    Understanding population-level responses to human-induced changes to habitats can elucidate the evolutionary consequences of rapid habitat alteration. Reservoirs constructed on streams expose stream fishes to novel selective pressures in these habitats. Assessing the drivers of trait divergence facilitated by these habitats will help identify evolutionary and ecological consequences of reservoir habitats. We tested for morphological divergence in a stream fish that occupies both stream and reservoir habitats. To assess contributions of genetic-level differences and phenotypic plasticity induced by flow variation, we spawned and reared individuals from both habitats types in flow and no flow conditions. Body shape significantly and consistently diverged in reservoir habitats compared with streams; individuals from reservoirs were shallower bodied with smaller heads compared with individuals from streams. Significant population-level differences in morphology persisted in offspring but morphological variation compared with field-collected individuals was limited to the head region. Populations demonstrated dissimilar flow-induced phenotypic plasticity when reared under flow, but phenotypic plasticity in response to flow variation was an unlikely explanation for observed phenotypic divergence in the field. Our results, together with previous investigations, suggest the environmental conditions currently thought to drive morphological change in reservoirs (i.e., predation and flow regimes) may not be the sole drivers of phenotypic change.

  9. Angler-caught piscivore diets reflect fish community changes in Lake Huron

    Science.gov (United States)

    Roseman, Edward F.; Schaeffer, Jeff; Bright, Ethan; Fielder, David G.

    2014-01-01

    Examination of angler-caught piscivore stomachs revealed that Lake Trout Salvelinus namaycush, Chinook Salmon Oncorhynchus tshawytscha, and Walleyes Sander vitreus altered theirdiets in response to unprecedented declines in Lake Huron's main-basin prey fish community.Diets varied by predator species, season, and location but were nearly always dominated numerically by some combination of Alewife Alosa pseudoharengus, Rainbow Smelt Osmerus mordax, Emerald Shiner Notropis atherinoides, Round Goby Neogobius melanostomus, or terrestrial insects. Rainbow Trout Oncorhynchus mykiss (steelhead), Coho Salmon Oncorhynchus kisutch, and Atlantic Salmon Salmo salar had varied diets that reflected higher contributions of insects. Compared with an earlier (1983–1986) examination of angler-caught predator fishes from Lake Huron, the contemporary results showed an increase in consumption of nontraditional prey (including conspecifics), use of smaller prey, and an increase in insects in the diet, suggesting that piscivores were faced with chronic prey limitation during this study. The management of all piscivores in Lake Huron will likely require consideration of the pervasive effects of changes in food webs, especially if prey fish remain at low levels.

  10. Heterogeneity of the HIV epidemic in agrarian, trading, and fishing communities in Rakai, Uganda: an observational epidemiological study.

    Science.gov (United States)

    Chang, Larry W; Grabowski, Mary K; Ssekubugu, Robert; Nalugoda, Fred; Kigozi, Godfrey; Nantume, Betty; Lessler, Justin; Moore, Sean M; Quinn, Thomas C; Reynolds, Steven J; Gray, Ronald H; Serwadda, David; Wawer, Maria J

    2016-08-01

    Understanding the extent to which HIV burden differs across communities and the drivers of local disparities is crucial for an effective and targeted HIV response. We assessed community-level variations in HIV prevalence, risk factors, and treatment and prevention service uptake in Rakai, Uganda. The Rakai Community Cohort Study (RCCS) is an open, population-based cohort of people aged 15-49 years in 40 communities. Participants are HIV tested and interviewed to obtain sociodemographic, behavioural, and health information. RCCS data from Aug 10, 2011, to May 30, 2013, were used to classify communities as agrarian (n=27), trading (n=9), or lakeside fishing sites (n=4). We mapped HIV prevalence with Bayesian methods, and characterised variability across and within community classifications. We also assessed differences in HIV risk factors and uptake of antiretroviral therapy and male circumcision between community types. 17 119 individuals were included, 9215 (54%) of whom were female. 9931 participants resided in agrarian, 3318 in trading, and 3870 in fishing communities. Median HIV prevalence was higher in fishing communities (42%, range 38-43) than in trading (17%, 11-21) and agrarian communities (14%, 9-26). Antiretroviral therapy use was significantly lower in both men and women in fishing communities than in trading (age-adjusted prevalence risk ratio in men 0·64, 95% CI 0·44-0·97; women 0·53, 0·42-0·66) and agrarian communities (men 0·55, 0·42-0·72; women 0·65, 0·54-0·79), as was circumcision coverage among men (vs trading 0·48, 0·42-0·55; vs agrarian 0·64, 0·56-0·72). Self-reported risk behaviours were significantly higher in men than in women and in fishing communities than in other community types. Substantial heterogeneity in HIV prevalence, risk factors, and service uptake in Rakai, Uganda, emphasises the need for local surveillance and the design of targeted HIV responses. High HIV burden, risk behaviours, and low use of combination

  11. Influence of mesoscale features on micronekton and large pelagic fish communities in the Mozambique Channel

    Science.gov (United States)

    Potier, Michel; Bach, Pascal; Ménard, Frédéric; Marsac, Francis

    2014-02-01

    We investigated the diversity and distribution of two communities, micronekton organisms and large predatory fishes, sampled in mesoscale features of the Mozambique Channel from 2003 to 2009, by combining mid-water trawls, stomach contents of fish predators and instrumented longline fishing surveys. The highest species richness for assemblages was found in divergences and fronts rather than in the core of eddies. Despite an unbalanced scheme, diversity indices did not differ significantly between cyclonic and anticyclonic eddies, divergences and fronts. We found that eddies and associated physical cues did not substantially affect the distribution of micronektonic species which are mainly driven by the diel vertical migration pattern. Top predators exhibited a more complex response. Swordfish (Xiphias gladius) associated better with mesoscale features than tunas, with a clear preference for divergences which is consistent with the diel vertical migrations and occurrence of its main prey, the flying squids Sthenoteuthis oualaniensis (Ommastrephidae). On the other hand, the probability of presence of yellowfin tuna was not tied to any specific eddy structure. However, the highest values of positive yellowfin CPUEs were associated with low horizontal gradients of sea-level anomalies. We also showed a non-linear response of positive yellowfin CPUEs with respect to the depth of the minimal oxygen content. The larger the distance between the hooks and the minimal oxygen layer, towards the surface or at greater depths, the higher the CPUE, highlighting that yellowfin congregated in well-oxygenated waters. Micronekton sampled by mid-water trawls and stomach contents exhibited different species composition. The highly mobile organisms were not caught by trawling whereas they remain accessible to predators. The combination of stomach contents and mid-water trawls undoubtedly improved our understanding of the micronekton assemblage distribution. Our results provide some

  12. Fish communities of the Wilderness Lakes System in the southern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Alexis A. Olds

    2016-08-01

    Full Text Available The Wilderness Lakes System, a temporarily open and closed estuary with three associated lakes situated in the southern Cape region of South Africa, was sampled using a range of sampling gears to assess the fish community. A total of 25 species were sampled throughout the system, with the highest diversity in the Touw Estuary (23 species and the lowest in Langvlei (11 species. Estuary-associated marine species (13 species dominated species richness with smaller proportions of estuarine resident (7 species, freshwater (3 species and catadromous species (2 species. Estuarine resident species dominated the catch numerically. The size–class distribution of euryhaline marine species indicated that upon entering the Touw Estuary as juveniles, the fish move up the system towards Rondevlei where they appear to remain. Three freshwater species were recorded in the system, all of which are alien to the Wilderness Lakes System. Decreasing salinity in the upper lakes appears to be a driving factor in the distribution and increasing abundance of the freshwater fishes. Sampling followed a drought, with the system experiencing substantially increased levels of mouth closure compared to a similar study conducted in the 1980s. The timing of mouth opening and the degree of connectivity between the lakes influence the nursery function of the system as a whole. Management actions need to focus on improving ecological functioning of this system, in particular how mouth opening is managed, to facilitate nursery function and limit the establishment of invasive species. Conservation implications: Key management actions are required to improve fish recruitment potential into and within the system. These include maintenance of adequate marine inflow through adherence to artificial mouth breaching protocols and improving connectivity between the lakes through sediment removal from localised deposition points within the connecting channels.

  13. Assessing the feasibility of native fish reintroductions: a framework and example applied to bull trout in the Clackamas River, Oregon

    Science.gov (United States)

    Dunham, Jason B.; Gallo, Kirsten

    2008-01-01

    In a species conservation context, translocations can be an important tool, but they frequently fail to successfully establish new populations. We consider the case of reintroductions for bull trout (Salvelinus confluentus), a federally-listed threatened species with a widespread but declining distribution in western North America. Our specific objectives in this work were to: 1) develop a general framework for assessing the feasibility of reintroduction for bull trout, 2) provide a detailed example of implementing this framework to assess the feasibility of reintroducing bull trout in the Clackamas River, Oregon, and 3) discuss the implications of this effort in the more general context of fish reintroductions as a conservation tool. Review of several case histories and our assessment of the Clackamas River suggest that an attempt to reintroduce bull trout could be successful, assuming adequate resources are committed to the subsequent stages of implementation, monitoring, and evaluation.

  14. How HIV diagnosis and disclosure affect sexual behavior and relationships in Ugandan fishing communities.

    Science.gov (United States)

    McArthur, Moriah; Birdthistle, Isolde; Seeley, Janet; Mpendo, Juliet; Asiki, Gershim

    2013-08-01

    In this article we examine how members of fishing communities on the shores of Lake Victoria in Uganda respond to HIV diagnosis in terms of disclosure to sexual partners. We then explore the subsequent changes in sexual behavior and relationships. To access this information, we collected life history data from 78 HIV-positive individuals in five fishing communities. We found that the strength of the sexual relationships shaped how and why individuals disclosed to partners, and that these relationships tended to be stronger when partners shared familial responsibility. Those who perceived their current sexual partnership to be weak sought to conceal their status by maintaining prediagnosis patterns of sexual behavior. The majority of the study's participants rarely changed their sexual behavior following HIV diagnosis, regardless of their relationship's strength. These findings elucidate barriers to disclosure and behavior change, and suggest that a life-course approach might enhance individual-level counseling so that counselors can provide tailored support to individuals regarding disclosure decisions and outcomes.

  15. Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa

    Science.gov (United States)

    Liao, H.; Pierce, C.L.; Larscheid, J.G.

    2004-01-01

    At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population. We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995-1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking

  16. Composition of Fish Communities in a European Macrotidal Salt Marsh (the Mont Saint-Michel Bay, France)

    Science.gov (United States)

    Laffaille, P.; Feunteun, E.; Lefeuvre, J.-C.

    2000-10-01

    At least 100 fish species are known to be present in the intertidal areas (estuaries, mudflats and salt marshes) of Mont Saint-Michel Bay. These and other comparable shallow marine coastal waters, such as estuaries and lagoons, play a nursery role for many fish species. However, in Europe little attention has been paid to the value of tidal salt marshes for fishes. Between March 1996 and April 1999, 120 tides were sampled in a tidal creek. A total of 31 species were caught. This community was largely dominated by mullets ( Liza ramada represent 87% of the total biomass) and sand gobies ( Pomatoschistus minutus and P. lozanoi represent 82% of the total numbers). These species and also Gasterosteus aculeatus , Syngnathus rostellatus, Dicentrarchus labrax, Mugil spp., Liza aurata and Sprattus sprattus were the most frequent species (>50% of monthly frequency of occurrence). In Europe, salt marshes and their creeks are flooded only during high spring tides. So, fishes only invade this environment during short immersion periods, and no species can be considered as marsh resident. But, the salt marsh was colonized by fish every time the tide reached the creek, and during the short time of flood, dominant fishes fed actively and exploited the high productivity. Nevertheless, this study shows that there is little interannual variation in the fish community and there are three ' seasons ' in the fish fauna of the marsh. Marine straggler and marine estuarine dependent species colonize marshes between spring (recruitment period in the bay) and autumn before returning into deeper adjacent waters. Estuarine fishes are present all year round with maximum abundances in the end of summer. The presence of fishes confirms that this kind of wetland plays an important trophic and nursery role for these species. Differences in densities and stages distribution of these species into Mont Saint-Michel systems (tidal mudflats, estuaries and tidal salt marshes) can reduce the trophic

  17. Environmental Determinants Influencing Fish Community Structure and Diversity in Two Distinct Seasons among Wetlands of Northern Region (Ghana

    Directory of Open Access Journals (Sweden)

    Collins Ayine Nsor

    2016-01-01

    Full Text Available Fish community structure was assessed in six wetlands using cast nets, to correlate with environmental variables with diversity and distribution patterns, from 2010 to 2012. A total of 2,239 individuals belonging to 44 species and 1,938 individuals belonging to 40 species were sampled in the dry and wet seasons. Mochokid and Mormyrid families dominated fish community and constituted 14.8%, respectively, followed by Alestids (12.9% and Chlariids (11.1%. Rarer taxons were centropomids, channids, malapteruds, and oesteoglossids and represented 1.9%, respectively. Overall, CPUE per net did not vary significantly (Tukey HSD test, p=0.27 in the dry and wet seasons. Wuntori marsh consistently showed dominance in mean monthly CPUE per net (dry = 115±4.5; wet = 107±7.7 seasons, while Bunglung constructed wetland was the least recorded (dry = 56.5±6.2; wet = 58.3±4.1 seasons. Fish diversity and richness differed significantly (F=0.11, p=0.03 among seasons. Environmental disturbances were season-specific and did not differ significantly (F=0.16, df=14, p=0.97 among sites. A DCA ordination explained 69% variability in fish distribution patterns, while PCA showed that 81.8% of nitrate-nitrogen, phosphate, and grazing intensity on axis 1 and conductivity, temperature, and turbidity on axis 2 influenced fish community structure. Wetland conservation must be promoted to sustain fish abundance and overall ecosystem stability.

  18. Tailoring an Alcohol Intervention for American Indian Alaska Native Women of Childbearing Age: Listening to the Community.

    Science.gov (United States)

    Montag, Annika C; Dusek, Marlené L; Ortega, Marina L; Camp-Mazzetti, Alexandrea; Calac, Dan J; Chambers, Christina D

    2017-11-01

    Reduction of risky drinking in women of childbearing age is 1 strategy that may be employed to prevent fetal alcohol spectrum disorder, a sequela of prenatal alcohol exposure. Communities differ in risk and protective factors, necessitating culturally informed interventions for maximal efficacy. This article describes the modification of an existing web-based screening, brief intervention, and referral to treatment intervention to reduce risky drinking among American Indian Alaska Native (AIAN) women of childbearing age in Southern California into a peer-to-peer-based intervention using motivational interviewing (MI). The modification process was iterative and included various community focus groups, interviews, and a final review. Intervention modification was required for cultural congruence. Components of the peer-to-peer intervention designed by this project included a flip chart used to guide the motivational interviewing, charts of the financial and physical costs of alcohol consumption, revised baseline and follow-up questionnaires, and guidance regarding the application of MI techniques. This study may inform the modification of future interventions among AIAN communities. Copyright © 2017 by the Research Society on Alcoholism.

  19. Conservation of Native Fishes of the San Francisco Estuary: Considerations for Artificial Propagation of Chinook Salmon, Delta Smelt, and Green Sturgeon

    Directory of Open Access Journals (Sweden)

    Joshua A. Israel

    2011-04-01

    Full Text Available Many native fishes in the San Francisco Estuary and its watersheds have reached all-time low abundances. Some of these declining species (e.g., Chinook salmon Oncorhynchus tschawytscha have been under artificial propagation for decades. For others (e.g., delta smelt, Hypomesus transpacificus, and green sturgeon, Acipenser medirostris, this management option is just beginning to be discussed and implemented. Propagation strategies, in which organisms spend some portion of their lives in captivity, pose well-documented genetic and ecological threats to natural populations. Negative impacts of propagation have been documented for all Central Valley Chinook salmon runs, but limited efforts have been made to adapt hatchery operations to minimize the genetic and ecological threats caused by propagated fishes. A delta smelt propagation program is undergoing intensive design and review for operations and monitoring. However, if limiting factors facing this species in its estuarine habitat are not effectively addressed, captive propagation may not be a useful conservation approach, regardless of how carefully the propagation activity is designed or monitored. Scientifically defensible, ecologically based restoration programs that include monitoring and research aimed at quantifying natural population vital rates should be fully implemented before there is any attempt to supplement natural populations of delta smelt. Green sturgeon are also likely to face risks from artificial propagation if a large–scale program is implemented before this species’ limiting factors are better understood. In each of these cases, restoring habitats, and reducing loss from human actions, are likely to be the best strategy for rebuilding and supporting self–sustaining populations.

  20. Host specificity and the structure of helminth parasite communities of fishes in a Neotropical river in Mexico

    Science.gov (United States)

    Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa; Caspeta-Mandujano, Juan Manuel; Vazquez-Hurtado, Gabriela; Quiroz-Martínez, Benjamin; Mercado-Silva, Norman; Favila, Mario

    2016-01-01

    In a tropical locality of Río La Antigua, Veracruz, Mexico, 11 fish species, represented by 244 individual fish from six freshwater fish families living sympatrically and synchronically, were examined for helminth parasites. A total of 36 taxa of helminths were recorded, 24 autogenic and 12 allogenic forms, including 6 monogeneans, 14 trematodes, 1 cestode, and 15 nematodes. Most helminth taxa were recovered for 10/11 of the component communities we analyzed. The results contribute empirical evidence that host specificity is an important force in the development of helminth communities of freshwater fishes. Each fish family has their own set of parasites, host species belonging to the same taxon share parasite species. High component community similarity among related host species was recorded, demonstrated by high prevalence and abundance, as well as dominance, of autogenic specialist species in each component community. Most autogenic helminth species are numerically and reproductively successful in relatively few host species. Autogenic helminths common in one host species are not common in others. Our findings give empirical support to the idea that low levels of sharing of parasites favor animal coexistence and high species richness, because large phylogenetic differences allow potentially competing animals to consume the same resources without being sensitive of another’s parasites. PMID:28004635

  1. Biodiversity and spatial patterns of benthic habitat and associated demersal fish communities at two tropical submerged reef ecosystems

    Science.gov (United States)

    Abdul Wahab, Muhammad Azmi; Radford, Ben; Cappo, Mike; Colquhoun, Jamie; Stowar, Marcus; Depczynski, Martial; Miller, Karen; Heyward, Andrew

    2018-06-01

    Submerged reef ecosystems can be very diverse and may serve as important refugia for shallow-water conspecifics. This study quantified the benthic and fish communities of two proximate, predominantly mesophotic coral ecosystems (MCEs), Glomar Shoal and Rankin Bank, which are geographically isolated from other similar features in the region. Glomar Shoal is identified as a key ecological feature (KEF) in the North West Marine Region of Australia. Multibeam surveys were performed to characterise the seafloor and to derive secondary environmental variables, used to explain patterns in benthic and fish communities. Towed video surveys quantified benthic cover, and stereo baited remote underwater stations were used to survey fish abundance and diversity. Surveys were completed in depths of 20-115 m. The two MCEs exhibited distinct communities; Rankin Bank consistently had higher cover (up to 30×) of benthic taxa across depths, and fish communities that were twice as abundant and 1.5× more diverse than Glomar Shoal. The location of the MCEs, depth and rugosity were most influential in structuring benthic communities. Phototrophic taxa, specifically macroalgae and hard corals, had up to 22 × higher cover at Rankin Bank than at Glomar Shoal and were dominant to 80 m (compared to 60 m at Glomar Shoal), presumably due to greater light penetration (lower turbidity) and lower sand cover at greater depths. The 20% coral cover at Rankin Bank was comparable to that reported for shallow reefs. The cover of sand, hard corals and sponges influenced fish communities, with higher abundance and diversity of fish associated with shallow hard coral habitats. This study demonstrated that the two MCEs were unique within the local context, and when coupled with their geographical isolation and biodiversity, presents compelling support for the additional recognition of Rankin Bank as a KEF.

  2. Rapidly shifting baselines in Yangtze fishing communities and local memory of extinct species.

    Science.gov (United States)

    Turvey, Samuel T; Barrett, Leigh A; Yujiang, Hao; Lei, Zhang; Xinqiao, Zhang; Xianyan, Wang; Yadong, Huang; Kaiya, Zhou; Hart, Tom; Ding, Wang

    2010-06-01

    Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create "shifting baseline syndrome," in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of "community memory" of extinct species on the basis of extensive interviews with fishers in communities across the middle-lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21(st) century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves' shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to

  3. Fish-mediated changes in bacterioplankton community composition: an in situ mesocosm experiment

    Science.gov (United States)

    Luo, Congqiang; Yi, Chunlong; Ni, Leyi; Guo, Longgen

    2017-06-01

    We characterized variations in bacterioplankton community composition (BCC) in mesocosms subject to three different treatments. Two groups contained fish (group one: Cyprinus carpio; group two: Hypophthalmichthys molitrix); and group three, the untreated mesocosm, was the control. Samples were taken seven times over a 49-day period, and BCC was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (qPCR). Results revealed that introduction of C. carpio and H. molitrix had a remarkable impact on the composition of bacterioplankton communities, and the BCC was significantly different between each treatment. Sequencing of DGGE bands revealed that the bacterioplankton community in the different treatment groups was consistent at a taxonomic level, but differed in its abundance. H. molitrix promoted the richness of Alphaproteobacteria and Actinobacteria, while more bands affiliated to Cyanobacteria were detected inC. carpio mesocosms. The redundancy analysis (RDA) result demonstrated that the BCC was closely related to the bottom-up (total phosphorus, chlorophyll a, phytoplankton biomass) and top-down forces (biomass of copepods and cladocera) in C. carpio and control mesocosms, respectively. We found no evidence for top-down regulation of BCC by zooplankton in H. molitrix mesocosms, while grazing by protozoa (heterotrophic nanoflagellates, ciliates) became the major way to regulate BCC. Total bacterioplankton abundances were significantly higher in C. carpio mesocosms because of high nutrient concentration and suspended solids. Our study provided insights into the relationship between fish and bacterioplankton at species level, leading to a deep understanding of the function of the microbial loop and the aquatic ecosystem.

  4. Fish-mediated changes in bacterioplankton community composition: an in situ mesocosm experiment

    Science.gov (United States)

    Luo, Congqiang; Yi, Chunlong; Ni, Leyi; Guo, Longgen

    2018-03-01

    We characterized variations in bacterioplankton community composition (BCC) in mesocosms subject to three different treatments. Two groups contained fish (group one: Cyprinus carpio; group two: Hypophthalmichthys molitrix); and group three, the untreated mesocosm, was the control. Samples were taken seven times over a 49-d period, and BCC was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (qPCR). Results revealed that introduction of C. carpio and H. molitrix had a remarkable impact on the composition of bacterioplankton communities, and the BCC was significantly different between each treatment. Sequencing of DGGE bands revealed that the bacterioplankton community in the different treatment groups was consistent at a taxonomic level, but differed in its abundance. H. molitrix promoted the richness of Alphaproteobacteria and Actinobacteria, while more bands affiliated to Cyanobacteria were detected in C. carpio mesocosms. The redundancy analysis (RDA) result demonstrated that the BCC was closely related to the bottom-up (total phosphorus, chlorophyll a, phytoplankton biomass) and top-down forces (biomass of copepods and cladocera) in C. carpio and control mesocosms, respectively. We found no evidence for top-down regulation of BCC by zooplankton in H. molitrix mesocosms, while grazing by protozoa (heterotrophic nanoflagellates, ciliates) became the major way to regulate BCC. Total bacterioplankton abundances were significantly higher in C. carpio mesocosms because of high nutrient concentration and suspended solids. Our study provided insights into the relationship between fish and bacterioplankton at species level, leading to a deep understanding of the function of the microbial loop and the aquatic ecosystem.

  5. Individual-based analyses reveal limited functional overlap in a coral reef fish community.

    Science.gov (United States)

    Brandl, Simon J; Bellwood, David R

    2014-05-01

    Detailed knowledge of a species' functional niche is crucial for the study of ecological communities and processes. The extent of niche overlap, functional redundancy and functional complementarity is of particular importance if we are to understand ecosystem processes and their vulnerability to disturbances. Coral reefs are among the most threatened marine systems, and anthropogenic activity is changing the functional composition of reefs. The loss of herbivorous fishes is particularly concerning as the removal of algae is crucial for the growth and survival of corals. Yet, the foraging patterns of the various herbivorous fish species are poorly understood. Using a multidimensional framework, we present novel individual-based analyses of species' realized functional niches, which we apply to a herbivorous coral reef fish community. In calculating niche volumes for 21 species, based on their microhabitat utilization patterns during foraging, and computing functional overlaps, we provide a measurement of functional redundancy or complementarity. Complementarity is the inverse of redundancy and is defined as less than 50% overlap in niche volumes. The analyses reveal extensive complementarity with an average functional overlap of just 15.2%. Furthermore, the analyses divide herbivorous reef fishes into two broad groups. The first group (predominantly surgeonfishes and parrotfishes) comprises species feeding on exposed surfaces and predominantly open reef matrix or sandy substrata, resulting in small niche volumes and extensive complementarity. In contrast, the second group consists of species (predominantly rabbitfishes) that feed over a wider range of microhabitats, penetrating the reef matrix to exploit concealed surfaces of various substratum types. These species show high variation among individuals, leading to large niche volumes, more overlap and less complementarity. These results may have crucial consequences for our understanding of herbivorous processes on

  6. Variation in fish community structure, richness and diversity of 56 Danish lakes with contrasting depth and trophic state: Does the method matter?

    DEFF Research Database (Denmark)

    Menezes, Rosemberg

    2011-01-01

    The understanding of the variables that determine the structure and composition of fish communities is crucial for developing fish monitoring programs for lakes. Although electrofishing has long been recognized as an efficient method for quantitative investigations of fish populations, it has typ...... are not well caught in the gill nets such as eel, common carp (Carassius carassius) and stickleback (Gasterosteus aculeatus)....

  7. 78 FR 25473 - Information Collection: Northern Alaska Native Community Surveys; Proposed Collection for OMB...

    Science.gov (United States)

    2013-05-01

    ...). An action's ``aesthetic, historic, cultural, economic, social or health'' effects must be assessed... subsistence (harvest data) and sharing networks of the communities. The Social Indicators Study will be given... use a systematic, interdisciplinary approach to ensure the integrated use of the natural and social...

  8. Current and potential use of broadleaf herbs for reestablishing native communities

    Science.gov (United States)

    Scott C. Walker; Nancy L. Shaw

    2005-01-01

    Use of forbs for revegetation in the Intermountain West has been problematic due to the large number of species and lack of research data. Some forbs are found in numerous plant communities and distributed over wide geographic ranges while others are more narrowly adapted. Seed sources for revegetation use may be selected from species and ecotypes indigenous to the...

  9. Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen

    NARCIS (Netherlands)

    Do, Huyen Thi; Dao, Khoa Trong; Nguyen, Viet Khanh Hoang; Le Ngoc, Giang; Nguyen, Phuong Thi Mai; Le, Lam Tung; Phung, Nguyet Thu; M. van Straalen, Nico; Roelofs, Dick; Truong, Hai Nam

    2017-01-01

    Objective: In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats' rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen

  10. A Community Stakeholder Analysis of Drug Resistance Strategies of Rural Native Hawaiian Youth

    Science.gov (United States)

    Okamoto, Scott K.; Helm, Susana; Delp, Justin A.; Stone, Kristina; Dinson, Ay-Laina; Stetkiewicz, Jennifer

    2011-01-01

    This study examines and validates the drug resistance strategies identified by rural Hawaiian youth from prior research with a sample of community stakeholders on the Island of Hawai'i. One hundred thirty-eight stakeholders with a vested interest in reducing youth substance use (i.e., teachers, principals, social service agency providers, and…

  11. Aquatic macroinvertebrate responses to native and non-native predators

    Directory of Open Access Journals (Sweden)

    Haddaway N. R.

    2014-01-01

    Full Text Available Non-native species can profoundly affect native ecosystems through trophic interactions with native species. Native prey may respond differently to non-native versus native predators since they lack prior experience. Here we investigate antipredator responses of two common freshwater macroinvertebrates, Gammarus pulex and Potamopyrgus jenkinsi, to olfactory cues from three predators; sympatric native fish (Gasterosteus aculeatus, sympatric native crayfish (Austropotamobius pallipes, and novel invasive crayfish (Pacifastacus leniusculus. G. pulex responded differently to fish and crayfish; showing enhanced locomotion in response to fish, but a preference for the dark over the light in response to the crayfish. P.jenkinsi showed increased vertical migration in response to all three predator cues relative to controls. These different responses to fish and crayfish are hypothesised to reflect the predators’ differing predation types; benthic for crayfish and pelagic for fish. However, we found no difference in response to native versus invasive crayfish, indicating that prey naiveté is unlikely to drive the impacts of invasive crayfish. The Predator Recognition Continuum Hypothesis proposes that benefits of generalisable predator recognition outweigh costs when predators are diverse. Generalised responses of prey as observed here will be adaptive in the presence of an invader, and may reduce novel predators’ potential impacts.

  12. Market access and community size influence pastoral management of native and exotic livestock species: A case study in communities of the Cordillera Real in Bolivia's high Andean wetlands.

    Directory of Open Access Journals (Sweden)

    Quentin Struelens

    Full Text Available Grazing areas management is of utmost importance in the Andean region. In the valleys of the Bolivian Cordillera Real near La Paz, pastoralism constitutes the traditional way for people to insure food security and economical sustainability. In these harsh mountains, unique and productive wetlands sustained by glacial water streams are of utmost importance for feeding cattle herds during the dry season. After the colonization by the Spanish, a shift in livestock species has been observed, with the introduction of exotic species such as cows and sheep, resulting in a different impact on pastures compared to native camelid species-llamas and alpacas. Here we explored some of the social-economical and environmental drivers that motivate Bolivian pastoralists to prefer exotic over native livestock species, based on 36 household surveys in the Cordillera Real. We constructed a Partial Least Squares Structural Equation Model in order to assess the relationships between these drivers. Our results suggest that the access to market influenced pastoralists to reshape their herd composition, by increasing the number of sheep. They also suggest that community size increased daily grazing time in pastures, therefore intensifying the grazing pressure. At a broader scale, this study highlights the effects of some social-economical and environmental drivers on mountain herding systems.

  13. Market access and community size influence pastoral management of native and exotic livestock species: A case study in communities of the Cordillera Real in Bolivia's high Andean wetlands.

    Science.gov (United States)

    Struelens, Quentin; Gonzales Pomar, Karina; Loza Herrera, Susi; Nina Huanca, Gaby; Dangles, Olivier; Rebaudo, François

    2017-01-01

    Grazing areas management is of utmost importance in the Andean region. In the valleys of the Bolivian Cordillera Real near La Paz, pastoralism constitutes the traditional way for people to insure food security and economical sustainability. In these harsh mountains, unique and productive wetlands sustained by glacial water streams are of utmost importance for feeding cattle herds during the dry season. After the colonization by the Spanish, a shift in livestock species has been observed, with the introduction of exotic species such as cows and sheep, resulting in a different impact on pastures compared to native camelid species-llamas and alpacas. Here we explored some of the social-economical and environmental drivers that motivate Bolivian pastoralists to prefer exotic over native livestock species, based on 36 household surveys in the Cordillera Real. We constructed a Partial Least Squares Structural Equation Model in order to assess the relationships between these drivers. Our results suggest that the access to market influenced pastoralists to reshape their herd composition, by increasing the number of sheep. They also suggest that community size increased daily grazing time in pastures, therefore intensifying the grazing pressure. At a broader scale, this study highlights the effects of some social-economical and environmental drivers on mountain herding systems.

  14. Speaking out about physical harms from tobacco use: response to graphic warning labels among American Indian/Alaska Native communities.

    Science.gov (United States)

    Patterson Silver Wolf, David A; Tovar, Molly; Thompson, Kellie; Ishcomer, Jamie; Kreuter, Matthew W; Caburnay, Charlene; Boyum, Sonia

    2016-03-23

    This study is the first to explore the impact of graphic cigarette labels with physical harm images on members of American Indian/Alaska Native (AI/AN) communities. The aim of this article is to investigate how AI/AN respond to particular graphic warning labels. The parent study recruited smokers, at-risk smokers and non-smokers from three different age groups (youths aged 13-17 years, young adults aged 18-24 years and adults aged 25+ years) and five population subgroups with high smoking prevalence or smoking risk. Using nine graphic labels, this study collected participant data in the field via an iPad-administered survey and card sorting of graphic warning labels. This paper reports on findings for AI/AN participants. After viewing graphic warning labels, participants rated their likelihood of talking about smoking risks to friends, parents and siblings higher than their likelihood of talking to teachers and doctors. Further, this study found that certain labels (eg, the label of the toddler in the smoke cloud) made them think about their friends and family who smoke. Given the influence of community social networks on health beliefs and attitudes, health communication using graphic warning labels could effect change in the smoking habits of AI/AN community members. Study findings suggest that graphic labels could serve as stimuli for conversations about the risks of smoking among AI/AN community members, and could be an important element of a peer-to-peer smoking cessation effort. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. An adaptive approach to invasive plant management on U.S. Fish and Wildlife Service-owned native prairies in the Prairie Pothole Region: decision support under uncertainity

    Science.gov (United States)

    Gannon, Jill J.; Moore, Clinton T.; Shaffer, Terry L.; Flanders-Wanner, Bridgette

    2011-01-01

    Much of the native prairie managed by the U.S. Fish and Wildlife Service (Service) in the Prairie Pothole Region (PPR) is extensively invaded by the introduced cool-season grasses smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. We describe the technical components of a USGS management project, and explain how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. In partnership with the Service, the U.S. Geological Survey is developing an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. The framework is built around practical constraints faced by refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen Service field stations, spanning four states of the PPR, are participating in the project. They share a common management objective, available management strategies, and biological uncertainties. While the scope is broad, the project interfaces with individual land managers who provide refuge-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators.

  16. Invasive non-native species of fish in upper Paraná river Basin, Brazil: variations of caloric content in Cichla kelberi

    Directory of Open Access Journals (Sweden)

    Luis Alberto Espínola

    Full Text Available The allocation of assimilated energy may be influenced by seasonal changes, growth, and reproductive cycle of fish, food consumption and environmental conditions. The objective of this research was to evaluate the energetic variations of Cichla kelberi in the upper Paraná River floodplain, analyzing the caloric content in muscles, gonadosomatic index (GSI, and the condition factor between assessed systems, sex, and stage of gonadal maturation. The results obtained in the present study permit assuring that this is a species that efficiently converts the resources of the environment into energy. Although presenting higher condition factor in the environment where there is a greater ease in getting food (Paraná subsystem, the energy identified in the muscles was the same in both subsystems. During the process of gonadal maturation there is optimization in energy accumulation in the muscles of females, before and after reproductive period, and somatic growth occurs significantly when the individual is not reproducing. Further detailed studies on ecological mechanisms influencing the success of the species, as the presence of competitors and preference for native preys, are needed to implement effective management measures aimed at preventing that the species proliferation in the environment is even more damaging to local biodiversity.

  17. Coding early naturalists' accounts into long-term fish community changes in the Adriatic Sea (1800-2000.

    Directory of Open Access Journals (Sweden)

    Tomaso Fortibuoni

    Full Text Available The understanding of fish communities' changes over the past centuries has important implications for conservation policy and marine resource management. However, reconstructing these changes is difficult because information on marine communities before the second half of the 20(th century is, in most cases, anecdotal and merely qualitative. Therefore, historical qualitative records and modern quantitative data are not directly comparable, and their integration for long-term analyses is not straightforward. We developed a methodology that allows the coding of qualitative information provided by early naturalists into semi-quantitative information through an intercalibration with landing proportions. This approach allowed us to reconstruct and quantitatively analyze a 200-year-long time series of fish community structure indicators in the Northern Adriatic Sea (Mediterranean Sea. Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species. This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources. To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

  18. From native to outlander: exploring informal community in Chengzhongcun of China

    Directory of Open Access Journals (Sweden)

    Xue Ni PENG

    2014-12-01

    Full Text Available In the existing research on Chinese migration, rural domestic Chinese migrants are often portrayed as a community of intruders with a detached culture who invade a host destination city. Usually, as a first step, they settle down in a so-called “Chengzhongcun” (literally a village encircled by the city boundaries, hereafter CZC, which is a kind of “urban village”, or an undeveloped part of a city that is overshadowed by the more developed areas. The present paper tries to give an image of the rural-to-urban migrants as a more vigorous mediator that forms their migration destination. The aims are the following: first, to achieve a detailed written analysis of an existing CZC community and its functioning as a mirror of the discriminating division between the rural and urban life in China. Secondly, by taking into account the experiences of migrant communities in their host cities, this paper seeks to highlight the migrants' emotional conflict and increasing loss of values that occurs in the migration process from the rural to the urban. Thirdly, the migrants' household survival strategies shall be explored. Finally, weaving these strands together, this paper presents a case study of a Tulou collective housing project in Guangzhou Province, China.

  19. Exploring the larval fish community of the central Red Sea with an integrated morphological and molecular approach

    KAUST Repository

    Isari, Stamatina

    2017-08-03

    An important aspect of population dynamics for coral reef fishes is the input of new individuals from the pelagic larval pool. However, the high biodiversity and the difficulty of identifying larvae of closely related species represent obstacles to more fully understanding these populations. In this study, we combined morphology and genetic barcoding (Cytochrome Oxidase I gene) to characterize the seasonal patterns of the larval fish community at two sites in close proximity to coral reefs in the central-north Red Sea: one shallower inshore location (50 m depth) and a nearby site located in deeper and more offshore waters (~ 500 m depth). Fish larvae were collected using oblique tows of a 60 cm-bongo net (500 μm mesh size) every month for one year (2013). During the warmer period of the year (June-November), the larval fish stock was comparable between sampling sites. However, during the colder months, abundances were higher in the inshore than in the offshore waters. Taxonomic composition and temporal variation of community structure differed notably between sites, potentially reflecting habitat differences, reproductive patterns of adults, and/or advective processes in the area. Eleven out of a total of 62 recorded families comprised 69–94% of the fish larval community, depending on sampling site and month. Richness of taxa was notably higher in the inshore station compared to the offshore, particularly during the colder period of the year and especially for the gobiids and apogonids. Two mesopelagic taxa (Vinciguerria sp. and Benthosema spp.) comprised an important component of the larval community at the deeper site with only a small and sporadic occurrence in the shallower inshore waters. Our data provide an important baseline reference for the larval fish communities of the central Red Sea, representing the first such study from Saudi Arabian waters.

  20. Potential impacts of sea level rise on native plant communities and associated cultural sites in coastal areas of the main Hawaiian Islands

    Science.gov (United States)

    Jacobi, James D.; Warshauer, Frederick R.

    2017-01-01

    Hawaiian coastal vegetation is comprised of plant species that are adapted to growing in extremely harsh conditions (salt spray, wave wash, wind, and substrates with limited nutrients) found in this habitat zone. Prior to human colonization of Hawai‘i coastal vegetation extended as a continuous ring around each of the islands, broken only by stretches of recent lava flows or unstable cliff faces. However, since humans arrived in Hawai‘i many areas that originally supported native coastal plant communities have been highly altered or the native vegetation totally removed for agriculture, housing, or resort development, destroyed by fire, displaced by invasive plants, eaten by introduced mammals, or damaged by recreational use. This study was focused on identifying sites that still retain relatively intact and highly diverse native coastal plant communities throughout the main Hawaiian Islands that may be further impacted by projected sea level rise. Approximately 40 percent of Hawai‘i’s coastlines were found to still contain high quality native coastal plant communities. Most of these sites were located in areas where the coastal vegetation can still migrate inshore in response to rising sea level and associated inundation by waves. However, six sites with high-quality native coastal vegetation were found on low-lying offshore islets that will be totally inundated with a one meter increase in sea level and thirty sites were found to have some type of fixed barrier, such as a paved road or structure, which would restrict the plants from colonizing the adjacent inland areas. Many of these sites also have other cultural resources that are fixed in place and will definitely be impacted by rising sea level. The results of this study can help refine our understanding of Hawai‘i’s remaining native coastal vegetation and aid with the development of management and restoration strategies to ensure the long-term survival of these unique plant communities.

  1. Environmental changes on freshwater fish communities in South America in the last five decades: a case study in northeast Argentina.

    Directory of Open Access Journals (Sweden)

    Alejandra Volpedo

    2017-01-01

    Full Text Available Environmental changes together with other stressors, such as habitat destruction, may cause widespread extinctions, decrease in biodiversity and disrupt natural communities, resulting in novel species assemblages. South America has a large diversity of freshwater fishes with complex evolutionary histories, mainly due to the presence of a wide variety of aquatic environments. Argentina has experienced an increase in rainfall in the last five decades leading to important climatic and hydrological changes. These changes caused the displacement of the isohyets towards the west. This study reports changes in the composition of freshwater fishes in northeast Argentina during the last five decades, and investigated a causal relationship between the variation in fish assemblages and climate change. The changes in the distribution and composition of fish communities between 1962 and 2010 were analyzed in 22 stations. These stations were agrouped in relation to the ichthyogeographic provinces: Great Rivers province (GRp and Pampean province (Pp. The correlation between rainfall in relation to the number total species from each of the studied provinces showed a significant positive correlation in Pp and not correlation in GRp. The annual mean river discharge and the number of total species from each ecoregion showed a significant positive correlation in GRp, and not correlation in Pp. The results of this study strongly suggest that the rainfall variations and river discharges observed in northeast Argentina induced changes in the composition of fish assemblages that lead to the redistribution of fish species among ichthyogeographic provinces.

  2. Alcohol consumption and risky sexual behaviour in the fishing communities: evidence from two fish landing sites on Lake Victoria in Uganda.

    Science.gov (United States)

    Tumwesigye, Nazarius M; Atuyambe, Lynn; Wanyenze, Rhoda K; Kibira, Simon Ps; Li, Qing; Wabwire-Mangen, Fred; Wagner, Glenn

    2012-12-11

    The fishing communities are among population groups that are most at risk of HIV infection, with some studies putting the HIV prevalence at 5 to 10 times higher than in the general population. Alcohol consumption has been identified as one of the major drivers of the sexual risk behaviour in the fishing communities. This paper investigates the relationship between alcohol consumption patterns and risky behaviour in two fishing communities on Lake Victoria. Face-to-face interviews were conducted among 303 men and 172 women at the fish landing sites; categorised into fishermen, traders of fish or fish products and other merchandise, and service providers such as casual labourers and waitresses in bars and hotels, including 12 female sexual workers. Stratified random sampling methodology was used to select study units. Multivariable analysis was conducted to assess independent relationship between alcohol consumption and sexual risky behaviour. Measures of alcohol consumption included the alcohol use disorder test score (AUDIT), having gotten drunk in previous 30 days, drinking at least 2 times a week while measures for risky behaviour included engaging in transactional sex, inconsistent condom use, having sex with non-regular partner and having multiple sexual partners. The level of harmful use of alcohol in the two fishing communities was quite high as 62% of the male and 52% of the female drinkers had got drunk in previous 30 days. The level of risky sexual behaviour was equally high as 63% of the men and 59% of the women had unprotected sex at last sexual event. Of the 3 occupations fishermen had the highest levels of harmful use of alcohol and risky sexual behaviour followed by service providers judging from values of most indicators. The kind of alcohol consumption variables correlated with risky sexual behaviour variables, varied by occupation. Frequent alcohol consumption, higher AUDIT score, having got drunk, longer drinking hours and drinking any day of

  3. Alcohol consumption and risky sexual behaviour in the fishing communities: evidence from two fish landing sites on Lake Victoria in Uganda

    Directory of Open Access Journals (Sweden)

    Tumwesigye Nazarius M

    2012-12-01

    Full Text Available Abstract Background The fishing communities are among population groups that are most at risk of HIV infection, with some studies putting the HIV prevalence at 5 to 10 times higher than in the general population. Alcohol consumption has been identified as one of the major drivers of the sexual risk behaviour in the fishing communities. This paper investigates the relationship between alcohol consumption patterns and risky behaviour in two fishing communities on Lake Victoria. Methods Face-to-face interviews were conducted among 303 men and 172 women at the fish landing sites; categorised into fishermen, traders of fish or fish products and other merchandise, and service providers such as casual labourers and waitresses in bars and hotels, including 12 female sexual workers. Stratified random sampling methodology was used to select study units. Multivariable analysis was conducted to assess independent relationship between alcohol consumption and sexual risky behaviour. Measures of alcohol consumption included the alcohol use disorder test score (AUDIT, having gotten drunk in previous 30 days, drinking at least 2 times a week while measures for risky behaviour included engaging in transactional sex, inconsistent condom use, having sex with non-regular partner and having multiple sexual partners. Results The level of harmful use of alcohol in the two fishing communities was quite high as 62% of the male and 52% of the female drinkers had got drunk in previous 30 days. The level of risky sexual behaviour was equally high as 63% of the men and 59% of the women had unprotected sex at last sexual event. Of the 3 occupations fishermen had the highest levels of harmful use of alcohol and risky sexual behaviour followed by service providers judging from values of most indicators. The kind of alcohol consumption variables correlated with risky sexual behaviour variables, varied by occupation. Frequent alcohol consumption, higher AUDIT score, having

  4. The community structure of over-wintering larval and small juvenile fish in a large estuary

    Science.gov (United States)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele; Rudolphi, Ann-Christin

    2014-02-01

    The Skagerrak and Kattegat are estuarine straits of high hydrographical and ecological diversity, situated between the saline waters of the North Sea and the brackish waters of the Baltic Sea. These sustain important nursery grounds of many fish species, of which several overwinter during the larval and early juvenile stages. In order to give more insight into the communities of the overwintering ichthyoplankton in estuarine areas, we examine an annual series of observations from a standard survey carried out 1992-2010. Species differences and annual variability in distributions and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed large annual fluctuations in abundances. The species showed quite specific patterns of distribution although species assemblages with common distributional characteristics were identified. Within these assemblages, the ichthyoplankton abundances showed linkage to environmental characteristics described by bottom-depth and surface temperature and salinity. Hence the study points to a significant structuring of overwintering ichthyoplankton communities in large estuaries, based on the species habitat choice and its response to physical gradients.

  5. Functional diversity and redundancy across fish gut, sediment and water bacterial communities.

    Science.gov (United States)

    Escalas, Arthur; Troussellier, Marc; Yuan, Tong; Bouvier, Thierry; Bouvier, Corinne; Mouchet, Maud A; Flores Hernandez, Domingo; Ramos Miranda, Julia; Zhou, Jizhong; Mouillot, David

    2017-08-01

    This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. The Effects of Crop Intensification on the Diversity of Native Pollinator Communities.

    Science.gov (United States)

    Mogren, Christina L; Rand, Tatyana A; Fausti, Scott W; Lundgren, Jonathan G

    2016-08-01

    Increases in agricultural conversion are leading to declines in native grasslands and natural resources critical for beneficial insects. However, little is known regarding how these changes affect pollinator diversity. Land use types were categorized within 300 m and 3 km radii of pollinator sampling locations in Brookings County, SD. Pollinator abundance and species richness were regressed on the proportion of the landscape dedicated to row crops, grass and pasture, forage crops, small grains, and aquatic habitats using variance components modeling. Row crops had a negative effect on bee abundance at 300 m, after fixed effects modeling accounted for outliers skewing this relationship. At 3 km, corn positively affected bee abundance and richness, while soybean acreage decreased species richness. The landscape matrix of outlying sites consisted of large monocultured areas with few alternative habitat types available, leading to inflated populations of Melissodes and Halictidae. Syrphids had a positive parabolic relationship between diversity and row crops, indicating potential for competitive exclusion from intermediate landscapes. Unlike other studies, landscape diversity within 300 m was not found to significantly benefit pollinator diversity. Within especially agriculturally developed areas of the region, high abundances of pollinators suggest selection for a few dominant species. There was no effect of forage crops or aquatic habitats on pollinator diversity, indicating that less highly managed areas still represent degraded habitat within the landscape. Incorporating pollinator-friendly crops at the farm level throughout the region is likely to enhance pollinator diversity by lessening the negative effects of large monocultures. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Variation in fish community structure, richness, and diversity in 56 Danish lakes with contrasting depth, size, and trophic state: does the method matter?

    DEFF Research Database (Denmark)

    Menezes, Rosemberg; Borchsenius, Finn; Svenning, J.-C.

    2013-01-01

    a better understanding of fish communities. We compare fish community composition, richness, and diversity in 56 Danish lakes using data obtained by gillnetting in different lake zones and near-shore electrofishing, respectively. On average, electrofishing captured more species than offshore gillnets......, but not more than littoral gillnets. Overall, the different fish sampling methods showed consistency as to fish community structure, but noticeable differences in community–environment relationships. Lake area was the best predictor for fish species richness in the littoral samplings, while it was poor...... community, as all methods miss some important species that other methods capture. However, electrofishing seems to be a fast alternative to gillnets for monitoring fish species richness and composition in littoral habitats of Danish lakes....

  8. Using fish communities to assess streams in Romania: Initial development of an index of biotic integrity

    Science.gov (United States)

    Angermeier, P.L.; Davideanu, G.

    2004-01-01

    Multimetric biotic indices increasingly are used to complement physicochemical data in assessments of stream quality. We initiated development of multimetric indices, based on fish communities, to assess biotic integrity of streams in two physiographic regions of central Romania. Unlike previous efforts to develop such indices for European streams, our metrics and scoring criteria were selected largely on the basis of empirical relations in the regions of interest. We categorised 54 fish species with respect to ten natural-history attributes, then used this information to compute 32 candidate metrics of five types (taxonomic, tolerance, abundance, reproductive, and feeding) for each of 35 sites. We assessed the utility of candidate metrics for detecting anthropogenic impact based on three criteria: (a) range of values taken, (b) relation to a site-quality index (SQI), which incorporated information on hydrologic alteration, channel alteration, land-use intensity, and water chemistry, and (c) metric redundancy. We chose seven metrics from each region to include in preliminary multimetric indices (PMIs). Both PMIs included taxonomic, tolerance, and feeding metrics, but only two metrics were common to both PMIs. Although we could not validate our PMIs, their strong association with the SQI in each region suggests that such indices would be valuable tools for assessing stream quality and could provide more comprehensive assessments than the traditional approaches based solely on water chemistry.

  9. The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

    Science.gov (United States)

    Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

    2015-07-01

    Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile

  10. Appropriate Model for Zoning Local Fish Conservation in front of Buddhist Temple on the Bank of the Chi River by Sustainable Community Participation

    OpenAIRE

    Somchob Poo-Inna; Song-Koon Jantakajon; Terdthai Pantachai

    2009-01-01

    Problem statement: The fresh water fish in The Chi River was a major source of food of people living in this area. The objectives of this research were: (1) to study the historical background, current situation and problems of local fish conservation in front of The Chi River by community participation and (2) to find the opriate model for zoning the local fish conservation on the bank of The Chi River by sustainable community participation. Approach: The research area in Esan Reg...

  11. Assessing Caribbean Shallow and Mesophotic Reef Fish Communities Using Baited-Remote Underwater Video (BRUV) and Diver-Operated Video (DOV) Survey Techniques

    Science.gov (United States)

    Macaya-Solis, Consuelo; Exton, Dan A.; Gress, Erika; Wright, Georgina; Rogers, Alex D.

    2016-01-01

    Fish surveys form the backbone of reef monitoring and management initiatives throughout the tropics, and understanding patterns in biases between techniques is crucial if outputs are to address key objectives optimally. Often biases are not consistent across natural environmental gradients such as depth, leading to uncertainty in interpretation of results. Recently there has been much interest in mesophotic reefs (reefs from 30–150 m depth) as refuge habitats from fishing pressure, leading to many comparisons of reef fish communities over depth gradients. Here we compare fish communities using stereo-video footage recorded via baited remote underwater video (BRUV) and diver-operated video (DOV) systems on shallow and mesophotic reefs in the Mesoamerican Barrier Reef, Caribbean. We show inconsistent responses across families, species and trophic groups between methods across the depth gradient. Fish species and family richness were higher using BRUV at both depth ranges, suggesting that BRUV is more appropriate for recording all components of the fish community. Fish length distributions were not different between methods on shallow reefs, yet BRUV recorded more small fish on mesophotic reefs. However, DOV consistently recorded greater relative fish community biomass of herbivores, suggesting that studies focusing on herbivores should consider using DOV. Our results highlight the importance of considering what component of reef fish community researchers and managers are most interested in surveying when deciding which survey technique to use across natural gradients such as depth. PMID:27959907

  12. Building research capacity with members of underserved American Indian/Alaskan Native communities: training in research ethics and the protection of human subjects.

    Science.gov (United States)

    Jetter, Karen M; Yarborough, Mark; Cassady, Diana L; Styne, Dennis M

    2015-05-01

    To develop a research ethics training course for American Indian/Alaskan Native health clinic staff and community researchers who would be conducting human subjects research. Community-based participatory research methods were used in facilitated discussions of research ethics centered around topics included in the Collaborative Institutional Training Initiative research ethics course. The community-based participatory research approach allowed all partners to jointly develop a research ethics training program that was relevant for American Indian/Alaskan Native communities. All community and clinic partners were able to pass the Collaborative Institutional Training Initiative course they were required to pass so that they could be certified to conduct research with human subjects on federally funded projects. In addition, the training sessions provided a foundation for increased community oversight of research. By using a collaborative process to engage community partners in research ethics discussions, rather than either an asynchronous online or a lecture/presentation format, resulted in significant mutual learning about research ethics and community concerns about research. This approach requires university researchers to invest time in learning about the communities in which they will be working prior to the training. © 2014 Society for Public Health Education.

  13. Impact of hydraulic well restoration on native bacterial communities in drinking water wells.

    Science.gov (United States)

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production system before, during, and after hydraulic purging. Variations were observed in bacterial communities between different wells of the same production system before maintenance, despite them having practically identical water chemistries. This may have reflected the distinct usage practices of the different wells, and also local aquifer heterogeneity. Hydraulic jetting of one well preferentially purged a subset of the dominating taxa, including lineages related to Diaphorobacter, Nitrospira, Sphingobium, Ralstonia, Alkanindiges, Janthinobacterium, and Pseudomonas spp, suggesting their tendency for growth in well-associated biofilms. Lineages of potential drinking water concern (i.e. Legionellaceae, Pseudomonadaceae, and Acinetobacter spp.) reacted distinctly to hydraulic jetting. Bacterial diversity was markedly reduced in drinking water 2 weeks after the cleaning procedure. The results of the present study provide a better understanding of drinking water wells as a microbial habitat, as well as their role in the microbiology of drinking water systems.

  14. Impact of Hydraulic Well Restoration on Native Bacterial Communities in Drinking Water Wells

    Science.gov (United States)

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production system before, during, and after hydraulic purging. Variations were observed in bacterial communities between different wells of the same production system before maintenance, despite them having practically identical water chemistries. This may have reflected the distinct usage practices of the different wells, and also local aquifer heterogeneity. Hydraulic jetting of one well preferentially purged a subset of the dominating taxa, including lineages related to Diaphorobacter, Nitrospira, Sphingobium, Ralstonia, Alkanindiges, Janthinobacterium, and Pseudomonas spp, suggesting their tendency for growth in well-associated biofilms. Lineages of potential drinking water concern (i.e. Legionellaceae, Pseudomonadaceae, and Acinetobacter spp.) reacted distinctly to hydraulic jetting. Bacterial diversity was markedly reduced in drinking water 2 weeks after the cleaning procedure. The results of the present study provide a better understanding of drinking water wells as a microbial habitat, as well as their role in the microbiology of drinking water systems. PMID:25273229

  15. Retention of habitat complexity minimizes disassembly of reef fish communities following disturbance: a large-scale natural experiment.

    Directory of Open Access Journals (Sweden)

    Michael J Emslie

    Full Text Available High biodiversity ecosystems are commonly associated with complex habitats. Coral reefs are highly diverse ecosystems, but are under increasing pressure from numerous stressors, many of which reduce live coral cover and habitat complexity with concomitant effects on other organisms such as reef fishes. While previous studies have highlighted the importance of habitat complexity in structuring reef fish communities, they employed gradient or meta-analyses which lacked a controlled experimental design over broad spatial scales to explicitly separate the influence of live coral cover from overall habitat complexity. Here a natural experiment using a long term (20 year, spatially extensive (∼ 115,000 kms(2 dataset from the Great Barrier Reef revealed the fundamental importance of overall habitat complexity for reef fishes. Reductions of both live coral cover and habitat complexity had substantial impacts on fish communities compared to relatively minor impacts after major reductions in coral cover but not habitat complexity. Where habitat complexity was substantially reduced, species abundances broadly declined and a far greater number of fish species were locally extirpated, including economically important fishes. This resulted in decreased species richness and a loss of diversity within functional groups. Our results suggest that the retention of habitat complexity following disturbances can ameliorate the impacts of coral declines on reef fishes, so preserving their capacity to perform important functional roles essential to reef resilience. These results add to a growing body of evidence about the importance of habitat complexity for reef fishes, and represent the first large-scale examination of this question on the Great Barrier Reef.

  16. Human activities as a driver of spatial variation in the trophic structure of fish communities on Pacific coral reefs.

    Science.gov (United States)

    Ruppert, Jonathan L W; Vigliola, Laurent; Kulbicki, Michel; Labrosse, Pierre; Fortin, Marie-Josée; Meekan, Mark G

    2018-01-01

    Anthropogenic activities such as land-use change, pollution and fishing impact the trophic structure of coral reef fishes, which can influence ecosystem health and function. Although these impacts may be ubiquitous, they are not consistent across the tropical Pacific Ocean. Using an extensive database of fish biomass sampled using underwater visual transects on coral reefs, we modelled the impact of human activities on food webs at Pacific-wide and regional (1,000s-10,000s km) scales. We found significantly lower biomass of sharks and carnivores, where there were higher densities of human populations (hereafter referred to as human activity); however, these patterns were not spatially consistent as there were significant differences in the trophic structures of fishes among biogeographic regions. Additionally, we found significant changes in the benthic structure of reef environments, notably a decline in coral cover where there was more human activity. Direct human impacts were the strongest in the upper part of the food web, where we found that in a majority of the Pacific, the biomass of reef sharks and carnivores were significantly and negatively associated with human activity. Finally, although human-induced stressors varied in strength and significance throughout the coral reef food web across the Pacific, socioeconomic variables explained more variation in reef fish trophic structure than habitat variables in a majority of the biogeographic regions. Notably, economic development (measured as GDP per capita) did not guarantee healthy reef ecosystems (high coral cover and greater fish biomass). Our results indicate that human activities are significantly shaping patterns of trophic structure of reef fishes in a spatially nonuniform manner across the Pacific Ocean, by altering processes that organize communities in both "top-down" (fishing of predators) and "bottom-up" (degradation of benthic communities) contexts. © 2017 John Wiley & Sons Ltd.

  17. Spatial variability in fish species assemblage and community structure in four subtropical lagoons of the Okavango Delta, Botswana

    Science.gov (United States)

    Mosepele, K.; Mosepele, B.; Bokhutlo, T.; Amutenya, K.

    The species assemblage and community structure of four lagoons was assessed through time series data collected between 2001 and 2005 in the Okavango Delta. The main aim of this study was to evaluate the importance of lagoons as fish habitats in the Delta. Therefore, this study assessed the importance of these habitats through determining fish species diversity, composition, relative abundance, and community structure between the lagoons. Forty six species belonging to 11 families and five orders were collected over the study period. Main results showed that Cichlidae was the most important family and had the highest species richness in the lagoons. Significant differences ( p lodges are constructed, which makes subsequently makes them vulnerable to pollution. Therefore, the integrity of lagoon habitats needs to be maintained so that their ecosystem functioning (i.e. fish repositories) is maintained.

  18. Hierarchical spatial structure of stream fish colonization and extinction

    Science.gov (United States)

    Hitt, N.P.; Roberts, J.H.

    2012-01-01

    Spatial variation in extinction and colonization is expected to influence community composition over time. In stream fish communities, local species richness (alpha diversity) and species turnover (beta diversity) are thought to be regulated by high extinction rates in headwater streams and high colonization rates in downstream areas. We evaluated the spatiotemporal structure of fish communities in streams originally surveyed by Burton and Odum 1945 (Ecology 26: 182-194) in Virginia, USA and explored the effects of species traits on extinction and colonization dynamics. We documented dramatic changes in fish community structure at both the site and stream scales. Of the 34 fish species observed, 20 (59%) were present in both time periods, but 11 (32%) colonized the study area and three (9%) were extirpated over time. Within streams, alpha diversity increased in two of three streams but beta diversity decreased dramatically in all streams due to fish community homogenization caused by colonization of common species and extirpation of rare species. Among streams, however, fish communities differentiated over time. Regression trees indicated that reproductive life-history traits such as spawning mound construction, associations with mound-building species, and high fecundity were important predictors of species persistence or colonization. Conversely, native fishes not associated with mound-building exhibited the highest rates of extirpation from streams. Our results demonstrate that stream fish colonization and extinction dynamics exhibit hierarchical spatial structure and suggest that mound-building fishes serve as keystone species for colonization of headwater streams.

  19. Disentangling the influences of habitat structure and limnological predictors on stream fish communities of a coastal basin, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Fabio Cop Ferreira

    Full Text Available In stream environments habitat structure and limnological factors interact regulating patterns of energy and material transfer and affecting fish communities. In the coastal basins of Southeastern Brazil, limnological and structural characteristics differ between clear and blackwaters streams. The former have a diversity of substrate types, higher water velocities, and lower water conductivity, while the latter have sandy substrate, tea-colored and acidic waters, and low water velocities. In this study, we verified the relative importance of habitat structure and limnological variables in predicting patterns of variation in stream fish communities. Eight first to third order streams were sampled in the coastal plain of Itanhaém River basin. We captured 34 fish species and verified that community structure was influenced by physical habitat and limnology, being the former more important. A fraction of the variation could not be totally decomposed, and it was assigned to the joint influence of limnology and habitat structure. Some species that were restricted to blackwater streams, may have physiological and behavioral adaptations to deal with the lower pH levels. When we examined only the clearwater streams, all the explained variation in fish community composition was assigned to structural factors, which express specific preferences for different types of habitats.

  20. Relationships between fish, sea urchins and macroalgae: The structure of shallow rocky sublittoral communities in the Cyclades, Eastern Mediterranean

    Science.gov (United States)

    Giakoumi, Sylvaine; Cebrian, Emma; Kokkoris, Giorgos D.; Ballesteros, Enric; Sala, Enric

    2012-08-01

    Historical overfishing is the most likely explanation for the depletion of the shallow sublittoral communities in many areas not least in the Cyclades Archipelago, Greece. The present study is the first quantitative study of the shallow rocky sublittoral of the Cyclades based on in situ underwater surveys of algal cover, and fish and sea urchin abundance at 181 sampling sites in 25 islands to provide a baseline and investigate the relationship between these communities. Algal turf was the most abundant algal functional group, and canopy algae of the genus Cystoseira were more abundant at the northern islands. A range in fish biomass of almost two orders of magnitude was found across islands, but overall the Cyclades displayed much lower values than fished areas of the Western Mediterranean. We observed apex predators only in 25% of our sampling sites, and their biomass was uncorrelated to total fish biomass, indicating a depleted ecosystem. Sea urchin biomass was also low but similar to values found in other Mediterranean islands and was positively correlated with barrens. We observed a gradient of benthic community complexity from sea urchin barrens to communities dominated by Cystoseira spp. There was no correlation between sea urchins and their predators Diplodus spp., which presented extremely low densities.

  1. Changes in marine fish community under influence of Leningrad nuclear power plant and another human activities in the watershed of Koporskaya Bay (Gulf of Finland, Baltic Sea)

    International Nuclear Information System (INIS)

    Zimin, V.L.

    1999-01-01

    The long-time observations (1978-1997) in the Leningrad nuclear power plant cooling water-body (Koporskaya Bay) in the frame of the Regional Ecological Monitoring Program provided reliable data on the local fish community state. Regular observations allow us to trace structural changes in fish community, because they follow changes on physiological and population levels in this community. 45 species of fishes and lamprey were recorded during all investigation period. However, the species diversity is very poor. Wittaker dominance-diversity curves reflect degradation in the coastal fish community being under influence of the complex industrial and agricultural factors. The fish community is now dominated by only 2-3 species, especially threespined stickleback and ninespined stickleback; while the first species more abundant then the second one as far as ∼10 times

  2. Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen.

    Science.gov (United States)

    Do, Thi Huyen; Dao, Trong Khoa; Nguyen, Khanh Hoang Viet; Le, Ngoc Giang; Nguyen, Thi Mai Phuong; Le, Tung Lam; Phung, Thu Nguyet; van Straalen, Nico M; Roelofs, Dick; Truong, Nam Hai

    2018-05-01

    In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats' rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen was conducted to elucidate a role of bacterial structure for effective degradation of plant materials. The metagenomic data had been subjected into Basic Local Alignment Search Tool (BLASTX) algorithm and the National Center for Biotechnology Information non-redundant sequence database. Here the BLASTX hits were further processed by the Metagenome Analyzer program to statistically analyze the abundance of taxa. Microbial community in the rumen is defined by dominance of Bacteroidetes compared to Firmicutes. The ratio of Firmicutes versus Bacteroidetes was 0.36:1. An abundance of Synergistetes was uniquely identified in the goat microbiome may be formed by host genotype.