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Sample records for atlantic bight zooplankton

  1. Diel Vertical Dynamics of Gelatinous Zooplankton (Cnidaria, Ctenophora and Thaliacea) in a Subtropical Stratified Ecosystem (South Brazilian Bight)

    OpenAIRE

    Nogueira Júnior, Miodeli; Brandini, Frederico Pereira; Codina, Juan Carlos Ugaz

    2015-01-01

    The diel vertical dynamics of gelatinous zooplankton in physically stratified conditions over the 100-m isobath (~110 km offshore) in the South Brazilian Bight (26°45’S; 47°33’W) and the relationship to hydrography and food availability were analyzed by sampling every six hours over two consecutive days. Zooplankton samples were taken in three depth strata, following the vertical structure of the water column, with cold waters between 17 and 13.1°C, influenced by the South Atlantic Central Wa...

  2. Biological processes in the water column of the South Atlantic bight. Progress report, July 12--August 20, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhofer, G.A.; Dunstan, W.M.

    1977-02-01

    Preliminary results are reported from a study of the relationship between intrusions of phytoplankton, zooplankton, and particulate matter in the South Atlantic Bight off the coast of Georgia and Northeast Florida. The relationship between temperature, chlorophyll, and particle volume in bottom water from various locations was determined and the data were correlated with data on water mass movements. Samples were collected from a ship following a specified grid pattern.

  3. Diel Vertical Dynamics of Gelatinous Zooplankton (Cnidaria, Ctenophora and Thaliacea in a Subtropical Stratified Ecosystem (South Brazilian Bight.

    Directory of Open Access Journals (Sweden)

    Miodeli Nogueira Júnior

    Full Text Available The diel vertical dynamics of gelatinous zooplankton in physically stratified conditions over the 100-m isobath (~110 km offshore in the South Brazilian Bight (26°45'S; 47°33'W and the relationship to hydrography and food availability were analyzed by sampling every six hours over two consecutive days. Zooplankton samples were taken in three depth strata, following the vertical structure of the water column, with cold waters between 17 and 13.1°C, influenced by the South Atlantic Central Water (SACW in the lower layer (>70 m; warm (>20°C Tropical Water in the upper 40 m; and an intermediate thermocline with a deep chlorophyll-a maximum layer (0.3-0.6 mg m-3. Two distinct general patterns were observed, emphasizing the role of (i physical and (ii biological processes: (i a strong influence of the vertical stratification, with most zooplankton absent or little abundant in the lower layer. The influence of the cold SACW on the bottom layer apparently restricted the vertical occupation of most species, which typically inhabit epipelagic warm waters. Even among migratory species, only a few (Aglaura hemistoma, Abylopsis tetragona eudoxids, Beroe sp., Thalia democratica, Salpa fusiformis crossed the thermocline and reached the bottom layer. (ii A general tendency of partial migrations, with variable intensity depending on the different species and developmental stages; populations tended to be more widely distributed through the water column during daylight, and to become more aggregated in the upper layer during the night, which can be explained based on the idea of the "hunger-satiation hypothesis", maximizing feeding and minimizing the chances of being predated.

  4. Diel Vertical Dynamics of Gelatinous Zooplankton (Cnidaria, Ctenophora and Thaliacea) in a Subtropical Stratified Ecosystem (South Brazilian Bight).

    Science.gov (United States)

    Nogueira Júnior, Miodeli; Brandini, Frederico Pereira; Codina, Juan Carlos Ugaz

    2015-01-01

    The diel vertical dynamics of gelatinous zooplankton in physically stratified conditions over the 100-m isobath (~110 km offshore) in the South Brazilian Bight (26°45'S; 47°33'W) and the relationship to hydrography and food availability were analyzed by sampling every six hours over two consecutive days. Zooplankton samples were taken in three depth strata, following the vertical structure of the water column, with cold waters between 17 and 13.1°C, influenced by the South Atlantic Central Water (SACW) in the lower layer (>70 m); warm (>20°C) Tropical Water in the upper 40 m; and an intermediate thermocline with a deep chlorophyll-a maximum layer (0.3-0.6 mg m-3). Two distinct general patterns were observed, emphasizing the role of (i) physical and (ii) biological processes: (i) a strong influence of the vertical stratification, with most zooplankton absent or little abundant in the lower layer. The influence of the cold SACW on the bottom layer apparently restricted the vertical occupation of most species, which typically inhabit epipelagic warm waters. Even among migratory species, only a few (Aglaura hemistoma, Abylopsis tetragona eudoxids, Beroe sp., Thalia democratica, Salpa fusiformis) crossed the thermocline and reached the bottom layer. (ii) A general tendency of partial migrations, with variable intensity depending on the different species and developmental stages; populations tended to be more widely distributed through the water column during daylight, and to become more aggregated in the upper layer during the night, which can be explained based on the idea of the "hunger-satiation hypothesis", maximizing feeding and minimizing the chances of being predated. PMID:26637179

  5. Continental shelf processes affecting the oceanography of the South Atlantic Bight. Progress report, June 1, 1978--May 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, L P

    1979-03-01

    Progress is reported on the following research projects: nitrogen inputs to the South Atlantic Bight; eddy experiments for obtaining quasi-synoptic map of South Atlantic Bight; cruise experiment for observation of stranded intrusion in the South Atlantic Bight; geographic distribution of hydrographic data; and computer plotting and contouring of data. (HLW)

  6. Multibeam Mapping of the South Atlantic Bight: Georgia 2005, a Proposed MPA on the Continental Shelf

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Fisheries laboratory in Panama City, Florida coordinated an acoustic survey at the new proposed Marine Protected Areas in the South Atlantic Bight area...

  7. Habitat classification from multibeam. SEFIS Survey Areas in the South Atlantic Bight, 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a vector shapefile describing the geomorphology of 21 areas along the shelf edge off the South Atlantic Bight where NOAA South East Fisheries...

  8. Biological processes in the water column of the South Atlantic bight

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.; Yoder, J.A.

    1980-01-31

    Progress is reported on research conducted during 1979 on the biological oceanography of the South Atlantic Bight. The presentation consists of a number of published articles and abstracts of oral presentations. (ACR)

  9. Phytoplankton Assemblage Patterns in the Southern Mid-Atlantic Bight

    Science.gov (United States)

    Makinen, Carla; Moisan, Tiffany A. (Editor)

    2012-01-01

    As part of the Wallops Coastal Oceans Observing Laboratory (Wa-COOL) Project, we sampled a time-series transect in the southern Mid-Atlantic Bight (MAB) biweekly. Our 2-year time-series data included physical parameters, nutrient concentrations, and chlorophyll a concentrations. A detailed phytoplankton assemblage structure was examined in the second year. During the 2-year study, chlorophyll a concentration (and ocean color satellite imagery) indicated that phytoplankton blooms occurred in January/February during mixing conditions and in early autumn under stratified conditions. The chlorophyll a concentrations ranged from 0.25 microgram 1(exp -1) to 15.49 microgram 1(exp -1) during the 2-year period. We were able to discriminate approximately 116 different species under phase contrast microscopy. Dominant phytoplankton included Skeletonema costatum, Rhizosolenia spp., and Pseudo-nitzschia pungens. In an attempt to determine phytoplankton species competition/succession within the assemblage, we calculated a Shannon Weaver diversity index for our diatom microscopy data. Diatom diversity was greatest during the winter and minimal during the spring. Diatom diversity was also greater at nearshore stations than at offshore stations. Individual genera appeared patchy, with surface and subsurface patches appearing abruptly and persisting for only 1-2 months at a time. The distribution of individual species differed significantly from bulk variables of the assemblage (chlorophyll a ) and total phytoplankton assemblage (cells), which indicates that phytoplankton species may be limited in growth in ways that differ from those of the total assemblage. Our study demonstrated a highly diverse phytoplankton assemblage throughout the year, with opportunistic species dominating during spring and fall in response to seasonal changes in temperature and nutrients in the southern MAB.

  10. Marine zooplanktonic diversity: a view from the South Atlantic

    OpenAIRE

    Boltovskoy, D.; Correa, N.; Boltovskoy, A.

    2002-01-01

    Approximately 7000 marine zooplanktonic species have been described so far for the World Ocean; in the South Atlantic the presence of 40% of these has been confirmed, and an additional 20-30% are expected to be recorded in the future. The overall number of described species is very low when compared with other communities, and yet it may not be too far from the final, complete inventory. Very ample geographic distributional ranges, compositional similarity between the major oceanic basins, an...

  11. Multibeam Mapping of the South Atlantic Bight: South Carolina 2005, a Proposed MPA on the Continental Shelf

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Fisheries laboratory in Panama City, Florida coordinated an acoustic survey at the new proposed Marine Protected Areas in the South Atlantic Bight area...

  12. Zooplankton species identities and other data collected from zooplankton net casts in the NE Atlantic Ocean from DISCOVERY; 12 November 1969 to 01 July 1988 (NODC Accession 9500097)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities and other data were collected by DISCOVERY using zooplankton net casts in the Northeast Atlantic Ocean. Data were collected from 12...

  13. MOCHA: A three dimensional climatology of salinity and temperature of the Middle Atlantic Bight

    Science.gov (United States)

    Fleming, N. E.; Wilkin, J. L.

    2013-05-01

    A 3-D climatology of the salinity and temperature of the Middle Atlantic Bight (MAB) is developed to provide a synthesis of observations and a tool for understanding the heat and freshwater budgets, and dynamics, of this area. 150 years of historical data are quality controlled and combined by weighted least squares to a 3-D grid encompassing the Middle Atlantic Bight and the Gulf of Maine, including Chesapeake Bay, Delaware Bay, and the Hudson River Estuary. Half degree grid spacing, along with weighted fitting in horizontal distance, vertical distance, time and bathymetry provide highly resolved maps for each month of the year that compare well to independent data sets. Features such as the MAB "Cold Pool", and the seasonal cycle of heating and cooling are clearly visible throughout the months.

  14. Atlantic surfclam connectivity within the Middle Atlantic Bight: Mechanisms underlying variation in larval transport and settlement

    Science.gov (United States)

    Zhang, Xinzhong; Munroe, Daphne; Haidvogel, Dale; Powell, Eric N.

    2016-05-01

    Larval transport and settlement have been shown in various studies to be essential in determining population abundance and connectivity for benthic invertebrates. This transport is influenced by both the physical environment and biological behavior. The Atlantic surfclam, Spisula solidissima, is a commercially important benthic invertebrate fishery species along the U.S northeastern coast. In this study, a physical circulation model is coupled to a surfclam larval model to investigate the dynamics of larval transport and settlement within the Middle Atlantic Bight (MAB) shelf in 2006. The main physical mechanisms causing variability in larval transport and settlement are also examined. Model results show that surfclam larvae released from July to early October experience relatively larger settlement rates, due to higher average temperatures experienced by larvae. Larval along-shore transport exhibits a mean down-coast pattern following the coastal current from the northeast to the southwest, with most high-frequency (period of 2-10 days) variations caused by fluctuations in the along-shore surface wind stress, and with seasonal variations speculated to be driven mainly by changes in the across-shelf density gradient. Larval across-shelf movement is highly correlated with the along-shore surface wind stress mediated by coastal upwelling and downwelling episodes, but the correlation is further dependent on the vertical distribution of the larvae, particularly their position relative to the thermocline. Most surfclam larvae released from the Middle Atlantic shelf stay below the thermocline and experience a net onshore transport during the summer-stratified season when upwelling-favorable wind forcing dominates. A proposed critical value of water temperature at the thermocline successfully regulates the observed patterns of vertical distribution of surfclam larvae and their across-shelf movement off the New Jersey and South Virginia shelves; that is, when the water

  15. Zooplankton data from zooplankton net casts and other instruments in the Delaware Bay and North Atlantic Ocean as part of the Ocean Continental Shelf (OCS - Mid Atlantic) project, 03 November 1976 - 18 November 1977 (NODC Accession 7800340)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts and other instruments in the Delaware Bay and North Atlantic Ocean from November 3, 1976 to November 18,...

  16. Continental shelf processes affecting the oceanography of the South Atlantic Bight. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Pietrafesa, L.J.

    1978-03-01

    The objectives of the project were to determine the physical/dynamical processes controlling/affecting the distribution of phytoplankton nutrients on the continental shelf in the South Atlantic Bight. The initial objectives were to determine the short term, i.e., 2 to 10 day and longer term flux of nutrients onto the continental shelf. This is clearly related to the more general problem of combined physical and biogenic control of phytoplankton nutrients. During the period from June, 1975 to March, 1978 the study of the continental shelf processes affecting the oceanography of the South Atlantic Bight has been principally involved with a substantial, coordinated field effort. The success of the data acquisition phase of the program has now required an intensive data analysis phase which has been slowly increasing in effort. Emphasis is placed on the main phase of the field program, located in Onslow Bay, which has beel completed and the data are being analyzed. During the three-year period 20 cruises were made into the Carolina Capes area and samples were collected. A list is included of some 100 publications during the period.

  17. NOAA TIFF Image - 10m Bathymetric Rugosity, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the rugosity of several deep coral priority areas off the South Atlantic Bight,...

  18. NOAA TIFF Image - 30m Rugosity, South Atlantic Bight - Deep Coral Priority Areas - Navy Pathfinder - (2003), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

  19. NOAA TIFF Image - 10m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2009), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

  20. Temperature and salinity profile data collected by CTD in the Mid-Atlantic Bight from 2/4/1999 - 2/14/2000 (NODC Accession 0000063)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using CTD casts in the Mid-Atlantic Bight from 04 February 1999 to 14 February 2000.

  1. NOAA TIFF Image - 10m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

  2. NOAA TIFF Image - 30m Backscatter, South Atlantic Bight - Deep Coral Priority Areas - Navy Pathfinder - (2003), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

  3. NOAA TIFF Image - 10m Bathymetric Rugosity, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2009), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the rugosity of several deep coral priority areas off the South Atlantic Bight,...

  4. Zooplankton data collected from zooplankton net casts in TOGA Area - Atlantic and Indian Ocean by GAVESHANI and other platforms from 01 March 1963 to 31 March 1965 (NODC Accession 9400163)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected from GAVESHANI and other platforms using zooplankton net casts in the TOGA Area - Atlantic and Indian Ocean. Data were collected...

  5. Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms

    Directory of Open Access Journals (Sweden)

    R. He

    2011-10-01

    Full Text Available A high-resolution, 3-dimensional coupled biophysical model is used to simulate ocean circulation and ecosystem variations at the shelfbreak front of the Middle Atlantic Bight (MAB. Favorable comparisons between satellite observations and model hindcast solutions from January 2004 to November 2007 indicate the model has intrinsic skills in resolving fundamental physical and biological dynamics at the MAB shelfbreak. Seasonal and interannual variability of ocean physical and biological states and their driving mechanisms are further analyzed. The domain-wide upper water column nutrient content is found to peak in late winter-early spring. Phytoplankton spring bloom starts 1–2 months later, followed by zooplankton bloom in early summer. Our analysis shows the variability of shelfbreak nutrient supply is controlled by local mixing that deepens the mixed layer and injects deep ocean nutrients into the upper water column and alongshore nutrient transport by the shelfbreak jet and associated currents. Nutrient vertical advection associated with the shelfbreak bottom boundary layer convergence is another significant contributor. Spring mean nutrient budget diagnostics along the Nantucket transect are compared between nutrient rich 2004 and nutrient poor 2007. Physical advection and diffusion play the major role in determining strong interannual variations in shelfbreak nutrient content. The biological (source minus sink term is very similar between these two years.

  6. Identification of polyamine-responsive bacterioplankton taxa in South Atlantic Bight.

    Science.gov (United States)

    Lu, Xinxin; Sun, Shulei; Hollibaugh, James T; Mou, Xiaozhen

    2015-12-01

    Putrescine and spermidine are short-chained aliphatic polyamines (PAs) that are ubiquitously distributed in seawater. These compounds may be important sources of dissolved organic carbon and nitrogen for marine bacterioplankton. Here, we used pyrotag sequencing to quantify the response of bacterioplankton to putrescine and spermidine amendments in microcosms established using surface waters collected at various stations in the South Atlantic Bight in October 2011. Our analysis showed that PA-responsive bacterioplankton consisted of bacterial taxa that are typically dominant in marine systems. Rhodobacteraceae (Alphaproteobacteria) was the taxon most responsive to PA additions at the nearshore site. Gammaproteobacteria of the families Piscirickettsiaceae; Vibrionaceae; and Vibrionaceae and Pseudoalteromonadaceae, were the dominant PA-responsive taxa in samples from the river-influenced coastal station, offshore station and open ocean station, respectively. The spatial variability of PA-responsive taxa may be attributed to differences in composition of the initial bacterial community and variations of in situ physiochemical conditions among sites. Our results also provided the first empirical evidence that Gammaproteobacteria might play an important role in PA transformation in marine systems. PMID:26109269

  7. Invertebrate communities associated with hard bottom habitats in the South Atlantic Bight

    Science.gov (United States)

    Wenner, E. L.; Knott, D. M.; Van Dolah, R. F.; Burrell, V. G.

    1983-08-01

    Epibenthic invertebrates associated with nine hard bottom areas in the South Atlantic Bight between South Carolina and northern Florida were collected with dredge, trawl, suction and grab samplers to evaluate species composition, biomass, abundance, diversity, spatial distributions, and seasonality (winter and summer). Species composition changed noticeably with depth and season. Inner and outer shelf stations were least similar in species composition. Middle shelf areas were transitional and contained taxa characteristic of both inner and outer sites. Bryozoa (88 taxa), Cnidaria (85 taxa), Porifera (67 taxa), Annelida (261 taxa) and Mollusca (203 taxa) represented the richest taxonomic groups of the 1175 taxa collected. Both diversity (1175 total taxa) and biomass (1995 kg total) of invertebrates from hard bottom areas exceeded those reported in the literature for sand bottom communities. Sponges accounted for >60% of the total invertebrate biomass collected by dredge and trawl during both seasons. High diversity values were attributed primarily to habitat complexity and did not exhibit any discernible pattern with depth or latitude.

  8. Biological processes in the water column of the South Atlantic Bight: Phytoplankton response. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Verity, P.G.; Yoder, J.A.

    1992-03-10

    This study addressed shelf-wide processes and nearshore (coastal boundary zone) processes occurring in the southeastern. Coastal boundary zone (CBZ) US continental shelf dynamics involve studies of circulation and of biological and chemical transformations. Continental shelf processes affect the removal of material from the coastal boundary zone into areas where the material no longer interacts with or influences concentrations in the CBZ. The two arbitrarily separate components are, in fact, unified. The CBZ typically extends about 300 km along-shore and about 20 km offshore from its center off Savannah, Georgia, where most runoff occurs. The rates of biological and chemical transformations are controlled by proximity to the bottom and the amounts of fine suspended organic matter originating from rivers and salt marshes. Once material is removed from this zone, either by a long-shelf or cross-shelf advection to regions where the materials are no longer in contact with the bottom, the suite of factors governing the rates of chemical and biological transformations changes. The determination of contrasting rates in these two environments was one of the central focuses of the South Atlantic Bight program.

  9. Chemical composition and cycling of dissolved organic matter in the Mid-Atlantic Bight

    Science.gov (United States)

    Aluwihare, Lihini I.; Repeta, Daniel J.; Chen, Robert F.

    This study focuses on the chemical characterization of high molecular-weight dissolved organic matter (HMW DOM) isolated from the Middle Atlantic Bight in April 1994 and March 1996. Using proton nuclear magnetic resonance spectroscopy ( 1HNMR) and monosaccharide analysis we compared both spatial and temporal variations in the chemical structure of HMW DOM across this region. Our analyses support the presence of at least two compositionally distinct components to HMW DOM. The major component is acyl polysaccharide (APS), a biopolymer rich in carbohydrates, acetate and lipid, accounting for between 50% and 80% of the total high molecular-weight dissolved organic carbon (HMW DOC) in surface samples. APS is most abundant in fully marine, surface-water samples, and is a product of autochthonous production. Organic matter with spectral properties characteristic of humic substances is the second major component of HMW DOM. Humic substances are most abundant (up to 49% of the total carbon) in samples collected from estuaries, near the coast, and in deep water, suggesting both marine and perhaps terrestrial sources. Radiocarbon analyses of neutral monosaccharides released by the hydrolysis of APS have similar and modern (average 71‰) Δ 14C values. Radiocarbon data support our suggestion that these sugars occur as part of a common macromolecule, with an origin via recent biosynthesis. Preliminary radiocarbon data for total neutral monosaccharides isolated from APS at 300 and 750 m show this fraction to be substantially enriched relative to total HMW DOC and DOC. The relatively enriched radiocarbon values of APS at depth suggest APS is rapidly transported into the deep ocean.

  10. Terrestrially derived dissolved organic matter in the chesapeake bay and the middle atlantic bight

    Science.gov (United States)

    Mitra, Siddhartha; Bianchi, Thomas S.; Guo, Laodong; Santschi, Peter H.

    2000-10-01

    Concentrations of lignin-phenols were analyzed in high molecular weight dissolved organic matter (0.2 μm > HMW DOM > 1 kDa) isolated from surface waters of the Chesapeake Bay (C. Bay), and surface and bottom waters of the Middle Atlantic Bight (MAB). The abundance of lignin-phenols in HMW DOM was higher in the C. Bay (0.128 ± 0.06 μg L -1) compared to MAB surface waters (0.016 ± 0.004 μg L -1) and MAB bottom waters (0.005 ± 0.003 μg L -1). On an organic carbon-normalized basis, lignin-phenol abundances in the HMW DOM (i.e., Λ 6), were significantly higher ( p vanillin (Ad/Al) V in HMW DOM, indicative of lignin decay, ranged from 0.611 to 1.37 in C. Bay, 0.534 to 2.62 in MAB surface waters, and 0.435 to 1.96 in MAB bottom water. Ratios of S/V and (Ad/Al) V showed no significant differences between each environment, providing no evidence of any compositionally distinct input of terrestrial organic matter into each environment. When considering depth profiles of suspended particulate matter in the MAB, with C:N ratios, and bulk radiocarbon ages and stable carbon isotopic values in HMW DOM isolated from these areas, two scenarios present themselves regarding the sources and transport of terrestrially derived HMW DOM in the MAB. Scenario #1 assumes that a low amount of refractory terrestrial organic matter and old DOC are uniformly distributed in the oceans, both in surface and bottom waters, and that primary production in surface waters increases DOC with low lignin and younger DOC which degrades easily. In this case, many of the trends in age and biomarker composition likely reflect general patterns of Atlantic Ocean surface and bottom water circulation in the area of the MAB. Scenario 2 assumes terrestrial organic matter in bottom waters of the MAB may have originated from weathered shelf and slope sediments in nearshore areas via a combination of mechanisms (e.g., diffusion, recent resuspension events, and/or desorption of DOM from riverine POM buried deep

  11. Temperature and other data collected using visual observations and other instruments in the Mid-Atlantic Bight and other Seas from GYRE from 01 August 1985 to 26 May 1990 (NODC Accession 9300074)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and other data were collected using visual observations, bottle casts, and other instruments from GYRE and other platforms in the Mid-Atlantic Bight and...

  12. Current, temperature, backscatter, and other data from bottom instrument packages deployed from the RV Oceanus and other platforms in support of sediment transport observation in the Middle Atlantic Bight from 11 December 1975 to 30 October 1980 (NODC Accession 0066005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A series of studies to assess environmental hazards to petroleum development in the Middle Atlantic Bight. Long-term observations of currents and near-bottom...

  13. Physical trajectory profile data from glider ru23 deployed by Rutgers, the State University of New Jersey in the Mid-Atlantic Bight from 2012-10-25 to 2012-11-05 (NCEI Accession 0145723)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slocum glider ru23 was deployed prior to the movement of Hurrican Sandy into the Mid-Atlantic Bight and was deployed to sample the sub-surface waters during the...

  14. Distribution of planktonic cnidarians in response to South Atlantic Central Water intrusion in the South Brazilian Bight

    Science.gov (United States)

    Nogueira Júnior, Miodeli; Brandini, Frederico P.; Codina, Juan C. U.

    2014-10-01

    Five oceanographic cruises were made between November 2005 and June 2006, sampling a cross-shelf transect off the South Brazilian Bight (SBB; 26°46‧S) to follow the seasonal development of the South Atlantic Central Water (SACW) intrusion over the shelf and its influence on the assemblage of planktonic cnidarians. An onshore wind-driven bottom intrusion of the SACW was clearly perceptible, reaching the coast in January. From March onward, the SACW influence was gradually displaced seaward due to wind and tidal mixing. By late June the SACW influence was offshore and the inshore was dominated by low-salinity waters (20 mm in diameter) Solmaris corona were observed exclusively in cold waters, suggesting this medusa is a SACW indicator.

  15. Biological processes in the water column of the south Atlantic bight. Annual progress report, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.; Yoder, J.A.

    1980-01-31

    A study of Summer Intrusions, consisting of 7 weekly cruises between 28/sup 0/50' and 31/sup 0/00'N, was conducted from July 5 to August 17, 1979. Additional chlorophyll and nutrient samples were collected in the study area during the week of August 23. Our goal was to follow a newly intruded water mass for several seeks to determine rates and magnitudes of phyto- and zooplankton for development.

  16. Modelling the future biogeography of North Atlantic zooplankton communities in response to climate change

    KAUST Repository

    Villarino, E

    2015-07-02

    Advances in habitat and climate modelling allow us to reduce uncertainties of climate change impacts on species distribution. We evaluated the impacts of future climate change on community structure, diversity, distribution and phenology of 14 copepod species in the North Atlantic. We developed and validated habitat models for key zooplankton species using continuous plankton recorder (CPR) survey data collected at mid latitudes of the North Atlantic. Generalized additive models (GAMs) were applied to relate the occurrence of species to environmental variables. Models were projected to future (2080–2099) environmental conditions using coupled hydroclimatix–biogeochemical models under the Intergovernmental Panel on Climate Change (IPCC) A1B climate scenario, and compared to present (2001–2020) conditions. Our projections indicated that the copepod community is expected to respond substantially to climate change: a mean poleward latitudinal shift of 8.7 km per decade for the overall community with an important species range variation (–15 to 18 km per decade); the species seasonal peak is expected to occur 12–13 d earlier for Calanus finmarchicus and C. hyperboreus; and important changes in community structure are also expected (high species turnover of 43–79% south of the Oceanic Polar Front). The impacts of the change expected by the end of the century under IPCC global warming scenarios on copepods highlight poleward shifts, earlier seasonal peak and changes in biodiversity spatial patterns that might lead to alterations of the future North Atlantic pelagic ecosystem. Our model and projections are supported by a temporal validation undertaken using the North Atlantic climate regime shift that occurred in the 1980s: the habitat model built in the cold period (1970–1986) has been validated in the warm period (1987–2004).

  17. Zooplankton species identities and other data collected by ATLANTIS II from net casts in NW Atlantic Ocean from 23 November 1988 to 04 December 1988 (NODC Accession 9500081)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities and other data were collected using net casts in the Northwest Atlantic Ocean from ATLANTIS II. Data were collected from 23 November...

  18. Zooplankton and other data collected in Northwest Atlantic Ocean from CTD, bottle casts, and other instruments from 10 September 1963 to 24 August 1964 (NODC Accession 7101509)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton and other data were collected using CTD, bottle casts, and other instruments in the Northwest Atlantic Ocean. Data were collected from 10 September 1963...

  19. Zooplankton data collected using net casts from the ALMIRANTE SALDANHA in the Northeast Atlantic Ocean from 05 November 1958 to 15 January 1959 (NODC Accession 0000942)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using net casts in the Northeast Atlantic Ocean from ALMIRANTE SALDANHA. Data were collected from 05 November 1958 to 15 January...

  20. The modulation of the seasonal cross-shelf sea level variation by the cold pool in the Middle Atlantic Bight

    Science.gov (United States)

    Sha, Jin; Jo, Young-Heon; Yan, Xiao-Hai; Liu, W. T.

    2015-11-01

    This study explores the influence of the cold pool in the Middle Atlantic Bight (MAB) to cross-shelf sea surface slope by fitting an annual harmonic to temperature and salinity profiles from 1993 to 2012 and compares to the 20 year averaged altimetry sea level anomaly (SLA). The consistency within the bottom temperature, thermal steric height, total steric height, and altimetry observation validates that the cold pool induces a depressed sea level in the middle shelf overlapping with the dominant surface seasonal cycles. Temporally, the cold pool pattern is most apparent in July and August as a result of magnitude competition between the thermal and haline steric height. In addition, Ensemble Empirical Mode Decomposition (EEMD) is employed to reconstruct the altimetry SLA and reveals the middle-shelf depression pattern from single year's SLA data. The locations of the SLA depression from 1993 to 2012 agree with the cold pool locations identified from in situ measurements, suggesting a promising application of altimetry SLA in the cold pool study. Conclusively, this study reveals the modulation of the cross-shelf sea level variation by the cold pool, and contributes to the understanding of the sea level response to water masses on the continental shelf.

  1. Simulation analysis of moored fluorometer time series from the Mid-Atlantic Bight during 1987--1990

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, J.J.

    1990-01-01

    The goal of the previous research during 1987-1990 within the DOE (Department of Energy) Shelf Edge Exchange Processes (SEEP) program in the Mid-Atlantic Bight was to understand the physical and biogeochemical processes effecting the diffusive exchange of the proxies of energy-related, by-products associated with particulate matter between estuarine, shelf, and slope waters on this continental margin. As originally envisioned in the SEEP program plan, SEEP-III would take place at Cape Hatteras to study the advective exchange of materials by a major boundary current. One problem of continuing interest is the determination of the local assimilative capacity of slope waters and sediments off the eastern seaboard of the US to lengthen the pathway between potentially harmful energy by-products and man. At basin scales, realistic specification of the lateral transport by western boundary currents of particulate matter is a necessary input to global models of carbon/nitrogen cycling. Finally, at these global scales, the generic role of continental margins in cycling greenhouse gases, e.g. CO{sub 2}, CH{sub 4}, and N{sub 2}O, is now of equal interest. This continuing research of model construction and evaluation within the SEEP program focuses on all three questions at local, regional, and basin scales. Results from SEEP-I and II are discussed as well as plans for SEEP-III. 14 figs., 3 tabs.

  2. South Atlantic Bight Habitat Mapping on NOAA Ship Nancy Foster in North Atlantic Ocean between 20070626 and 20070702

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This expedition on the NOAA Ship Nancy Foster used the recently-developed National Undersea Research Center for the North Atlantic and Great Lakes (NURC-NAGL) ROV...

  3. On the mass and salt budgets for a region of the continental shelf in the southern Mid-Atlantic Bight

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoo Yin; Weatherly, Georges L.; Pietrafesa, Leonard J.

    2001-12-01

    Two field studies were conducted across and along the continental shelf, one from February to May 1996 (deployment 1) and the other from July to October 1996 (deployment 2), in part to determine the mass and salt budgets of shelf water from south of Cape Henry to north of Cape Hatteras, the southernmost portion of the Mid-Atlantic Bight. The temporal means of current meter records indicated that most of the water enters the region across its northern boundary near the shelf break as part of a southward, alongshore current and exits the southeast corner as a southeastward flowing current. Estimates of the volume transports indicated that not all the transport across the northern boundary was accounted for by transport across the southern boundary, and that the remainder occurred as a broad, diffusive flow across the eastern boundary at the shelf break. Time series of volume transport across northern and southern boundaries were very similar and associated with variations in the alongshore wind stress and sea level, indicative of a geostrophic balance. Examination of the individual current meter records indicated these fluctuations were very barotropic even during deployment 2, which included the stratified summer season. Time series of the volume transport across the eastern boundary at the shelf break strongly mirrored the volume transport across the northern boundary minus that across the southern boundary, suggesting that the inferred eastern boundary transport was real and accommodated whatever the southern boundary could not. The turbulent salt flux across each boundary contributes very little to the net respective mass fluxes because the salt fluxes are almost governed by current velocity fields. The instantaneous and mean salt fluxes across each boundary were very well approximated by the instantaneous and mean volume transports across the boundary times the deployment average salinity across that boundary, respectively. The Ocean Margins Program (OMP) moored

  4. Zooplankton structure and dynamics in two estuaries from the Atlantic coast in relation to multi-stressors exposure

    Science.gov (United States)

    Vieira, L. R.; Guilhermino, L.; Morgado, F.

    2015-12-01

    The aim of this research was to investigate the response of pelagic zooplankton to different levels of abiotic multi-stressors in the North Atlantic coast, taking advantage of the comparison of the communities of two adjacent estuaries with different levels of historical pollution (estuaries of Minho and Lima Rivers). The zooplankton community structure, composition and temporal variation were comparatively investigated for 15 months, using different net meshes. Several abiotic factors were measured in situ and water samples were simultaneously collected for determination of nutrients and chlorophyll a. The overall results revealed a diverse community represented by species that have been found in subtropical and temperate zones. Although the highest diversity was observed in the Lima estuary, supported by higher contributions of marine taxa, the total zooplankton biomass was found to be significantly higher in the Minho estuary. The salinity gradient differences between estuaries, associated to significant differences in water nutrients levels, were found to be the main forcing factors affecting micro and mesozooplankton. Considering the importance of the impacts resulting from abiotic variation on the basis of aquatic food webs, the present investigation represented a case-study, based in two contrasting estuaries, one strongly influenced by freshwater discharges (Minho estuary) and the other with higher salinity levels (Lima estuary), contributing to a better understanding of the effects of multi-stressors on pelagic zooplankton communities, providing useful information for studies related with climate change impacts, biogeography, conservation and providing data contributing to the improvement of pelagic fisheries management models.

  5. [The role of zooplankton and micronektron in the cycling and remineralization of chemical materials in the Southern California Bight: Progress report, November 1985-June 1986

    International Nuclear Information System (INIS)

    A Progress Report on Grant FG05-85ER60340 has already been submitted to DOE, and is appended here. The appended report covers much of the work completed during the current contract period. Work on the just-completed May 1986 cruise samples is just beginning at the time of writing. Sediment traps deployed at two locations in Santa Monica Basin in October 1985 were recovered in February 1986. The traps have sequentially rotating cups set to collect material for 14 days each during the deployment period. We have finished radiochemical analyses on the sediment trap samples collected on the February 1986 Cruise. Pellet production rates for salps and euphausiids were reported earlier. The February cruise was principally a hydrographic and trap recovery cruise, and there was no time for pellet production rate experiments. Thus, all the February hauls are being analyzed to assess diel biomass estimates of selected size classes of zooplankton in the vicinity of the traps. 5 tabs

  6. Regional and inter-annual variability in Atlantic zooplankton en route to the Arctic Ocean: potential effects of multi-path Atlantic water advection through Fram Strait and the Barents Sea

    Science.gov (United States)

    Kwasniewski, Slawomir; Gluchowska, Marta; Trudnowska, Emilia; Ormanczyk, Mateusz; Walczowski, Waldemar; Beszczynska-Moeller, Agnieszka

    2016-04-01

    The Arctic is among the regions where the climate change effects on ecosystem will be the most rapid and consequential, with Arctic amplification recognized as an integral part of the process. Great part of the changes are forced by advection of warm waters from the North Atlantic and the expected modifications of Arctic marine ecosystem will be induced not only by changing environmental conditions but also as a result of introducing Atlantic biota. Thus, the knowledge of physical and biological heterogeneity of Atlantic inflow is requisite for understanding the effects of climate change on biological diversity and ecosystem functioning in the Arctic. The complex and variable two-branched structure of the Atlantic Water flow via Fram Strait and the Barents Sea most likely has a strong influence on the ocean biology in these regions, especially in the pelagic realm. Zooplankton are key components of marine ecosystems which form essential links between primary producers and grazer/predator consumers, thus they are important for functioning of the biological carbon pump. Changes in zooplankton distribution and abundance may have cascading effects on ecosystem functioning, with regulatory effects on climate. Based on data collected in summers of 2012-2014, within the scope of the Polish-Norwegian PAVE research project, we investigate zooplankton distribution, abundance and selected structural characteristics of communities, in relation to water mass properties in the Atlantic Water complex flow to the Arctic Ocean. The main questions addressed here are: what are the differences in zooplankton patterns between the Fram Strait and Barents Sea branches, and how does the inter-annual variability of Atlantic Water advection relate to changes in zooplankton? The results of the investigation are precondition for foreseeing changes in the pelagic realm in the Arctic Ocean and are necessary for constructing and tuning plankton components of ecosystem models.

  7. Zooplankton biomass (displacement volume, dry mass, ash-free dry mass) data collected in Eastern Central Atlantic during CIPREA project from 1978-07-25 to 1978-09-12 by France (NODC Accession 0070783)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton biomass (displacement volume, dry mass, and ashfree dry mass) data collected in Eastern Central Atlantic during CIPREA project in Jul - Sep 1978 by...

  8. Zooplankton and other data from net and bottle casts in the North Atlantic from the CARVALHO ALMEIDA by Miya Fisheries High School from 24 October 1972 to 29 October 1973 (NODC Accession 0000502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton and other data were collected using net and bottle casts in the North Atlantic from the CARVALHO ALMEIDA from 24 October 1972 to 29 October 1973. Data...

  9. Abundance, distribution and size structure of zooplankton along a 20° west meridional transect of the northeast Atlantic Ocean in July

    Science.gov (United States)

    Gallienne, C. P.; Robins, D. B.; Woodd-Walker, R. S.

    Zooplankton distribution, abundance and size structure were characterised on leg 2 of the PRIME cruise in the northeast Atlantic during July 1996. Latitudinal sampling was carried out from 60°N to 37°N along a meridian at approximately 20°W. Zooplankton were characterised using an Optical Plankton Counter (OPC), and from traditional depth-integrated net hauls for taxonomy and carbon. The former method allows zooplankton to be described in terms of biovolume and size. There was good agreement between the two methods for abundance and a good correlation between OPC biovolume and carbon analysis. These data also showed compatibility with concurrent acoustic measurements of zooplankton. Results for the cruise compared to recent studies in the region, show that, overall abundance was generally low, although most of the previous studies were closer to spring bloom conditions. The size structure over latitude shows that mean size fluctuated, but there was a general trend of decreasing mean size from the north of the transect to about 47°N. Further statistical treatment of the OPC data, using principal component analysis, showed that zooplankton size structure changed at five positions along the transect. Three of these coincided with changes in physical structure, one each side of the front at 48°N and the third on the outer edge of an eddy. The other two occurred in regions of high-surface chlorophyll concentration.

  10. Absorption and Attenuation Coefficients Using the WET Labs ac-s in the Mid-Atlantic Bight: Field Measurements and Data Analysis

    Science.gov (United States)

    Ohi, Nobuaki; Makinen, Carla P.; Mitchell, Richard; Moisan, Tiffany A.

    2008-01-01

    Ocean color algorithms are based on the parameterization of apparent optical properties as a function of inherent optical properties. WET Labs underwater absorption and attenuation meters (ac-9 and ac-s) measure both the spectral beam attenuation [c (lambda)] and absorption coefficient [a (lambda)]. The ac-s reports in a continuous range of 390-750 nm with a band pass of 4 nm, totaling approximately 83 distinct wavelengths, while the ac-9 reports at 9 wavelengths. We performed the ac-s field measurements at nine stations in the Mid-Atlantic Bight from water calibrations to data analysis. Onboard the ship, the ac-s was calibrated daily using Milli Q-water. Corrections for the in situ temperature and salinity effects on optical properties of water were applied. Corrections for incomplete recovery of the scattered light in the ac-s absorption tube were performed. The fine scale of spectral and vertical distributions of c (lambda) and a (lambda) were described from the ac-s. The significant relationships between a (674) and that of spectrophotometric analysis and chlorophyll a concentration of discrete water samples were observed.

  11. Start feeding of salmonids with lake zooplankton

    OpenAIRE

    Holm, Jens Christian; Hansen, Tom; Møller, Dag

    1982-01-01

    Fry and small fingerlings of Atlantic salmon (Salmo salar) and rainbow trout (Salmo gairdneri) were fed with lake zooplankton in small fine-meshed cages. The zooplankton were pumped into cages. Growth rates and food selection are discussed.

  12. Upslope transport of near-bed zooplankton

    Science.gov (United States)

    Zimmer, Cheryl Ann

    2009-09-01

    Zooplankton residing just above the deep-sea floor is an important component of the benthic/benthopelagic food chain. Consuming planktonic particulates and organisms, holoplankton and meroplankton are prey for fish and large invertebrates. Mechanisms controlling their abundances have been explored over relatively long time scales (months to years). Here, zooplankton were sampled every 2 h for 2.2 d using a moored, automated, serial zooplankton pump. The physical regime (currents and temperature) 1-100 m above bottom was measured during an inclusive 24-d period. The study site was located on the upper continental slope (750 m) of the Mid-Atlantic Bight, between the productive shelf and more impoverished rise and abyss. The coupled biological and physical records indicated tidally driven, net upslope transport of the holoplankton. The copepod (74.5% of collections) time series showed marked periodicity with a peak frequency of ˜13 h, approximately the diurnal tide (Fourier analysis). Local maxima corresponded with minimal water temperatures. Moreover, tidal cross-slope flow was highly coherent and 90° out of phase with temperature. Thus, maximal copepod concentrations, originating in colder deeper water, would be transported up the slope by the tide. Estimated net displacement of ˜1 km/d would deliver the animals to continental-shelf depths within a couple weeks. Time series of the much less abundant larvaceans (urochordates) (15.3%) and polychaete larvae (8.9%) showed periodicities with peak frequencies of 8-9 h. Statistical significance of the periodic signals could not be determined due to low numbers. Revealing holoplankton dynamics on scales of hours, this study may contribute to understanding of, for example, copepod feeding and aggregation near the deep-sea floor.

  13. A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

    Science.gov (United States)

    Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

    2010-12-01

    Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean

  14. Zooplankton species identities and other data from net tows from the ALBATROSS IV and other platforms from NE Atlantic (limit-40 W) as part of the Marine Resources Monitoring, Assessment and Prediction (MARMAP) project from 20 April 1977 to 10 December 1986 (NODC Accession 9400006)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities and other data were collected from net tows from the ALBATROSS IV and other platforms in the NE Atlantic (limit-40 W) from 20 April...

  15. NOAA TIFF Image - 3m Multibeam Bathymetry, Miami, South Atlantic Bight - Deep Coral Priority Areas - Lost Coast Explorer - (2010), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 3x3 meter cell size representing the bathymetry of the continental shelf off of Jacksonville, FL in the South Atlantic...

  16. NOAA TIFF Image - 10m Bathymetric Slope, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the slope (in degrees) of several deep coral priority areas off the South Atlantic...

  17. The complex influences of back-barrier deposition, substrate slope and underlying stratigraphy in barrier island response to sea-level rise: Insights from the Virginia Barrier Islands, Mid-Atlantic Bight, U.S.A.

    Science.gov (United States)

    Brenner, Owen T.; Moore, Laura J.; Murray, A. Brad

    2015-10-01

    To understand the relative importance of back barrier environment, substrate slope and underlying stratigraphy in determining barrier island response to RSLR (relative sea-level rise), we use a morphological-behavior model (GEOMBEST) to conduct a series of sensitivity experiments, based on late-Holocene hindcast simulations of an island in the U.S. mid-Atlantic Bight (Metompkin Island, VA) having both salt marsh and lagoonal back-barrier environments, and we draw comparisons between these results and future simulations (2000-2100 AD) of island response to RSLR. Sensitivity analyses indicate that, as a whole, the island is highly sensitive to factors that reduce overall sand availability (i.e., high sand-loss rates and substrates containing little sand). Results also indicate that for all predicted future RSLR scenarios tested, islands having high substrate sand proportions (if allowed to migrate freely) will likely remain subaerial for centuries because of sufficient substrate sand supply and elevation to assist in keeping islands above sea level. Simulation results also lead to basic insights regarding the interactions among substrate slope, back-barrier deposition and island migration rates. In contrast to previous studies, which suggest that changes in substrate slope directly affect the island migration trajectory, we find that-in the presence of back-barrier deposition-the connection between substrate slope and island behavior is modulated (i.e., variability in migration rates is dampened) by changes in back-barrier width. These interactions-which tend to produce changes in shoreface sand content-lead to a negative feedback when the back-barrier deposit contains less sand than the underlying layer, resulting in a stable back-barrier width. Alternatively, a positive feedback arises when the back-barrier deposit contains more sand than the underlying layer, resulting in either back-barrier disappearance or perpetual widening.

  18. Zooplankton Hydrodynamics

    DEFF Research Database (Denmark)

    Wadhwa, Navish

    flow disturbances that may attract predators. The first part of this thesis attempts to quantify the trade-offs associated with the swimming behaviour of diverse zooplankton. We measured the swimming kinematics and flow fields around the 'jumping' copepod Acartia tonsa at various stages of its life....... We studied how sensing modes and their respective ranges depend on body size. We investigated the physiological constraints on sense organs, together with the physics of signal generation, transmission, and reception. Our analysis revealed a hierarchy of sensing modes - with increasing size, a larger...

  19. Zooplankton in the Arctic outflow

    Science.gov (United States)

    Soloviev, K. A.; Dritz, A. V.; Nikishina, A. B.

    2009-04-01

    Climate changes in the Arctic cause the changes in the current system that may have cascading effect on the structure of plankton community and consequently on the interlinked and delicately balanced food web. Zooplankton species are by definition incapable to perform horizontal moving. Their transport is connected with flowing water. There are zooplankton species specific for the definite water masses and they can be used as markers for the different currents. That allows us to consider zooplankton community composition as a result of water mixing in the studied area. Little is known however about the mechanisms by which spatial and temporal variability in advection affect dynamics of local populations. Ice conditions are also very important in the function of pelagic communities. Melting time is the trigger to all "plankton blooming" processes, and the duration of ice-free conditions determines the food web development in the future. Fram Strait is one of the key regions for the Arctic: the cold water outflow comes through it with the East Greenland Current and meets warm Atlantic water, the West Spitsbergen Current, producing complicated hydrological situation. During 2007 and 2008 we investigated the structure functional characteristics of zooplankton community in the Fram Strait region onboard KV "Svalbard" (April 2007, April and May 2008) and RV "Jan Mayen" (May 2007, August 2008). This study was conducted in frame of iAOOS Norway project "Closing the loop", which, in turn, was a part of IPY. During this cruises multidisciplinary investigations were performed, including sea-ice observations, CTD and ADCP profiling, carbon flux, nutrients and primary production measurements, phytoplankton sampling. Zooplankton was collected with the Hydro-Bios WP2 net and MultiNet Zooplankton Sampler, (mouth area 0.25 m2, mesh size 180 um).Samples were taken from the depth strata of 2000-1500, 1500-1000, 1000-500,500-200, 200-100, 100-60, 60-30, 30-0 m. Gut fluorescence

  20. Physical trajectory profile data from glider ru23 deployed by Rutgers, the State University of New Jersey in the Mid-Atlantic Bight from 2014-09-16 to 2014-09-29 (NCEI Accession 0137968)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. IOOS Mid-Atlantic Regional Consortium of Ocean Observing Systems (MARACOOS) glider deployment to survey the physical and biological properties of Mid-Atlantic...

  1. Physical trajectory profile data from glider ru23 deployed by Rutgers, the State University of New Jersey in the Mid-Atlantic Bight from 2013-10-17 to 2013-11-06 (NCEI Accession 0137966)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. IOOS Mid-Atlantic Regional Consortium of Ocean Observing Systems (MARACOOS) glider deployment to survey the physical and biological properties of Mid-Atlantic...

  2. Zooplankton and fisheries

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    is dominatEd. by herbivores. Zooplankton constitutes the main food item of several economic important animals. The pelagic fishes migrate in shoals to the feeding ground rich in food and hence zooplankton are used as indicators of rich potential fishing...

  3. A Biogeographic Assessment of the Stellwagen Bank National Marine Sanctuary - Kriged Predictive Map of Zooplankton Samples

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton communities have been well studied in the northeast Atlantic (Sherman et al., 1983) and on Georges Bank within the Gulf of Maine (Bigelow, 1927; Davis,...

  4. A Biogeographic Assessment of the Stellwagen Bank National Marine Sanctuary - Kriged Probability Map of Zooplankton Samples

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton communities have been well studied in the northeast Atlantic (Sherman et al., 1983) and on Georges Bank within the Gulf of Maine (Bigelow, 1927; Davis,...

  5. Physical trajectory profile data from glider blue deployed by University of Massachusetts; University of Massachusetts - Dartmouth in the Mid-Atlantic Bight from 2015-06-27 to 2015-07-17 (NCEI Accession 0138008)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. IOOS Mid-Atlantic Regional Consortium of Ocean Observing Systems (MARACOOS) glider deployment. This is the first of a series of yearly seasonal deployments to...

  6. Zooplankton body composition

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2013-01-01

    I compiled literature on zooplankton body composition, from protozoans to gelatinous plankton, and report allometric relations and average body composition. Zooplankton segregate into gelatinous and non-gelatinous forms, with few intermediate taxa (chaetognaths, polychaetes, and pteropods). In most...... groups body composition is size independent. Exceptions are protozoans, chaetognaths, and pteropods, where larger individuals become increasingly watery. I speculate about the dichotomy in body composition and argue that differences in feeding mechanisms and predator avoidance strategies favor either a...

  7. Zooplankton of Mida Creek.

    OpenAIRE

    Mwaluma, J.; Osore, M.

    1996-01-01

    The objective of the zooplankton group was to establish an inventory of zooplankton resident in Mida creek, their diversity and quantify their abundance, spatial and temporal distribution. Apart from this, various hydrographic parameters were measured simultaneously in order to find out whether any correlation existed between the two. Among the hydrographic parameters measured were temperature, salinity, turbidity, and dissolved oxygen. In April 1996, the research team...

  8. Benthic dynamics at the carbonate mound regions of the Porcupine Sea Bight continental margin

    Science.gov (United States)

    White, Martin

    2007-02-01

    A brief review is given of some dynamical processes that influence the benthic dynamics within the carbonate mound provinces located at the Porcupine Bank/Sea Bight margin, NE Atlantic. The depth range of the mounds in this region (600-1,000 m) marks the upper boundary of the Mediterranean outflow water above which Eastern North Atlantic Water dominates. Both water masses are carried northwards by the eastern boundary slope current. In the benthic boundary layer both the action of internal waves, and other tidal period baroclinic waves, may enhance the bottom currents and add to both the residual and maximum flow strength. Both residual and maximum bottom currents vary at different mound locations, with stronger currents found at Belgica (SE Porcupine Sea Bight) mound and Pelagia (NW Porcupine Bank) mound regions, whilst weakest currents are found at the Hovland and Magellan Mounds at the northern Sea Bight margin. The differences may be attributed to the presence of internal waves (Pelagia) or bottom intensified diurnal waves (Belgica). These different dynamical regimes are likely to have implications for the distribution patterns of live coral at the different locations.

  9. Temperature, salinity, oxygen, zooplankton biomass, zooplankton count, phytoplankton count, and fish count measurements collected from multiple Soviet Union research vessels in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico from 1963-03-09 to 1989-11-20 (NODC Accession 0001310)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection of physical, chemical, and biological data presented on CD-ROM "Pelagic Ecosystems of the Tropical Atlantic Ocean". Data were collected from Atlantic...

  10. Zooplankton of West Madagascar

    Science.gov (United States)

    Bemiasa, John; Remanevy, Sitraka

    2014-05-01

    During six week survey (August - October 2009) in Western and Northern coast of Madagascar, the R/V 'Dr. Fridtjof Nansen' has carried out a study of the pelagic ecosystem. In collaboration with Agulhas & Somali Current Large Marine Ecosystems project (ASCLME) and South West Indian Ocean Fisheries Project (SWIOFP), the aim of the survey was to establish the physical, chemical and biological characteristics of the Western Madagascar shelf region as a whole. Zooplankton samples were collected with Hydrobios Multinet at all environmental stations ranging from 200 m depth to the surface. The Multinet was equipped with 5 nets for depth-stratified sampling. The nets were fitted with 180 µm mesh size and the water flow through the nets was measured. The Multinet was deployed and retrieved at a rate of ~ 1.5 m per second and was obliquely hauled. The five nets were triggered at the pre-selected depth intervals 0-25m, 25-50m, 50-80m, 80-120m and 120-200m. All samples were stored in marked bottles and preserved with buffered formaldehyde of 4% for further analysis. As results,the zooplankton abundance was influenced by physico-chemical factors. During the study period 34 Family of zooplankton were identified which are dominated by Copepoda (58,69%) followed by Radiolaria (12,06%), Appendicularia (6,47%), Sagitta (5,11%), Larvae (4,57%), Ostracoda (3,13%), pelagic Foraminifera (2,15%). Family of zooplankton with abundance sampling sites. The findings of the present study will help to improve the scientific knowledge of the marine ecosystem of the west coast of Madagascar.

  11. Zooplankton intermittency and turbulence

    Science.gov (United States)

    Schmitt, François G.

    2010-05-01

    Planktonic organisms usually live in a turbulent world. Since marine turbulence is characterized by very high Reynolds numbers, it possesses very intermittent fluctuations which in turn affect marine life. We consider here such influence on zooplankton on 2 aspects. First we consider zooplankton motion in the lab. Many copepods display swimming abilities. More and more species have been recently recorded using normal or high speed cameras, and many trajectories have been extracted from these movies and are now available for analysis. These trajectories can be complex, stochastic, with random switching from low velocity to high velocity events and even jumps. These complex trajectories show that an adequate modeling is necessary to understand and characterize them. Here we review the results published in the literature on copepod trajectories. We discuss the random walk, Levy walk modeling and introduce also multifractal random walks. We discuss the way to discriminate between these different walks using experimental data. Stochastic simulations will be performed to illustrate the different families. Second, we consider zooplankton contact rates in the framework of intermittent turbulence. Intermittency may have influence on plankton contact rates. We consider the Particle Stokes number of copepods, in a intermediate dissipation range affected by intermittent fluctuations. We show that they may display preferential concentration effects, and we consider the influence on contact rates of this effect in the intermediate dissipation range.

  12. Variations of zooplankton in the frontal area of the Alboran sea (Mediterranean sea) in winter 1997

    OpenAIRE

    Youssara, F; Gaudy, R

    2001-01-01

    Zooplankton from the upper 200 m of the Almeria-Oran frontal region, (east of the Alboran sea, western Mediterranean) was sampled during winter 1997, using two nets equipped with 200 and 80 mum mesh. Eight sites representative of the different hydrodynamic structures (Mediterranean water, geostrophic Atlantic jet, associated anticyclonic gyre) were investigated over 2 d, using two day- and two night-samples per site. Zooplankton biomass was correlated to chlorophyll abundance, with lowest val...

  13. Zooplankton - Study methods, importance and significant observations

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.

    The intent of this section is to review briefly current knowledge of the structure and dynamics of the zooplankton and its ecology. Zooplankton are mysids of animal organisms that drift with currents. In an aquatic ecosystem zooplankton form...

  14. Towards an integrated view of benthic and pelagic processes in the southern North Sea (German Bight)

    Science.gov (United States)

    Friedrich, Jana; van Beusekom, Justus; Neumann, Andreas; Naderipour, Celine

    2015-04-01

    The North Sea can be classified as a semi-enclosed shelf on the western-European continent. Atlantic influences are mainly through the Fair Isle current Channel in the North, and through the Strait of Dover in the South. An anti-clockwise circulation prevails, driven by mainly semi-diurnal tides and winds. The German Bight is located in the south-eastern part of the North Sea, and is strongly influenced by continental rivers. The outflow from the rivers Scheldt, Maas and Rhine is carried towards the German Bight with the residual currents. The German rivers Ems, Weser and Elbe directly debouche into the German Bight. On the shallow shelf, the water column is completely mixed by tidal forces and wind, largely preventing downward flux of particles and instead fostering temporary deposition and resuspension, which influences benthic mineralization. Hence, complex interactions between pelagic and benthic processes occur. Previous budget calculations indicate that the nutrient inventory has to be processed several times to support observed primary production, and, depending on water depth; only 10-20% remineralisation occurs in sediments of the German Bight whereas about 50% of organic matter is remineralised in the sediments of the shallow Wadden Sea. In this presentation, we use in-situ and ex-situ field data on pelagic and benthic oxygen respiration and benthic nutrient fluxes to assess the intense mineralization activity in the German Bight, the partitioning of benthic and pelagic processes and the factors influencing organic matter mineralization. Measurements of pelagic oxygen respiration based on Winkler titration, in-situ benthic oxygen uptake measurements based on flux-chamber landers and ex-situ incubations of intact sediment cores revealed that benthic remineralisation rates are about an order of magnitude smaller than pelagic rates, in agreement with previous budget estimates. Both benthic and pelagic oxygen respiration show a strong seasonality; with higher

  15. Zooplankton biomass data collected by Research Institute of Marine Fisheries & Oceanography (PINRO) from 1958-03-25 to 1964-06-18 (NODC Accession 0070127)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton biomass data collected in North Atlantic Ocean, Greenland Sea, North Sea, Norwegian Sea, and Bering Sea from 03 Mar 1958 to 18 Jun 1964 by PINRO. Data...

  16. Zooplankton: its biochemistry and significance in aquaculture

    OpenAIRE

    Kibria, G; Nugegoda, D.; Fairclough, R.; Lam, P.; Bradly, A.

    1997-01-01

    Zooplankton are an important food source for many species of fish. They can provide an inexpensive alternative to other commercial feeds. Zooplankton have several advantages, among them a faster growth and greater feed efficiency for some species. The flavor and texture of fish are also improved with zooplankton as feed. Further research is needed on the chemical composition of zooplankton, the development of zooplankton-based dry diets and the effects of the replacement of fish meal with zoo...

  17. Fishery survey, benthic organism, and zooplankton data collected using trawls and tows from the EASTWARD and other platforms in the North Atlantic Ocean and Others from 16 January 1980 to 14 March 1984 (NODC Accession 8500245)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fishery survey, fishing duration and other benthic organism data from unknown and other platforms from North Atlantic Ocean was collected over four years between...

  18. US AMLR Program zooplankton dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton research in the US AMLR Program focuses on the link between prey production, availability, and climate variability in relation to predator and fishery...

  19. Trace element geochemistry of the South Atlantic Bight. Progress report

    International Nuclear Information System (INIS)

    This report summarizes research conducted during the past year under DOE Contract EY-76-S-09-0890. During this time, studies have been continued in the mid to outer continental shelf region. We have also initiated nearshore studies designed to elucidate processes influencing the fate of trace elements in estuaries and the coastal frontal zone. A smaller effort has been concerned with preliminary geochemical studies of uranium-thorium natural decay series radionuclides and with improvement, calibration, and expansion of our trace element laboratory procedures

  20. Modelling cyclonic eddies in the Delagoa Bight region

    Science.gov (United States)

    Cossa, O.; Pous, S.; Penven, P.; Capet, X.; Reason, C. J. C.

    2016-05-01

    The objective of this study is to document and shed light on the circulation around the Delagoa Bight region in the southern Mozambique Channel using a realistic modelling approach. A simulation including mesoscale forcings at the boundaries of our regional configuration succeeds in reproducing the general circulation in the region as well as the existence of a semi-permanent cyclonic eddy, whose existence is attested by in situ measurements in the Bight. Characterised by a persistent local minimum in SSH located around 26°S-34°E, this cyclonic eddy termed herein the Delagoa Bight lee eddy occurs about 25% of the time with no clear seasonal preference. Poleward moving cyclones, mostly generated further north, occur another 25% of the time in the Bight area. A tracking method applied to eddies generated in Delagoa Bight using model outputs as well as AVISO data confirms the model realism and provides additional statistics. The diameter of the eddy core varies between 61 and 147 km and the average life time exceeds 20 days. Additional model analyses reveal the systematic presence of negative vorticity in the Bight that can organise and form a Delagoa Bight lee eddy depending on the intensity of an intermittent southward flow along the shore and the spatial distribution of surrounding mesoscale features. In addition, the model solution shows other cyclonic eddies generated near Inhambane and eventually travelling through the Bight. Their generation and pathways appears to be linked with large Mozambique Channel rings.

  1. Turbulence and zooplankton production: insights from PROVESS

    DEFF Research Database (Denmark)

    Visser, Andre; Stips, A.

    2002-01-01

    Zooplankton are directly influenced by turbulence in both a passive and an active manner. Passively, zooplankton are at the mercy of turbulence in how it affects their vertical mixing, encounter rate, detection abilities and feeding current efficiency. Many zooplankton species, however, are...

  2. Future marine zooplankton research - a perspective

    DEFF Research Database (Denmark)

    Bathmann, U.; Bundy, M.H.; Clarke, M.E.;

    2001-01-01

    During the Second Marine Zooplankton Colloquium (MZC2) 3 issues were added to those developed 11 yr ago during the First Marine Zooplankton Colloquium (MZC1). First, we focused on hot spots, i.e., locations where zooplankton occur in higher than regular abundance and/or operate at higher rates, W...

  3. Modelling cyclonic eddies in the Delagoa Bight region

    OpenAIRE

    Cossa, O.; Pous, Stéphane; Penven, P.; Capet, Xavier; Reason, C.J.C.

    2016-01-01

    The objective of this study is to document and shed light on the circulation around the Delagoa Bight region in the southern Mozambique Channel using a realistic modelling approach. A simulation including mesoscale forcings at the boundaries of our regional configuration succeeds in reproducing the general circulation in the region as well as the existence of a semi-permanent cyclonic eddy, whose existence is attested by in situ measurements in the Bight. Characterised by a persistent local m...

  4. ZOOPLANKTON AS A FOOD SOURCE

    Science.gov (United States)

    While thousands of zooplankton species could potentially serve as food for larval stages of cultured fish and crustaceans, the aquaculturists practical choice of a reproducible live food ratio is quite limited. In practice, rotifers and brine shrimp are the most commonly used zoo...

  5. Dipole vortices in the Great Australian Bight

    DEFF Research Database (Denmark)

    Cresswell, George R.; Lund-Hansen, Lars C.; Nielsen, Morten Holtegaard

    2015-01-01

    Shipboard measurements from late 2006 made by the Danish Galathea 3 Expedition and satellite sea surface temperature images revealed a chain of cool and warm mushroom' dipole vortices that mixed warm, salty, oxygen-poor waters on and near the continental shelf of the Great Australian Bight (GAB......) with cooler, fresher, oxygen-rich waters offshore. The alternating jets' flowing into the mushrooms were directed mainly northwards and southwards and differed in temperature by only 1.5 degrees C; however, the salinity difference was as much as 0.5, and therefore quite large. The GAB waters were slightly...... denser than the cooler offshore waters. The field of dipoles evolved and distorted, but appeared to drift westwards at 5km day-1 over two weeks, and one new mushroom carried GAB water southwards at 7km day(-1). Other features encountered between Cape Leeuwin and Tasmania included the Leeuwin Current...

  6. Trait-based approaches to zooplankton communities

    DEFF Research Database (Denmark)

    Lichtman, E.; Ohman, M.D.; Kiørboe, Thomas

    2013-01-01

    Zooplankton are major primary consumers and predators in most aquatic ecosystems. They exhibit tremendous diversity of traits, ecological strategies and, consequently, impacts on other trophic levels and the cycling of materials and energy. An adequate representation of this diversity in community...... zooplankton in ecosystem models. Characterizing zooplankton traits and trade-offs will also be helpful in understanding the selection pressures and diversity patterns that emerge in different ecosystems along major environmental gradients. Zooplankton traits can be characterized according to their function...... and type. Some traits, such as body size and motility, transcend several functions and are major determinants of zooplankton ecological strategies. Future developments of trait-based approaches to zooplankton should assemble a comprehensive matrix of key traits for diverse groups and explore it for...

  7. The unique south: marine biodiversity in the Great Australian Bight

    Energy Technology Data Exchange (ETDEWEB)

    Edyvane, K.S. [South Australian Research and Development Institute, Henley Beach, SA (Australia)

    1996-12-31

    The Great Australian Bight is an area of international conservation significance, containing globally significant breeding populations of rare and endangered marine mammals, and also, some of the highest levels of endemism and marine biodiversity in Australia (and the world). The fauna and flora of the in-shore and offshore regions of the Bight, however, particularly the seabirds, fish and invertebrates, remains poorly known. Existing marine biodiversity research and conservation management efforts in the region are low with, until recently, only 260 hectares of the 18.6 million hectares of the Bight being formally protected and managed as marine Protected Areas. Despite the risk of increasing conflicts with marine biodiversity in the region from existing uses, such as commercial fisheries, and also from emerging uses such as marine mammal-based ecotourism (in WA and SA) and sea-based aquaculture (in SA), regional multiple-use management arrangements or management plans are generally lacking. The proposed Great Australian Bight Marine Park, which has been developed with industry and community participation, will, if established, represent the first multiple-use management regime and the first formal reservation of the ecosystems and habitats of the Great Australian Bight. (author). 6 figs., refs.

  8. Zooplankton species identities, zooplankton species number per sample, and zooplankton abundance collected using zooplankton net as part of the California Cooperative Fisheries Investigation (CALCOFI) project, for 1994-03-01 (NODC Accession 9700104)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities, zooplankton species number per sample, and zooplankton abundance were collected from March 1, 1994 to March 1, 1994. Data were...

  9. Zooplankton research off Peru: A review

    Science.gov (United States)

    Ayón, Patricia; Criales-Hernandez, Maria I.; Schwamborn, Ralf; Hirche, Hans-Jürgen

    2008-10-01

    A review of zooplankton studies conducted in Peruvian marine waters is given. After a short history of the development of zooplankton research off Peru, we review zooplankton methodology, taxonomy, biodiversity, spatial distribution, seasonal and interannual variability, trophodynamics, secondary production, and modelling. We review studies on several micro-, meso-, macro-, and meroplankton groups, and give a species list from both published and unpublished reports. Three regional zooplankton groups have been identified: (1) a continental shelf group dominated by Acartia tonsa and Centropages brachiatus; (2) a continental slope group characterized by siphonophores, bivalves, foraminifera and radiolaria; (3) and a species-rich oceanic group. The highest zooplankton abundances and biomasses were often found between 4-6°S and 14-16°S, where continental shelves are narrow. Species composition changes with distance from the shore. Species composition and biomass also vary strongly on short time scales due to advection, peaks of larval production, trophic interactions, and community succession. The relation of zooplankton to climatic variability (ENSO and multi-decadal) and fish stocks is discussed in the context of ecological regime shifts. An intermediate upwelling hypothesis is proposed, based on the negative effects of low upwelling intensity in summer or extremely strong and enduring winter upwelling on zooplankton abundance off Peru. According to this hypothesis, intermediate upwelling creates an optimal environmental window for zooplankton communities. Finally, we highlight important knowledge gaps that warrant attention in future.

  10. Microscale nutrient patches produced by zooplankton

    OpenAIRE

    John T. LEHMAN; Scavia, Donald

    1982-01-01

    Both track autoradiography and grain-density autoradiography show that individual zooplankton create miniature patches of dissolved nutrients and that algae exploit those regions to absorb phosphate. The patches are short lived and can be dispersed artificially by small-scale turbulence. Our data support a simple model of encounters between algae and nutrient plumes produced by swimming zooplankton.

  11. High evolutionary potential of marine zooplankton

    NARCIS (Netherlands)

    Peijnenburg, K.T.C.A.; Goetze, E.

    2013-01-01

    Open ocean zooplankton often have been viewed as slowly evolving species that have limited capacity to respond adaptively to changing ocean conditions. Hence, attention has focused on the ecological responses of zooplankton to current global change, including range shifts and changing phenology. Her

  12. Zooplankton of the Zaporiz’ke Reservoir

    Directory of Open Access Journals (Sweden)

    T. V. Mykolaichuk

    2006-01-01

    Full Text Available The paper is devoted to zooplankton species composition in the Zaporiz’ke Reservoir. The greatest species diversity was found in the macrophyte communities of the upper reservoir’s littoral, but the least zooplankton diversity – in the pelagic zone of the lower reservoir.

  13. Zooplankton of the Zaporiz’ke Reservoir

    OpenAIRE

    T. V. Mykolaichuk

    2006-01-01

    The paper is devoted to zooplankton species composition in the Zaporiz’ke Reservoir. The greatest species diversity was found in the macrophyte communities of the upper reservoir’s littoral, but the least zooplankton diversity – in the pelagic zone of the lower reservoir.

  14. Article Review: Lessepsian migration of zooplankton through Suez Canal and its impact on ecological system

    Directory of Open Access Journals (Sweden)

    Howaida Y. Zakaria

    2015-01-01

    Full Text Available The marine environment of the East Mediterranean has been considerably impacted in modern times by two man-made changes: the creation of a waterway between the Indo-Pacific and the Mediterranean basins and the control of the Nile fresh-water outflow. The opening of the Suez Canal caused a migration generally from the Red Sea to the Mediterranean, and rarely in the opposite direction as the Red Sea is generally saltier and more nutrient-poor than the Atlantic, so the Red Sea species have advantages over Atlantic species in the salty and nutrient-poor eastern Mediterranean. Accordingly Red Sea species invaded the Mediterranean ecosystem and not vice versa; this phenomenon is known as the Lessepsian migration or erythrean invasion. The composition of zooplankton in the eastern Mediterranean has been shown to include a large proportion of Indo-Pacific and other circumtropical species which have successfully settled and proliferated in this environment. During the present study, an overview is provided on zooplankton migration through Suez Canal and its impact on the ecological system based on published literature. It is also meant with the hydrographic and zooplankton characteristics of the adjacent seas. It is clear that, except jellyfish Rhopilema nomadica, the negative impact of zooplankton Lessepsian migratory species in the Egyptian Mediterranean waters is not evident. Finally, it would be concluded that, a continuous monitoring programme will be needed to record the recent erythrean zooplankton species and follow up the distribution and abundance of those previously recorded as aliens to assess their impacts on the native biodiversity of the Mediterranean.

  15. Avoidance of strobe lights by zooplankton

    Science.gov (United States)

    Hamel, Martin J.; Richards, Nathan S.; Brown, Michael L.; Chipps, Steven R.

    2010-01-01

    Underwater strobe lights can influence the behavior and distribution of fishes and are increasingly used as a technique to divert fish away from water intake structures on dams. However, few studies examine how strobe lights may affect organisms other than targeted species. To gain insight on strobe lighting effects on nontarget invertebrates, we investigated whether underwater strobe lights influence zooplankton distributions and abundance in Lake Oahe, South Dakota. Zooplankton were collected using vertical tows at 3 discrete distances from an underwater strobe light to quantify the influence of light intensity on zooplankton density. Samples were collected from 3 different depth ranges (0–10 m, 10–20 m and 20–30 m) at zooplankton sampled from 17 August to 15 September 2004. Night time zooplankton densities significantly decreased in surface waters when strobe lights were activated. Copepods exhibited the greatest avoidance patterns, while Daphnia avoidance varied throughout sampling depths. These results indicate that zooplankton display negative phototaxic behavior to strobe lights and that researchers must be cognizant of potential effects to the ecosystem such as altering predator–prey interactions or affecting zooplankton distribution and growth.

  16. Zooplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Madhu, N.V.

    ://www.ngdc.noaa.gov/mgg/topo/globe.html. Godhantaraman N. (1994) Species composition and abundance of tintinnids and copepods in the Pichavaram mangroves (South India); Ciencias Marinas 20 371?391. Goswami S. C. (1983) Coexistence and succession of copepod species in the Mandovi and Zuari estuaries...

  17. Bacterial diversity associated with freshwater zooplankton

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Dziallas, Claudia; Tang, Kam W.

    2009-01-01

    Bacterial community compositions (BCC) associated with the cladoceran Bosmina coregoni and the cyclopoid copepod Thermocyclops oithonoides in oligotrophic Lake Stechlin versus eutrophic Lake Dagow (northeastern Germany) were compared using molecular techniques. We also transplanted the zooplankton...

  18. Biomass measurements collected using net in the North and South Atlantic from several platforms from 1950 to 989 (NODC Accession 0053277)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton biomass data collected by Institute of Biology of the Southern Seas from the Atlantic Ocean in 1950-1989 years and received from the NMFS.

  19. Changes in the non-crustacean zooplankton community in the middle Adriatic Sea during the Eastern Mediterranean Transient

    OpenAIRE

    Batistić, Mirna; Garić, Rade; MOROVIĆ, Mira

    2016-01-01

    Background and Purpose: Here we presented changes in the non-crustacean zooplankton community in the years characterized by the large scale changes in the thermohaline circulation in the East Mediterranean known as the Eastern Mediterranean transient (EMT) and stronger inflow of colder and less saline Modified Atlantic Water (MAW) into the Adriatic Sea. Material and Method: Monthly samplings from February 1995 to February 1996, were performed at fixed station Stončica near the Island of V...

  20. UV radiation and freshwater zooplankton: damage, protection and recovery

    OpenAIRE

    Rautio, Milla; Tartarotti, Barbara

    2010-01-01

    While many laboratory and field studies show that zooplankton are negatively affected when exposed to high intensities of ultraviolet radiation (UVR), most studies also indicate that zooplankton are well adapted to cope with large variations in their UVR exposure in the pelagic zone of lakes. The response mechanisms of zooplankton are diverse and efficient and may explain the success and richness of freshwater zooplankton in optically variable waters. While no single behavioural or physiologi...

  1. Carbon export by vertically migrating zooplankton

    DEFF Research Database (Denmark)

    Hansen, Agnethe Nøhr; Visser, André W.

    2016-01-01

    Through diel vertical migration (DVM), zooplankton add an active transport to the otherwise passive sinking of detrital material that constitutes the biological pump. This active transport has proven difficult to quantify. We present a model that estimates both the temporal and depth characteristic...... of optimal DVM behavior based on a trade-off between feeding opportunity and predation risk; factors that vary with latitude, time of year, and the size of the migrating animal. This behavioral component, coupled to a nutrient-phytoplankton-zooplankton (NPZ) productivity model provides estimates of...... the active transport of carbon by different size fractions of the migrating zooplankton population as function of time and space. The approach is motivated by the difficulty in incorporating behavioral aspects of carbon transport into large scale carbon budgets of the world's oceans. The results show...

  2. Zooplankton use of chemodetection to find and eat particles

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2004-01-01

    The ability of raptorial zooplankton to find large particles such as marine aggregates is crucial to their use of the particles as food and to the fate of the particles. Kiorboe & Thygesen (2001) developed a numerical approach to describe particle detection by chemosensory zooplankton. In this...... sensitivity of chemodetection in zooplankton, a process that has not been well studied experimentally....

  3. Zooplankton characteristics of the coastal ecosystem off Bombay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Ramaiah, Neelam

    The nearshore waters of Bombay sustain a rich and diverse zooplankton fauna. Continuous observations for a period of 15 months indicated a variation from 0.4 to 19.9 mg C.m sup(3) (av. 4.3 mg C.m sup(-3)) in zooplankton biomass. The zooplankton...

  4. Circulation in the Hudson Shelf Valley: MESA Physical Oceanographic Studies in New York Bight, 1

    Science.gov (United States)

    Mayer, Dennis A.; Han, Gregory C.; Hansen, Donald V.

    1982-11-01

    Over 900 days of current velocity data were obtained at mainly two locations in the inner and outer Hudson Shelf Valley (HSV). The large cross-axis depth gradients in the HSV, together with the strong winter cyclones and the baroclinic density distribution over the shelf, are primarily responsible for the major circulation features observed in the valley. CSTD data from 12 cruises and meteorological data from JFK International Airport and an environmental buoy were collected concurrently with the current meter data. Although the mean cross-shelf pressure gradient is generally seaward in the Middle Atlantic Bight, it is shoreward in the HSV below the level of the adjacent continental shelf (shelf horizon), thus imposing a bias toward upvalley flow. The average velocity below the surrounding shelf horizon in the HSV is upvalley or shoreward (west-northwestward ≈ 290° T) in the range of 2-5 cm/s. The circulation in the HSV is seasonal and individual events can drastically alter the mean picture. The several day average upvalley flow can sometimes approach 20 cm/s when intense winter cyclones pass over the bight and can sometimes also be directed downvalley depending upon the path of the winter cyclone. A topographically controlled barotropic flow commonly opposes the dominant (southeast-ward) wind direction even near the surface in the winter. In the context of circulation on the open shelf, upvalley (downvalley) flow events generated by winter cyclones are associated with reduced (enhanced) southwestward flow or flow reversals that are northeastward in the lower half of the water column at LTM, a typical mid/shelf site (Mayer et al., 1979). Current meter data suggest that whether or not reversals occur on the open shelf depends upon the interannual variability of the winter wind regime. Upvalley flow events are not confined only to the winter (unstratified) season but are stronger in the winter and can last for several days and longer. During the summer

  5. Fish-mediated trait compensation in zooplankton

    DEFF Research Database (Denmark)

    Hylander, Samuel; Souza, M.S.; Balseiro, E.;

    2012-01-01

    pigmentation and antioxidant enzymes are flexible UVR defence systems, which can be induced when needed. Zooplankton may employ antioxidant defences when pigmentation is reduced to counteract predation risk and thereby rapidly respond to detrimental effects of UVR exposure, that is, they can compensate one...... exposed to fish predators. Hence, reduced pigmentation because of the presence of fish could potentially lead to UVR damage, which calls for alternative protective echanisms. 2. We exposed zooplankton to fish cues and UVR stress to assess whether body pigmentation and cellular antioxidants are flexible...

  6. Future marine zooplankton research - a perspective

    DEFF Research Database (Denmark)

    Bathmann, U.; Bundy, M.H.; Clarke, M.E.; Cowles, T.J.; Daly, K.; Dam, H.G.; Dekshenieks, M.M.; Donaghay, P.L.; Gibson, D.M.; Gifford, D.J.; Hansen, B.W.; Hartline, D.K.; Head, E.J.H; Hofmann, E.E.; Hopcroft, R.R.; Jahnke, R.A.; Jonasdottir, Sigrun; Kiørboe, Thomas; Kleppel, G.S.; Klinck, J.M.; Kremer, P.M.; Landry, M.R.; Lee, R.F.; Lenz, P.H.; Madin, L.P.; Manahan, D.T.; Mazzocchi, M.G.; McGillicuddy, D.J.; Miller, C.B.; Nelson, J.R.; Osborn, T.R.; Paffenhofer, G.A.; Pieper, R.E.; Prusova, I.; Roman, M.R.; Schiel, S.; Seim, H.E.; Smith, S.L.; Torres, J.J.; Verity, P.G.; Wakeham, S.G.; Wishner, K.F.

    2001-01-01

    .g., Oithona spp,, Calanus spp., Oikopleura spp., Euphausia superba) to determine what governs their abundance and its variability. Third, zooplankton clearly influence biogeochemical cycling in the ocean, but our knowledge of the underlying processes remains fragmentary. Therefore a thorough assessment of...... variables that still need to be quantified is required to obtain an understanding of zooplankton contributions to biogeochemical cycling. Combining studies on the 7 issues from MZC1 with the 3 from MZC2 should eventually lead to a comprehensive understanding of (1) the mechanisms governing the abundance and...

  7. Zooplankton succession in fingerling production ponds

    Science.gov (United States)

    Many pond cultured species require a range of zooplankton species for consumption before they can be weaned onto manufactured feed. The widest variety of plankton species develops when empty ponds are filled and fertilized. Use of organic and inorganic fertilizers facilitates the development of ba...

  8. Is the zooplankton of the tropics different?

    Institute of Scientific and Technical Information of China (English)

    Henri J.Dumont

    2008-01-01

    @@ The zooplankton,defined a the assemblage of animals and animal-like creatures that lives in the water column of small to big waterbodies,has primarily been studied in the temperate zone,so most "received" concepts about it derive from the temperate,not the tropical belt of this planet.

  9. Monitoring in beech forest stands in the Westphalian Bight

    International Nuclear Information System (INIS)

    The results of monitoring immissions by the observation of the so-called trunk base phenomena in beech forests of the Westphalian Bight are presented and compared with those of two other monitoring methods: recording heavy metal accumulation of mosses and repetition of phytosociological releves. Results from investigations of the trunk base phenomena (differences of Fe + H cation exchange saturation between the soil of trunk base areas and soil only influenced by canopy drip and the exchangeable Pb-content of trunk base areas) and the Pb accumulation of the moss Mnium hornum show similar patterns of immission load in the Westphalian Bight: high immissions in the Ruhr area, decreasing immissions with increasing distance from the Ruhr area in east and north directions and increasing immissions with increasing altitude in the adjoining fringe mountains. The results obtained by repetition of phytosociological releves were less detailed. This, however, does not seem to be a fault of the method itself but results from the fact that the releve areas were not selected to monitor effects of air pollution but to classify vegetation. The combined investigation of trunk base phenomena of beeches and heavy metal accumulation of mosses is a suitable method monitoring immissions in larger areas. Nevertheless, attention should also be paid to observation of permanent plots and root investigations. (orig.)

  10. Ecological stress and the New York Bight: science and management

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, G.F.

    1982-01-01

    An often-voiced criticism of the environmental regulatory process is the failure to maintain adequate lines of communication among legislators and managers charged with developing and implementing environmental policy and scientists engaged in environmental research. The former two groups have a need for definitive information and unequivocal pronouncements on the environmental effects or ecological implications of specific actions. Members of the latter group, on the other hand, often are unable to respond precisely. They are trained to report on observations, to avoid speculation, and to enumerate the strengths and weaknesses of conclusions. Such opposing approaches have estranged these groups and have limited their interactions. The organization of the volume reflects that of the symposium. In all, nine panels were convened: five on science and four on management. Three science panels reviewed organismic effects of pollutants on fishes, bottom-dwelling organisms, and plankton/neuston (i.e., effects on cells, tissues, and individual plants and animals). The remaining two science panels explored implications of toxicant additions and nutrient and carbon loadings to communities and ecosystems of the New York Bight. Reports of the science panels are presented in the first section of the volume. By adopting a two-part format, the Editorial Board sought to produce a volume on the New York Bight of use to a range of readers from technical specialists to governmental leaders, decision-makers, members of the public, and students who may lack extensive technical backgrounds.

  11. Oceanographic profile; phosphate, silicate and other measurements collected using bottle and high resolution CTD from the DANA, JAN MAYEN (LAHV) and other platforms in the Coastal N Atlantic, Arctic and other locations from 1995 to 1997 (NODC Accession 0000566)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, zooplankton, and nutrients data were collected using net and bottle casts from DANA and JAN MAYEN in the North Atlantic Ocean. Data were...

  12. The impact of different hydrographic conditions and zooplankton communities on provisioning Little Auks along the West coast of Spitsbergen

    Science.gov (United States)

    Kwasniewski, Slawomir; Gluchowska, Marta; Jakubas, Dariusz; Wojczulanis-Jakubas, Katarzyna; Walkusz, Wojciech; Karnovsky, Nina; Blachowiak-Samolyk, Katarzyna; Cisek, Malgorzata; Stempniewicz, Lech

    2010-10-01

    Composition and abundance of zooplankton were studied simultaneously with feeding ecology of planktivorous Little Auks ( Alle alle) in two different sea shelf areas of West Spitsbergen, Norway, in summer 2007. Zooplankton was collected adjacent to bird colonies in Magdalenefjorden (influenced by Atlantic West Spitsbergen Current) and Hornsund (dominated by the Arctic Sørkapp Current). In spite of different hydrological situations, the abundance of prey preferred by Little Auks, Arctic Calanus glacialis copepodids stage V, among zooplankton was similar in both localities. However, there was much more of Atlantic Calanus finmarchicus on the shelf outside Magdalenefjorden compared to Hornsund, resulting in different abundance ratios of Arctic to Atlantic copepods in the two areas (1:14 and 1:1, respectively). Even greater differences between the two areas occurred in the ratio of C. glacialis CV to other zooplankters, amounting to 1:40 in Magdalenefjorden and 1:6 in Hornsund. In both Little Auk colonies food brought by parents to their chicks contained mainly C. glacialis CV, albeit the proportion of this copepod in meals was significantly higher in Hornsund. Meals delivered to Little Auk chicks in Hornsund had also higher zooplankton numbers, biomass and energy content. In Magdalenefjorden, on the other hand, a higher number of feedings and longer duration of foraging trips were recorded. These differences became more apparent with increasing energy requirements of the fast growing nestlings. This was probably a consequence of lower relative abundance of the Little Auks’ preferred prey in the sea adjacent to Magdalenefjorden colony. It seems that searching for the preferred food items, such as C. glacialis, among abundant but less favored C. finmarchicus, may require more time and energy demanding foraging behavior. As a consequence, foraging effort of the Little Auk parents from Magdalenefjorden was higher, and feeding efficiency lower, than those of birds from

  13. Marine Ecosystems Analysis (MESA) Program, New York Bight Surficial Sediment Analyses

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Ecosystems Analysis (MESA) Program, New York Bight Study was funded by NOAA and the Bureau of Land Management (BLM). The Atlas was a historical...

  14. The organization of zooplankton epibiont communities.

    Science.gov (United States)

    Threlkeld, S T; Chiavelli, D A; Willey, R L

    1993-09-01

    Recent findings suggest that a diverse set of interactions exists between crustacean zooplankton and the algae, protozoans and metazoans that live attached to them. The frequent molting of the crustacean exoskeleton keeps these epibiont populations in a state of constant renewal and makes this epibiont community an ideal experimental system for examining the organization of communities whose populations are distributed among ephemeral habitat patches. PMID:21236181

  15. Zooplankton Methodology, Collection & identyification - A field manual

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C

    First Edition : March 2004 S.C. Goswami (Retd.) National Institute of Oceanography Dona Paula, Goa - 403 004 Editors V.K. Dhargalkar X.N. Verlecar National Institute of Oceanography, Dona Paula, Goa - 403 004 DTP Devanand Kavlekar Bioinformatics Centre..., preservation, analysis and computation of data. The detailed procedures on all these aspects are given in this manual. I do hope that the manual on zooplankton methodology will be useful to research scholars, teachers and planktonologists. S.C. Goswami 5...

  16. Zooplankton composition and abundance in Mida Creek, Kenya

    OpenAIRE

    Osore, M.K.W.; Mwaluma, J.M.; FIERS, F; Daro, M.H.

    2004-01-01

    In order to determine the resident assemblages of zooplankton in Mida Creek, Kenya, a survey was conducted from May 1996 to Apr. 1997 for which we studied their seasonal composition, abundance, and distribution. Twenty-seven major zooplankton taxa were identified. The order Copepoda was the most abundant taxon dominated mainly by the genera Acartia, Paracalanus, Labidocera, Temora, Centropages, and Calanopia. Other common zooplankton taxa included the Medusae, Ctenophora, Brachyura larvae, an...

  17. Zooplankton community structure in a cyclonic and mode-water eddy in the Sargasso Sea

    Science.gov (United States)

    Eden, Bethany R.; Steinberg, Deborah K.; Goldthwait, Sarah A.; McGillicuddy, Dennis J., Jr.

    2009-10-01

    Mesoscale eddies are important suppliers of nutrients to the surface waters of oligotrophic gyres, but little is known about the biological response, particularly that of higher trophic levels, to these physical perturbations. During the summers of 2004 and 2005, we followed the development of a cyclonic eddy and an anti-cyclonic mode-water eddy in the Sargasso Sea. Zooplankton (>150 μm) were collected across both eddies in 9 discrete depth intervals between 0 and 700 m. Comparison of the abundance of major taxa of mesozooplankton in the upper 150 m at eddy center and outside the eddies (day and night) indicated that the cyclone and mode-water eddy supported similar mesozooplankton communities, with several taxa significantly higher in abundance inside than outside the eddies, when compared with the Bermuda Atlantic Time-series Study site as representative of mean conditions. In both eddies copepod peak abundance occurred in the 50-100 m depth interval, coincident with the chlorophyll a maximum, suggesting elevated food concentration in the eddies may have influenced zooplankton vertical distribution. The two eddies differed in the strength of diel vertical migration of zooplankton, as indicated by the ratio of night:day abundance in the epipelagic zone, which was higher at the center of the mode-water eddy for most taxa. Over the sampling interval of 1-2 months, abundance of the three most common taxa (copepods, chaetognaths, and ostracods) decreased in the cyclone and increased in the mode-water eddy. This further supports previous findings that over the sampling period the cyclone was in a decay phase, while the mode-water eddy was sustaining nutrient fluxes and high phytoplankton concentrations. A more detailed analysis of community structure in the mode-water eddy indicated the 0-700 m integrated abundance of doliolids was significantly higher inside the mode-water eddy than outside. The presence of a mesopelagic (200-700 m) layer of lepadid barnacle cyprids

  18. Feeding analysis of larvae and juveniles of the common hake Patagonian stock (Merluccius hubbsi) in relation to the zooplankton taxonomic composition, abundance and nutritional quality.

    OpenAIRE

    Temperoni, B.

    2015-01-01

    The trophic relationships among early life stages (larvae and age-0 juveniles) of Patagonian hake (Merluccius hubbsi) stock and the zooplanktonic community in the spawning (between Isla Escondida and Bahía Camarones) and nursery (Golfo San Jorge) areas in the Argentine Sea (SW Atlantic ocean) were investigated. The study took place in the north Patagonian region (42°-47° S) during hake reproductive season (December-March). The effect of environmental features, including frontal regions, up...

  19. Systematics and distribution of zooplankton in Lake Victoria basin, Kenya

    OpenAIRE

    Masai, D.M.; Omondi, R.; Owili, M.

    2006-01-01

    Zooplankton samples were collected, using a 60~km nansen net, from Lake Victoria (Kenya) and adjacent water bodies with emphasis being placed on the different habitats within the ecosystems. A total of 116 species were identified, 63 rotifers, 24 cladocerans and 29 copepods. A number of these were new records for the zooplankton fauna for the country.

  20. Zooplankton composition in Dharamtar creek adjoining Bombay harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Tiwari, L.R.; Nair, V.R.

    Dharamtar creek (Bombay, India) creek maintained rich zooplankton standing stock (av. 30.3 ml 100 m/3) with peak production during August-November. Zooplankton production rate for the entire system amounted to 10.32 mg C.100 m/3 d/1 with an annual...

  1. Census of Marine Zooplankton CmarZ Information

    NARCIS (Netherlands)

    A.C. Pierrot-Bults; A. Bucklin

    2005-01-01

    The Census of Marine Zooplankton (CMarZ) will work toward a taxonomically comprehensive assessment of biodiversity of animal plankton throughout the world ocean. The project goal is to produce accurate and complete information on zooplankton species diversity, biomass, biogeographic distribution, ge

  2. Biochemical composition of Antarctic zooplankton from the Indian Ocean sector

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Parulekar, A

    Zooplankton samples were analysed for faunal composition, organic carbon, protein, carbohydrate and lipid content. Total zooplankton biomass (as displacement volume) varied from 0.032 to 0.500 ml.m sup(-3) (x = 0.23 + or - 0.14) in upper 200 m...

  3. Harvesting and Processing Zooplankton for Use as Supplemental Fry Feed

    Science.gov (United States)

    We present the methods that we used to capture and dry large zooplankton from ponds to feed to channel catfish Ictalurus punctatus fry. Using a submersible pump and canister filter, we were able to capture about 1.0 kg (wet weight; 200 g in terms of dry weight) of zooplankton from well-fertilized po...

  4. Zooplanktonic diversity in the western Pacific

    OpenAIRE

    Mao Lin; Chunguang Wang; Yanguo Wang; Peng Xiang; Yu Wang; Guangshan Lian; Ruixiang Chen; Xiaoyin Chen; Youyin Ye; Yanyu Dai; Jinghong Lin; Zhenzu Xu; Jiaqi Huang; Donghui Guo

    2011-01-01

    The western Pacific region has been operating as a centre for the origin of marine biodiversity: the richest diversity of many marine taxa was found in these waters. Therefore, biodiversity research and con-servation efforts in this area are necessary in order to promote the integrative and international management of this resource. The present work is a compilation of numbers of all the families, genera and species of ma-jor taxa of zooplankton known in the western Pacific Ocean(106°–150°E, ...

  5. Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

    OpenAIRE

    Chust, Guillem; Castellani, Claudia; Licandro, Priscilla; Ibaibarriaga, Leire; Sagarminaga, Yolanda; Irigoien, Xabier

    2014-01-01

    In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was trigger...

  6. Zooplankton from Lake Magelungen, Central Sweden 1960-1963

    International Nuclear Information System (INIS)

    The investigation of the zooplankton of Lake Magelungen, Central Sweden, was carried out over a period of three years. The aim of the investigation was to illustrate the qualitative and quantitative composition of the zooplankton before the release of waste water from the Aagesta Heat and Power Station began. Vertical sampling series were collected once a month at three different stations in the lake. The highest volumes of zooplankton were obtained in the summer. The ciliates predominated when the conditions were unfavourable for other zooplankton, as in winter just below the ice. The rotifers dominated during and immediately after the spring circulation. With one exception the crustaceans reached their peak volume values in August or September. The composition of the zooplankton indicates that Lake Magelungen is highly eutrophic

  7. Fine-scale spatial and temporal plankton distributions in the Southern California Bight: lessons from in situ microscopes and broadband echosounders

    Science.gov (United States)

    Briseno-Avena, Christian

    Phytoplankton and zooplankton are important components of marine ecosystems, and play a major role in the biological pump, affecting carbon transport in the global oceans. Their dynamic heterogeneous spatial and temporal distributions require special tools for observing them at the ecological scales relevant to the individual organisms. In this work, I used optic and acoustic methods to study plankton organisms at spatial scales of meters and temporal scales ranging from minutes to months. Using two in situ microscopes I described the fine-scale vertical distribution of phytoplankton and several zooplankton taxa in a coastal location in the Southern California Bight. Highly resolved spatial observations revealed cryptic maxima of fluorescent particles not observed with traditional fluorometers. Furthermore, this high sampling resolution revealed that water density, and not depth, regulated the vertical position, and interactions between observed phytoplankton and zooplankton distributions. Underwater acoustic echosounders can be powerful tools to observe in situ plankton distributions. Interpreting the acoustic echoes, however, requires highly calibrated instruments and ground-truthing experiments to identify the source of acoustic signals. This work presents the description of a novel combination of a broadband, high-frequency (1.5-2.5 MHz) echosounder and a stereoscopic camera --combined, these systems can localize the echo produced by an individual target while simultaneously providing visual identification of the target. This work has provided one of the first comparisons of in situ measured broadband target strength (BTS) and the expected signal using a physical model. The results of this experiment revealed unexpected, important differences between measured and modeled BTS. This system was also used to make in situ observations of individual fragile gelatinous organisms, marine snow particles and phytoplankton, providing evidence of their significant acoustic

  8. Biological processes in the water column of the South Atlantic Bight. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.; Yoder, J.A.

    1981-02-01

    Research progress for 1980 is reported. The development of a wind-induced upwelling and its effect on outer shelf chlorophyll distributions was followed. Phytoplankton productivity measurements obtained during GABEX I and other DOE-sponsored cruises were used to estimate primary and new production of the outer shelf during winter and spring. (ACR)

  9. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Visser, Andre; Richardson, Katherine;

    2015-01-01

    Significance Every autumn across the North Atlantic, large numbers of zooplankton copepods migrate from the surface waters into the ocean's interior to hibernate at depths of 600–1,400 m. Through this migration, they actively transport lipid carbon to below the permanent thermocline, where it is...

  10. Late-summer zooplankton community structure, abundance, and distribution in the Hudson Bay system (Canada) and their relationships with environmental conditions, 2003-2006

    Science.gov (United States)

    Estrada, Rafael; Harvey, Michel; Gosselin, Michel; Starr, Michel; Galbraith, Peter S.; Straneo, Fiammetta

    2012-08-01

    weakly stratified Arctic-North Atlantic waters coming from southwestern Davis Strait (inflow). In general, the RDA models tested among the HBS regions were very consistent with its general surface circulation pattern for summer conditions in terms of environmental variables and distinct zooplankton assemblages. Overall, zooplankton biomass and diversity indices (H‧, J‧, and S) were lower in the most stratified environment (i.e., HB) than in the deeper (FB) and more dynamic (HS) regions. The results of this work clearly show that the spatial differentiation and structure of the zooplankton communities are strongly influenced by the hydrodynamic conditions in the HBS that, trough their actions on temperature, salinity, stratification, mixing conditions and depth strata, lead to the spatial differentiation of these communities.

  11. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae – can we identify the underlying factors?

    OpenAIRE

    Ørjan Karlsen; Terje van der Meeren; Ivar Rønnestad; Anders Mangor-Jensen; Galloway, Trina F.; Elin Kjørsvik; Kristin Hamre

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemi...

  12. Spatio-temporal distribution of floating objects in the German Bight (North Sea)

    Science.gov (United States)

    Thiel, Martin; Hinojosa, Iván A.; Joschko, Tanja; Gutow, Lars

    2011-04-01

    Floating objects facilitate the dispersal of marine and terrestrial species but also represent a major environmental hazard in the case of anthropogenic plastic litter. They can be found throughout the world's oceans but information on their abundance and the spatio-temporal dynamics is scarce for many regions of the world. This information, however, is essential to evaluate the ecological role of floating objects. Herein, we report the results from a ship-based visual survey on the abundance and composition of flotsam in the German Bight (North Sea) during the years 2006 to 2008. The aim of this study was to identify potential sources of floating objects and to relate spatio-temporal density variations to environmental conditions. Three major flotsam categories were identified: buoyant seaweed (mainly fucoid brown algae), natural wood and anthropogenic debris. Densities of these floating objects in the German Bight were similar to those reported from other coastal regions of the world. Temporal variations in flotsam densities are probably the result of seasonal growth cycles of seaweeds and fluctuating river runoff (wood). Higher abundances were often found in areas where coastal fronts and eddies develop during calm weather conditions. Accordingly, flotsam densities were often higher in the inner German Bight than in areas farther offshore. Import of floating objects and retention times in the German Bight are influenced by wind force and direction. Our results indicate that a substantial amount of floating objects is of coastal origin or introduced into the German Bight from western source areas such as the British Channel. Rapid transport of floating objects through the German Bight is driven by strong westerly winds and likely facilitates dispersal of associated organisms and gene flow among distant populations.

  13. Impact of climate change on zooplankton communities, seabird populations and arctic terrestrial ecosystem—A scenario

    Science.gov (United States)

    Stempniewicz, Lech; Błachowiak-Samołyk, Katarzyna; Węsławski, Jan M.

    2007-11-01

    Many arctic terrestrial ecosystems suffer from a permanent deficiency of nutrients. Marine birds that forage at sea and breed on land can transport organic matter from the sea to land, and thus help to initiate and sustain terrestrial ecosystems. This organic matter initiates the emergence of local tundra communities, increasing primary and secondary production and species diversity. Climate change will influence ocean circulation and the hydrologic regime, which will consequently lead to a restructuring of zooplankton communities between cold arctic waters, with a dominance of large zooplankton species, and Atlantic waters in which small species predominate. The dominance of large zooplankton favours plankton-eating seabirds, such as the little auk ( Alle alle), while the presence of small zooplankton redirects the food chain to plankton-eating fish, up through to fish-eating birds (e.g., guillemots Uria sp.). Thus, in regions where the two water masses compete for dominance, such as in the Barents Sea, plankton-eating birds should dominate the avifauna in cold periods and recess in warmer periods, when fish-eaters should prevail. Therefore under future anthropogenic climate scenarios, there could be serious consequences for the structure and functioning of the terrestrial part of arctic ecosystems, due in part to changes in the arctic marine avifauna. Large colonies of plankton-eating little auks are located on mild mountain slopes, usually a few kilometres from the shore, whereas colonies of fish-eating guillemots are situated on rocky cliffs at the coast. The impact of guillemots on the terrestrial ecosystems is therefore much smaller than for little auks because of the rapid washing-out to sea of the guano deposited on the seabird cliffs. These characteristics of seabird nesting sites dramatically limit the range of occurrence of ornithogenic soils, and the accompanying flora and fauna, to locations where talus-breeding species occur. As a result of climate

  14. Zooplankton species identities collected from zooplankton net casts in Indian Ocean from 17 February 1960 to 23 July 1962 (NODC Accession 9400059)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities and other data were collected using zooplankton net casts in the Indian Ocean. Data were collected from 17 February 1960 to 23 July...

  15. Zooplankton data collected from zooplankton net by PERVENETS in the Bering Sea from 13 July 1959 to 12 August 1959 (NODC Accession 9500034)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected by PERVENETS using zooplankton net casts in the Bering Sea. Data were collected from 13 July 1959 to 12 August 1959 by Pacific...

  16. Zooplankton data collected by ELTANIN in Southern Oceans from zooplankton net casts; 13 October 1963 to 06 June 1968 (NODC Accession 9500111)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts from ELTANIN in the Southern Oceans. Data were collected from 13 October 1963 to 06 June 1968 by...

  17. Dead zone or oasis in the open ocean? Zooplankton distribution and migration in low-oxygen modewater eddies

    Science.gov (United States)

    Hauss, H.; Christiansen, S.; Schütte, F.; Kiko, R.; Edvam Lima, M.; Rodrigues, E.; Karstensen, J.; Löscher, C. R.; Körtzinger, A.; Fiedler, B.

    2015-11-01

    The eastern tropical North Atlantic (ETNA) features a mesopelagic oxygen minimum zone (OMZ) at approximately 300-600 m depth. Here, oxygen concentrations rarely fall below 40 μmol O2 kg-1, but are thought to decline in the course of climate change. The recent discovery of mesoscale eddies that harbour a shallow suboxic (migration (DVM) from the surface layer to the mesopelagic continued through the shallow OMZ. Based upon vertically stratified multinet hauls, Underwater Vision Profiler (UVP5) and ADCP data, four strategies have been identified followed by zooplankton in response to the eddy OMZ: (i) shallow OMZ avoidance and compression at the surface (e.g. most calanoid copepods, euphausiids), (ii) migration to the shallow OMZ core during daytime, but paying O2 debt at the surface at nighttime (e.g. siphonophores, Oncaea spp., eucalanoid copepods), (iii) residing in the shallow OMZ day and night (e.g. ostracods, polychaetes), and iv) DVM through the shallow OMZ from deeper oxygenated depths to the surface and back. For strategy (i), (ii) and (iv), compression of the habitable volume in the surface may increase prey-predator encounter rates, rendering zooplankton more vulnerable to predation and potentially making the eddy surface a foraging hotspot for higher trophic levels. With respect to long-term effects of ocean deoxygenation, we expect zooplankton avoidance of the mesopelagic OMZ to set in if oxygen levels decline below approximately 20 μmol O2 kg-1. This may result in a positive feedback on the OMZ oxygen consumption rates, since zooplankton respiration within the OMZ as well as active flux of dissolved and particulate organic matter into the OMZ will decline.

  18. Inventory of ocean monitoring in the Southern California Bight.

    Science.gov (United States)

    Schiff, Kenneth C; Weisberg, Stephen B; Raco-Rands, Valerie

    2002-06-01

    Monitoring of the ocean environment in southern California, USA, has been conducted by a diverse array of public and private organizations with different motivations, working on a variety of spatial and temporal scales. To create a basis from which to integrate information from these diverse programs, we conducted an inventory of ocean monitoring activities in the Southern California Bight to address the following questions: (1) How much money is being expended annually on marine monitoring programs? (2) Which organizations are conducting the most monitoring? (3) How are resources allocated among the different types of monitoring programs? This inventory focused on programs existing, or those expected to be in existence, for at least 10 years and that were active at any time between 1994 and 1997. For each program identified for inclusion in this study, information was collected on the number of sites, sampling intensity, parameters measured, and methods used. Levels of effort were translated into cost estimates based upon a market survey of local consulting firms. One hundred fourteen marine monitoring programs, conducted by 65 organizations and costing US $31 million annually, were identified. Most of the effort (81 programs, 65% of samples, 70% of costs) was expended by ocean dischargers as part of their compliance with National Pollutant Discharge Elimination System (NPDES) permit requirements. Federal programs (11 programs, 25% of samples, 10% of total expenditures) expended more than state or local government programs. More than one quarter of monitoring expenditures were conducted to measure concentrations and mass of effluent inputs to the ocean. The largest effort expended on receiving water monitoring was for measuring bacteria, followed by sediments, fish/shellfish, water quality, and intertidal habitats. The large level of expenditures by individual agencies has presented opportunities for integrating small, site-specific ocean monitoring programs into

  19. Flow disturbances generated by feeding and swimming zooplankton

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, Haisong; Goncalves, R. J.;

    2014-01-01

    Interactions between planktonic organisms, such as detection of prey, predators, and mates, are often mediated by fluid signals. Consequently, many plankton predators perceive their prey from the fluid disturbances that it generates when it feeds and swims. Zooplankton should therefore seek to...... minimize the fluid disturbance that they produce. By means of particle image velocimetry, we describe the fluid disturbances produced by feeding and swimming in zooplankton with diverse propulsion mechanisms and ranging from 10-µm flagellates to greater than millimeter-sized copepods. We show that...... zooplankton, in which feeding and swimming are separate processes, produce flow disturbances during swimming with a much faster spatial attenuation (velocity u varies with distance r as u ∝ r−3 to r−4) than that produced by zooplankton for which feeding and propulsion are the same process (u ∝ r−1 to r−2). As...

  20. Understanding cyanobacteria-zooplankton interactions in a more eutrophic world

    NARCIS (Netherlands)

    Ger, K.A.; Hansson, L-A.; Lurling, M.

    2014-01-01

    1.We review and update recent observations of cyanobacteria–zooplankton interactions, identify theoretical and methodological limitations and evaluate approaches necessary for understanding the effects of increasing cyanobacterial blooms on plankton dynamics. The emphasis on oversimplified studies u

  1. Understanding cyanobacteria-zooplankton interactions in a more eutrophic world

    NARCIS (Netherlands)

    Ger, K.A.; Hansson, L.; Lurling, M.F.L.L.W.

    2014-01-01

    1.We review and update recent observations of cyanobacteria–zooplankton interactions, identify theoretical and methodological limitations and evaluate approaches necessary for understanding the effects of increasing cyanobacterial blooms on plankton dynamics. 2.The emphasis on oversimplified studies

  2. Rapid local adaptation mediates zooplankton community assembly in experimental mesocosms.

    Science.gov (United States)

    Pantel, Jelena H; Duvivier, Cathy; Meester, Luc De

    2015-10-01

    Adaptive evolution can occur over similar timescales as ecological processes such as community assembly, but its particular effects on community assembly and structure and their magnitude are poorly understood. In experimental evolution trials, Daphnia magna were exposed to varying environments (presence and absence of fish and artificial macrophytes) for 2 months. Then, in a common gardening experiment, we compared zooplankton community composition when either experimentally adapted or D. magna from the original population were present. Local adaptation of D. magna significantly altered zooplankton community composition, leading to a suppression of abundances for some zooplankton taxa and facilitation for others. The effect size of D. magna adaptation was similar to that of adding fish or macrophytes to mesocosms, two important drivers of zooplankton community structure. Our results suggest that substantial amounts of variation in community composition in natural systems may be unexplained if evolutionary dynamics are ignored. PMID:26251339

  3. Zooplankton ecology of the mangrove habitats of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    and fish larvae constituted bulk of zooplankton. Majority of these organisms were stragglers. The zooplankters showing better eco-physiological adaptations colonized in pools surroundEd. by thick mangroves vegetation...

  4. Effect of hydrodynamic cavitation on zooplankton: A tool for disinfection

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Anil, A.C.; Venkat, K.; Gaonkar, C.; Kolwalkar, J.; Khandeparker, L.; Desai, D.V.; Mahulkar, A.V.; Ranade, V.V.; Pandit, A.B.

    and that created by flowing through a cavitating element (orifice plates) on the microbes (zooplankton in sea water) is described. The experimental results are compared with modelling of cavitating conditions that includes cavity dynamics, turbulence generated...

  5. Zooplankton distribution in the polluted environment around Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Abidi, S.A.H.

    Zooplankton distribution, abundance and composition with reference to polluted environments off Bombay was estimated. This study was taken up along three transects viz. Versova, Mahim and Thana covering eleven stations around Bombay during 1980...

  6. Next Generation Sequencing Reveals the Hidden Diversity of Zooplankton Assemblages

    OpenAIRE

    Lindeque, Penelope K.; Helen E Parry; Harmer, Rachel A.; Somerfield, Paul J.; Angus Atkinson

    2013-01-01

    BACKGROUND: Zooplankton play an important role in our oceans, in biogeochemical cycling and providing a food source for commercially important fish larvae. However, difficulties in correctly identifying zooplankton hinder our understanding of their roles in marine ecosystem functioning, and can prevent detection of long term changes in their community structure. The advent of massively parallel next generation sequencing technology allows DNA sequence data to be recovered directly from whole ...

  7. On autumn zooplankton of Semipalatinsk test site water-bodies

    International Nuclear Information System (INIS)

    The autumn zooplankton in six water-bodies with mineralization diapason from 0.27 to 343.0 g/l was investigated. The species composition and number of structural characteristics were determined. The state of the zooplankton community by biodiversity and development indices is determined as normal. The observed increase of body dimensions in some species of Rotatoria and Microcrustacea requires the additional research. (author)

  8. Next Generation Sequencing Reveals the Hidden Diversity of Zooplankton Assemblages

    OpenAIRE

    Penelope K Lindeque; Parry, Helen E; Harmer, Rachel A.; Somerfield, Paul J; Atkinson, Angus

    2013-01-01

    Background Zooplankton play an important role in our oceans, in biogeochemical cycling and providing a food source for commercially important fish larvae. However, difficulties in correctly identifying zooplankton hinder our understanding of their roles in marine ecosystem functioning, and can prevent detection of long term changes in their community structure. The advent of massively parallel next generation sequencing technology allows DNA sequence data to be recovered directly from whole c...

  9. Improved Method for Determining Bacterial Filtration Rates in Zooplankton

    OpenAIRE

    Marvalin, Olivier; Lazarek, Stanislaw

    1988-01-01

    Filtration rates were determined for a natural population of zooplankton grazers (Bosmina longirostris [Müll.], Cyclops vicinus vicinus [Ulianine], Acanthodiaptomus denticornis [Wierz.], and Daphnia longispina [Müll.]) by using 3H-labeled bacteria as food for these organisms. There was a relationship between filtration rates of the major zooplankton grazers and the prevailing algal and bacterial composition in the lake water. Low filtration rates were obtained in the presence of colonial and ...

  10. High Mortality of Red Sea Zooplankton under Ambient Solar Radiation

    OpenAIRE

    Al-Aidaroos, Ali M.; El-Sherbiny, Mohsen M. O.; Sathianeson Satheesh; Gopikrishna Mantha; Susana Agustī; Beatriz Carreja; Duarte, Carlos M.

    2014-01-01

    High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiatio...

  11. Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs?

    Science.gov (United States)

    Paes, T A S V; Costa, I A S; Silva, A P C; Eskinazi-Sant'Anna, E M

    2016-06-01

    The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = - 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton. PMID:26959954

  12. Variasi Geografik Kelimpahan Zooplankton di Perairan Terganggu, Kepulauan Seribu, Indonesia

    Directory of Open Access Journals (Sweden)

    Elok Faiqoh

    2015-10-01

    Full Text Available Zooplankton play a significant role in ecosystem as secondary producer. Climate change will potentially affect the abundance and global composition of zooplankton. This research aimed to study the geographical variation of zooplankton abundance relative to anthropogenic pressure. The research was conducted in April 2014 in area with presumably distinct anthropogenic level by its relative distance to the mainland of Jakarta. Samples were collected at Pramuka Island, Karang Beras Island, Kotok Island, and Sepa Island where subsequently lying to the nearest until furthest distance from mainland. Zooplankton samples were collected by towing the plankton net for 10 minutes for each site for three replicates. Abundance was obtained from Pramuka Island was 266698,214 ind/L, Karang Beras Island was 597363,1 ind/L, Kotok Island was 526447,8 ind/L and Sepa Island was 438225,3 ind/L. Overall, the closer to mainland, the richer nutrient and the more abundant zooplankton was conceived in the waters. Surprisingly, in Pramuka Island, the nearest island to mainland among other sites, had the lowest abundance of zooplankton although nutrient level was the richest among others.

  13. Summary of marine mammal and seabird surveys of the Southern California Bight area, 1975-1978. Volume III - investigators' reports. Part I - pinnipeds of the Southern California Bight. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bonnell, M.L.; Le Boeuf, B.J.; Pierson, M.O.; Dettman, D.H.; Farrens, G.D.

    1981-04-01

    This volume contains the findings of a three year study of the Pinnipedia of the Southern California Bight area. The distribution, abundance, movements, seasonality and reproductive status of the pinnipedia of the SBC area are discussed.

  14. Invasion of Asian tiger shrimp, Penaeus monodon Fabricius, 1798, in the western north Atlantic and Gulf of Mexico

    Science.gov (United States)

    Fuller, Pam L.; Knott, David M.; Kingsley-Smith, Peter R.; Morris, James A.; Buckel, Christine A.; Hunter, Margaret E.; Hartman, Leslie D.

    2014-01-01

    After going unreported in the northwestern Atlantic Ocean for 18 years (1988 to 2006), the Asian tiger shrimp, Penaeus monodon, has recently reappeared in the South Atlantic Bight and, for the first time ever, in the Gulf of Mexico. Potential vectors and sources of this recent invader include: 1) discharged ballast water from its native range in Asia or other areas where it has become established; 2) transport of larvae from established non-native populations in the Caribbean or South America via ocean currents; or 3) escape and subsequent migration from active aquaculture facilities in the western Atlantic. This paper documents recent collections of P. monodon from the South Atlantic Bight and the Gulf of Mexico, reporting demographic and preliminary phylogenetic information for specimens collected between North Carolina and Texas from 2006 through 2012. The increased number of reports in 2011 and 2012, ranging from 102 mm to 298 mm total length, indicates that an adult population is present in densities sufficient for breeding, which is indicative of incipient establishment. Based on these reports of P. monodon, its successful invasion elsewhere, and its life history, we believe that this species will become common in the South Atlantic Bight and Gulf of Mexico in less than 10 years. Penaeus monodon is an aggressive predator in its native range and, if established, may prey on native shrimps, crabs, and bivalves. The impacts of an established P. monodon population are potentially widespread (e.g., alterations in local commercial fisheries, direct and indirect pressures on native shrimp, crab and bivalve populations, and subsequent impacts on the populations of other predators of those organisms) and should be considered by resource managers. The impacts of P. monodon on native fauna and the source(s) or vector(s) of the invasion, however, remain unknown at this time.

  15. Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.

    1993-08-01

    Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes at the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.

  16. Zooplanktonic community of six reservoirs in northeast Brazil.

    Science.gov (United States)

    Almeida, V L S; Dantas, E W; Melo-Júnior, M; Bittencourt-Oliveira, M C; Moura, A N

    2009-02-01

    The aim of the present study was to investigate the zooplankton community at six reservoirs in the state of Pernambuco (Brazil). Zooplankton assemblages were identified using current literature and quantitatively analysed under a microscope and stereomicroscope. Concurrently to the sampling of zooplanktonic and phytoplanktonic communities, in situ measurements of abiotic variables, such as water temperature, dissolved oxygen and pH, were determined using field probes and transparency was determined with a Secchi disk. Total phosphorus concentrations were used for the determination of the Trophic State Index. The reservoirs were classified between eutrophic and hypertrophic, oxygenated, with pH varying from slightly acid to alkaline, high temperatures and low water transparency. A total of 27 zooplankton taxa were identified. Phytoplankton was represented by Cyanophyta, Chlorophyta, Baccilariophyta and phytoflagellates. The highest richness of species was observed for Rotifera (17), followed by Crustacea (8), Protozoa (1) and Insecta (1). Rotifers shared quantitative importance with Crustacea, which were mainly represented by juvenile forms. Jazigo Reservoir presented the highest diversity and equitability. Lowest diversity and equitability were recorded at the Poço da Cruz and Mundaú reservoirs, respectively. Dissimilarity was detected between the environments studied regarding zooplankton composition and structure. PMID:19347146

  17. NODC Standard Format Marine Zooplankton (F124) Data (1965-1983) (NODC Accession 0014196)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data type contains data from sampling and analysis of marine zooplankton. Information on zooplankton abundance, distribution and productivity derived from...

  18. Zooplankton of the southwest coast of India: abundance, composition, temporal and spatial variability in 1987

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Haridas, P.; Ramaiah, Neelam; Achuthankutty, C.T.

    During early southwest and northeast monsoon periods of 1967, zooplankton standing stocks and abundances were high all along the west coast of India. Swarms of zooplankton were common in the shelf areas resulting in a low diversity-high biomass...

  19. Zooplankton abundance, biomass, and size structure in the coastal waters of the northeastern Mediterranean Sea

    OpenAIRE

    KURT, TUBA; POLAT, SEVİM

    2015-01-01

    Zooplankton was studied seasonally between 2009 and 2011 in İskenderun Bay in order to determine temporal variations in abundance, biomass, and size structure and their relationships with environmental factors. Zooplankton sampling was performed vertically using a WP-2 net (200-µm). A total of 30 zooplankton taxonomic groups were identified. Cladocera was the dominant group, and together with Copepoda and Appendicularia constituted approximately 90% of zooplankton. In respect to abundance and...

  20. The Diel Vertical Distribution of Zooplankton in the Southeast Black Sea

    OpenAIRE

    ERKAN, Funda; GÜCÜ, Ali Cemal

    2000-01-01

    The diel changes in the vertical distribution of zooplankton in the southeast Black Sea were described in this study. The zooplankton were sampled using two different sampling methods throughout one day in October 1996 and July 1997 at the same station. The zooplankton counts, the length measurements and biomass estimates showed that the zooplankton in the southeast Black Sea is dominated by small organisms, among which Noctiluca scintillans is the dominant species. In the vertical distributi...

  1. Irradiation effect on zooplankton eggs applied by bremsstrahlung induced from pulsed intense electron beam

    International Nuclear Information System (INIS)

    We have considered an irradiation effect on zooplankton eggs applied by bremsstrahlung induced from pulsed intense electron beam. Zooplankton eggs about 200 have been successfully inactivated using a bremsstrahlung at 3 kGy. We found that 63.9% of zooplankton eggs are inactivated by bremsstrahlung irradiation. It was the increase of 30 points in comparisons with 33.3% of zooplankton eggs inactivated for non-irradiation case. (author)

  2. Distribution characteristics of zooplankton biomass in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli; CHAO Min; CHEN Yaqu

    2004-01-01

    On the basis of the data of oceanographic survey in the East China Sea in four seasons during 1997~2000 (23°30′~33°00′N,118°30′~ 128°E), the variation of total biomass and diet biomass of zooplankton and their spatial-temporal distribution and relationship with the fishing ground of Engraulis japonicus are approached and analyzed. The results show that the average biomass is 65.32 mg/m3 in four seasons, autumn (86.18 mg/m3) being greater than summer (69.18 mg/m3) greater than spring (55.67 mg/m3) greater than winter (50.33 mg/m3). The average value of diet zooplankton hiomass is 40.9 mg/m3.The trends of horizontal distribution both in the total biomass and the diet biomass of zooplankton are similar. The high biomass region (250~500 mg/m3) is very limited, only accounting for 1% of the investigation area. Seasonal variation of the biomass is very remarkable in the west and north parts of East China Sea coastal waters (29°30'N,125°E). The horizontal distribution of diet zooplankton depends on the abundance distribution of crustacean. The distribution of diet zooplankton is related to the fishing ground of Engraulis japonicus and the high-density area of young fish and larval. In spring, the central fishing ground of Engraulis japonicus (>100 kg/h) and the high-density area of young fish and larval (>100 individuals per net) are located at the same place of high-density (100~250 mg/m3)area of diet zooplankton in the middle-southern part of East China Sea or the edge of its waters.

  3. Distribution characteristics of zooplankton biomass in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli; CHAO Min; CHEN Yaqu

    2004-01-01

    On the basis of the data of oceanographic survey in the East China Sea in four seasons during 1997~2000 (23°30′~33°00′N,118°30′~ 128°E), the variation of total biomass and diet biomass of zooplankton and their spatial-temporal distribution and relationship with the fishing ground of Engraulisjaponicus are approached and analyzed. The results show that the average biomass is 65.32 mg/m3 in four seasons, autumn (86.18 mg/m3) being greater than summer (69.18 mg/m3) greater than s pring ( 55.67 mg/m3) greater than winter (50.33 mg/m3). The average value of diet zooplankton biomass is 40.9 mg/m3.The trends of horizontal distribution both in the total biomass and the diet biomass of zooplankton are similar. The high biomass region (250~500 mg/m3) is very limited, only accounting for 1% of the investigation area. Seasonal variation of the biomass is very remarkable in the west and north parts of East China Sea coastal waters ( 29°30′N, 125°E). The horizontal distribution of diet zooplankton depends on the abundance distribution of crustacean. The distribution of diet zooplankton is related to the fishing ground of Engraulis japonicus and the high-density area of young fish and larval. In spring, the central fishing ground of Engraulis japonicus (>100 kg/h) and the high-density area of young fish and larval (>100 individuals per net) are located at the same place of high-density (100~250 mg/m3)area of diet zooplankton in the middle-southern part of East China Sea or the edge of its waters.

  4. Time series analysis of monthly mean data of temperature, salinity, nutrients, suspended matter, phyto- and zooplankton at eight locations on the northwest european shelf

    Science.gov (United States)

    Visser, M.; Batten, S.; Becker, G.; Bot, P.; Colijn, F.; Damm, P.; Danielssen, D.; van den Eynde, D.; Føyn, L.; Frohse, A.; Groeneveld, G.; Laane, R.; van Raaphorst, W.; Radach, G.; Schultz, H.; Sündermann, J.

    1996-09-01

    In this study an overview is given of the time series analysis of monthly mean data of physical, chemical and biological parameters. The time series are available at eight locations on the Northwest European Shelf. The integrated evaluation of those time series gives the opportunity to look for connections between the different parts of the shelf. Temperature and salinity seem to be externally forced. For the nutrients and biological parameters the local forcing is dominating the time series. It is concluded that there are areas that are comparable to each other (freshwater dominated boxes along the Belgian and Dutch coasts and German Bight; Atlantic dominated boxes in the English Channel and off the Scottish coast), although significant cross-correlations are hardly found. The Irish Sea can be regarded as a separate ecosystem.

  5. Atlantic Coastal experiment III, FRV Delaware II cruise, 17-27 May 1977 and R/V ONRUST cruise, 28-30, June 1977. Data report

    Energy Technology Data Exchange (ETDEWEB)

    Malloy, S.; Stoddard, A.; von Bock, K. (eds.)

    1980-09-01

    The DELAWARE II and ONRUST cruises, continuations of Atlantic Coastal Experiment III, were made during May and late June, 1977, to compare seasonal changes in chlorophyll a, nitrogen nutrient, dissolved oxygen and phytoplankton composition within the mid-Atlantic and New York Bights. Data from 106 stations and 3300 km of surface mapping are reported as classical hydrographic listings, areal and/or vertical contours of chlorophyll a, inorganic nitrogen and salinity, and listings of phytoplankton species abun- dance. Temperature profiles from 100 stations are included, as well as res- piration experiments [ETS assay] for the dinoflagellate, Ceratium tripos.

  6. Coprophagy in copepods and in a natural zooplankton community

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Kiørboe, Thomas

    Sediment trap studies have revealed that often only a minor fraction of the zooplankton fecal pellet production leave the upper ocean, and it has been suggested that copepod grazing on pellets (coprophagy) is the reason for this. A simple model is here used to estimate rate of coprophagy from lab...... than 5 % of the fecal pellet production in the upper 50 m was lost as flux below 50 m depth. Estimates of coprophagy rates showed, however, that the zooplankton community > 200 um could account for only a few percent of the fecal pellet loss. Thus, plankton organisms < 200 �m must be responsible for...

  7. VERMICOMPOST: QUALITY ORGANIC MANURE FOR ZOOPLANKTON PRODUCTION IN AQUACULTURE

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2012-08-01

    Full Text Available Purpose of the present study was to evaluate the effect of vermicompost on water quality parameters of fish pond and zooplankton production. No significant effect on the physico-chemical properties of pond water were observed though the zooplankton population was better with significant difference in rotifers population (68.38% comparing with cow dung treated pond. Application of vermicompost as an organic manure in fish pond is not only better but also safe than the raw cow dung. This is excellent manure for nursery and rearing pond as it has a potential to produce good rotifers population.

  8. Developing New Management Techniques for Sharks in the Drift Gillnet Fishery of the Southern California Bight

    OpenAIRE

    Graham, Jeffrey B.; Cartamil, Daniel P.

    2009-01-01

    The Southern California Bight (SCB) is a contiguous geographical region that extends from Point Conception, California to northern Baja California and west into the California Current. This region’s productive ecosystem supports various recreational and commercial fisheries, some of which target pelagic sharks. For example, the common thresher shark (Alopias vulpinus) comprises the largest commercial shark fishery in California waters (the California drift gillnet fishery, or CA-DGF. Mako sha...

  9. Cetaceans in the Southern California Bight : behavioral, acoustical and spatio-temporal modeling

    OpenAIRE

    Henderson, E Elizabeth

    2010-01-01

    This dissertation examines the behavior, occurrence patterns, and distribution of small cetaceans in the Southern California Bight (SCB) across a variety of temporal and spatial scales in order to elucidate how they interact with their environment. I begin by correlating the surface behavior and vocalizations of two exemplar species, the common dolphin (Delphinus sp.) and the Pacific white-sided dolphin (Lagenorhynchus obliquidens). Surface behaviors of both species were classified based on t...

  10. Coastal Ocean Observing System Elements for the Southern California Bight and Santa Monica

    OpenAIRE

    Gruber, Nicolas; Mcwilliams, James C.

    2004-01-01

    We propose to establish, maintain, and augment the sensors for UCLA's oceanographic mooring near the edge of the continental shelf in Santa Monica Bay; extensively sample the water quality within the surrounding region, and interpret the measurements in combination with satellite sensing and three-dimensional, fine-scale numerical simulations of the local region. This will be done in coordination with other proposed measurements in the Southern California Bight that collectively are establis...

  11. Coastal Ocean Observing System Elements for the Southern California Bight and Santa Monica Bay

    OpenAIRE

    Gruber, Nicolas; Mcwilliams, James C.

    2005-01-01

    We propose to establish, maintain, and augment the sensors for UCLA's oceanographic mooring near the edge of the continental shelf in Santa Monica Bay; extensively sample the water quality within the surrounding region; and interpret the measurements in combination with satellite sensing and three-dimensional, fine-scale numerical simulations of the local region. This will be done in coordination with other proposed measurements in the Southern California Bight that collectively are establish...

  12. Life history aspects of 19 rockfish species (Scorpaenidae: Sebastes) from the Southern California Bight

    OpenAIRE

    Love, Milton S.; Morris, Pamela; McCrae, Merritt; Collins, Robson

    1990-01-01

    The authors investigated various life history aspects of 19 rockfish species (Sebastes chlorostictus, S. constellatus, S. dalli, S. elongatus, S. ensifer, S. entomelas, S. flavidus, S. goodei, S. hopkinsi, S. levis, S. melanostomus, S. miniatus, S. ovalis, S. paucispinis, S. rosaceus, S. rosenblatti, S. rufus, s. saxicola, S. semicinctus) from the southern California Bight. These aspects included depth distribution, age-length relationships (of 7 species), length-weight relationships, size...

  13. Recruitment of meroplanktonic larvae in the Southern Bight of the North Sea

    OpenAIRE

    Belgrano, A.; Vincx, M.; Dewarumez, J.-M.; A. Richard; Craeymeersch, J.A.; Heip, C. H. R.

    1990-01-01

    The density distribution of meroplanktonic larvae is compared with the density distribution of adults in the benthos, at five coastal stations in the Southern Bight of the North Sea (Abra alba community). Plankton communities were sampled during one tidal cycle, along a buoy traject or at a fixed point; southern and northern locations, 250 m from each central sampling point, have been investigated too. Benthos samples were taken only at the central points of this traject. Meroplankton consist...

  14. Contaminated sediments database for Long Island Sound and the New York Bight

    Science.gov (United States)

    Mecray, Ellen L.; Reid, Jamey M.; Hastings, Mary E.; Buchholtz ten Brink, Marilyn R.

    2003-01-01

    The Contaminated Sediments Database for Long Island Sound and the New York Bight provides a compilation of published and unpublished sediment texture and contaminant data. This report provides maps of several of the contaminants in the database as well as references and a section on using the data to assess the environmental status of these coastal areas. The database contains information collected between 1956-1997; providing an historical foundation for future contaminant studies in the region.

  15. Virus-phytoplankton adhesion: a new WSSV transmission route to zooplankton

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The pathogenicity of white spot syndrome virus (WSSV) to zooplankton species, rotifer Brachionus urceus (Linnaeus), copepod Acartia clausi (Giesbrecht) and mysid shrimp Neomysis awatschensis (Brandt), was estimated by immersion challenge and virus-phytoplankton adhesion route to investigate a potential new transmission route of WSSV to zooplankton. WSSV succeeded in infecting these zooplankton species and nested-PCR revealed positive results for the virus-phytoplankton adhesion route, whereas WSSV cannot infect zooplankton by immersion challenge. These results indicated that virus-phytoplankton adhesion route is a successful new transmission route of WSSV to zooplankton and also implied that phytoplankton could be a carrier in WSSV transmission.

  16. DAMPAK KONSENTRASI FE DAN PB TERHADAP MORFOLOGI ZOOPLANKTON DI TAMBAK SOCAH BANGKALAN

    Directory of Open Access Journals (Sweden)

    Apri Arisandi

    2013-04-01

    Full Text Available Zooplankton dalam mata rantai antara produsen primer dengan karnivora besar dan kecil dapat mempengaruhi kompleksitas rantai makanan dalam ekosistem perairan. Penelitian ini dilakukan untuk mengetahui dampak konsentrasi Fe dan Pb terhadap morfologi zooplankton  di Tambak Socah. Morfologi zooplankton diamati menggunakan mikroskop dengan metode sensus melalui 3 kali ulangan. Konsentrasi Fe dan Pb di ukur menggunakan spektrofotometer. Zooplankton yang terdapat di tambak socah adalah jenis Copepoda, Nitzchia dan Nauplius. Hasil penelitian menunjukkan bahwa konsentrasi Fe dan Pb berada pada kisaran yang normal sehingga tidak mempengaruhi morfologi plankton. Kata kunci: Fe, Pb, zooplankton

  17. The ICES Working Group on Zooplankton Ecology: Accomplishments of the first 25 years

    Science.gov (United States)

    Wiebe, Peter H.; Harris, Roger; Gislason, Astthor; Margonski, Piotr; Skjoldal, Hein Rune; Benfield, Mark; Hay, Steve; O'Brien, Todd; Valdés, Luis

    2016-02-01

    The ICES Study Group on Zooplankton Ecology was created in 1991 to address issues of current and future concern within the field of zooplankton ecology. Within three years it became the ICES Working Group on Zooplankton Ecology (ICES WGZE) and this unique group in the world's oceanographic community has now been active for 25 years. This article reviews and synthesizes the products, and major accomplishments of the group. Achievements of the group, including the Zooplankton Methodology Manual, the Zooplankton Status Reports, and the International Zooplankton Symposia, have had an important impact on the wider field. Among the future issues that remain to be addressed by the group are the assessment of exploratory fisheries on zooplankton and micronekton species; further development of the zooplankton time-series; compilation and integration of allometric relationships for zooplankton species, and evaluation of new methodologies for the study of zooplankton distribution, abundance, physiology, and genetics. Marine science is an increasingly global undertaking and groups such as the ICES WGZE will continue to be essential to the advancement of understanding of zooplankton community structure and population dynamics in the world's oceans.

  18. Population dynamics and diet of the madamango Sea catfish Cathorops spixii (Agassiz, 1829 (Siluriformes: Ariidae in a tropical bight in Southeastern Brazil.

    Directory of Open Access Journals (Sweden)

    Márcia Denadai

    Full Text Available The madamango sea catfish, Cathorops spixii (Siluriformes: Ariidae, is often among the most abundant fishes on the South American Atlantic coast. In the present study, conducted in shallow, non-estuarine coastal areas of Caraguatatuba Bight in southeastern Brazil, collections of this species, the most abundant member of the ichthyofauna, included primarily medium-sized individuals, indicating that the area may play a specific role in their development. Although studies of the local ichthyofauna have been much neglected, the area is economically important and its ecological significance is undervalued. This study primarily treats habitat use by C. spixii, assessing certain population parameters and the dietary composition. Monthly samples were taken from August 2003 through October 2004, with three trawls in two areas, corresponding to depths of about 1 to 4 m. The catfish showed two main peaks of abundance in the area, in April/May and July 2004. A mode around 9 cm SL persisted through time, and the entrance of younger recruits peaked from January to April. The low estimate for body-growth parameters (K = 0.16 corroborates some K-strategist characteristics of the species. The asymptotic length was 27.3 cm SL and total mortality (Z was 1.01 yr(-1. Cathorops spixii showed an omnivorous feeding habit, preying mainly upon polychaetes, copepods and bivalves, with considerable seasonality in its diet.

  19. Lake St. Clair zooplankton: Evidence for post-dreissena changes

    Science.gov (United States)

    David, K.A.; Davis, B.M.; Hunter, R.D.

    2009-01-01

    We surveyed the zooplankton of Lake St. Clair at 12 sites over ten dates from May to October 2000. Mean zooplankton density by site and date was 168.6 individuals/L, with Dreissena spp. veligers the most abundant taxon at 122.7 individuals/L. Rotifers, copepods, and cladocerans were far lower in mean abundance than in the early 1970s (rotifers, 20.9/L; copepods, 18.1/L; and cladocerans, 6.8/L). Species richness of zooplankton taxa in 2000 was 147, which was virtually unchanged from that of the first reported survey in 1894. Overall, the decline in abundance was greatest for rotifers (-90%) and about equal for cladocerans (-69%) and copepods (-66%). The decrease in abundance of Daphnia spp. was especially dramatic in Canadian waters. The decline in the southeastern region was significant for all three major groups of zooplankton, whereas in the northwestern region the decline was significant only for rotifers. From June to August 2000, Lake St. Clair open waters were numerically dominated by Dreissena spp. veligers, with a reduced abundance of rotifers and crustaceans compared to pre-Dreissena spp. surveys. Mean nutrient concentrations were not different from the 1970s, but Secchi depth (greater) and chlorophyll a concentration (lower) were. Disproportionate reduction in rotifer abundance is consistent with hypotheses implicating direct consumption by settled Dreissena spp. Reduction of crustaceans is likely due to more complex interactions including removal of nauplii as well as resource competition for phytoplankton.

  20. Fatty acid transformation in zooplankton: from seston to benthos

    DEFF Research Database (Denmark)

    Tiselius, Peter; Hansen, Benni Winding; Calliari, Danilo

    2012-01-01

    activity. To test this hypothesis, we sampled seston, zooplankton and sediment trap material for FA analysis during 5 campaigns spanning 4 seasons at a coastal site on the west coast of Sweden. Saturated (SAFAs) and monounsaturated (MUFAs) FAs dominated seston and trap material, while copepods contained 75...

  1. Distribution and abundance of zooplankton populations in Crater Lake, Oregon

    Science.gov (United States)

    Larson, G.L.; McIntire, C.D.; Buktenica, M.W.; Girdner, S.F.; Truitt, R.E.

    2007-01-01

    The zooplankton assemblages in Crater Lake exhibited consistency in species richness and general taxonomic composition, but varied in density and biomass during the period between 1988 and 2000. Collectively, the assemblages included 2 cladoceran taxa and 10 rotifer taxa (excluding rare taxa). Vertical habitat partitioning of the water column to a depth of 200 m was observed for most species with similar food habits and/or feeding mechanisms. No congeneric replacement was observed. The dominant species in the assemblages were variable, switching primarily between periods of dominance of Polyarthra-Keratella cochlearis and Daphnia. The unexpected occurrence and dominance of Asplanchna in 1991 and 1992 resulted in a major change in this typical temporal shift between Polyarthra-K. cochlearis and Daphnia. Following a collapse of the zooplankton biomass in 1993 that was probably caused by predation from Asplanchna, Kellicottia dominated the zooplankton assemblage biomass between 1994 and 1997. The decline in biomass of Kellicottia by 1998 coincided with a dramatic increase in Daphnia biomass. When Daphnia biomass declined by 2000, Keratella biomass increased again. Thus, by 1998 the assemblage returned to the typical shift between Keratella-Polyarthra and Daphnia. Although these observations provided considerable insight about the interannual variability of the zooplankton assemblages in Crater Lake, little was discovered about mechanisms behind the variability. When abundant, kokanee salmon may have played an important role in the disappearance of Daphnia in 1990 and 2000 either through predation, inducing diapause, or both. ?? 2007 Springer Science+Business Media B.V.

  2. An Updated Zooplankton Biodiversity of Turkish Inland Waters

    Directory of Open Access Journals (Sweden)

    M. Ruşen USTAOĞLU

    2015-12-01

    Full Text Available In this study, zooplankton biodiversity in Turkish inland waters is updated by literature review. In 2004, a total of 427 taxa belong to 229 rotifers, 92 cladocerans and 106 copepods have determined in a zooplankton checklist (Ustaoğlu 2004. Between 2004 and 2011, rotifer biodiversity raised from 229 to 341 taxa in the checklist (Ustaoğlu et al. 2012. By the increasing studies on the subject in recent years and as a consequence of reviewing 263 literature from the studies; 5 new genera (Ceratotrocha, Donneria, Octotrocha, Otostephanos, Stephanoceros and 76 taxa from rotifer fauna; 1 new genus (Kurzia and 11 taxa from cladoceran fauna; 13 new genera (Calacalanus, Mecynocera, Paracalanus, Lernaea, Oithona, Echinocamptus, Maraenobiotus, Leptocaris, Harpacticus, Heterolaophonte, Metis, Phyllognathopu, Kinnecaris and 35 taxa from copepod fauna have been added to the zooplankton fauna. As a result, the recent checklist of inland waters zooplankton of Turkey has 661 taxa which include 417 rotifers, 103 cladocerans and 141 copepods namely.

  3. Evaluation of Zooplankton in Hatchery Diets for Channel Catfish Fry

    Science.gov (United States)

    The efficacy of zooplankton as a supplemental hatchery diet for fry of channel catfish Ictalurus punctatus was evaluated. When a commercial diet is used as a reference, fry fed exclusively on zooplankton–either live or dried–performed poorly in their growth rate. However, when live or dried zooplan...

  4. Zooplankton and Karenia brevis in the Gulf of Mexico

    Science.gov (United States)

    Lester, Kristen M.; Heil, Cynthia A.; Neely, Merry B.; Spence, Danylle N.; Murasko, Susan; Hopkins, Thomas L.; Sutton, Tracey T.; Burghart, Scott E.; Bohrer, Richard N.; Remsen, Andrew W.; Vargo, Gabriel A.; Walsh, John J.

    2008-01-01

    Blooms of the toxic dinoflagellate Karenia brevis are common in the Gulf of Mexico, yet no in situ studies of zooplankton and K. brevis have been conducted there. Zooplankton abundance and taxonomic composition at non-bloom and K. brevis bloom stations within the Ecology of Harmful Algal Blooms (ECOHAB) study area were compared. At non-bloom stations, the most abundant species of zooplankton were Parvocalanus crassirostris, Oithona colcarva, and Paracalanus quasimodo at the 5-m isobath and P. quasimodo, O. colcarva, and Oikopleura dioica at the 25-m isobath. There was considerable overlap in dominance of zooplankton species between the 5 and 25-m isobaths, with nine species contributing to 90% of abundance at both isobaths. At stations within K. brevis blooms however, Acartia tonsa, Centropages velificatus, Temora turbinata, Evadne tergestina, O. colcarva, O. dioica, and P. crassirostris were dominant. Variations in abundance between non-bloom and bloom assemblages were evident, including the reduction in abundance of three key species within K. brevis blooms.

  5. Potential acidification impacts on zooplankton in CCS leakage scenarios

    International Nuclear Information System (INIS)

    Highlights: • Effects of CCS techniques and ocean acidification on zooplankton are under-studied. • Vulnerable zooplankton are meso-, bathypelagic and vertically migrating species. • Impacts include impaired calcification, reproduction, development and survival. • Need for modelling studies combining physico-chemical with ecological impacts. -- Abstract: Carbon capture and storage (CCS) technologies involve localized acidification of significant volumes of seawater, inhabited mainly by planktonic species. Knowledge on potential impacts of these techniques on the survival and physiology of zooplankton, and subsequent consequences for ecosystem health in targeted areas, is scarce. The recent literature has a focus on anthropogenic greenhouse gas emissions into the atmosphere, leading to enhanced absorption of CO2 by the oceans and a lowered seawater pH, termed ocean acidification. These studies explore the effects of changes in seawater chemistry, as predicted by climate models for the end of this century, on marine biota. Early studies have used unrealistically severe CO2/pH values in this context, but are relevant for CCS leakage scenarios. Little studied meso- and bathypelagic species of the deep sea may be especially vulnerable, as well as vertically migrating zooplankton, which require significant residence times at great depths as part of their life cycle

  6. Distribution of zooplankton populations within and adjacent to a thermal plume

    International Nuclear Information System (INIS)

    Zooplankton distributions in the 1-m stratum differed between ambient waters and the thermal plume of the Donald C. Cook Nuclear Power Plant. Zooplankton were most abundant in the warmest waters of the plume with the region of high densities extending over an approximate area of 0.2 to 0.3 km2. Water temperature was not a reliable indicator of alterations in zooplankton populations. Alterations were primarily due to upward vertical displacment of deep-living zooplankton. Large horizontal variability in zooplankton densities and use of conventional sampling procedures (vertically hauled nets, widely spaced stations) prevent traditionally designed monitoring programs from detecting such alterations. Zooplankton may experience indirect mortality losses in the plume if transfer of deep-living zooplankton to the surface layers makes them more visible to visual-feeding fish predators, and turbulences in the plume reduce zooplankters' ability to detect and avoid such predators. (auth)

  7. Determination of shell deposition rates of Arctica islandica from the New York Bight using natural 228Ra and 228Th and bomb-produced 14C

    International Nuclear Information System (INIS)

    Shell deposition rates of specimens of Arctica islandica (Mollusca: Bivalvia) from the New York Bight were determined using natural 228Ra and 228Th and bomb 14C. The specimens from deep (>55 m) offshore waters show annual growth banding. A shell obtained from the inner bight at <30-m depth seems to be younger than indicated by band counting

  8. Size-based diel migration of zooplankton in mediterranean shallow lakes assessed from in situ experiments with artificial plants

    OpenAIRE

    Tavsanoglu, Ülkü Nihan; Brucet Balmaña, Sandra; Levi, Eti Ester; Bucak, Tuba; Bezirci, Gizem; Özen, Arda; Johansson, Liselotte S.; Jeppesen, Erik; Beklioglu, Meryem

    2015-01-01

    In warm lakes, fish aggregate within macrophytes, thereby weakening the role of these as a daytime refuge for zooplankton and altering the zooplankton size structure, predation pressure, and water clarity. To elucidate the role of macrophytes as a refuge for zooplankton and their effect on zooplankton size distribution, we established three sets of strandardized artificial plant beds in 11 lakes in Turkey with contrasting fish predation risk and turbidity. Zooplankton ...

  9. Zooplankton response to organic carbon level in lakes of differing trophic states

    Directory of Open Access Journals (Sweden)

    Bowszys M.

    2014-03-01

    Full Text Available Water eutrophication is associated with an increase in the organic carbon content (both particulate and dissolved forms, which may affect the functioning of the zooplankton community. Mesotrophic and eutrophic lakes in the Masurian Lake District (Poland were selected to evaluate the relationship between the organic carbon level and the zooplankton community. The lakes differed significantly in most environmental variables. RDA analysis was performed to evaluate the impact of environmental variables on zooplankton. The variables that significantly explained the variance in the zooplankton community abundance (Monte Carlo permutation test included dissolved and particulate organic carbon, Secchi disc visibility, soluble reactive phosphorus and total nitrogen. The response of zooplankton to an increasing level of organic carbon is functional rather than quantitative. In the mesotrophic system, the results of the redundancy analysis indicated relatively strong positive relationships between dissolved organic carbon and zooplankton biomass, and negative correlations between chlorophyll a and zooplankton biomass. The above suggests that indirect organic carbon utilization by zooplankton could partly compensate for the poor feeding conditions of planktonic animals (decreased phytoplankton availability. In the eutrophic lake, elevated organic carbon levels are partly limited by zooplankton, which is suggested by the positive relationship between particulate organic matter and the total zooplankton biomass (RDA results. The positive relationship between the biomass of copepods and organic carbon in particulate and dissolved forms implies that copepods benefit from the increased heterotrophic carbon flow that is activated in the eutrophic lake.

  10. The impact of fish predation and cyanobacteria on zooplankton size structure in 96 subtropical lakes.

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    Full Text Available Zooplankton are relatively small in size in the subtropical regions. This characteristic has been attributed to intense predation pressure, high nutrient loading and cyanobacterial biomass. To provide further information on the effect of predation and cyanobacteria on zooplankton size structure, we analyzed data from 96 shallow aquaculture lakes along the Yangtze River. Contrary to former studies, both principal components analysis and multiple regression analysis showed that the mean zooplankton size was positively related to fish yield. The studied lakes were grouped into three types, namely, natural fishing lakes with low nutrient loading (Type1, planktivorous fish-dominated lakes (Type 2, and eutrophic lakes with high cyanobacterial biomass (Type 3. A marked difference in zooplankton size structure was found among these groups. The greatest mean zooplankton size was observed in Type 2 lakes, but zooplankton density was the lowest. Zooplankton abundance was highest in Type 3 lakes and increased with increasing cyanobacterial biomass. Zooplankton mean size was negatively correlated with cyanobacterial biomass. No obvious trends were found in Type 1 lakes. These results were reflected by the normalized biomass size spectrum, which showed a unimodal shape with a peak at medium sizes in Type 2 lakes and a peak at small sizes in Type 3 lakes. These results indicated a relative increase in medium-sized and small-sized species in Types 2 and 3 lakes, respectively. Our results suggested that fish predation might have a negative effect on zooplankton abundance but a positive effect on zooplankton size structure. High cyanobacterial biomass most likely caused a decline in the zooplankton size and encouraged the proliferation of small zooplankton. We suggest that both planktivorous fish and cyanobacteria have substantial effects on the shaping of zooplankton community, particularly in the lakes in the eastern plain along the Yangtze River where

  11. A seafloor crater in the German Bight and its effect on the benthos

    OpenAIRE

    Thatje, S.; Gerdes, Dieter; Rachor, Eike

    1999-01-01

    In 1963 a deep crater was formed about 65 m below sea level in the western part of the German Bight, due to a gas eruption caused by drilling carried out from the platform ŽMr. LouieŽ. The study area is situated in a sandy to muddy bottom area inhabited by an Amphiura-filiformis-association (sensu Salzwedel et al., 1985). The crater, sometimes called ŽFigge-MaarŽ, functions as a sediment-trap, concentrating particles and organisms from the water column, thus leading to extreme sedimentation r...

  12. The recovery of benthos following the impact of low oxygen content in the German Bight

    Science.gov (United States)

    Niermann, U.; Bauerfeind, E.; Hickel, W.; Westernhagen, H. V.

    The oxygen deficiency in the German Bight and in Danish waters 1981-1983 with ensuing benthos mortality was the reason for studying the development and re-establishment of the macrofauna in the following years. These years, from 1984-1987, exhibited more favourable oxygen conditions. The macrofauna of this region with its predominantly sandy substrate belongs to the Tellina fabula community. It is dominated by regular seasonal and ephemeral species such as Spio filicornis, Phoronis spec., Spiophanes bombyx and Lanice conchilega. In 1983, a year with exceptionally low oxygen content in bottom waters (Echinocardium cordatum and crustaceans have been observed since 1984 in larger numbers.

  13. A seafloor crater in the German Bight and its effects on the benthos

    OpenAIRE

    Thatje, S.; Gerdes, D.; Rachor, E.

    1999-01-01

    In 1963 a deep crater was formed about 65 m below sea level in the western part of the German Bight, due to a gas eruption caused by drilling carried out from the platform ’Mr. Louie'. The study area is situated in a sandy to muddy bottom area inhabited by an Amphiura filiformis association (sensu Salzwedel et al. 1985). The crater, sometimes called ’Figge-Maar', functions as a sediment trap, concentrating particles and organisms from the water column, thus leading to extreme sedimentation ra...

  14. Reaction of fresh water zooplankton community to chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Osipov, D.; Pryakhin, E. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Ivanov, I. [FSUE Mayak PA (Russian Federation)

    2014-07-01

    The characteristic features of ecological community as a whole and cenosis of zooplankton organisms as part of it determine the intensity of the processes of self-purification of water and the formation of a particular body of water. Identifying features of the structure and composition of the zooplankton community of aquatic ecosystems exposed to different levels of radiation exposure, it is necessary to identify patterns of changes in zooplankton and hydro-biocenosis as a whole. Industrial reservoirs, the storage of liquid low-level radioactive waste 'Mayak' for decades, have high radiation load. A large range of levels of radioactive contamination (total volume beta-activity in water varies from 2.2x10{sup 3} to 2.3x10{sup 7} Bq/l, total volume alpha-activity - from 2.6x10{sup -1} to 3.1x10{sup 3} Bq/l) provides a unique opportunity to study ecosystems in a number of reservoirs with increasing impact of radiation factor. We studied five reservoirs that were used as the storage of low-and intermediate-level liquid radioactive waste pond and one comparison water body. In parallel with zooplankton sampling water samples were collected for hydro-chemical analysis. 41 indicators were analysed in order to assess the water chemistry. To determine the content of radionuclides in the various components of the ecosystem samples were collected from water, bottom sediments and plankton. Sampling of zooplankton for the quantitative analysis was performed using the method of weighted average auto bathometer. Apshteyn's plankton net of the surface horizon was used for qualitative analysis of the species composition of zooplankton. Software package ERICA Assessment Tool 2012 was used for the calculation of the absorbed dose rate. Species diversity and biomass of zooplankton, the share of rotifers in the number of species, abundance and biomass decrease with the increase of the absorbed dose rate and salinity. The number of species in a sample decreases with the

  15. Next generation sequencing reveals the hidden diversity of zooplankton assemblages.

    Directory of Open Access Journals (Sweden)

    Penelope K Lindeque

    Full Text Available BACKGROUND: Zooplankton play an important role in our oceans, in biogeochemical cycling and providing a food source for commercially important fish larvae. However, difficulties in correctly identifying zooplankton hinder our understanding of their roles in marine ecosystem functioning, and can prevent detection of long term changes in their community structure. The advent of massively parallel next generation sequencing technology allows DNA sequence data to be recovered directly from whole community samples. Here we assess the ability of such sequencing to quantify richness and diversity of a mixed zooplankton assemblage from a productive time series site in the Western English Channel. METHODOLOGY/PRINCIPLE FINDINGS: Plankton net hauls (200 µm were taken at the Western Channel Observatory station L4 in September 2010 and January 2011. These samples were analysed by microscopy and metagenetic analysis of the 18S nuclear small subunit ribosomal RNA gene using the 454 pyrosequencing platform. Following quality control a total of 419,041 sequences were obtained for all samples. The sequences clustered into 205 operational taxonomic units using a 97% similarity cut-off. Allocation of taxonomy by comparison with the National Centre for Biotechnology Information database identified 135 OTUs to species level, 11 to genus level and 1 to order, <2.5% of sequences were classified as unknowns. By comparison a skilled microscopic analyst was able to routinely enumerate only 58 taxonomic groups. CONCLUSIONS: Metagenetics reveals a previously hidden taxonomic richness, especially for Copepoda and hard-to-identify meroplankton such as Bivalvia, Gastropoda and Polychaeta. It also reveals rare species and parasites. We conclude that Next Generation Sequencing of 18S amplicons is a powerful tool for elucidating the true diversity and species richness of zooplankton communities. While this approach allows for broad diversity assessments of plankton it may

  16. Flow disturbances generated by feeding and swimming zooplankton.

    Science.gov (United States)

    Kiørboe, Thomas; Jiang, Houshuo; Gonçalves, Rodrigo Javier; Nielsen, Lasse Tor; Wadhwa, Navish

    2014-08-12

    Interactions between planktonic organisms, such as detection of prey, predators, and mates, are often mediated by fluid signals. Consequently, many plankton predators perceive their prey from the fluid disturbances that it generates when it feeds and swims. Zooplankton should therefore seek to minimize the fluid disturbance that they produce. By means of particle image velocimetry, we describe the fluid disturbances produced by feeding and swimming in zooplankton with diverse propulsion mechanisms and ranging from 10-µm flagellates to greater than millimeter-sized copepods. We show that zooplankton, in which feeding and swimming are separate processes, produce flow disturbances during swimming with a much faster spatial attenuation (velocity u varies with distance r as u ∝ r(-3) to r(-4)) than that produced by zooplankton for which feeding and propulsion are the same process (u ∝ r(-1) to r(-2)). As a result, the spatial extension of the fluid disturbance produced by swimmers is an order of magnitude smaller than that produced by feeders at similar Reynolds numbers. The "quiet" propulsion of swimmers is achieved either through swimming erratically by short-lasting power strokes, generating viscous vortex rings, or by "breast-stroke swimming." Both produce rapidly attenuating flows. The more "noisy" swimming of those that are constrained by a need to simultaneously feed is due to constantly beating flagella or appendages that are positioned either anteriorly or posteriorly on the (cell) body. These patterns transcend differences in size and taxonomy and have thus evolved multiple times, suggesting a strong selective pressure to minimize predation risk. PMID:25071196

  17. Metals in coastal zooplanktons - A coastal living resource hazard

    Digital Repository Service at National Institute of Oceanography (India)

    Paimpillil, J.S.; Joseph, T.; Rejomon, G.; Gerson, V.J.

    analyzed by Graphite Furnace Atomic Absorption Spectrophotometer (GFAAS, ZL-4110). Mn was determined separately by GFAAS, using sodium diethyl dithiocarbamate (Na-DDC)-MIBK extraction. The zooplankton samples were first powdered and aliquots of about 300 mg... coastal stations. This may be due to the land drainage in the investigated region. DISCUSSION Oceanographers usually held fast to the idea that phosphorus and nitrogen are the only nutrients vital in determining the distribution of the world's algae...

  18. Zooplankton fecal pellets link fossil fuel and phosphate deposits

    Science.gov (United States)

    Porter, K.G.; Robbins, E.I.

    1981-01-01

    Fossil zooplankton fecal pellets found in thinly bedded marine and lacustrine black shales associated with phosphate, oil, and coal deposits, link the deposition of organic matter and biologically associated minerals with planktonic ecosystems. The black shales were probably formed in the anoxic basins of coastal marine waters, inland seas, and rift valley lakes where high productivity was supported by runoff, upwelling, and outwelling. Copyright ?? 1981 AAAS.

  19. Zooplankton fauna of Lake İznik (Bursa, Turkey)

    OpenAIRE

    YAĞCI, Meral APAYDIN; USTAOĞLU, Mustafa Ruşen

    2012-01-01

    In the present study the zooplankton fauna of Lake İznik (Bursa) was investigated during January-December 2006. A total of 54 taxa-35 taxa from rotifers, 14 taxa from cladocerans, and 5 taxa from copepods-were identified in Lake İznik. Brachionus calyciflorus, B. angularis, Notholca squamula, N. acuminata, Euchlanis dilatata, E. deflexa, Platyias quadricornis, Trichocerca similis, T. cylindrica, T. chattoni, T. lophoessa, T. bicristata, Asplanchna girodi, Conochiulus dossuarius, Synchaeta pec...

  20. Zooplankton diversity across three Red Sea reefs using pyrosequencing

    OpenAIRE

    John K Pearman; Mohsen M El-Sherbiny; Lanzén, Anders; Al-Aidaroos, Ali M.; Irigoien, Xabier

    2014-01-01

    Coral reefs are considered among the most diverse ecosystems on Earth, yet little is known about the diversity of plankton in the surrounding water column. Moreover, few studies have utilized genomic methods to investigate zooplankton diversity in any habitat. This study investigated the diversity of taxa by sampling 45 stations around three reef systems in the central/southern Red Sea. The diversity of metazoan plankton was investigated by targeting the 18S rRNA gene and clustering OTUs at 9...

  1. Zooplankton diversity across three Red Sea reefs using pyrosequencing

    OpenAIRE

    John Kenneth Pearman; Mohsen M El-Sherbiny; Anders eLanzén; Ali eAl-Aidaroos; Xabier eIrigoien

    2014-01-01

    Coral reefs are considered among the most diverse ecosystems on Earth, yet little is known about the diversity of plankton in the surrounding water column. Moreover, few studies have utilised genomic methods to investigate zooplankton diversity in any habitat. This study investigated the diversity of taxa by sampling 45 stations around three reef systems in the central/southern Red Sea. The diversity of metazoan plankton was investigated by targeting the 18S rRNA gene and clustering OTUs at 9...

  2. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency.

    Science.gov (United States)

    Taipale, Sami J; Galloway, Aaron W E; Aalto, Sanni L; Kahilainen, Kimmo K; Strandberg, Ursula; Kankaala, Paula

    2016-01-01

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terrestrial-origin carbohydrates for energy and sparing essential fatty acids and amino acids for somatic growth and reproduction. Assimilated terrestrial-origin fatty acids from shoreline reed particles exceeded available diet, indicating that Daphnia may convert a part of their dietary carbohydrates to saturated fatty acids. This conversion was not observed with birch leaf diets, which had lower carbohydrate content. Subsequent analysis of 21 boreal and subarctic lakes showed that diet of herbivorous zooplankton is mainly based on high-quality phytoplankton rich in essential polyunsaturated fatty acids. The proportion of low-quality diets (bacteria and terrestrial particulate organic matter) was zooplankton was not directly related to the concentration of terrestrial organic matter in experiments or lakes, but rather to the low availability of phytoplankton. PMID:27510848

  3. Zooplankton structure in two interconnected ponds: similarities and differences

    Directory of Open Access Journals (Sweden)

    Špoljar Maria

    2016-03-01

    Full Text Available The research of zooplankton diversity, abundance and trophic structure was conducted during the summer period in pelagial zone on the longitudinal profile of the Sutla River Backwater. Investigated site consists of two interconnected basins: transparent Upper Basin with submerged macrophytes and turbid Lower Basin without macrophytes in the littoral zone. In the Upper Basin, abundance and diversity of zooplankton in the pelagial was higher in comparison to the Lower Basin, with prevailing species of genus Keratella as microfilter-feeder, and genera of Polyartha and Trihocerca as macrofilter-feeder rotifers. On the contrary, in the Lower Basin, crustaceans dominated in abundance. Microfilter-feeder cladoceran (Bosmina longirostris and larval and adult stages of macrofilter-feeder copepod (Macrocyclops albidus prevailed in the Lower Basin. Fish predation pressure was more pronounced in the pelagial of the Upper Basin, indicated by low cladoceran abundance in the surface layer. Although the studied basins were interconnected, results indicate significant (Mann-Whitney U test, p < 0.05 differences in the zooplankton structure as a potential result of the macrophyte impact on environmental conditions and fish predation pressure.

  4. Considerations on the biochemical composition of some freshwater zooplankton species.

    Directory of Open Access Journals (Sweden)

    Nicoletta RICCARDI

    1999-02-01

    Full Text Available The mean elemental (C, H, N and biochemical composition (lipids, carbohydrates and proteins of some abundant crustacean zooplankton species of Italian insubric lakes has been estimated by the analysis of samples collected at different seasons from various environments (Lake Maggiore, Lake Varese, Lake Comabbio, Lake Monate. From each sample an adequate number of specimens of each abundant species was sorted and analyzed by a CHN elemental analyzer. The percentage of lipids, carbohydrates and proteins and the calorific content were calculated from the elemental composition according to Gnaiger & Bitterlich (1984. Inter- and intraspecific variability of biochemical composition was quite high, while elemental composition and calorific content were less variable. An estimate of the mean elemental and biochemical composition of each species was obtained by pooling the data. These mean values have been used to estimate the pools of elements and compounds in the crustacean zooplankton of Lake Comabbio to provide an example of the importance of a multiple approach in zooplankton studies.

  5. Taxonomy, distribution, and ecology of crustacean zooplankton in trough waters of Ankara (Turkey)

    OpenAIRE

    BAŞAK, Elif; Aygen, Cem; KÜLKÖYLÜOĞLU, OKAN

    2014-01-01

    Troughs are one of the main components of villages in Turkey. They are constructed by converting springs or underground waters. Until now, there has been no extensive study investigating the composition and diversity of trough zooplankton species. In order to contribute knowledge on the zooplanktons in troughs, 142 troughs were randomly sampled from 17 districts in Ankara Province between 22 June and 3 July 2011. A total of 18 zooplanktons including 11 Copepoda and 7 Cladocera species were de...

  6. Zooplankton diversity analysis through single-gene sequencing of a community sample

    OpenAIRE

    Nishida Mutsumi; Hashiguchi Yasuyuki; Machida Ryuji J; Nishida Shuhei

    2009-01-01

    Abstract Background Oceans cover more than 70% of the earth's surface and are critical for the homeostasis of the environment. Among the components of the ocean ecosystem, zooplankton play vital roles in energy and matter transfer through the system. Despite their importance, understanding of zooplankton biodiversity is limited because of their fragile nature, small body size, and the large number of species from various taxonomic phyla. Here we present the results of single-gene zooplankton ...

  7. Aspects of the ecology of the crustacean zooplankton in the Sanyati Basin, Lake Kariba

    OpenAIRE

    Marshall, B.E.

    1980-01-01

    Investigations on the zooplankton in Lake Kariba were carried out as part of a broader programme investigating components of the sardine, Limnothrissa miodon, food chain and factors affecting their productivity. This report deals mainly with the crustacean zooplankton, Bosmina longirostris and Mesocyclops leuckarti, which are the most important species in the sardine's diet. Factors which influence the number and distribution of the zooplankton are discussed. The relationship between the zoop...

  8. Growth of Barents Sea capelin (Mallotus villosus) in relation to zooplankton abundance

    OpenAIRE

    Gjøsæter, Harald; Dalpadado, Padmini; Hassel, Arne

    2002-01-01

    Because capelin feed on zooplankton, the availability of the latter may be a limiting factor for capelin growth in at least some areas and at certain times. It was therefore hypothesized that a relationship exists between capelin growth and zooplankton biomass either in the same year or in the previous autumn. Capelin growth in a given year was more closely correlated with the estimate of zooplankton abundance in the previous autumn than with that in the present autumn. Growth of the youngest...

  9. Methane and zooplankton in the epilimnion of Lake Fukami-ike

    OpenAIRE

    Suda, Hiromi; FUNAHASHI, Junko; Yagi, Akihiko

    2004-01-01

    Accumulations of bubbled and dissolved methane concentrations in rpilimnion have been frequently observed in Lake Fukami-ike. Based on the idea that the feeding activities of living zooplankton contribute to the methane concentrations in the lake, we examined wheter investigate live zooplankton evolve methane as a consequence of their feeding activities. Dissolved methane concentrations were higher after 6 hours in the samples of zooplankton only. This result might be support the idea that th...

  10. Bacteria of the γ-Subclass Proteobacteria Associated with Zooplankton in Chesapeake Bay

    OpenAIRE

    Heidelberg, J. F.; Heidelberg, K. B.; Colwell, R R

    2002-01-01

    The seasonal abundance of γ-subclass Proteobacteria, Vibrio-Photobacterium, Vibrio cholerae-Vibrio mimicus, Vibrio cincinnatiensis, and Vibrio vulnificus in the Choptank River of Chesapeake Bay associated with zooplankton was monitored from April to December 1996. Large (>202-μm) and small (64- to 202-μm) size classes of zooplankton were collected, and the bacteria associated with each of the zooplankton size classes were enumerated by fluorescent oligonucleotide direct count. Large populatio...

  11. Zooplankton Seasonal Abundance and Vertical Distribution of Highly Alkaline Lake Burdur, Turkey

    OpenAIRE

    Gülle, Iskender; Turna, Ismail Ibrahim; Güçlü, Salim Serkan; Gülle, Pinar; Güçlü, Zekiye

    2010-01-01

    During the period from December 2003 to November 2004 a study has been held to examine the water quality and zooplankton of highly alkaline Lake Burdur. The lake showed thermal stratification between June and October. Six zooplankton taxa were determined, Hexarthra fennica, Brachionus plicatilis from Rotifera and Arctodiaptomus burduricus from Copepoda were the dominant species. Average zooplankton density was 399,074 ind.m-3 and they were 51% H. fennica, 9% B. plicatilis and 40% A. burdu...

  12. Structure and function of zooplankton colonization in twelve new experimental ponds

    OpenAIRE

    Jenkins, David Glenn

    1990-01-01

    This study examined the structural and functional development of zooplankton communities in 12 new experimental ponds for one year and tested four predictions derived from the Random Placement Hypothesis (Coleman 1981). Physico-chemistry, zooplankton colonization dynamics, zooplankton community structure and function were analyzed every two weeks from 5 February 1988 to 10 February 1989. Ponds varied in physico-chemistry at points in time but followed similar patter...

  13. Abundance and Distribution of Zooplankton in CoastalArea of Gokceada Island (Northern Aegean Sea)

    OpenAIRE

    Tarkan, Abmet Nuri

    2000-01-01

    Abstract This study was carried out in order to determine population of zooplankton in the coastal waters of Gokgeada. At the 10 stations of those depths ranging from 20 in to 30 in, the measurements of temperature, salinity and oxygen were made, and zooplankton samples were collected vertically and horizontally using plankton nets. In the neritic waters of the island, the effects of the Black Sea waters through Dardanelles were observed and zooplankton species of the Black Sea found. F...

  14. Seasonal variation of zooplankton abundance, composition and biomass in the Chabahar Bay, Oman Sea

    OpenAIRE

    Neda Fazeli; Ahmad Savari; Seyed Mohamad Bagher Nabavi; Rasool Zare

    2014-01-01

    Temporal and spatial variation of zooplankton abundance, composition and biomass were examined on the Chabahar Bay, Oman Sea. The Chabahar Bay, a subtropical and semi-enclosed bay, provides an ideal breeding ground for many fish and shellfish. Five stations were investigated along the Bay. This area is under the influence of the Indian Ocean seasonal monsoons. Zooplankton was collected with vertical plankton tows using 100 µm mesh nets. Copepods dominated the zooplankton community followed by...

  15. Model investigations of the North Atlantic spring bloom initiation

    Science.gov (United States)

    Kuhn, Angela M.; Fennel, Katja; Mattern, Jann Paul

    2015-11-01

    The spring bloom - a massive growth of phytoplankton that occurs annually during the spring season in mid and high latitudes - plays an important role in carbon export to the deep ocean. The onset of this event has been explained from bottom-up and top-down perspectives, exemplified by the "critical-depth" and the "dilution-recoupling" hypotheses, respectively. Both approaches differ in their key expectations about how seasonal fluctuations of the mixed layer affect the plankton community. Here we assess whether the assumptions inherent to these hypotheses are met inside a typical onedimensional Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) model, optimized to best represent climatological annual cycles of satellite-based phytoplankton biomass in the Subpolar North Atlantic. The optimized model is used in idealized experiments that isolate the effects of mixed layer fluctuations and zooplankton grazing, in order to elucidate their significance. We analyzed the model sensitivity qualitatively and using a second-order Taylor series decomposition of the model equations. Our results show that the conceptual bases of both bottom-up and top-down approaches are required to explain the process of blooming; however, neither of their bloom initiation mechanisms fully applies in the experiments. We find that a spring bloom can develop in the absence of mixed layer fluctuations, and both its magnitude and timing seem to strongly depend on nutrient and light availability. Furthermore, although zooplankton populations modulate the phytoplankton concentrations throughout the year, directly prescribed and physically driven changes in zooplankton grazing do not produce significant time shifts in bloom initiation, as hypothesized. While recognizing its limitations, our study emphasizes the processes that require further testing in order to discern among competing hypotheses.

  16. ECOLOGICAL STUDIES ON ZOOPLANKTON OF THE WEST LAKE AND THE INFLOWS

    OpenAIRE

    Li, Gouguo; Wei, Chongde; Zhou, Hong; Pei, Hongping

    1999-01-01

    Zooplankton ecology of the West Lake and the streams that flow into the lake were investigated during January-December 1995. Protozoans were the predominant group among 252 species of zooplankton, accounting for 50.4% of the total number. Due to the seasonal variations in density and biomass of zooplankton, were studied. Changqiao stream recorded the highest density of zooplankton among seven sampling points, with an average of 10,710 inds./L. The lowest density found was Jinsha stream (886 i...

  17. Zooplankton diversity analysis through single-gene sequencing of a community sample

    Directory of Open Access Journals (Sweden)

    Nishida Mutsumi

    2009-09-01

    Full Text Available Abstract Background Oceans cover more than 70% of the earth's surface and are critical for the homeostasis of the environment. Among the components of the ocean ecosystem, zooplankton play vital roles in energy and matter transfer through the system. Despite their importance, understanding of zooplankton biodiversity is limited because of their fragile nature, small body size, and the large number of species from various taxonomic phyla. Here we present the results of single-gene zooplankton community analysis using a method that determines a large number of mitochondrial COI gene sequences from a bulk zooplankton sample. This approach will enable us to estimate the species richness of almost the entire zooplankton community. Results A sample was collected from a depth of 721 m to the surface in the western equatorial Pacific off Pohnpei Island, Micronesia, with a plankton net equipped with a 2-m2 mouth opening. A total of 1,336 mitochondrial COI gene sequences were determined from the cDNA library made from the sample. From the determined sequences, the occurrence of 189 species of zooplankton was estimated. BLASTN search results showed high degrees of similarity (>98% between the query and database for 10 species, including holozooplankton and merozooplankton. Conclusion In conjunction with the Census of Marine Zooplankton and Barcode of Life projects, single-gene zooplankton community analysis will be a powerful tool for estimating the species richness of zooplankton communities.

  18. Material properties of zooplankton and nekton from the California current

    Science.gov (United States)

    Becker, Kaylyn

    This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density

  19. Geology and geochemistry of the Geyser Bight Geothermal Area, Umnak Island, Aleutian Islands, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Nye, C.J. (Alaska Univ., Fairbanks, AK (USA). Geophysical Inst. Alaska Dept. of Natural Resources, Fairbanks, AK (USA). Div. of Geological and Geophysical Surveys); Motyka, R.J. (Alaska Dept. of Natural Resources, Juneau, AK (USA). Div. of Geological and Geophysical Surveys); Turner, D.L. (Alaska Univ., Fairbanks, AK (USA). Geophysical Inst.); Liss, S.A. (Alaska Dept. of Natural Resources, Fairba

    1990-10-01

    The Geyser Bight geothermal area is located on Umnak Island in the central Aleutian Islands. It contains one of the hottest and most extensive areas of thermal springs and fumaroles in Alaska, and is only documented site in Alaska with geysers. The zone of hot springs and fumaroles lies at the head of Geyser Creek, 5 km up a broad, flat, alluvial valley from Geyser Bight. At present central Umnak is remote and undeveloped. This report describes results of a combined program of geologic mapping, K-Ar dating, detailed description of hot springs, petrology and geochemistry of volcanic and plutonic rock units, and chemistry of geothermal fluids. Our mapping documents the presence of plutonic rock much closer to the area of hotsprings and fumaroles than previously known, thus increasing the probability that plutonic rock may host the geothermal system. K-Ar dating of 23 samples provides a time framework for the eruptive history of volcanic rocks as well as a plutonic cooling age.

  20. Autotrophic and heterotrophic activity in Arctic first-year sea-ice: Seasonal study from Marlene Bight, SW Greenland

    DEFF Research Database (Denmark)

    Søgaard, Dorte Haubjerg; Kristensen, Morten; Rysgaard, Søren;

    2010-01-01

    We present a study of autotrophic and heterotrophic activities of Arctic sea ice (Malene Bight, SW Greenland) as measured by 2 different approaches: (1) standard incubation techniques ((HCO3-)-C-14 and [H-3] thymidine incubation) on sea ice cores brought to the laboratory and (2) cores incubated ...

  1. 210Pb balance and implications for particle transport on the continental shelf, U.S. Middle Atlantic Bight

    Science.gov (United States)

    Bacon, M.P.; Belastock, Rebecca A.; Bothner, Michael H.

    1994-01-01

    Supply of 210Pb to the continental shelf off the northeastern United States is dominated by the deposition from the atmosphere, the rate of which is reliably known from previously published work. Excess 210Pb inventories in the shelf sediments show accumulations that are nearly in balance with the supply, even in areas of relict sands where it is believed that no net accumulation of sediment presently occurs. The 210Pb distributions in shelf and slope water indicate that the two-way fluid exchange at the shelf-slope front and the net transport in the alongshore flow make comparatively small contributions to the shelf 210Pb budget. The near balance between supply and decay of 210Pb on the shelf implies a limit to the particle export flux. It is concluded that the export of particulate organic carbon does not exceed 60 g m−2 y−1 (∼25% of primary production) and is probably lower. The hypothesis is advanced that fine particulate matter introduced to the continental shelf is detained in its transit of the shelf because of bioturbational trapping in the sediment due to benthic animals. Distributions of 210Pb in suspended particulate matter and in the fine fraction of shelf sediments suggest that the average fine particle must undergo several cycles of deposition-bioturbation-resuspension-redeposition and requires a number of decades for its transit and ultimate export from the shelf. Thus, only the most refractory organic matter is likely to be exported.

  2. NOAA TIFF Image - 4m Multibeam Backscatter for Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Multibeam Backscatter GeoTiffs with 4x4 meter cell resolution describing the geomorphology of 15 areas along the shelf edge off the...

  3. A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight

    OpenAIRE

    Wenner, E. L.; Hinde, P.; Knott, D. M; Van Dolah, R. F.

    1984-01-01

    Species composition, biomass, density, and diversity of benthic invertebrates from six bard-bottom areas were evaluated. Seasonal collections using a dredge, trawl, and suction and grab samplers yielded 432, 525, and 845 taxa, respectively. Based on collections wltb the different gear types, species composition of invertebrates was found to change bathymetrically. Inner- and mlddle-shelf sites were more similar to each other in terms of invertebrate species composition than they were to outer...

  4. Environmental survey of two interim dumpsites, Middle Atlantic Bight from 05 November 1973 to 10 November 1973 (NODC Accession 7501280)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A second oceanographic survey cruise was made to an interim municipal sludge dumpsite and initially to an interim dumpsite for the disposal of industrial acid waste...

  5. NOAA TIFF Image - 4m Bathymetric Plan Curvature of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Plan Curvature GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the...

  6. NOAA TIFF Image - 4m Bathymetric Slope of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Slope GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the South...

  7. NOAA TIFF Image - 4m Bathymetric Depth Range of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Depth Range GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the...

  8. NOAA TIFF Image - 4m Bathymetric Depth of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Depth GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the South...

  9. NOAA TIFF Image - 4m Bathymetric Mean Depth of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Mean Depth GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the...

  10. NOAA TIFF Image - 4m Bathymetric Rugosity of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Rugosity GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the South...

  11. NOAA TIFF Image - 4m Bathymetric Curvature of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Curvature GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the South...

  12. NOAA TIFF Image - 4m Bathymetric Profile Curvature of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Profile Curvature GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off...

  13. NOAA TIFF Image - 4m Bathymetric Slope of Slope for Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric Slope of Slope GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the...

  14. NOAA TIFF Image - 4m Sun Illuminated Bathymetry for Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Sun Illuminated Bathymetry GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the...

  15. Zooplankton data collected from zooplankton net casts from RESEARCHER I and other platforms in TOGA Area of Pacific Ocean; 16 March 1968 to 02 July 1970 (NODC Accession 9500141)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities and other data were collected using zooplankton casts in the TOGA Area of Pacific Ocean from RESEARCHER I and other platforms. Data...

  16. Planktivory in the changing Lake Huron zooplankton community: Bythotrephes consumption exceeds that of Mysis and fish

    Science.gov (United States)

    Bunnell, D.B.; Davis, B.M.; 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

  17. Lipid and fatty acid digestibility in Calanus copepod and krill oil by Atlantic halibut (Hippoglossus hippoglossus L.)

    OpenAIRE

    Colombo-Hixson, Stefanie M.; Olsen, Rolf Erik; Milley, Joyce E.; Lall, Santosh P

    2010-01-01

    Marine zooplankton represent a significant biomass of marine lipid that could supply lipid in diets for farmed marine fish. Digestibility of lipid and fatty acids of the copepod, Calanus finmarchicus and Antarctic krill, Euphausia superba by farmed juvenile Atlantic halibut (Hippoglossus hippoglossus) was investigated. Halibut were fed diets containing one of the following test oils at 15% inclusion level: fish oil (FO), Calanus copepod oil (CO) and Euphausia krill oil (KO). KO contained the ...

  18. Zooplankton data collected from NERPA in Arctic Ocean; 11 August 1936 to 06 October 1936 (NODC Accession 9800135)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts in Arctic Ocean from NERPA. Data were collected from 11 August 1936 to 06 October 1936 by Arctic and...

  19. Zooplankton data collected from THOMAS G. THOMPSON in Bering Sea; 01 April 1980 to 13 October 1981 (NODC Accession 9800133)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts in Bering Sea from THOMAS G. THOMPSON. Data were collected from 01 April 1980 to 13 October 1981 by...

  20. Response of zooplankton to physical changes in the environment: coastal upwelling along central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Nair, S.R.S.; Haridas, P.; Padmavati, G.

    few species of herbivores and carnivores and was generally distinct from non-upwelling and offshore waters. Zooplankton had higher aggregations in the shallow upper mixed layer compared to the stratum below. High variability in zooplankton abundance...

  1. Zooplankton data collected from THOMAS G. THOMPSON in Arabian Sea; 18 September 1994 to 27 December 1995 (NODC Accession 9800077)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts in Arabian Sea from THOMAS G. THOMPSON. Data were collected from 18 September 1994 to 27 December 1995...

  2. Dead zone or oasis in the open ocean? Zooplankton distribution and migration in low-oxygen modewater eddies

    Science.gov (United States)

    Hauss, Helena; Christiansen, Svenja; Schütte, Florian; Kiko, Rainer; Edvam Lima, Miryam; Rodrigues, Elizandro; Karstensen, Johannes; Löscher, Carolin R.; Körtzinger, Arne; Fiedler, Björn

    2016-04-01

    The eastern tropical North Atlantic (ETNA) features a mesopelagic oxygen minimum zone (OMZ) at approximately 300-600 m depth. Here, oxygen concentrations rarely fall below 40 µmol O2 kg-1, but are expected to decline under future projections of global warming. The recent discovery of mesoscale eddies that harbour a shallow suboxic (zooplankton groups that may be negatively or positively affected by ongoing ocean deoxygenation. In spring 2014, a detailed survey of a suboxic anticyclonic modewater eddy (ACME) was carried out near the Cape Verde Ocean Observatory (CVOO), combining acoustic and optical profiling methods with stratified multinet hauls and hydrography. The multinet data revealed that the eddy was characterized by an approximately 1.5-fold increase in total area-integrated zooplankton abundance. At nighttime, when a large proportion of acoustic scatterers is ascending into the upper 150 m, a drastic reduction in mean volume backscattering (Sv) at 75 kHz (shipboard acoustic Doppler current profiler, ADCP) within the shallow OMZ of the eddy was evident compared to the nighttime distribution outside the eddy. Acoustic scatterers avoided the depth range between approximately 85 to 120 m, where oxygen concentrations were lower than approximately 20 µmol O2 kg-1, indicating habitat compression to the oxygenated surface layer. This observation is confirmed by time series observations of a moored ADCP (upward looking, 300 kHz) during an ACME transit at the CVOO mooring in 2010. Nevertheless, part of the diurnal vertical migration (DVM) from the surface layer to the mesopelagic continued through the shallow OMZ. Based upon vertically stratified multinet hauls, Underwater Vision Profiler (UVP5) and ADCP data, four strategies followed by zooplankton in response to in response to the eddy OMZ have been identified: (i) shallow OMZ avoidance and compression at the surface (e.g. most calanoid copepods, euphausiids); (ii) migration to the shallow OMZ core during

  3. ZOOPLANKTON DIVERSITY AND ITS RELATIONSHIP WITH PHYSICO-CHEMICAL PARAMETERS IN MANI RESERVOIR OF WESTERN GHATS, INDIA

    OpenAIRE

    D. N. Veerendra; S. Thirumala; H. Manjunatha; H. B. Aravinda

    2012-01-01

    Studies on relationship between zooplankton abundance and water quality parameter in Mani reservoir were made between January 2008 and December 2008.in the urrent investigation, impact of different physico-chemical parameters on zooplankton population was found. Ten genera of zooplankton were identified. The relationship between zooplankton and water quality parameters was varied from place to place depending upon the condition of the reservoir water.

  4. Variability of spatial and temporal distribution of zooplankton communities at Matrouh beaches, south-eastern Mediterranean Sea, Egypt

    OpenAIRE

    Sawsan M. Aboul Ezz; Ahmed M.M. Heneash; Gharib, Samiha M.

    2014-01-01

    The objectives of this work are to determine the main environmental drivers of zooplankton variability in water of Matrouh beach, south-eastern Mediterranean Sea and to evaluate the differences in zooplankton abundance and population structure in relation to chemical and biological parameters. Samples were collected seasonally from summer 2009 to summer 2010 at 10 sampling beaches. The zooplankton community was characterized by its high variability, and lower diversity. Zooplankton variabilit...

  5. PHYTOPLANKTON AND ZOOPLANKTON SEASONAL DYNAMICS IN A SUBTROPICAL ESTUARY: IMPORTANCE OF CYANOBACTERIA

    Science.gov (United States)

    Murrell, Michael C. and Emile M. Lores. 2004. Phytoplankton and Zooplankton Seasonal Dynamics in a Subtropical Estuary: Importance of Cyanobacteria. J. Plankton Res. 26(3):371-382. (ERL,GB 1190). A seasonal study of phytoplankton and zooplankton was conducted from 1999-20...

  6. Cyanobacteria as a carbon source for zooplankton in eutrophic Lake Taihu, China, measured by

    NARCIS (Netherlands)

    de Kluijver, A.; Yu, J.L.; Houtekamer, M.; Middelburg, J.J.; Liu, Z.W.

    2012-01-01

    Using a combined stable-isotope and fatty-acid approach, we examined carbon-transfer routes from the cyanobacterium Microcystis to zooplankton in eutrophic Lake Taihu, China. Microcystis is generally considered poor food for zooplankton, and we hypothesized that most Microcystis carbon flows to zoop

  7. A new sensitive tracer for the determination of zooplankton grazing activity

    NARCIS (Netherlands)

    Kwint, R.L J; Kramer, K.J M

    1996-01-01

    A new tracer compound is presented for determining zooplankton grazing activity. The gut content in zooplankton is measured as beta-dimethylsulphoniopropionate (DMSP), which can be measured even in individual copepods. Species specific DMSP/Chl-a ratios allow applications in, for example, prey selec

  8. Effect of Main-stem Dams on Zooplankton Communities of the Missouri River (USA)

    Science.gov (United States)

    We examined the distribution and abundance of zooplankton from 146 sites on the Missouri River and found large shifts in the dominance of major taxa between management zones of this regulated river. Crustacean zooplankton were dominant in the inter-reservoir zone of the river, an...

  9. Assessment of Zooplankton Size Fractionation for Monitoring Fry and Fingerling Culture Ponds

    Science.gov (United States)

    Methodology was formulated for use in the rapid assessment of zooplankton in channel catfish ponds. Understanding zooplankton prey size is useful for effective pond management. Size fractionation using differential sieve sizes was an effective means of separating size classes in live material, whe...

  10. Spatial and temporal variation in mercury bioaccumulation by zooplankton in Lake Champlain (North America)

    International Nuclear Information System (INIS)

    Trophic transfer of Hg across lakes within a region has been related to multiple environmental factors, but the nature of these relationships across distinct basins within individual large lakes is unknown. We investigated Hg bioaccumulation in zooplankton in basins of differing trophic status in Lake Champlain (Vermont, USA) to determine the strongest predictors of Hg bioaccumulation. Zooplankton were sampled in Malletts Bay (oligotrophic) and Missisquoi Bay (eutrophic) in 2005–2008. Zooplankton in the eutrophic basin had lower concentrations of total Hg and MeHg than those in the oligotrophic basin in all years but 2007, when no bloom occurred in Missisquoi. In addition, Hg concentrations in seston and small zooplankton, sampled during 2009 at 12 sites spanning the lake, decreased with increasing phytoplankton and zooplankton biomass. Thus, Hg bioaccumulation in zooplankton across basins in Lake Champlain is related to trophic status, as observed previously in multiple lake studies. - Highlights: ► Lake Champlain zooplankton Hg was lower in the eutrophic than the oligotrophic basin. ► Algal blooms in years present biodiluted Hg in plankton. ► Lake-wide spatial patterns of Hg in plankton decreased with increasing biomass. ► Lake-wide Hg bioaccumulation patterns are consistent with multiple lake studies. - Large spatiotemporal variations in MeHg bioaccumulation in zooplankton within a single large lake were linked to spatial variation in trophic status across basins and to inter-annual variation in algal density.

  11. Zooplankton data collected from zooplankton net casts from TOWNSEND CROMWELL in TOGA Area of Pacific Ocean; 09 February 1984 to 04 March 1992 (NODC Accession 9800046)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were taken on five cruises from 1984 through 1992 at Johnston Island, Hancock Seamounts, and Palmyra Island, the latter of which was concentrated...

  12. Micro-zooplankton and its abundance relative to the larger zooplankton and other seston components, 08 February 1967 to 27 February 1967 (NODC Accession 0000916)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Micro-zooplankton populations in the upper 100 m were sampled from 5 marine environments in the northeast Pacific Ocean extending from slope waters off San Diego to...

  13. Cladoceran zooplankton abundance under clear and snow-covered ice

    Science.gov (United States)

    DeBates, T.J.; Chipps, S.R.; Ward, M.C.; Werlin, K.B.; Lorenzen, P.B.

    2003-01-01

    We described the distribution of cladoceran zooplankton under the ice in a natural, glacial lake. Local light availability apparently altered the spatial distribution of cladocerans. Light levels measured under snow-covered areas (0.178 lux) were an order of magnitude less than those measured at the same depth under clear ice (1.750 lux). Cladoceran density under snow-covered areas was significantly higher (Bosmina spp.=3.34/L; Daphnia spp.=0.61/L) than cladoceran abundance under clear ice (Bosmina spp.=0.91/L; Daphnia spp.=0.19/L).

  14. Changing climate cues differentially alter zooplankton dormancy dynamics across latitudes.

    Science.gov (United States)

    Jones, Natalie T; Gilbert, Benjamin

    2016-03-01

    In seasonal climates, dormancy is a common strategy that structures biodiversity and is necessary for the persistence of many species. Climate change will likely alter dormancy dynamics in zooplankton, the basis of aquatic food webs, by altering two important hatching cues: mean temperatures during the ice-free season, and mean day length when lakes become ice free. Theory suggests that these changes could alter diversity, hatchling abundances and phenology within lakes, and that these responses may diverge across latitudes due to differences in optimal hatching cues and strategies. To examine the role of temperature and day length on hatching dynamics, we collected sediment from 25 lakes across a 1800 km latitudinal gradient and exposed sediment samples to a factorial combination of two photoperiods (12 and 16 h) and two temperatures (8 and 12 °C) representative of historical southern (short photoperiod, warm) and northern (long photoperiod, cool) lake conditions. We tested whether sensitivity to these hatching cues varies by latitudinal origin and differs among taxa. Higher temperatures advanced phenology for all taxa, and these advances were greatest for cladocerans followed by copepods and rotifers. Although phenology differed among taxa, the effect of temperature did not vary with latitude. The latitudinal origin of the egg bank influenced egg abundance and hatchling abundance and diversity, with these latter effects varying with taxa, temperature and photoperiod. Copepod hatchling abundances peaked at mid-latitudes in the high temperature and long photoperiod treatments, whereas hatchling abundances of other zooplankton were greatest at low latitudes and high temperature. The overall diversity of crustacean zooplankton (copepods and cladocerans) also reflected distinct responses of each taxa to our treatments, with the greatest diversity occurring at mid-latitudes (~56 °N) in the shorter photoperiod treatment. Our results demonstrate that hatching cues

  15. South Atlantic Shrimp System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SEFSC, in cooperation with the South Atlantic states, collects South Atlantic shrimp data from dealers and fishermen. These data are collected to provide catch,...

  16. 2005 Atlantic Hurricanes Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2005 Atlantic Hurricanes poster features high quality satellite images of 15 hurricanes which formed in the Atlantic Basin (includes Gulf of Mexico and...

  17. Bridging the gap between marine biogeochemical and fisheries sciences; configuring the zooplankton link

    DEFF Research Database (Denmark)

    Mitra, Aditee; Castellani, Claudia; Gentleman, Wendy;

    2014-01-01

    phytoplankton- dominated biogeochemistry or on aspects of fisheries regulation. In consequence the roles of zooplankton communities (protists and metazoans) linking phytoplankton and fish communities are typically under-represented if not (especially in fisheries models) ignored. Where represented in ecosystem...... models, zooplankton are usually incorporated in an extremely simplistic fashion, using empirical descriptions merging various interacting physiological functions governing zooplankton growth and development, and thence ignoring physiological feedback mechanisms. Here we demonstrate, within a modelled...... plankton food-web system, how trophic dynamics are sensitive to small changes in parameter values describing zooplankton vital rates and thus the importance of using appropriate zooplankton descriptors. Through a comprehensive review, we reveal the mismatch between empirical understanding and modelling...

  18. Daily variation of zooplankton abundance and evenness in the Rosana reservoir, Brazil: biotic and abiotic inferences

    Directory of Open Access Journals (Sweden)

    Érica M. Takahashi

    2014-03-01

    Full Text Available The zooplankton community presents stochastic temporal fluctuation and heterogeneous spatial variation determined by the relationships among the organisms and environmental conditions. We predicted that the temporal and spatial zooplankton distribution is heterogeneous and discrete, respectively, and that the daily variation of most abundant species is related to environmental conditions, specifically the availability of resources. Zooplankton samples were collected daily at three sampling stations in a lateral arm of the Rosana Reservoir (SP/PR. The zooplankton did not present significant differences in abundance and evenness among sampling stations, but the temporal variation of these attributes was significant. Abiotic variables and algal resource availability have significantly explained the daily variation of the most abundant species (p<0.001, however, the species distribution makes inferences on biotic relationships between them. Thus, not only the food resource availability is influential on the abundance of principal zooplankton species, but rather a set of factors (abiotic variables and biotic relationships.

  19. Zooplankton community analysis in the Changjiang River estuary by single-gene-targeted metagenomics

    Science.gov (United States)

    Cheng, Fangping; Wang, Minxiao; Li, Chaolun; Sun, Song

    2014-07-01

    DNA barcoding provides accurate identification of zooplankton species through all life stages. Single-gene-targeted metagenomic analysis based on DNA barcode databases can facilitate longterm monitoring of zooplankton communities. With the help of the available zooplankton databases, the zooplankton community of the Changjiang (Yangtze) River estuary was studied using a single-gene-targeted metagenomic method to estimate the species richness of this community. A total of 856 mitochondrial cytochrome oxidase subunit 1 (cox1) gene sequences were determined. The environmental barcodes were clustered into 70 molecular operational taxonomic units (MOTUs). Forty-two MOTUs matched barcoded marine organisms with more than 90% similarity and were assigned to either the species (similarity>96%) or genus level (similaritymetagenomic analysis is a useful tool for zooplankton studies, with which specimens from all life history stages can be identified quickly and effectively with a comprehensive database.

  20. The effect of salinity levels on the structure of zooplankton communities

    Directory of Open Access Journals (Sweden)

    Paturej Ewa

    2015-01-01

    Full Text Available The objective of this study was to determine the qualitative and quantitative structure of zooplankton communities in the Vistula Lagoon and to establish whether zooplankton abundance and biodiversity are affected by salinity levels. Samples for biological analyses were collected in the summer (June-September of 2007-2011 at eleven sampling sites. Statistical analysis revealed a significant correlation between salinity levels and the number of species (r= -0.2020, abundance (r= 0.1967 and biomass (r= 0.3139 of zooplankton. No significant correlations were found between salinity and the biodiversity of zooplankton. The results of the study suggest that salinity affects the abundance and structure, but not the diversity of zooplankton communities in the Vistula Lagoon.

  1. Zooplankton size selection relative to gill raker spacing in rainbow trout

    Science.gov (United States)

    Budy, P.; Haddix, T.; Schneidervin, R.

    2005-01-01

    Rainbow trout Oncorhynchus mykiss are one of the most widely stocked salmonids worldwide, often based on the assumption that they will effectively utilize abundant invertebrate food resources. We evaluated the potential for feeding morphology to affect prey selection by rainbow trout using a combination of laboratory feeding experiments and field observations in Flaming Gorge Reservoir, Utah-Wyoming. For rainbow trout collected from the reservoir, inter-gill raker spacing averaged 1.09 mm and there was low variation among fish overall (SD = 0.28). Ninety-seven percent of all zooplankton observed in the diets of rainbow trout collected in the reservoir were larger than the interraker spacing, while only 29% of the zooplankton found in the environment were larger than the interraker spacing. Over the size range of rainbow trout evaluated here (200-475 mm), interraker spacing increased moderately with increasing fish length; however, the size of zooplankton found in the diet did not increase with increasing fish length. In laboratory experiments, rainbow trout consumed the largest zooplankton available; the mean size of zooplankton observed in the diets was significantly larger than the mean size of zooplankton available. Electivity indices for both laboratory and field observations indicated strong selection for larger-sized zooplankton. The size threshold at which electivity switched from selection against smaller-sized zooplankton to selection for larger-sized zooplankton closely corresponded to the mean interraker spacing for both groups (???1-1.2 mm). The combination of results observed here indicates that rainbow trout morphology limits the retention of different-sized zooplankton prey and reinforces the importance of understanding how effectively rainbow trout can utilize the type and sizes of different prey available in a given system. These considerations may improve our ability to predict the potential for growth and survival of rainbow trout within and

  2. Cephalopods and cetaceans as indicators of offshore bioavailability of cadmium off Central South Brazil Bight

    International Nuclear Information System (INIS)

    Regarding Brazilian coast, industrial and urban developments are concentrated along Central South Brazil Bight. Samples from inshore and offshore species from the concerned area were analyzed, comprising 24 cetaceans (9 species) and 32 squids (2 species). Cadmium was determined by GFAAS and our results were in agreement with certified values (DOLT-2, NRCC). Mean cadmium concentration (in μg/g, wet weight) observed in the digestive gland of sexually mature Argentine short-finned squids (Illex argentinus) was 1002.9. To our knowledge this is the highest cadmium level ever reported for a cephalopod. Concerning cetaceans, our results include one of the highest renal cadmium concentrations described for striped dolphins (71.29 μg/g, wet weight). Anthropogenic action, upwelling and cannibalism of Argentine short-finned squid on the studied area are possible reasons for such remarkable cadmium concentrations. - Cd levels in ommastrephid squids from Brazil are the highest ever reported for cephalopods

  3. Cephalopods and cetaceans as indicators of offshore bioavailability of cadmium off Central South Brazil Bight

    Energy Technology Data Exchange (ETDEWEB)

    Dorneles, Paulo Renato [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), 21941-900 Rio de Janeiro, RJ (Brazil) and Laboratorio de Mamiferos Aquaticos, Dept. Oceanografia, UERJ, 20550-013 Rio de Janeiro, RJ (Brazil)]. E-mail: dorneles@biof.ufrj.br; Lailson-Brito, Jose [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), 21941-900 Rio de Janeiro, RJ (Brazil) and Laboratorio de Mamiferos Aquaticos, Dept. Oceanografia, UERJ, 20550-013 Rio de Janeiro, RJ (Brazil)]. E-mail: lailson@uerj.br; Aguiar dos Santos, Roberta [Centro de Pesquisa e Gestao de Recursos Pesqueiros do Litoral Sudeste e Sul, IBAMA, 88301-700 Itajai, SC (Brazil)]. E-mail: gibteuthis@yahoo.com.br; Silva da Costa, Paulo Alberto [Laboratorio de Dinamica de Populacoes Marinhas, UNIRIO, 22290-240 Rio de Janeiro, RJ (Brazil)]. E-mail: pauloascosta@uol.com.br; Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), 21941-900 Rio de Janeiro, RJ (Brazil)]. E-mail: olaf@biof.ufrj.br; Azevedo, Alexandre Freitas [Laboratorio de Mamiferos Aquaticos, Dept. Oceanografia, UERJ, 20550-013 Rio de Janeiro, RJ (Brazil)]. E-mail: azevedo.alex@uol.com.br; Machado Torres, Joao Paulo [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), 21941-900 Rio de Janeiro, RJ (Brazil)]. E-mail: jptorres@biof.ufrj.br

    2007-07-15

    Regarding Brazilian coast, industrial and urban developments are concentrated along Central South Brazil Bight. Samples from inshore and offshore species from the concerned area were analyzed, comprising 24 cetaceans (9 species) and 32 squids (2 species). Cadmium was determined by GFAAS and our results were in agreement with certified values (DOLT-2, NRCC). Mean cadmium concentration (in {mu}g/g, wet weight) observed in the digestive gland of sexually mature Argentine short-finned squids (Illex argentinus) was 1002.9. To our knowledge this is the highest cadmium level ever reported for a cephalopod. Concerning cetaceans, our results include one of the highest renal cadmium concentrations described for striped dolphins (71.29 {mu}g/g, wet weight). Anthropogenic action, upwelling and cannibalism of Argentine short-finned squid on the studied area are possible reasons for such remarkable cadmium concentrations. - Cd levels in ommastrephid squids from Brazil are the highest ever reported for cephalopods.

  4. A seafloor crater in the German Bight and its effects on the benthos

    Science.gov (United States)

    Thatje, S.; Gerdes, D.; Rachor, E.

    1999-08-01

    In 1963 a deep crater was formed about 65 m below sea level in the western part of the German Bight, due to a gas eruption caused by drilling carried out from the platform 'Mr. Louie'. The study area is situated in a sandy to muddy bottom area inhabited by an Amphiura filiformis association (sensu Salzwedel et al. 1985). The crater, sometimes called 'Figge-Maar', functions as a sediment trap, concentrating particles and organisms from the water column, thus leading to extreme sedimentation rates of about 50 cm, on average, per year. Crater stations, compared with stations situated in the vicinity, show enrichments of juveniles. Echinoderms, especially the subsurface-dwelling heart urchin Echinocardium cordatum and ophiuroids are responsive to enrichment. Other species that are typical of the Amphiura filiformis association are shown to be unable to cope with the special conditions in the crater.

  5. Ocean-atmosphere pollutant circulation processes: The Heligoland Bight ecosystem (PRISMA). 2. interim report (1991)

    International Nuclear Information System (INIS)

    The PRISMA BMFT project is an important stage on the way to a comprehensive knowledge of the impacts of pollutants on the North Sea/Heligoland Bight ecosystem. The overall project is dedicated to the development, verification and application of a complex shelf-sea model which provides qualitative and quantitative data about the causal interactions between the basic atmospheric conditions, the hydrodynamics and thermodynamics of the water, the chemical reactons in the air, in the water and the sediments, and the activity of organisms. The model comprises a compact set of formulae, process formulations, initial and marginal conditions and empirical parameters which serves to describe the origin, transport, reactions and final deposition of pollutants in the North Sea, helps to analyze and elucidate the present condition of the ecosystem and its spatial and temporal variability, and provides forecasts in accordance with the changing natural and anthropogenic environmental conditions. (orig.)

  6. Occurrence and distribution of triclosan in the German Bight (North Sea)

    International Nuclear Information System (INIS)

    The potential of triclosan (TCS) acting as an endocrine disruptor has led to growing concern about the presence of TCS in the environment. In this study, seawater samples were collected from the German Bight during sampling campaigns conducted with the German research ships Gauss and Ludwig Prandtl. TCS was determined both in the dissolved phase and in the suspended particulate matters with concentrations ranging 0.8-6870 pg L-1 and -1, respectively. High concentrations of TCS were present in the estuaries of the Elbe and the Weser, indicating significant input of TCS by the river discharge. The correlation coefficient (R2) between the dissolved concentration and salinity was 0.79 for the data obtained from the Gauss cruise, showing an obvious declining trend from the coast to the open sea. - Investigation with coastal survey reveals distribution of triclosan in marine waters

  7. Occurrence and distribution of triclosan in the German Bight (North Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Xie Zhiyong [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck Strasse 1, D-21502 Geesthacht (Germany); Institute of Ecology and Environmental Chemistry, University of Lueneburg, Scharnhorststrasse 1, D-21335 Lueneburg (Germany)], E-mail: zhiyong.xie@gkss.de; Ebinghaus, Ralf; Floeser, Goetz; Caba, Armando [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck Strasse 1, D-21502 Geesthacht (Germany); Ruck, Wolfgang [Institute of Ecology and Environmental Chemistry, University of Lueneburg, Scharnhorststrasse 1, D-21335 Lueneburg (Germany)

    2008-12-15

    The potential of triclosan (TCS) acting as an endocrine disruptor has led to growing concern about the presence of TCS in the environment. In this study, seawater samples were collected from the German Bight during sampling campaigns conducted with the German research ships Gauss and Ludwig Prandtl. TCS was determined both in the dissolved phase and in the suspended particulate matters with concentrations ranging 0.8-6870 pg L{sup -1} and <1-95 pg L{sup -1}, respectively. High concentrations of TCS were present in the estuaries of the Elbe and the Weser, indicating significant input of TCS by the river discharge. The correlation coefficient (R{sup 2}) between the dissolved concentration and salinity was 0.79 for the data obtained from the Gauss cruise, showing an obvious declining trend from the coast to the open sea. - Investigation with coastal survey reveals distribution of triclosan in marine waters.

  8. Brazilian sardine (Sardinella brasiliensis spawning in the southeast Brazilian Bight over the period 1976-1993

    Directory of Open Access Journals (Sweden)

    Yasunobu Matsuura

    1998-01-01

    Full Text Available Based on sampling over the period 1976-1993 in the southeast Brazilian Bight, the distribution of spawning of the Brazilian sardine (Sardinella brasi/iensis is described in relation to environmental conditions. The area of intense spawning occurs in the southern part of the bight where coastal upwelling was less /Tequent. Spawning intensity showed high interannllal variation and the egg abundance in the survey area ranged /Tom 99 billion eggs in the January 1988 cruise to 4669 billion eggs in the January 1981 cruise. Peak spawning takes place one hour after midnight and eggs hatch . out within 19 hours with a water temperature of 24 °e.Baseado nos dados coletados durante nove cruzeiros oceanográficos realizados na região sudeste, as áreas de desova da sardinha-verdadeira (Sardinella brasiliensis foram apresentadas c discutidas em relação às condições oceanográficas. As áreas de desova intensiva foram localizadas na parte sul da área de investigação, onde a ressurgência costeira foi menos freqüente. A intensidade de desova demonstrou uma variação anual relativamente grande. A produção total de ovos da sardinha- ­verdadeira variou de 99 bilhões de ovos durante o cruzeiro de janeiro de 1988 para 4669 bilhões de ovos em janeiro de 1981. O pico de desova ocorre na camada de mistura de superfície uma hora após a meia noite e os ovos eclodem em 19 horas com a temperatura de água 24 °e.

  9. Zooplankton feeding on the nuisance flagellate Gonyostomum semen.

    Directory of Open Access Journals (Sweden)

    Karin S L Johansson

    Full Text Available The large bloom-forming flagellate Gonyostomum semen has been hypothesized to be inedible to naturally occurring zooplankton due to its large cell size and ejection of long slimy threads (trichocysts induced by physical stimulation. In a grazing experiment using radiolabelled algae and zooplankton collected from lakes with recurring blooms of G. semen and lakes that rarely experience blooms, we found that Eudiaptomus gracilis and Holopedium gibberum fed on G. semen at high rates, whereas Daphnia cristata and Ceriodaphnia spp. did not. Grazing rates of E. gracilis were similar between bloom-lakes and lakes with low biomass of G. semen, indicating that the ability to feed on G. semen was not a result of local adaptation. The high grazing rates of two of the taxa in our experiment imply that some of the nutrients and energy taken up by G. semen can be transferred directly to higher trophic levels, although the predominance of small cladocerans during blooms may limit the importance of G. semen as a food resource. Based on grazing rates and previous observations on abundances of E. gracilis and H. gibberum, we conclude that there is a potential for grazer control of G. semen and discuss why blooms of G. semen still occur.

  10. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

    Science.gov (United States)

    Taipale, Sami J.; Galloway, Aaron W. E.; Aalto, Sanni L.; Kahilainen, Kimmo K.; Strandberg, Ursula; Kankaala, Paula

    2016-01-01

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terrestrial-origin carbohydrates for energy and sparing essential fatty acids and amino acids for somatic growth and reproduction. Assimilated terrestrial-origin fatty acids from shoreline reed particles exceeded available diet, indicating that Daphnia may convert a part of their dietary carbohydrates to saturated fatty acids. This conversion was not observed with birch leaf diets, which had lower carbohydrate content. Subsequent analysis of 21 boreal and subarctic lakes showed that diet of herbivorous zooplankton is mainly based on high-quality phytoplankton rich in essential polyunsaturated fatty acids. The proportion of low-quality diets (bacteria and terrestrial particulate organic matter) was directly related to the concentration of terrestrial organic matter in experiments or lakes, but rather to the low availability of phytoplankton. PMID:27510848

  11. The distribution, diversity, and importance of cephalopods in top predator diets from offshore habitats of the Northwest Atlantic Ocean

    Science.gov (United States)

    Staudinger, M. D.; Juanes, F.; Salmon, B.; Teffer, A. K.

    2013-10-01

    Large pelagic predators were used as biological samplers to gain information on cephalopod diversity, abundance, distribution, and their role as prey in the Northwest Atlantic Ocean. Fish predators were caught by recreational anglers in offshore waters of New England (NE; 2007-2010), the Mid-Atlantic Bight (MAB; 2009-2010) and the South Atlantic Bight (SAB; 2010-2011). In total, 2362 cephalopods, including 22 species of squid and 4 octopods, were identified in the diets of 13 species of predatory fishes. Cephalopod body sizes were obtained for 1973 specimens through direct measurement of mantle lengths (ML) or estimated using lower rostral/hood lengths of lower beaks. Cephalopod diversity (number of species) was highest in predator diets from the SAB (N=19), intermediate in NE (N=18), and lowest in the MAB (N=9); however, differences may reflect unequal sampling effort among regions. The most important cephalopods across predator diets by number and frequency of occurrence were from the families Ommastrephidae, Argonautidae, Loliginidae, and Histioteuthidae. Shortfin squid (Illex illecebrosus) and paper nautilus (Argonauta sp.) were the most recurrent species identified across spatiotemporal scales; size distributions of these two species varied significantly among regions, and the largest individuals on average were found in the MAB. Results demonstrate that although pelagic predators consumed a broad range of cephalopod species, octopods and squids from the families Argonautidae and Ommastrephidae dominated the collective diets of numerous pelagic teleosts and elasmobranchs, and play a key role in offshore food-webs of the Northwest Atlantic Ocean. This study emphasizes the value of using predators as biological samplers to gain information on cephalopod biogeography, and as a potential approach to track ecosystem changes in this region due to environmental and anthropogenic stressors.

  12. Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles

    Science.gov (United States)

    Le Quéré, C.; Buitenhuis, E. T.; Moriarty, R.; Alvain, S.; Aumont, O.; Bopp, L.; Chollet, S.; Enright, C.; Franklin, D. J.; Geider, R. J.; Harrison, S. P.; Hirst, A.; Larsen, S.; Legendre, L.; Platt, T.; Prentice, I. C.; Rivkin, R. B.; Sathyendranath, S.; Stephens, N.; Vogt, M.; Sailley, S.; Vallina, S. M.

    2015-07-01

    Global ocean biogeochemistry models currently employed in climate change projections use highly simplified representations of pelagic food webs. These food webs do not necessarily include critical pathways by which ecosystems interact with ocean biogeochemistry and climate. Here we present a global biogeochemical model which incorporates ecosystem dynamics based on the representation of ten plankton functional types (PFTs); six types of phytoplankton, three types of zooplankton, and heterotrophic bacteria. We improved the representation of zooplankton dynamics in our model through (a) the explicit inclusion of large, slow-growing zooplankton, and (b) the introduction of trophic cascades among the three zooplankton types. We use the model to quantitatively assess the relative roles of iron vs. grazing in determining phytoplankton biomass in the Southern Ocean High Nutrient Low Chlorophyll (HNLC) region during summer. When model simulations do not represent crustacean macrozooplankton grazing, they systematically overestimate Southern Ocean chlorophyll biomass during the summer, even when there was no iron deposition from dust. When model simulations included the developments of the zooplankton component, the simulation of phytoplankton biomass improved and the high chlorophyll summer bias in the Southern Ocean HNLC region largely disappeared. Our model results suggest that the observed low phytoplankton biomass in the Southern Ocean during summer is primarily explained by the dynamics of the Southern Ocean zooplankton community rather than iron limitation. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean.

  13. Short-term variation in zooplankton community from Daya Bay with outbreaks of Penilia avirostris

    Directory of Open Access Journals (Sweden)

    Kaizhi Li

    2014-06-01

    Full Text Available The zooplankton community structure in bays fluctuates as a result of anthropogenic activities in such waters. We focused on the short-term variability of a zooplankton community and compared its differences at the outflow of a nuclear power plant (ONPP, in a marine cage-culture area (MCCA and in unpolluted waters (UW in the south-west part of Daya Bay from 28 April to 1 June 2001. Environmental factors and zooplankton abundance differed significantly among stations at ONPP, MCCA and UW: high temperatures and a high zooplankton abundance occurred at ONPP, while a high chlorophyll a concentration and a low zooplankton abundance prevailed in MCCA. Statistical analysis revealed that the zooplankton diversity and abundance could be reduced by the activity of the marine cage-culture in a short time. Penilia avirostris made up an important component of the zooplankton in the study area, its abundance ranging widely from 16 to 7267 indiv. m-3 from April to June and peaking at the ONPP outflow. The outbreak of P. avirostris probably resulted from the combined effects of favourable water temperature, food concentration and its parthenogenetic behaviour.

  14. Seasonal variation of zooplankton abundance, composition and biomass in the Chabahar Bay, Oman Sea

    Directory of Open Access Journals (Sweden)

    Neda Fazeli

    2014-01-01

    Full Text Available Temporal and spatial variation of zooplankton abundance, composition and biomass were examined on the Chabahar Bay, Oman Sea. The Chabahar Bay, a subtropical and semi-enclosed bay, provides an ideal breeding ground for many fish and shellfish. Five stations were investigated along the Bay. This area is under the influence of the Indian Ocean seasonal monsoons. Zooplankton was collected with vertical plankton tows using 100 µm mesh nets. Copepods dominated the zooplankton community followed by larvacea, cladocera and chaetognatha. Fifteen taxa of zooplankton were identified. Oithona nana and Euterpina acutifrons were dominated in the whole year and Larvacea showed a bloom in Northeast Monsoon. A Two-way ANOVA indicated that there were differences in abundance and biomass between sampling periods and between stations were significant. The peak zooplankton abundance in NE Monsoon could be due to winter cooling, with entrainment of nutrients into the upper layer producing phytoplankton blooms. The decline of zooplankton abundance and biomass in South West Monsoon and post-monsoon could be explained by decrease in chlorophyll a concentrations. The present result showed the composition and distribution of zooplankton differed between the monsoon seasons, resulted from changes in hydrographic conditions.

  15. Stable isotope and signature fatty acid analyses suggest reef manta rays feed on demersal zooplankton.

    Directory of Open Access Journals (Sweden)

    Lydie I E Couturier

    Full Text Available Assessing the trophic role and interaction of an animal is key to understanding its general ecology and dynamics. Conventional techniques used to elucidate diet, such as stomach content analysis, are not suitable for large threatened marine species. Non-lethal sampling combined with biochemical methods provides a practical alternative for investigating the feeding ecology of these species. Stable isotope and signature fatty acid analyses of muscle tissue were used for the first time to examine assimilated diet of the reef manta ray Manta alfredi, and were compared with different zooplankton functional groups (i.e. near-surface zooplankton collected during manta ray feeding events and non-feeding periods, epipelagic zooplankton, demersal zooplankton and several different zooplankton taxa. Stable isotope δ(15N values confirmed that the reef manta ray is a secondary consumer. This species had relatively high levels of docosahexaenoic acid (DHA indicating a flagellate-based food source in the diet, which likely reflects feeding on DHA-rich near-surface and epipelagic zooplankton. However, high levels of ω6 polyunsaturated fatty acids and slightly enriched δ(13C values in reef manta ray tissue suggest that they do not feed solely on pelagic zooplankton, but rather obtain part of their diet from another origin. The closest match was with demersal zooplankton, suggesting it is an important component of the reef manta ray diet. The ability to feed on demersal zooplankton is likely linked to the horizontal and vertical movement patterns of this giant planktivore. These new insights into the habitat use and feeding ecology of the reef manta ray will assist in the effective evaluation of its conservation needs.

  16. Horizontal distribution of Fukushima-derived radiocesium in zooplankton in the northwestern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    M. Kitamura

    2013-04-01

    Full Text Available The magnitude of the 9.0 Tohoku earthquake and the ensuing tsunami on 11 March 2011, inflicted heavy damage on the Fukushima Dai-ichi nuclear power plant (FNPP1. Fission products were emitted, falling over a broad range in the northern hemisphere, and water contaminated with radionuclides leaked into the ocean. In this study, we described the horizontal distribution of the Fukushima-derived radiocesium in zooplankton and in seawater in the western North Pacific Ocean (500–2100 km from the FNPP1 10 months after the accident. 134Cs and 137Cs were detected in zooplankton and seawater from all the stations. Because of its short half-lives, 134Cs detected in our samples could only be derived from the FNPP1 accident. The highest 137Cs activity in zooplankton was same order of magnitude as that one month after the accident, and average activity was one or two orders of magnitude higher than 137Cs activities observed before the accident around Japan. Horizontally, the radiocesium activity concentrations in zooplankton were high at around 25° N while those in surface seawater were high at around the transition area between the Kuroshio and the Oyashio Currents (36–40° N. We observed subsurface radiocesium maxima in density range of the North Pacific Subtropical Mode Water and occurrence of many diel vertical migratory zooplanktons. These suggested that the high activity concentrations in the subtropical zooplankton at around 25° N were connected to the subsurface radiocesium and active vertical migration of zooplankton. However, the high activity concentrations of radiocesium in subsurface seawater did not necessarily follow the higher radiocesium activity in zooplankton. Biological characteristics of zooplankton community possibly influenced how large was contamination of radiocesium in the community but it is still unknown what kind of biological factors were important.

  17. Horizontal distribution of Fukushima-derived radiocesium in zooplankton in the northwestern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    M. Kitamura

    2013-08-01

    Full Text Available The magnitude of the 9.0 Tohoku earthquake and the ensuing tsunami on 11 March 2011, inflicted heavy damage on the Fukushima Dai-ichi nuclear power plant (FNPP1. Fission products were emitted, falling over a broad range in the Northern Hemisphere, and water contaminated with radionuclides leaked into the ocean. In this study, we described the horizontal distribution of the Fukushima-derived radiocesium in zooplankton and in seawater in the western North Pacific Ocean (500–2100 km from the FNPP1 10 months after the accident. 134Cs and 137Cs were detected in zooplankton and seawater from all the stations. Because of its short half-life, the 134Cs detected in our samples could only be derived from the FNPP1 accident. The highest 137Cs activity in zooplankton was the same order of magnitude as it was one month after the accident, and average activity was one or two orders of magnitude higher than 137Cs activities observed before the accident around Japan. Horizontally, the radiocesium activity concentrations in zooplankton were high at around 25° N while those in surface seawater were high at around the transition area between the Kuroshio and the Oyashio currents (36–40° N. We observed subsurface radiocesium maxima in density range of the North Pacific Subtropical Mode Water and the occurrence of many diel vertical migratory zooplankton. These suggested that the high activity concentrations in the subtropical zooplankton at around 25° N were connected to the subsurface radiocesium and active vertical migration of zooplankton. However, the high activity concentrations of radiocesium in subsurface seawater did not necessarily correlate with the higher radiocesium activity in zooplankton. Activity concentrations of radiocesium in zooplankton might be influenced not only by the environmental radiocesium activity concentrations but also by other factors, which are still unknown.

  18. Movement patterns, habitat preferences, and fisheries biology of the common thresher shark (Alopias vulpinus) in the Southern California Bight

    OpenAIRE

    Cartamil, Daniel Patrick

    2009-01-01

    The common thresher shark (Alopias vulpinus) is a pelagic species that constitutes the largest commercial shark fishery in California waters. Despite its commercial value, little is known of thresher shark biology, nor is there adequate data on which to base fishery management decisions. This dissertation entails four studies dealing with the biology and fisheries interactions of common thresher shark in the Southern California Bight (SCB). Chapter 1 examines the movement patterns of adult an...

  19. Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay.

    Science.gov (United States)

    Ziyaadini, Morteza; Mehdinia, Ali; Khaleghi, Leila; Nassiri, Mahmoud

    2016-06-15

    The amounts and sources of polycyclic aromatic hydrocarbons (PAHs) and their bioaccumulation factors (BAFs) in the zooplankton community of Chabahar Bay were investigated. The highest amounts of total PAHs (tPAHs) in the water and zooplankton samples were 62.2ngL(-1) and 1478.6ngg(-1) dry weights, in near the Shahid Beheshti Port and desalination, respectively. The greatest amount of BAF (51,780) was obtained in the entry of Bay, and it was related to the phenanthrene accumulation. Using molecular ratio, the results showed that the major input source of PAH compounds in zooplankton of Chabahar Bay was pyrolytic (fuel) source. PMID:26944700

  20. Dynamical Complexity of a Spatial Phytoplankton-Zooplankton Model with an Alternative Prey and Refuge Effect

    Directory of Open Access Journals (Sweden)

    Weiwei Zhang

    2013-01-01

    Full Text Available The spatiotemporal dynamics of a phytoplankton-zooplankton model with an alternative prey and refuge effect is investigated mathematically and numerically. The stability of the equilibrium point and the traveling wave solution of the phytoplankton-zooplankton model are described based on theoretical mathematical work, which provides the basis of the numerical simulation. The numerical analysis shows that refuges have a strong effect on the spatiotemporal dynamics of the model according to the pattern formation. These results may help us to understand prey-predator interactions in water ecosystems. They are also relevant to research into phytoplankton-zooplankton ecosystems.

  1. Instantaneous threat escape and differentiated refuge demand among zooplankton taxa.

    Science.gov (United States)

    Hansson, Lars-Anders; Bianco, Giuseppe; Ekvall, Mikael; Heuschele, Jan; Hylander, Samuel; Yang, Xi

    2016-02-01

    Most animals, including aquatic crustacean zooplankton, perform strong avoidance movements when exposed to a threat, such as ultraviolet radiation (UVR). We here show that the genera Daphnia and Bosmina instantly adjust their vertical position in the water in accordance with the present UVR threat, i.e., seek refuge in deeper waters, whereas other taxa show less response to the threat. Moreover, Daphnia repeatedly respond to UVR pulses, suggesting that they spend more energy on movement than more stationary taxa, for example, during days with fluctuating cloud cover, illustrating nonlethal effects in avoiding UVR threat. Accordingly, we also show that the taxa with the most contrasting behavioral responses differ considerably in photoprotection, suggesting different morphological and behavioral strategies in handling the UVR threat. In a broader context, our studies on individual and taxa specific responses to UVR provide insights into observed spatial and temporal distribution in natural ecosystems. PMID:27145603

  2. Biogeography of key mesozooplankton species in the North Atlantic, by manual counting methods, and egg production of Calanus finmarchicus

    DEFF Research Database (Denmark)

    Melle, W.; Runge, J. A.; Head, E.;

    2014-01-01

    Here we present a new, pan-Atlantic compilation of data on key mesozooplankton species, including the possibly most important copepod, Calanus finmarchicus. Distributional data of ten representative zooplankton taxa, from recent (2000–2009) Continuous Plankton Recorder data, are presented, along ...... scientists and their institutions. http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393....

  3. Biogeography of key mesozooplankton species in the North Atlantic, by manual counting methods, and egg production of Calanus finmarchicus

    DEFF Research Database (Denmark)

    Melle, W.; Runge, J. A.; Head, E.;

    2015-01-01

    Here we present a new, pan-Atlantic compilation of data on key mesozooplankton species, including the possibly most important copepod, Calanus finmarchicus. Distributional data of ten representative zooplankton taxa, from recent (2000–2009) Continuous Plankton Recorder data, are presented, along ...... scientists and their institutions. http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393....

  4. Diel vertical migration of zooplankton at the S1 biogeochemical mooring revealed from acoustic backscattering strength

    Science.gov (United States)

    Inoue, Ryuichiro; Kitamura, Minoru; Fujiki, Tetsuichi

    2016-02-01

    We examined the diel vertical migration of zooplankton by using the backscatter strength obtained from moored acoustic Doppler current profilers at mooring site S1 in the North Pacific subtropical gyre. There was seasonal variability in the vertical distribution and migration of the high-backscatter layers in that they became deeper than the euphotic zone (zooplankton near the surface by changing the light intensity. Physical events, such as mixed-layer deepening and restratification and the passage of a mesoscale eddy, also affected zooplankton behavior possibly by changing food environment in the euphotic zone. Since the comparison with net samples indicated that the backscatter likely represents the bulk biomass, the accuracy of biomass estimates based on net samples could be influenced by the high temporal variability of zooplankton distributions.

  5. Production of certain hydrolytic enzymes by psychrophilic bacteria from the Antarctic krill, zooplankton and seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.

    Psychrophilic bacteria isolated from krill, zooplankton and water samples collected in the Indian Ocean Sector of Southern Ocean during the Ninth India Expedition (1989-1990) were enumerated and several strains subjected to various biochemical tests...

  6. Elemental (C, H, N) composition of zooplankton from north Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Matondkar, S.G.P.; Bhat, K.L.; Ansari, Z.A.; Parulekar, A.H.

    found to be much lower than the values presently used in routine conversion factors. Such factors are now essentially needed for accounting role of zooplankton in sediment trap collections in Arabian Sea region...

  7. Zooplankton production, composition and diversity in the coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Padmavati, G.

    , siphonophores, chaetognaths and fish eggs were the other common taxa. Zooplankton population was never dominated by a single group. Swarms of copepods (Temora turbinata), cladocerans (Evadne tergestina), and pteropods (Creseis acicula) occurred in the nutrient...

  8. Relative abundance and diel variation of zooplankton from south west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.; Peter, K.J.

    abundant group, of which calanoids predominated. A swarm of the hydromedusan species, Aequorea conica, (181/m sup(-3)) was seen at night. Quantitative and qualitative variations of various zooplankton groups from six stations in relation to selected physico...

  9. Biomass and biochemical composition of zooplankton from northwest Bay of Bengal during January 1990

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Goswami, S.C.

    Biomass, proximate composition, organic carbon and calorie content of assorted zooplankton from the surface waters were studied. Day and night stations revealed significant difference in biomass (displacement volume, dry wt and organic carbon...

  10. Studies on the associates and parasites of zooplankton from southwest and southeast coasts of India

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    Associates and parasites of zooplankton from southwest and southeast coasts of India were studied. Among the epizoic forms two species of ciliates infesting copepods were new records from Indian waters. Eight species of suctorians were found epizoic...

  11. Zooplankton mortality due to entrainment in the cooling water circuit of a power station

    International Nuclear Information System (INIS)

    Zooplankton mortality, both the instant (0 h) and delayed (24 h) due to entrainment has been studied at two different locations in the cooling water circuit of Madras Atomic Power Station at Kalpakkam. Among the four dominant groups of zooplankton studied, calanoids the largest organisms (average length 1036±246 μm) with regards to the size as compared to other groups, registered the highest mortality (70.63%). However, the barnacle larvae with their smallest average size (408±105 μm), suffered the lowest mortality. Thus, the mortality occurred corresponded to the average size of the zooplankton groups. The mortality showed significant difference among the four different groups of zooplankton (p=6 ml/day (in terms of displacement volume) is equivalent to 116.2 kg C/Day. (author)

  12. Development and validation of hydroacoustic monitoring concepts for the coastal German Bight (SE North Sea)

    Science.gov (United States)

    Mielck, Finn; Hass, H. Christian; Holler, Peter; Bartholomä, Alexander; Neumann, Andreas; Kröncke, Ingrid; Reimers, Hans-Christian; Capperucci, Ruggero

    2016-04-01

    The joint research project WIMO (Wissenschaftliche Monitoringkonzepte für die Deutsche Bucht/Scientific Monitoring Concepts for the German Bight, NE North Sea) aims at providing methods for detection and analysis of seabed habitats using modern remote sensing techniques. Our subproject focuses on hydroacoustic techniques in order to gain information about seafloor environments and sediment dynamics. In a timeframe of four years, several key areas in the German Bight were repeatedly observed using different hydroacoustic gear (i. e. sidescan sonars, single/multibeam echo sounders and sub-bottom profilers). In order to ground-truth the acoustic data, hundreds of grab samples and underwater videos were taken. With these techniques it is possible to distinguish between different seafloor habitats, which range from muddy to sandy seafloors (esp. near the barrier islands) to rugged or vegetated/populated reefs around Helgoland. The conducted monitoring program revealed seasonal changes regarding the abundance of the sand mason worm (Lanice conchilega) and the brittle star (Amphiora filiformis) as well as ongoing sedimentary processes driven by tidal currents and wind/storms. It was also possible to determine relationships between sediment characteristics and benthos in some key areas. An essential part of our project included a comparison between the datasets obtained with different hydroacoustic devices, configurations, and evaluation methods in the same study areas. The investigation reveals that there could be distinct differences in interpreting the data and hence in the determination of prevailing seafloor habitats, especially in very heterogeneous areas and at transition zones between the habitats. Therefore, it is recommended to employ more than one hydroacoustic system (preferably a singlebeam device combined with a wide-swath sonar system) synchronously during a survey in order to gain more reliable and detailed information about the seafloor environments. The

  13. Spatial and temporal patterns in oxygen and nutrient fluxes in sediment of German Bight (North Sea)

    Science.gov (United States)

    Neumann, Andreas; Friedrich, Jana; van Beusekom, Justus; Naderipour, Céline

    2016-04-01

    The German Bight in the southern North Sea is affected by intensive anthropogenic exploitation. Over a century of intensive use by shipping, fishery, and input by polluted rivers has pushed the coastal ecosystem far from its pristine state. The nutrient load reached a maximum in the early 1990s (Amann et al. 2012), and implementation of environmental protection policies substantially decreased the riverine nutrient load. While the riverine input of pollutants has constantly reduced since then, new forms of sea exploitation emerge. The most noticeable example is the installation of more than 600 wind turbines over the past few years in the German EEZ, and additionally 1,200 are already planned. The impact of these installations on hydrology and biogeochemical cycles is largely unclear. In a series of monitoring cruises we repeatedly sampled the sediment at a set of monitoring stations, which represent all typical habitats of the German Bight. We deployed benthic landers for in-situ chamber incubations and performed ex-situ whole-core incubations to investigate the benthic fluxes of oxygen and nutrients, and their spatial and temporal variability. Our first results indicate that benthic nutrient recycling is more intense during summer than during winter, which suggests that biological processes contribute substantially to the recycling of nutrients. The fluxes of reactive nitrogen appear lower than observations from 1992 (Lohse et al. 1993), when riverine N loads were at their maximum (Amann et al. 2012). The comparison of our recent measurements with observations from the past decades will enable us to assess the effect of decreasing nutrient discharge into the coastal North Sea. Our results will further set a baseline for elucidating the impact of the massive installation of wind turbines in the near future. This study contributes to the NOAH project (North Sea; Observation and Assessment of Habitats). References Amann T., A. Weiss, and J. Hartmann (2012): Carbon

  14. High Resolution Quaternary Seismic Stratigraphy of the New York Bight Continental Shelf

    Science.gov (United States)

    Schwab, William C.; Denny, J.F.; Foster, D.S.; Lotto, L.L.; Allison, M.A.; Uchupi, E.; Swift, B.A.; Danforth, W.W.; Thieler, E.R.; Butman, Bradford

    2003-01-01

    A principal focus for the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (marine.usgs.gov) is regional reconnaissance mapping of inner-continental shelf areas, with initial emphasis on heavily used areas of the sea floor near major population centers. The objectives are to develop a detailed regional synthesis of the sea-floor geology in order to provide information for a wide range of management decisions and to form a basis for further investigations of marine geological processes. In 1995, the USGS, in cooperation with the U.S. Army Corps of Engineers (USACOE), New York District, began to generate reconnaissance maps of the continental shelf seaward of the New York - New Jersey metropolitan area. This mapping encompassed the New York Bight inner-continental shelf, one of the most heavily trafficked and exploited coastal regions in the United States. Contiguous areas of the Hudson Shelf Valley, the largest physiographic feature on this segment of the continental shelf, also were mapped as part of a USGS study of contaminated sediments (Buchholtz ten Brink and others, 1994; 1996). The goal of the reconnaissance mapping was to provide a regional synthesis of the sea-floor geology in the New York Bight area, including: (a) a description of sea-floor morphology; (b) a map of sea-floor sedimentary lithotypes; (c) the geometry and structure of the Cretaceous strata and Quaternary deposits; and (d) the geologic history of the region. Pursuing the course of this mapping effort, we obtained sidescan-sonar images of 100 % of the sea floor in the study area. Initial interpretations of these sidescan data were presented by Schwab and others, (1997a, 1997b, 2000a). High-resolution seismic-reflection profiles collected along each sidescan-sonar line used multiple acoustic sources (e.g., watergun, CHIRP, Geopulse). Multibeam swath-bathymetry data also were obtained for a portion of the study area (Butman and others, 1998;). In this report, we present a series

  15. Vertical distribution, composition, and abundance of crustacean zooplankton in the offshore waters of Lake Michigan

    International Nuclear Information System (INIS)

    During 1975, zooplankton samples were collected on eight cruises (April to November) in the southern basin of Lake Michigan. Four stations in the northern basin were also sampled in January during a cruise aboard the USCGC Westwind. One of the goals of this study was to quantitatively estimate the standing crop of herbivorous crustacean zooplankton in units that would represent their functional roles as consumers of phytoplankton

  16. The past and the future of zooplankton diversity studies in China seas

    OpenAIRE

    Zhaoli Xu

    2011-01-01

    China has among the largest latitudinal ranges of any country on Earth. Environmental factors such as diverse climate, hydrology and topography jointly determine levels of marine environmental diversityand therefore patterns in zooplankton diversity in China seas. Studies of zooplankton diversity in China progressed through different stages from a main focus on species taxonomy, diversity of distribution pattern, to a focus on environment influences on the ecological group, and finally a focu...

  17. Zooplankton diversity and abundance of mangrove ecosystem of Kali estuary, Karwar, west coast of India

    OpenAIRE

    Kumar, V; S.V. Roopa; B.K. Gangadhar

    2013-01-01

    The present study conducted at the mangrove ecosystem of Kali estuary. Samples were collected from the three fixed stations for the period of thirteen months from January 2008 to January 2009 at regular monthly interval to identify and quantify the abundance, taxonomy and relative ratio of phytoplankton and zooplankton. In the present study of species diversity of zooplankton groups in the mangrove area, composed of twelve groups comprising fifty two species major share comes from the copepod...

  18. The effects of juvenile American shad planktivory on zooplankton production in Columbia River food webs

    Science.gov (United States)

    Haskell, Craig A.; Tiffan, Kenneth F.; Rondorf, Dennis W.

    2013-01-01

    Columbia River reservoirs support a large population of nonnative American Shad Alosa sapidissima that consume the zooplankton that native fishes also rely on. We hypothesized that the unprecedented biomass of juvenile American Shad in John Day Reservoir is capable of altering the zooplankton community if these fish consume a large portion of the zooplankton production. We derived taxon-specific estimates of zooplankton production using field data and a production model from the literature. Empirical daily ration was estimated for American Shad and expanded to population-level consumption using abundance and biomass data from hydroacoustic surveys. Daphnia spp. production was high in early summer but declined to near zero by September as shad abundance increased. American Shad sequentially consumed Daphnia spp., copepods, and Bosmina spp., which tracked the production trends of these taxa. American Shad evacuation rates ranged from 0.09 to 0.24/h, and daily rations ranged from 0.008 to 0.045 g·g−1·d−1 (dry weight) over all years. We observed peak American Shad biomass (45.2 kg/ha) in 1994, and daily consumption (1.6 kg/ha) approached 30% (5.3 kg/ha) of zooplankton production. On average, American Shad consumed 23.6% of the available zooplankton production (range, zooplankton community are consistent with a top-down effect of planktivory by American Shad associated with their unprecedented biomass and consumption, but the effects are likely constrained by temperature, nutrient flux, and the seasonal production patterns of zooplankton in John Day Reservoir. American Shad add to the planktivory exerted by other species like Neomysis mercedis to reduce the capacity of the reservoir to support other planktivorous fishes. The introduction of American Shad and other nonnative species will continue to alter the food web in John Day Reservoir, potentially affecting native fishes, including Pacific salmon Oncorhynchus spp.

  19. Indicator Properties of Baltic Zooplankton for Classification of Environmental Status within Marine Strategy Framework Directive

    Science.gov (United States)

    Lehtiniemi, Maiju; Postel, Lutz; Rubene, Gunta; Amid, Callis; Lesutiene, Jurate; Uusitalo, Laura; Strake, Solvita; Demereckiene, Natalja

    2016-01-01

    The European Marine Strategy Framework Directive requires the EU Member States to estimate the level of anthropogenic impacts on their marine systems using 11 Descriptors. Assessing food web response to altered habitats is addressed by Descriptor 4 and its indicators, which are being developed for regional seas. However, the development of simple foodweb indicators able to assess the health of ecologically diverse, spatially variable and complex interactions is challenging. Zooplankton is a key element in marine foodwebs and thus comprise an important part of overall ecosystem health. Here, we review work on zooplankton indicator development using long-term data sets across the Baltic Sea and report the main findings. A suite of zooplankton community metrics were evaluated as putative ecological indicators that track community state in relation to Good Environmental Status (GES) criteria with regard to eutrophication and fish feeding conditions in the Baltic Sea. On the basis of an operational definition of GES, we propose mean body mass of zooplankton in the community in combination with zooplankton stock measured as either abundance or biomass to be applicable as an integrated indicator that could be used within the Descriptor 4 in the Baltic Sea. These metrics performed best in predicting zooplankton being in-GES when considering all datasets evaluated. However, some other metrics, such as copepod biomass, the contribution of copepods to the total zooplankton biomass or biomass-based Cladocera: Copepoda ratio, were equally reliable or even superior in certain basin-specific assessments. Our evaluation suggests that in several basins of the Baltic Sea, zooplankton communities currently appear to be out-of-GES, being comprised by smaller zooplankters and having lower total abundance or biomass compared to the communities during the reference conditions; however, the changes in the taxonomic structure underlying these trends vary widely across the sea basins due to

  20. Tidal and diel influence on zooplankton occurrence in the Mandovi estuary, Goa

    OpenAIRE

    Selvakumar, R.A.; Goswami, S.C.; Goswami, U.

    1986-01-01

    Distribution and abundance of zooplankton over the tidal cycle were studied in the Mandovi estuary, Goa, during August and December 1971 and May 1972. Tide induced salinity fluctuations were obvious with high values during spring tides. Salinity was low during August, apparently due to precipitation and land run off but increased subsequently. The mean biomass values for the day and night collections were 13.6 and 19.8 ml/100 m super(3) respectively. Occurrence of most of the zooplankton taxa...

  1. The Impact of Fish Predation and Cyanobacteria on Zooplankton Size Structure in 96 Subtropical Lakes

    OpenAIRE

    Jing Zhang; Ping Xie; Min Tao; Longgen Guo; Jun De Chen; Li Li; Xuezhen Zhang; Lu Zhang

    2013-01-01

    Zooplankton are relatively small in size in the subtropical regions. This characteristic has been attributed to intense predation pressure, high nutrient loading and cyanobacterial biomass. To provide further information on the effect of predation and cyanobacteria on zooplankton size structure, we analyzed data from 96 shallow aquaculture lakes along the Yangtze River. Contrary to former studies, both principal components analysis and multiple regression analysis showed that the mean zooplan...

  2. Linking light and productivity in lakes to zooplankton biodiversity, biomass and resource use efficiency

    OpenAIRE

    2013-01-01

    Introduction: Lake productivity is determined by the amount of nutrients and light available. While phosphorus is the main limiting nutrient in freshwater systems light availability can be reduced by several factors, while the most important one in Scandinavian lakes is the amount of dissolved organic compounds (DOC). Primary productivity can affect zooplankton biomass and diversity by bottom-up driven mechanisms while zooplankton biomass and diversity can also be affected by fish via top-dow...

  3. Climate-induced signatures in the zooplankton communities: a meta-analysis at a European scale.

    OpenAIRE

    Sónia Cotrim Marques; Anda Ikauniece; Catriona Clemmesen; Frederiz Azemar; Ilppo Vuorinen; Myron Peck; Patrick Meire; Ulf Bamstedt; Sami Souissi

    2014-01-01

    Several recent studies have revealed the impacts of the climate variability in the dynamic of zooplankton in different estuarine ecosystems, imposing a need for more and continued global studies. Presently, there is a growing appreciation in international collaborations to compare and contrast estuarine ecosystem response to climate variability across geographical gradients, including long-term changes in zooplankton. We performed a meta-analysis comprising field data from 7 location (Mondego...

  4. Trace metal concentrations in zooplankton from the eastern Arabian Sea and western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; Balachandran, K.K.; Nair, M.; Joseph, T.; DineshKumar, P.K.; Achuthankutty, C.T.; Nair, K.K.C.; Pillai, N.G.K.

    : [Petrisor, Ioana] At: 06:22 9 April 2008 Environmental Forensics, 9:22–32, 2008 Copyright C© Taylor & Francis Group, LLC ISSN: 1527–5922 print / 1527–5930 online DOI: 10.1080/15275920701506193 Trace Metal Concentrations in Zooplankton from the Eastern... to the bioavailability of this metal in the seawater. Keywords: Arabian Sea, Bay of Bengal, zooplankton, trace metals, bioaccumulation Introduction Trace metals in aquatic systems are distributed over different compartments, such as the dissolved state, colloidal state...

  5. Vertical distribution of zooplankton: density dependence and evidence for an ideal free distribution with costs

    OpenAIRE

    Lampert Winfried

    2005-01-01

    Abstract Background In lakes with a deep-water algal maximum, herbivorous zooplankton are faced with a trade-off between high temperature but low food availability in the surface layers and low temperature but sufficient food in deep layers. It has been suggested that zooplankton (Daphnia) faced with this trade-off distribute vertically according to an "Ideal Free Distribution (IFD) with Costs". An experiment has been designed to test the density (competition) dependence of the vertical distr...

  6. Acoustic insights into the zooplankton dynamics of the eastern Weddell Sea

    OpenAIRE

    Cisewski, Boris; Strass, Volker

    2016-01-01

    The success of any efforts to determine the effects of climate change on marine ecosystems depends on understanding in the first instance the natural variations, which contemporarily occur on the interannual and shorter time scales. Here we present results on the environmental controls of zooplankton distribution patterns and behaviour in the eastern Weddell Sea, Southern Ocean. Zooplankton abundance and vertical migration are derived from the mean volume backscattering strength (MVBS) and th...

  7. Zooplankton biomass dynamics in oligotrophic versus eutrophic conditions : a test of the PEG model

    OpenAIRE

    Straile, Dietmar

    2015-01-01

    1. The model of the International Society of Limnology (SIL) Plankton Ecology working group (hereafter the PEG model) is a verbal model describing the patterns and driving factors of seasonal phytoplankton and zooplankton succession in oligotrophic and eutrophic lakes (Sommer et al., 1986). Despite being a citation classic, tests of the PEG model with respect to differences in zooplankton biomass dynamics between oligotrophic and eutrophic lakes are lacking.2. Here, I use the long-term data f...

  8. Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles

    DEFF Research Database (Denmark)

    Le Quéré, Corinne; Buitenhuis, Erik T.; Moriarty, Róisín;

    2016-01-01

    Global ocean biogeochemistry models currently employed in climate change projections use highly simplified representations of pelagic food webs. These food webs do not necessarily include critical pathways by which ecosystems interact with ocean biogeochemistry and climate. Here we present a global...... Ocean zooplankton community, despite iron limitation of phytoplankton community growth rates. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean....

  9. Vertical variability of trophic positions of zooplankton in the deep ocean.

    OpenAIRE

    Bode, A.; Mompeán-de-la-Rosa, M.C. (María del Carmen); Álvarez-Ossorio-Costa, M.T. (María Teresa); Fernández de Puelles, M.L.; Echevarría, F.; González-Gordillo, J.I.; Hernández-León, S.; Irigoien, X.; Acuña, J. L.

    2015-01-01

    presentation and abstract Zooplankton plays a key role in oceanic ecosystems. However, the trophic ecology of organisms in deep layers of the ocean is poorly known. In this study we analyze the variability of trophic positions of zooplankton collected across three ocean basins in the epi-, meso and bathypelagic domains. Stable carbon and nitrogen isotopes were used as indicators of the sources of nutrients and positions within the food web. The enrichment in heavy nitrogen isotopes with de...

  10. Influence Of Wastewater On Zooplankton Community Of The Daugava River After Daugavpils Wastewater Treatment Plant Modernization

    OpenAIRE

    Deksne, Rasma

    2015-01-01

    During seasonal studies 2010 (May-October, once/ thrice a month), samples of zooplankton were collected at the Daugava River section from 10 km upstream to 10 km downstream from the Daugavpils treatment plant wastewater discharge into the Daugava River. Changes in the quantitative and qualitative characteristics, saprobity index and species diversity (Shannon-Wiener index) were employed for the analysis of zooplankton community structure in the Daugava River. The Daugava River is polluted by ...

  11. Predicting zooplankton response to environmental changes in a temperate estuarine ecosystem

    OpenAIRE

    Marques, Sónia; Azeiteiro, Ulisses; Leandro, Sérgio; Queiroga, Henrique; Primo, Ana; Martinho, Filipe; Viegas, Ivan; Pardal, Miguel

    2008-01-01

    Abstract A novel strategy that allows to predict the responses of zooplanktonic species to environmental conditions in an estuarine temperate ecosystem (Mondego estuary) is presented. It uses 12 indicator species from the zooplanktonic Mondego database (102 species) that are common members of the different habitats, characterized by their specific hydrological conditions. Indicator-species analysis (ISA) was used to define and describe which species were typical of each of the five sampling ...

  12. Effect of salinity and fish predation on zooplankton dynamics in Hooghly-Matla estuarine system, India

    OpenAIRE

    Roy, Ujjwal; Sarwardi, S.; N. C. Majee; Ray, Santanu

    2016-01-01

    The Hooghly-Matla estuarine complex is the unique estuarine system of the world. Nutrient from the litterfall enrich the adjacent estuary through tidal influence which in turn regulate the phytoplankton, zooplankton and fish population dynamics. Environmental factors regulate the biotic components of the system, among which salinity plays a leading role in the regulation of phytoplankton, zooplankton and fish dynamics of the estuary. In this article, a $PZF$ model is considered with Holling t...

  13. Intraspecific density dependence in the dynamics of zooplankton under hypertrophic conditions

    OpenAIRE

    Declerck, S.; Geenens, V.; Podoor, N.; Conde Porcuna, J.M.; De Meester, L.

    2003-01-01

    Intraspecific interactions may limit population growth of small cladoceran taxa under food-rich, hypertrophic conditions. Multiple-regression models significantly explained a large proportion of the variation in the body size adjusted fecundity and population growth rate of crustacean zooplankton taxa in a shallow, hypertrophic lake. The results of partial correlation analyses suggested exploitative competition to have only limited significance in determining the zooplankton dynamics. The ana...

  14. Indicator Properties of Baltic Zooplankton for Classification of Environmental Status within Marine Strategy Framework Directive.

    Science.gov (United States)

    Gorokhova, Elena; Lehtiniemi, Maiju; Postel, Lutz; Rubene, Gunta; Amid, Callis; Lesutiene, Jurate; Uusitalo, Laura; Strake, Solvita; Demereckiene, Natalja

    2016-01-01

    The European Marine Strategy Framework Directive requires the EU Member States to estimate the level of anthropogenic impacts on their marine systems using 11 Descriptors. Assessing food web response to altered habitats is addressed by Descriptor 4 and its indicators, which are being developed for regional seas. However, the development of simple foodweb indicators able to assess the health of ecologically diverse, spatially variable and complex interactions is challenging. Zooplankton is a key element in marine foodwebs and thus comprise an important part of overall ecosystem health. Here, we review work on zooplankton indicator development using long-term data sets across the Baltic Sea and report the main findings. A suite of zooplankton community metrics were evaluated as putative ecological indicators that track community state in relation to Good Environmental Status (GES) criteria with regard to eutrophication and fish feeding conditions in the Baltic Sea. On the basis of an operational definition of GES, we propose mean body mass of zooplankton in the community in combination with zooplankton stock measured as either abundance or biomass to be applicable as an integrated indicator that could be used within the Descriptor 4 in the Baltic Sea. These metrics performed best in predicting zooplankton being in-GES when considering all datasets evaluated. However, some other metrics, such as copepod biomass, the contribution of copepods to the total zooplankton biomass or biomass-based Cladocera: Copepoda ratio, were equally reliable or even superior in certain basin-specific assessments. Our evaluation suggests that in several basins of the Baltic Sea, zooplankton communities currently appear to be out-of-GES, being comprised by smaller zooplankters and having lower total abundance or biomass compared to the communities during the reference conditions; however, the changes in the taxonomic structure underlying these trends vary widely across the sea basins due to

  15. Vertical variability of trophic positions of zooplankton in the deep Ocean

    OpenAIRE

    A. Bode; Mompeán-de-la-Rosa, M.C. (María del Carmen); Álvarez-Ossorio-Costa, M.T. (María Teresa); Fernández-de-Puelles, M.L. (María Luz); Echevarria, F. (Fidel); González-Gordillo, J.I.; S. Hernández-León; Irigoien, X.; Acuña, J.L.

    2015-01-01

    Zooplankton plays a key role in oceanic ecosystems. However, the trophic ecology of organisms in deep layers of the ocean is poorly known. In this study we analyze the variability of trophic positions of zooplankton collected across three ocean basins in the epi-, meso and bathypelagic domains. Stable carbon and nitrogen isotopes were used as indicators of the sources of nutrients and positions within the food web. The enrichment in heavy nitrogen isotopes with depth and the co...

  16. Kelimpahan dan Struktur Komunitas Zooplankton di Perairan Pulau Samalona, Kota Makassar, Provinsi Sulawesi Selatan

    OpenAIRE

    Rukminasari, Nita; Thana, Daud; Ilham B., Muhammad

    2012-01-01

    Penelitian ini bertujuan untuk mengetahui kelimpahan dan struktur komunitas zooplankton di perairan Pulau Samalona, Makassar. Hasil penelitian ini diharapkan dapat memberi gambaran tentang kondisi kestabilan komunitas zooplankton di perairan Pulau Samalona saat ini. Penelitian ini dilakukan pada bulan Juni sampai dengan Agustus 2008 di perairan Pulau Samalona, Makassar. Pengambilan sampel dilakukan sebanyak 4 kali dengan interval waktu 2 minggu, berdasarkan fase bulan terang dan bulan gelap. ...

  17. Seasonal Distribution of Zooplankton in Mahanadi Estuary (Odisha), East Coast of India: A Taxonomical Approach

    OpenAIRE

    C. R. Panda; S. Srichandan; N. C. Rout

    2013-01-01

    Study of coastal and estuarine water is important as they act as a medium of exchange of materials between land and ocean. Mahanadi estuarine system forms the largest system of its kind in Odisha. Zooplankton, the secondary producers plays a vital role in the hydrobiology and food chain regulation. The zooplankton diversity of Mahanadi estuary (Odisha) was investigated during postmonsoon (December 2009), premonsoon (April 2010) and monsoon (July 2010). Important hydrographical parameter...

  18. Nonlinear Analysis in a Nutrient-Algae-Zooplankton System with Sinking of Algae

    OpenAIRE

    Chuanjun Dai; Min Zhao

    2014-01-01

    A reaction-diffusion-advection model is proposed for the Zeya Reservoir to study interactions between algae and zooplankton, including the diffusive spread of algae and zooplankton and the sinking of algae. The model is investigated both with and without sinking. Conditions of Hopf and Turing bifurcation in the spatial domain are obtained, and conditions for differential-flow instability that gives rise to the formation of spatial patterns are derived. Using numerical simulation, the authors ...

  19. Zooplankton assemblages in montane lakes and ponds of Mount Rainier National Park, Washington State, USA

    Science.gov (United States)

    Larson, G.L.; Hoffman, R.; McIntire, C.D.; Lienkaemper, G.; Samora, B.

    2009-01-01

    Water quality and zooplankton samples were collected during the ice-free periods between 1988 and 2005 from 103 oligotrophic montane lakes and ponds located in low forest to alpine vegetation zones in Mount Rainier National Park, Washington State, USA. Collectively, 45 rotifer and 44 crustacean taxa were identified. Most of the numerically dominant taxa appeared to have wide niche breadths. The average number of taxa per lake decreased with elevation and generally increased as maximum lake depths increased (especially for rotifers). With one exception, fish presence/absence did not explain the taxonomic compositions of crustacean zooplankton assemblages. Many rotifer species were common members of zooplankton assemblages in montane lakes and ponds in western North America, whereas the crustacean taxa were common to some areas of the west, but not others. Constraints of the environmental variables did not appear to provide strong gradients to separate the distributions of most zooplankton species. This suggests that interspecific competitive interactions and stochastic processes regulate the taxonomic structures of the zooplankton assemblages at the landscape level. Crustacean species that had broad niche breadths were associated with different rotifer taxa across the environmental gradients. Studies of zooplankton assemblages need to address both crustacean and rotifer taxa, not one or the other.

  20. Lake Ontario zooplankton in 2003 and 2008: community changes and vertical redistribution

    Science.gov (United States)

    Rudstam, Lars G.; Holeck, Kristen T.; Bowen, Kelly L.; Watkins, James M.; Weidel, Brian C.; Luckey, Frederick J.

    2014-01-01

    Lake-wide zooplankton surveys are critical for documenting and understanding food web responses to ecosystem change. Surveys in 2003 and 2008 during the binational intensive field year in Lake Ontario found that offshore epilimnetic crustacean zooplankton declined by a factor of 12 (density) and factor of 5 (biomass) in the summer with smaller declines in the fall. These declines coincided with an increase in abundance of Bythotrephes and are likely the result of direct predation by, or behavioral responses to this invasive invertebrate predator. Whole water column zooplankton density also declined from 2003 to 2008 in the summer and fall (factor of 4), but biomass only declined in the fall (factor of 2). The decline in biomass was less than the decline in density because the average size of individual zooplankton increased. This was due to changes in the zooplankton community composition from a cyclopoid/bosminid dominated community in 2003 to a calanoid dominated community in 2008. The increase in calanoid copepods was primarily due to the larger species Limnocalanus macrurus and Leptodiaptomus sicilis. These coldwater species were found in and below the thermocline associated with a deep chlorophyll layer. In 2008, most of the zooplankton biomass resided in or below the thermocline during the day. Increased importance of copepods in deeper, colder water may favor cisco and rainbow smelt over alewife because these species are better adapted to cold temperatures than Alewife.

  1. Terrestrial carbon is a resource, but not a subsidy, for lake zooplankton

    Science.gov (United States)

    Kelly, Patrick T.; Solomon, Christopher T.; Weidel, Brian C.; Jones, Stuart E.

    2014-01-01

    Inputs of terrestrial organic carbon (t-OC) into lakes are often considered a resource subsidy for aquatic consumer production. Although there is evidence that terrestrial carbon can be incorporated into the tissues of aquatic consumers, its ability to enhance consumer production has been debated. Our research aims to evaluate the net effect of t-OC input on zooplankton. We used a survey of zooplankton production and resource use in ten lakes along a naturally occurring gradient of t-OC concentration to address these questions. Total and group-specific zooplankton production was negatively related to t-OC. Residual variation in zooplankton production that was not explained by t-OC was negatively related to terrestrial resource use (allochthony) by zooplankton. These results challenge the designation of terrestrial carbon as a resource subsidy; rather, the negative effect of reduced light penetration on the amount of suitable habitat and the low resource quality of t-OC appear to diminish zooplankton production. Our findings suggest that ongoing continental-scale increases in t-OC concentrations of lakes will likely have negative impacts on the productivity of aquatic food webs.

  2. FORMATION OF BACTERIAL AND ZOOPLANKTON COMPONENT OF NATURAL FOOD BASE UNDER EFFECT OF TRADITIONAL ORGANIC FERTILIZERS

    Directory of Open Access Journals (Sweden)

    S. Krazhan

    2013-12-01

    Full Text Available Purpose. Characterization of bacteria and zooplankton in rearing ponds using traditional fertilizers: cattle manure and bird droppings in modern conditions for fish farming. Methodology. Material collection and processing were carried out according to conventional hydrochemical and hydrobiological methods. Findings. We consider forming of bacteria and zooplankton component of natural food base of Irkliiv herbivorous fish nursery rearing ponds under the influenced of traditional organic fertilizers such as bird droppings (0,12 t/ha and cattle manure (2,0 t/ha. Each pond was planted by ongrowing Nyvka carp larvae (40,0 thousand ind./ha with silver carp (1,0 thousand ind./ha and grass carp larvae (1,0 thousand ind./ha. Qualitative and quantitative development of bacteria and zooplankton in fish-breeding ponds was investigated. The results show that in the development of the studied invertebrate groups of zooplankton in production ponds had no significant differences, except for rotifers, which group prevailed by the biomass to 3,6 times in the pond with the introduction of humus. Originality. The parameters of bacteria and zooplankton by the application of traditional organic fertilizers at present fish farming are studied. Practical value. These quantitative indicators of bacteria and zooplankton of fish-rearing ponds with water supply from Kremenchug reservoir, the application of cattle manure and bird droppings could be offered as an optimum data at present fish production stage.

  3. Predation by jellyfish on large and emergent zooplankton: Implications for benthic pelagic coupling

    Science.gov (United States)

    Pitt, Kylie A.; Clement, Anne-Laure; Connolly, Rod M.; Thibault-Botha, Delphine

    2008-03-01

    Stable carbon isotopes were used to determine the contribution of emergent demersal zooplankton to the diet of the scyphozoan jellyfish Catostylus mosaicus at Smiths Lake, New South Wales, Australia. A preliminary study in 2004 indicated that there was no difference in the δ13C of ectodermal tissue and mesoglea of the medusae. In 2005, medusae and zooplankton present during the day and night were sampled and isotopic signatures were modelled using IsoSource. Modelling indicated that: (1) mollusc veligers and copepods sampled during the day contributed Lucifer sp. contributed 88-94%. We hypothesised, therefore, that medusae derive most of their carbon from emergent species of zooplankton. In 2006, sampling done in 2005 was repeated three times over a period of 4 weeks to measure short-term temporal variation in isotopic signatures of medusae and zooplankton, and emergent demersal zooplankton was specifically sampled using emergence traps. Short-term temporal variation in isotopic signatures was observed for some taxa, however, actual variations were small (Lucifer sp. or mysid shrimp. Small but abundantly captured zooplankton (such as mollusc veligers) contribute only minor amounts of carbon. Jellyfish have a major role in the transfer of carbon between benthic and pelagic food webs in coastal systems.

  4. Biomagnification of PBDEs and PCBs in food webs from the Baltic Sea and the northern Atlantic Ocean

    International Nuclear Information System (INIS)

    Biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) in food webs from the Baltic Sea and the northern Atlantic Sea was investigated. For this, we used PCB and PBDE concentration data, together with data on fish body weight and δ 15N of fish and zooplankton as a measure of trophic position. In the Baltic Sea material, consisting of zooplankton, sprat, herring and salmon, we report biomagnification of all PCB congeners but PCB no. 209 and of PBDEs with 3-6 or 7 bromine atoms. Higher brominated PBDEs and PCB 209 did not biomagnify likely due to their high molecular weights or sizes and subsequent inefficient dietary uptake in fish. If salmon was excluded from the statistical analysis, strong biomagnification of PCB no. 209 was evident, indicating species differences in biomagnification. In the Baltic Sea material δ 15N and body weight covaried. In the Atlantic Sea material, consisting of fish samples (herring and salmon) of larger body sizes, we show positive correlation between concentrations of most PCBs and PBDEs and body weight without increasing δ 15N. This shows that biomagnification in some cases depends on body size and not trophic position. We conclude that there probably is trophic position dependence in biomagnification, which was manifested in a food chain from zooplankton to piscivores, but no further trophic position influence on biomagnification in fish at the highest trophic levels. In these fish, there was a body size effect leading to biomagnification, probably due to slower clearance in larger fish. PCB concentrations were generally between 2 and 6 times higher in Baltic Sea salmon than in Atlantic Sea salmon. Higher PBDE concentrations in the Baltic compared to the Atlantic Sea salmon were also found, but with a larger variation between congeners. Nona- to deca-BDEs were found in most investigated samples, which illustrates the bioavailability of these compounds. Unidentified penta-, hexa-, hepta-, and

  5. On analysing sea level rise in the German Bight since 1844

    Directory of Open Access Journals (Sweden)

    T. Wahl

    2010-02-01

    Full Text Available In this paper, a methodology to analyse observed sea level rise (SLR in the German Bight, the shallow south-eastern part of the North Sea, is presented. The paper focuses on the description of the methods used to generate and analyse mean sea level (MSL time series. Parametric fitting approaches as well as non-parametric data adaptive filters, such as Singular System Analysis (SSA are applied. For padding non-stationary sea level time series, an advanced approach named Monte-Carlo autoregressive padding (MCAP is introduced. This approach allows the specification of uncertainties of the behaviour of smoothed time series near the boundaries. As an example, the paper includes the results from analysing the sea level records of the Cuxhaven tide gauge and the Heligoland tide gauge, both located in the south-eastern North Sea. For comparison, the results from analysing a worldwide sea level reconstruction are also presented. The results for the North Sea point to a weak negative acceleration of SLR since 1844 with a strong positive acceleration at the end of the 19th century, to a period of almost no SLR around the 1970s with subsequent positive acceleration and to high recent rates.

  6. Seasonal patterns of surface wind stress and heat flux over the Southern California Bight

    Science.gov (United States)

    Winant, Clinton D.; Dorman, Clive E.

    1997-03-01

    Patterns of wind stress and heat flux between the atmosphere and the ocean over the Southern California Bight are described based on observations from buoys and ships. During the winter, the wind stress is spatially homogeneous and temporally variable, with strong events corresponding to low-pressure systems sweeping through the area. During the summer, spatial patterns are more persistent, with large gradients. Inshore of a line running approximately between Point Conception and Ensenada, Mexico, winds are weak. Offshore wind speeds are comparable in magnitude to those found over the continental shelf north of Point Conception. The boundary is the location of maximum wind stress curl, and the spatial resolution afforded by California Cooperative Fisheries Investigation (CalCOFI) observations suggests maximum wind stress curls over 3 times larger than the values proposed by Nelson [1977]. Net heat flux estimates derived from the CalCOFI measurements are somewhat larger than the values proposed by Nelson and Husby [1983], due to differences in latent heat flux estimates. Possible mechanisms responsible for the spring-summer spatial structure in the wind and the relationship between these gradients and the properties of the underlying ocean are discussed.

  7. The role of density gradients on tidal asymmetries in the German Bight

    Science.gov (United States)

    Stanev, Emil V.; Al-Nadhairi, Rahma; Valle-Levinson, Arnoldo

    2015-01-01

    The dynamics of the German Bight associated with river plumes and fresh water intrusions from tidal flats have been studied with numerical simulations. The horizontal and vertical patterns of the M2, M4 and M6 tides revealed complex distortions along the bathymetric channels connecting the coast and the open sea. A major focus was on the surface-to-bottom change in tidal asymmetries, which provides a major control on draining the tidal flats around the Elbe and Weser River mouths. Comparisons between baroclinic and barotropic experiments demonstrated that the estuarine gravitational circulation is responsible for pronounced differences in surface and bottom asymmetries. These differences could be considered as a basic control mechanism for sediment dynamics. The most prominent area of tidal distortions, manifested by a delay of the tidal wave, was located between the estuarine turbidity maximum and the estuarine mouth north of Cuxhaven. This area was characterized by the strongest periodic convergence and divergence of the flow and by the largest salinity gradients. The enhancement of the gravitational circulation occurred during the transition between spring and neap tides. The large-scale dynamics and small-scale topographic features could impact the sediment distribution as there was a marked interplay in the channels between stratification and turbulence. Also an explanation has been given for the mechanisms supporting the existence of a mud area ( Schlickgebiet) south of Helgoland Island, associated with trapping suspended particular matter.

  8. Newly Digitized Historical Climate Data of the German Bight and the Southern Baltic Sea Coasts

    Science.gov (United States)

    Röhrbein, Dörte; Tinz, Birger; von Storch, Hans

    2015-04-01

    The detection of historical climate information plays an important role with regard to the discussion on climate change, particularly on storminess. The German Meteorological Service houses huge archives of historical handwritten journals of weather observations. A considerable number of original observation sheets from stations along the coast of the German Bight and the southern Baltic Sea exists which has been until recently almost unnoticed. These stations are called signal stations and are positioned close to the shore. However, for this region meteorological observation data of 128 stations exist from 1877 to 1999 and are partly digitized. In this study we show an analysis of firstly newly digitized wind and surface air pressure data of 15 stations from 1877 to 1939 and we also present a case study of the storm surge at the coast of the southern Baltic Sea in December 1913. The data are quality controlled by formal, climatological, temporal and consistency checks. It is shown that these historical climate data are usable in consistency and quality for further investigations on climate change, e.g. as input for regional and global reanalysis.

  9. RNA-Based Assessment of Diversity and Composition of Active Archaeal Communities in the German Bight

    Directory of Open Access Journals (Sweden)

    Bernd Wemheuer

    2012-01-01

    Full Text Available Archaea play an important role in various biogeochemical cycles. They are known extremophiles inhabiting environments such as thermal springs or hydrothermal vents. Recent studies have revealed a significant abundance of Archaea in moderate environments, for example, temperate sea water. Nevertheless, the composition and ecosystem function of these marine archaeal communities is largely unknown. To assess diversity and composition of active archaeal communities in the German Bight, seven marine water samples were taken and studied by RNA-based analysis of ribosomal 16S rRNA. For this purpose, total RNA was extracted from the samples and converted to cDNA. Archaeal community structures were investigated by pyrosequencing-based analysis of 16S rRNA amplicons generated from cDNA. To our knowledge, this is the first study combining next-generation sequencing and metatranscriptomics to study archaeal communities in marine habitats. The pyrosequencing-derived dataset comprised 62,045 archaeal 16S rRNA sequences. We identified Halobacteria as the predominant archaeal group across all samples with increased abundance in algal blooms. Thermoplasmatales (Euryarchaeota and the Marine Group I (Thaumarchaeota were identified in minor abundances. It is indicated that archaeal community patterns were influenced by environmental conditions.

  10. North Atlantic Temperature Anomaly

    OpenAIRE

    Vukcevic, M.A.

    2009-01-01

    The author postulates the existence of a high correlation between North Atlantic Temperature Anomaly and the variations of magnetic field over the Hudson Bay region. Post-glacial uplift and convection in the underlying mantle uplift (as reflected in changes of the area's magnetic intensity) are making significant contribution to the Atlantic basin climate change.

  11. Zooplankton Responses In A Tropical System With Environmental Stress

    Directory of Open Access Journals (Sweden)

    Nelson Javier Aranguren Riaño

    2014-03-01

    Full Text Available Processes of environmental transformation that currently occur in the climatic change context generate changes in ecosystems and biological communities. ¿How populations respond to these stressors? ¿what effects could occur on taxonomic and ecological diversity? The taxonomic composition and structure of the zooplankton was analyzed with relationship to environmental changes in a tropical water reservoir located at 6º02`18``N and 73º29`16`` W. During four months, samples were taken weekly covering stations of low, medium, and high precipitation. A high degree of temporal variability was established, it associated with a short hydraulic retention time estimated at 8 days.  Nine species were collected, of which Keratella tropica tropica and Thermocyclops decipiens were the two most abundant and constant species. Found values of H’ diversity and S richness were considered low, corresponding to a little mature community associated with a fluctuating physical environment and supported by high variation coefficients of electrical conductivity and Sechhi disk transparency. Drastic variations on the system volume in short time lapses generate important changes in the physical expression of system with a direct effect on composition and structure of the zooplankton. In general, the response model of the zooplankton in the reservoir according to the statement by the intermediate disturbance hypothesis.  RESPUESTAS DEL ZOOPLANCTON EN UN SISTEMA TROPICAL CON ALTA TENSIÓN AMBIENTAL Los procesos de transformación ambiental que se dan en la actualidad, en un marco de cambio climático, generan modificaciones en los ecosistemas y comunidades biológicas, ¿Cómo responden las poblaciones a estos factores de tensión? ¿Qué efectos se darían sobre la diversidad taxonómica y ecológica? Se analizó la variación de la composición taxonómica y estructura del zooplancton en función de los cambios ambientales en un reservorio tropical ubicado a 6º

  12. Marine zooplankton studies in Brazil: a brief evaluation and perspectives

    Directory of Open Access Journals (Sweden)

    Rubens M. Lopes

    2007-09-01

    Full Text Available Marine zooplankton research in Brazil has been primarily descriptive, with most studies focusing on community structure analysis and related issues. The composition and spatial distribution of several taxonomic groups are currently well known, although less-abundant and small-sized taxa as well as initial stages of almost all species have received little attention. Some numerically important taxa such as heterotrophic protists, ctenophores, acoel turbellarians and ostracods remain virtually unstudied. Large sectors of the continental shelf have not been sampled in detail, particularly those areas influenced by the North Brazil Current (5ºN-15ºS. Zooplankton abundance and biomass in offshore waters have seldom been quantified, and information on the distribution and vertical migration of meso- and bathypelagic species are lacking. Additional faunistic assessments must target those less-studied taxa and geographical locations. However, priority in ecological studies should be given to process-oriented investigations aimed at understanding the mechanisms controlling zooplankton distribution, trophic interactions within pelagic food webs and production cycles in relation to the physical environment. An effort should be made to incorporate state-of-the-art sampling technology and analytical methods into future research projects.As pesquisas sobre o zooplâncton marinho no Brasil têm sido primariamente descritivas, com a maioria dos estudos enfocando a análise da estrutura da comunidade e assuntos relacionados. A composição e a distribuição espacial de muitos grupos taxonômicos encontram-se bem estudadas, embora os táxons menos abundantes e de menores dimensões, assimcomo os estágios iniciais do ciclo de vida da maioria das espécies, tenham recebido pouca atenção. Alguns táxons numericamenteimportantes encontram-se pouco estudados, como no caso dos protistas heterotróficos, ctenóforos, turbelários acelos e ostrácodes. Amplos

  13. The impact of environmental variability on Atlantic mackerel Scomber scombrus larval abundance to the west of the British Isles

    DEFF Research Database (Denmark)

    Pitois, Sophie G.; Jansen, Teunis; Pinnegar, John

    2015-01-01

    abundances of zooplankton and the larger phytoplankton groups, to a system characterized by higher temperature, lower salinities, lower abundances of zooplankton and larger phytoplankton and higher abundances of the small phytoplankton species. Analysis revealed a very weak positive correlation between......The value of the Continuous Plankton Recorder (CPR) fish larvae dataset, with its extensive spatiotemporal coverage, has been recently demonstrated with studies on long-term changes over decadal scales in the abundance and distribution of fish larvae in relation to physical and biological factors...... the Second principal component and mackerel larvae yearly abundance, attributed to the North Atlantic Oscillation (NAO). The results presented here are in broad accord with recent investigations that link climatic variability and dynamics of mackerel reproduction. However, the growing body of literature...

  14. The Spatial Structure of Zooplankton Communities of Pedu Reservoir,Malaysia%The Spatial Structure of Zooplankton Communities of Pedu Reservoir, Malaysia

    Institute of Scientific and Technical Information of China (English)

    Amir Shah Ruddin Md Shah; Johan Ismail; Diana Latief; Wan Maznah Wan Omar

    2012-01-01

    A total of 22 species of zooplankton were identified from 8 sampling stations located in the limnetic zone of Pedu reservoir.The zooplankton community was dominated by rotifers (11 species),followed by cladocerans (9species) and copepods (2 species).Four species of zooplankton comprised of 3 rotifers,Brachionus quadridentata,Brachionus caudatus and Keratella cochlearis and one cladoceran,Ceriodaphnia cornuta were present at all sampling stations.Species richness was highest at Station 2 (17 species) followed by Station 4 and Station 8 (14 species),Station 5 (15 species),Station 7 (11 species),Station 6 (10 species),Station 3 (9 species) and Station 1 (7 species).With an exception of water transparency,all other water quality parameters such as temperature,dissolved oxygen,conductivity,pH and total dissolved solids were not significant when compared between sampling stations.The study found that station 5 which was located in a calm strait,protected from strong wave and wind was a suitable area for zooplankton growth and establishment.Factors supporting the findings included highest water transparency (3.4 m),rich in species numbers (15 species),high diversity index (0.950) and evenness index (0.808).

  15. Zooplankton of an urban coastal lagoon: composition and association with environmental factors and summer fish kill

    Directory of Open Access Journals (Sweden)

    Leonardo C. e Souza

    2011-06-01

    Full Text Available Zooplankton may be regarded as a sensitive tool for monitoring environmental variations in coastal lagoons due to their ability to immediately react to changes in the water column trophic features and salinity levels. As a coastal lagoon with a broad history of anthropic influence, Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil is widely used for water sports and artisanal fishing. The present study aimed to expand the knowledge base about zooplankton in the Rodrigo de Freitas Lagoon by assessing the composition and time-spatial distribution of the major zooplankton groups. Samples were collected fortnightly from at four distinct sampling points August 2001 to July 2002. At each point, salinity, temperature, dissolved oxygen and water transparency were measured. During the study period, the lagoon behaved as an spatially homogeneous environment in what regards the abiotic variables. However, all these variables showed significant differences along the time, mainly related to seasonality (air temperature and rainy and dry periods. The zooplankton community showed low taxonomic richness, with the predominance of species commonly found in coastal lagoons, especially with mesohaline conditions, as well as those found in estuaries. An interesting fact was the rise in zooplankton abundance at all sampling points right after a fish kill event. Such increase was caused mainly by the Brachionus plicatilis O.F. Müller 1786 species. Thus, the zooplankton community was affected by physical and chemical factors, mainly by the dissolved oxygen decline event and variations in the influx of seawater into the lagoon. In addition, phytoplankton availability and fish predation pressure were suggested as important regulating factors of the zooplankton community.

  16. Environmental assessment of spatial distribution of zooplankton community in Lake Manzalah, Egypt

    Directory of Open Access Journals (Sweden)

    Howaida Yehia ZAKARIA

    2007-12-01

    Full Text Available Lake Manzalah is the largest of the four Nile Delta lakes in Egypt. It provides more than 50% of the total inland fisheries of the country. During the last two decades the Lake has been exposed to multiple changes mainly due to local human activities. Monthly zooplankton samples were collected during an integrated environmental monitoring program within the MELMARINA Project that extended from July 2003 to September 2004 to study the distribution and occurrence of zooplankton community in Lake Manzalah. Results showed that, the average zooplankton standing crop was 1277 x 103 individuals m-3 . Spring was the most productive season (2127 x 103 individuals m-3 representing 41.65% to the total zooplankton counts. Five groups dominated zooplankton community; Rotifera, Copepoda, Ostracoda, Protozoa and Cladocera. The meroplanktonic larvae of Polychaeta, Cirripedia, Mysidacea and Gastropoda as well as free living nematods were rarely recorded. Rotifera contributed 81.89% to the total zooplankton community. They were represented by 38 species belonging to 19 genera dominated by genus Brachionus (86.65% of the total Rotifera followed by genus Keratella (8.68%. Keratella species has been indicated as an indicator of pollution. Copepoda (including their larval stages was the second group in order of abundance forming about 14.28% of the total zooplankton counts and represented by seven species. Acanthocyclops americanus was the dominant species. The productivity of Lake Manzalah decreased from 1979 to become highly eutrophic lake during the present study, but with higher production than the other Egyptian lakes. Management is needed to stabilize the Manzalah lake ecosystem in a way that promotes the sustainability of the system.

  17. Seasonal Distribution of Zooplankton in Mahanadi Estuary (Odisha, East Coast of India: A Taxonomical Approach

    Directory of Open Access Journals (Sweden)

    C. R. Panda

    2013-01-01

    Full Text Available Study of coastal and estuarine water is important as they act as a medium of exchange of materials between land and ocean. Mahanadi estuarine system forms the largest system of its kind in Odisha. Zooplankton, the secondary producers plays a vital role in the hydrobiology and food chain regulation. The zooplankton diversity of Mahanadi estuary (Odisha was investigated during postmonsoon (December 2009, premonsoon (April 2010 and monsoon (July 2010. Important hydrographical parameters such as water temperature, salinity, pH and dissolved oxygen, NO2 (nitrite, NO3 (nitrate, NH4 (ammonia, TN (total nitrogen, PO4 (phosphate, TP (total phosphorous and SiO4 (silicate were measured during the present study along with the study of the qualitative and quantitative aspects of zooplankton. Zooplankton population dominated by copepod at all the stations in all the seasons except during low tide of premonsoon season where caridean larvae were dominant. In total, 86 species of zooplankton, mostly belonging to Crustacea, Chaetognatha, Mollusca, Polychaeta, Cnidaria, Ctenophora, Protozoa, Larvacea among the holoplankton and 16 different types of larval forms were encountered. The population density ranged from 52 to 885 org. m-3 with highest density during high tide of post-monsoon i.e., 885 org. m-3. The copepods like Subeucalanus mucronatus, Subeucalanus subcrassus, Sapphirina maculosa, Sapphirina auronitens are recorded for the first time from marine and estuarine ecosystem of Odisha. Presence of 16 different crustacean dominated larval forms signifies the conduciveness of estuary during the whole period for breeding and spawning of shell fishes in the estuary. During the present study, zooplankton population density was positively related with zooplankton biomass.

  18. Parasitic chytrids sustain zooplankton growth during inedible algal bloom.

    Science.gov (United States)

    Rasconi, Serena; Grami, Boutheina; Niquil, Nathalie; Jobard, Marlène; Sime-Ngando, Télesphore

    2014-01-01

    This study assesses the quantitative impact of parasitic chytrids on the planktonic food web of two contrasting freshwater lakes during different algal bloom situations. Carbon-based food web models were used to investigate the effects of chytrids during the spring diatom bloom in Lake Pavin (oligo-mesotrophic) and the autumn cyanobacteria bloom in Lake Aydat (eutrophic). Linear inverse modeling was employed to estimate undetermined flows in both lakes. The Monte Carlo Markov chain linear inverse modeling procedure provided estimates of the ranges of model-derived fluxes. Model results confirm recent theories on the impact of parasites on food web function through grazers and recyclers. During blooms of "inedible" algae (unexploited by planktonic herbivores), the epidemic growth of chytrids channeled 19-20% of the primary production in both lakes through the production of grazer exploitable zoospores. The parasitic throughput represented 50% and 57% of the zooplankton diet, respectively, in the oligo-mesotrophic and in the eutrophic lakes. Parasites also affected ecological network properties such as longer carbon path lengths and loop strength, and contributed to increase the stability of the aquatic food web, notably in the oligo-mesotrophic Lake Pavin. PMID:24904543

  19. Zooplankton diversity across three Red Sea reefs using pyrosequencing

    KAUST Repository

    Pearman, John K.

    2014-07-30

    Coral reefs are considered among the most diverse ecosystems on Earth, yet little is known about the diversity of plankton in the surrounding water column. Moreover, few studies have utilized genomic methods to investigate zooplankton diversity in any habitat. This study investigated the diversity of taxa by sampling 45 stations around three reef systems in the central/southern Red Sea. The diversity of metazoan plankton was investigated by targeting the 18S rRNA gene and clustering OTUs at 97% sequence similarity. A total of 754 and 854 metazoan OTUs were observed in the data set for the 1380F and 1389F primer sets respectively. The phylum Arthropoda dominated both primer sets accounting for ~60% of reads followed by Cnidaria (~20%). Only about 20% of OTUs were shared between all three reef systems and the relation between geographic distance and Jaccard Similarity measures was not significant. Cluster analysis showed that there was no distinct split between reefs and stations from different reefs clustered together both for metazoans as a whole and for the phyla Arthropoda, Cnidaria and Chordata separately. This suggests that distance may not be a determining factor in the taxonomic composition of stations.

  20. Zooplankton of Lake Orta after liming: an eleven years study

    Directory of Open Access Journals (Sweden)

    Andrea PASTERIS

    2001-02-01

    Full Text Available Lake Orta (N. Italy was severely polluted from 1927 by an effluent from a rayon factory, which discharged great amounts of ammonium nitrogen and copper into the lake. In the mid nineteen fifties, some plating factories also started dumping chromium and aluminum. As a result of ammonium oxidation, the lake became very acid and the concentration of metals in the waters reached very high values. Phytoplankton, zooplankton and fish disappeared suddenly from the lake which was by 1930 classified as “sterile”. Later on, about the fifties, a small population of Cyclops abyssorum re-colonised the lake together with some rotifers, in particular Hexarthra fennica. In mid eighties following the introduction of anti-pollution legislation, ammonium loads were greatly reduced and Daphnia obtusa was recorded. The lake waters however were still very acid, prompting the proposal of the Istituto Italiano di Idrobiologia to lime the lake with calcium carbonate to neutralise the excess acidity and reconstruct the alkaline reserve. This was done successfully from May 1989 to June 1990. pH values began to rise and in the same time the metal concentrations decreased, so that at present the lake waters are almost “normal”. In the meantime, due to the increased pH values, D. obtusa was replaced by D. longispina and, as toxic metal concentrations became lower, Megacyclops viridis, Bosmina longirostris, Diaphanosoma brachyurum, Keratella quadrata, Asplanchna priodonta. and other Brachionidae species appeared. Diaptomidae are still absent, except for some specimens of Arctodiaptomus wierzejskii.

  1. Parasitic Chytrids sustain zooplankton growth during inedible algal bloom

    Directory of Open Access Journals (Sweden)

    SerenaRasconi

    2014-05-01

    Full Text Available This study assesses the quantitative impact of parasitic chytrids on the planktonic food web of two contrasting freshwater lakes during different algal bloom situations. Carbon-based food web models were used to investigate the effects of chytrids during the spring diatom bloom of Lake Pavin (oligo-mesotrophic and the autumn cyanobacteria bloom of Lake Aydat (eutrophic. Linear inverse modelling was employed to estimate undetermined flows in both lakes. The Monte Carlo Markov chain linear inverse modelling procedure provided estimates of the ranges of model-derived fluxes. Model results confirm recent theories on the probable impact of parasites on food web function as grazers and recyclers. During blooms of “inedible” algae (unexploited by planktonic herbivores, the epidemic growth of chytrids channelled 19-20% of the primary production in both lakes through the production of grazer-exploitable zoospores. The parasitic throughput represents 50 and 57% of the zooplankton diet respectively in the oligo-mesotrophic and in the eutrophic lakes. Parasites also affected ecological network properties as longer carbon path lengths and loop strength, and contributed to increase the stability of the aquatic food web, notably in the oligo-mesotrophic Lake Pavin.# The first two authors contributed equally to this work

  2. Zooplankton diversity across three Red Sea reefs using pyrosequencing

    Directory of Open Access Journals (Sweden)

    John Kenneth Pearman

    2014-07-01

    Full Text Available Coral reefs are considered among the most diverse ecosystems on Earth, yet little is known about the diversity of plankton in the surrounding water column. Moreover, few studies have utilised genomic methods to investigate zooplankton diversity in any habitat. This study investigated the diversity of taxa by sampling 45 stations around three reef systems in the central/southern Red Sea. The diversity of metazoan plankton was investigated by targeting the 18S rRNA gene and clustering OTUs at 97% sequence similarity. A total of 754 and 854 metazoan OTUs were observed in the data set for the 1380F and 1389F primer sets respectively. The phylum Arthropoda dominated both primer sets accounting for ~60% of reads followed by Cnidaria (~ 20%. Only about 20% of OTUs were shared between all three reef systems and the relation between geographic distance and Jaccard Similarity measures was not significant. Cluster analysis showed that there was no distinct split between reefs and stations from different reefs clustered together both for metazoans as a whole and for the phyla Arthropoda, Cnidaria and Chordata separately. This suggests that distance may not be a determining factor in the taxonomic composition of stations.

  3. Fluorescence of dissolved organic matter: A comparison of north Pacific and north Atlantic Oceans during April 1991

    Science.gov (United States)

    Hoge, Frank E.; Swift, Robert N.; Yungel, James K.; Vodacek, Anthony

    1993-01-01

    Profiles of airborne-laser-induced fluorescence emission from dissolved organic matter in the upper ocean have been produced and compared for the Southern California Bight (SCB) and the Mid-Atlantic Bight (MAB). Findings were as follows. (1) The fluorescent components of dissolved organic matter (FDOM) are present in easily measurable quantities from near shore to well over 300 km offshore in the SCB and are likewise easily measurable in the coastal, shelf, slope, and Gulf Stream waters of the MAB. (2) The reange of FDOM in the MAB is considerably greater than that in the SCB. (3) The lowest FDOM levels observed in the SCB were higher than those found in the Gulf Stream. (4) The onshore-to-offshore spatial gradient of the FDOM was found to be considerably lower in the SCB than in the MAB, with the highest levels of FDOM being found immediately adjacent to the coast in the MAB. This suggests that the water adjacent to the SCB shoreline is not as strongly influenced by terrestrial and estuarine sources of FDOM as the MAB is. (5) The spatial distribution of the FDOM within both the SCB and the MAB is frequently coherent with the spatial distribution of chlorophyll determined form the concurrent airborne- laser- induced phytoplankton pigment fluorescence measurements. However, distinct noncoherency is sometimes observed, especially at water mass boundaries.

  4. Analysis of the upscaling problem - A case study for the barotropic dynamics in the North Sea and the German Bight

    Science.gov (United States)

    Schulz-Stellenfleth, J.; Stanev, E. V.

    2016-04-01

    The upscaling problem is investigated using the barotropic dynamics of the North Sea and the German Bight as an example. The impact of small scale perturbations of bathymetry, bottom roughness, wind forcing, and boundary forcing is quantified using a two-dimensional linear barotropic model for the entire North Sea with 5 km resolution. The model is solved in the spectral domain for the dominant M2 tide. Comparisons with results from a fully nonlinear 3D circulation model show that the main circulation features are well captured by the spectral model. The impact of different types of perturbations is estimated by inversion of the model using the perturbation covariance matrix as input. Case studies with white noise and fully correlated noise are presented. It is shown that the German Bight area stands out in its sensitivity with respect to small scale uncertainties of bathymetry. Small scale changes of bottom roughness have a particularly strong effect in the English Channel. Small scale wind perturbations have a significant local effect only in very shallow near coastal areas. It is shown that uncorrelated noise introduced along an open boundary around the German Bight only has a very local effect. Perturbations with long correlation length are shown to lead to significant far field effects along the east coast of England. It is demonstrated that this effect is related to the boundary conditions used for the North Sea model. In a next step a German Bight grid with 1 km resolution is nested into the North Sea grid and the spectral model is solved in a two way nested configuration. It is shown that there are some significant local and far field effects caused by the change of resolution in this coastal area. Finally, the potential impact of observations taken in coastal areas is investigated by evaluating the Kalman a posteriori distribution of analysis vectors based on different assumptions about model errors. The area of influence of a single tide gauge is

  5. Drifter Observations Of Wave-Current Evolution Through The San Francisco Bight

    Science.gov (United States)

    Pearman, D. W.; Herbers, T. H.; Janssen, T. T.; McIntyre, S.; Jessen, P.

    2012-12-01

    Ocean waves approaching the Golden Gate, the narrow strait connecting the San Francisco Bay to the Pacific Ocean, are affected by refraction over the San Francisco Bar and the strong tidal currents in the area. During ebb tides, when currents through the Golden Gate can exceed 2.5 m/s, the approach to San Francisco Bay is characterized by focusing and steepening of the incident wave field on the opposing current jet. These dynamics are not uncommon in coastal inlets and are known to present hazardous navigation conditions. The strong inhomogeneity and enhanced nonlinearity of the waves can result in deviations from non-Gaussian statistics and changes in the likelihood of extreme waves. However, since observations of wave-current dynamics are so difficult to make with conventional instruments, these dynamics remain still poorly understood. In this work we present the development and testing of a compact, low-cost, Wave-Resolving Drifter (WRD), designed to resolve the wave orbital surface motions and surface drifts in high-energy areas. The WRDs consist of a 30cm buoy equipped with an off-the-shelf GPS receiver and a three-axis accelerometer. The combined GPS-accelerometer package is functionally equivalent to a conventional pitch-roll (or PUV) wave height and direction instrument, but at a fraction of the price. In our presentation we will discuss results from several WRD array deployments in the San Francisco Bight during high-energy conditions with strong ebb currents. The buoys are shown to resolve the surface waves and surface drift with remarkable accuracy and allow the analysis of the evolution of the wave group structure over the opposing current. To obtain statistical results for currents and waves, WRDs were released in clusters (ensemble) from which shoaling effects over the bar and wave-current interaction can be identified.

  6. Seasonal dynamics and grazing rate of zooplankton in Yueqing Bay,China

    Institute of Scientific and Technical Information of China (English)

    LIU Zhensheng; WANG Chunsheng; ZHANG Zhinan; CAI Yuming; ZHANG Dongsheng

    2006-01-01

    The species composition,biomass,abundance,and species diversity of zooplankton were determined for samples collected from August 2002 to May 2003 from 14 stations in Yueqing Bay,China.Phytoplankton growth rate and microzooplankton grazing rate were obtained by using the dilution method developed by Landry and Hassett.The spatial and temporal variations of zooplankton and its relationship with environmental factors were also analyzed.The results showed that the zooplankton in the Yueqing Bay could be divided into four ecotypes,namely coastal low saline species,estuary brackish water species,offshore warm water species,and eurytopic species.A total of 75 species of zooplankton belonging to 56 genera and 17 groups of pelagic larva were identified in the Yueqing Bay.The coastal low saline species was the dominant ecotype in the study area,and the dominant species were Labidocera euchaeta,Acartia pacifica,Acrocalanus gibber,Pseudeuphausia sinica,and Sagitta bedoti among others.There was considerable seasonal variation in zooplankton biomass and abundance in the surveyed areas.The peak biomass appeared in August,descending in November and in May,and the lowest biomass appeared in February.Similarly,the highest abundance of zooplankton was observed in August,with the abundance descending in the following months:May,November,and February.There were similar horizontal distribution patterns for the biomass and the abundance of zooplankton.They both increased from the upper to the lower bay in February and May,but decreased from the upper to the lower bay in August.Biomass and abundance were evenly distributed in the Yueqing Bay in November.Moreover,there was marked seasonal variation in the species diversity of zooplankton,which conformed to the abundance of zooplankton.Results of the dilution experiments indicated that there was grazing pressure of microzooplankton on phytoplankton in the Yueqing Bay throughout the year though the rate of microzooplankton grazing on

  7. Zooplankton characterisation of Pampean saline shallow lakes, habitat of the Andean flamingoes

    Directory of Open Access Journals (Sweden)

    Yamila S. Battauz

    2013-10-01

    Full Text Available The lowland saline shallow lakes in the Pampa de las Lagunas (Argentina, constitute an important habitat for flamingoes Phoenicopterus chilensis Molina and Phoenicoparrus andinus (Philippii. Little is known about the zooplankton communities of these systems, and their relationships with the temporal and spatial distribution of flamingoes. Ten shallow lakes in the Pampean region were studied in 2009 and 2010 winters, and in 2010 summer in order to assess the abundance, size and biomass of zooplankton and the density of flamingoes populations. Zooplankton was represented by 28 species. Copepods and cladocerans were dominant when salinity was lower (winter and summer of 2010. Seasonal changes were recorded in composition and mean abundance of zooplankton. Significant differences were  observed in mean size of zooplankton showing a negative relationship with the abundance of P. chilensis, which can be interpreted as a consequence of the selective flamingoes zooplanktophagy feeding upon the largest members of this community. Other community parameters, such as abundance, biomass, diversity and composition, did not show an apparent direct relationship with the presence or abundance of flamingoes.

  8. Diurnal Changes of Zooplankton Community Reduction Rate at Lake Outlets and Related Environmental Factors

    Science.gov (United States)

    Czerniawski, Robert; Sługocki, Łukasz

    2016-01-01

    The reduced zooplankton abundance at the outlet sections of lakes depends on the occurrence of preying fry. Therefore, light conditions can play a major role in the drift of zooplankton along river outlets. The aim of this study was to determine the influence of diurnal light conditions on the decline of zooplankton densities at lake outlets. Photosynthetically active radiation (PAR) levels were measured to determine their effect on the rate of reduced zooplankton abundance. Cladocerans and copepods showed a significantly greater reduction in abundance than rotifers and nauplii. A significant positive relationship was observed between the PAR levels and the reduced abundance of Asplanchna sp., small cladocerans, large cladocerans and Copepoda at the lake outlets. Among the rotifers, small pelagic rotifers drifted the farthest at all hours of the day. Large crustaceans, especially the large cladocerans and copepodites and adult copepods, had the lowest chance of dispersing over a wide area. Our results indicate that light conditions play an important role in the reduction of zooplankton abundance at lake outlets and have an indirect influence on the downstream food web. PMID:27392017

  9. Zooplankton diversity and distribution in a deep and anoxic Mediterranean coastal lake

    Directory of Open Access Journals (Sweden)

    G. KEHAYIAS

    2013-04-01

    Full Text Available The variation of the smaller size fraction of zooplankton was investigated during a two-year period in a brackish deep and anoxic coastal lake of western Greece (Aitoliko, along with the specific environmental characteristics of this ecosystem. The zooplanktonic community comprised a relatively small number of taxa and it was dominated by brackish-water calanoid copepods (Paracartia latisetosa, Calanipeda aquaedulcis and in certain periods by rotifers and tintinnids. The zooplankton abundance showed an increase in the warmer period starting from late spring and reached maximum values in July. In the well oxygenated surface layer, temperature was the most important parameter influencing the seasonal cycles of all groups. In contrast, the oxygen depletion a few meters under the surface affected the vertical distribution of most of the zooplankton groups, which were found restricted in the surface layer especially from spring until autumn. Only the meroplanktonic larvae of polychaetes presented increased proportions in the deeper layers. Salinity has not significantly influenced the zooplanktonic assemblages. The results point out the degraded status of the Aitoliko basin where the hypoxic/anoxic layers resulted to a high portion of dead organic material identified as copepod carcasses, and underlines the necessity of monitoring of this ecosystem.

  10. The relation between distribution of zooplankton and salinity in the Changjiang Estuary

    Institute of Scientific and Technical Information of China (English)

    GAO Qian; XU Zhaoli; ZHUANG Ping

    2008-01-01

    Seasonal netzplankton samples from stations in the Changjiang (Yangtze River) Estuary were collected from May,2004 to February,2005.The dominant species and their contribution to the total zooplankton abundance were determined.Moreover,the relationship between the salinity and abundance was studied with stepwise linear regression.During the whole year,the salinity was positively correlated with the abundance,while the temperature,negatively.Linear regression analysis showed also a high positive correlation with salinity for total abundance in August and November,while in February and May,no obvious relations were found.The most abundant community was composed of neritic and brackish-water species.The North Passage (NP) (salinity<5) was greatly diluted by freshwater while the North Branch (NB) was brackish water with salinity range of 12-28.Consequently,clear decline in abundance of zooplankton was along the estuarine haloclines from the maximum in the area of high salinity to the minimum in the limnetic zone.Total zooplankton abundance and biomass were lower in NP than the NB in all seasons.In short,the salinity influenced the abundance of each species of zooplankton,and ultimately determined the total abundance of zooplankton.Furthermore,a winter peak in the abundance existed,which might be caused by the flourishing of Sinocalanus sinensis,a widely distributed species in the Changjiang Estuary.

  11. Vertical distribution of zooplankton in the epipelagic zone off Sharm El-Sheikh, Red Sea, Egypt

    Directory of Open Access Journals (Sweden)

    Mahnoud Hassan Hanafi

    2012-06-01

    Full Text Available The purpose of the present study was to track the seasonal vertical distribution of zooplankton abundance in the epipelagic zone off Sharm El-Sheikh, Red Sea. Zooplankton samples were collected seasonally within the depth ranges of 0-25, 25-50, 50-75, 75-100 m at a single station off Sharm El-Sheikh City. The present study is a trial to expand knowledge about the structure as well as the vertical distribution of the epipelagic zooplankton community in the Gulf of Aqaba in general and in its southern part in particular. The results indicate the occurrence of 52 copepod species and several species of other planktonic groups in the study area; the zooplankton standing crop fluctuated between 1124 and 4952 organisms m-3. Copepods appeared to be the predominant component, forming an average of 86.5% of the total zooplankton count, and with other groups demonstrated a markedly different seasonal vertical distribution. Twelve bathypelagic copepod species were reported during the present study, and five species were new to the area, having migrated northwards from the main basin of the Red Sea.

  12. Eclipse effects on field crops and marine zooplankton: the 29 March 2006 total solar eclipse

    Directory of Open Access Journals (Sweden)

    G. Economou

    2008-08-01

    Full Text Available Some effects in the biosphere from the Total Solar Eclipse of 29 March 2006 were investigated in field crops and marine zooplankton. Taking into account the decisive role of light on plant life and productivity, measurements of photosynthesis and stomatal behaviour were conducted on seven important field-grown cereal and leguminous crops. A drop in photosynthetic rates, by more than a factor of 5 in some cases, was observed, and the minimum values of photosynthetic rates ranged between 3.13 and 10.13 μmol CO2 m−2 s−1. The drop in solar irradiance and the increase in mesophyll CO2-concentration during the eclipse did not induce stomatal closure thus not blocking CO2 uptake by plants. Light effects on the photochemical phase of photosynthesis may be responsible for the observed depression in photosynthetic rates. Field studies addressing the migratory responses of marine zooplankton (micro-zooplankton (ciliates, and meso-zooplankton due to the rapid changes in underwater light intensity were also performed. The light intensity attenuation was simulated with the use of accurate underwater radiative transfer modeling techniques. Ciliates, responded to the rapid decrease in light intensity during the eclipse adopting night-time behaviour. From the meso-zooplankton assemblage, various vertical migratory behaviours were adopted by different species.

  13. Temporal and spatial distribution of microcrustacean zooplankton in relation to turbidity and other environmental factors in a large tropical lake (L. Tana, Ethiopia)

    NARCIS (Netherlands)

    Dejen, E.; Vijverberg, J.; Nagelkerke, L.A.J.; Sibbing, F.A.

    2004-01-01

    The spatial and seasonal distribution of microcrustacean zooplankton of Lake Tana (Ethiopia) was monthly studied for 2 years. Concurrently, various environmental parameters were measured and related to zooplankton distribution. Canonical Correspondence Analysis (CCA) was used to estimate the influen

  14. Zooplankton data collected from BUREVESTNIK and other platforms in White Sea; 28 October 1952 to 12 February 1958 (NODC Accession 9900004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts in White Sea from BUREVESTNIK and other platforms. Data were collected from 28 October 1952 to 12...

  15. Atlantic Salmon Telemetry Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Annual telemetry data are collected as part of specific projects (assessments within watersheds) or as opportunistic efforts to characterize Atlantic salmon smolt...

  16. Effects of the proximal factors on the diel vertical migration of zooplankton in a plateau meso-eutrophic Lake Erhai, China

    OpenAIRE

    Cuilin Hu; Shengrui Wang; Longgen Guo; Ping Xie

    2014-01-01

    To study the proximal factors inducing diel vertical migration (DVM) in large and small zooplankton species in a plateau lake in China, we investigated the DVM of crustacean zooplankton in lake Erhai bimonthly from November 2009 to September 2010. We hypothesized that the factors affecting DVM behaviour in different-sized zooplankton were different. A linear regression was used to assess the relationships between environmental variables and the vertical distribution of zooplankton. All crusta...

  17. DNA Barcoding of Metazoan Zooplankton Copepods from South Korea

    Science.gov (United States)

    Ryu, Shi Hyun; Kim, Sang Ki; Lee, Jin Hee; Lim, Young Jin; Lee, Jimin; Jun, Jumin; Kwak, Myounghai; Lee, Young-Sup; Hwang, Jae-Sam; Venmathi Maran, Balu Alagar; Chang, Cheon Young; Kim, Il-Hoi; Hwang, Ui Wook

    2016-01-01

    Copepods, small aquatic crustaceans, are the most abundant metazoan zooplankton and outnumber every other group of multicellular animals on earth. In spite of ecological and biological importance in aquatic environment, their morphological plasticity, originated from their various lifestyles and their incomparable capacity to adapt to a variety of environments, has made the identification of species challenging, even for expert taxonomists. Molecular approaches to species identification have allowed rapid detection, discrimination, and identification of cryptic or sibling species based on DNA sequence data. We examined sequence variation of a partial mitochondrial cytochrome C oxidase I gene (COI) from 133 copepod individuals collected from the Korean Peninsula, in order to identify and discriminate 94 copepod species covering six copepod orders of Calanoida, Cyclopoida, Harpacticoida, Monstrilloida, Poecilostomatoida and Siphonostomatoida. The results showed that there exists a clear gap with ca. 20 fold difference between the averages of within-specific sequence divergence (2.42%) and that of between-specific sequence divergence (42.79%) in COI, suggesting the plausible utility of this gene in delimitating copepod species. The results showed, with the COI barcoding data among 94 copepod species, that a copepod species could be distinguished from the others very clearly, only with four exceptions as followings: Mesocyclops dissimilis–Mesocyclops pehpeiensis (0.26% K2P distance in percent) and Oithona davisae–Oithona similis (1.1%) in Cyclopoida, Ostrincola japonica–Pseudomyicola spinosus (1.5%) in Poecilostomatoida, and Hatschekia japonica–Caligus quadratus (5.2%) in Siphonostomatoida. Thus, it strongly indicated that COI may be a useful tool in identifying various copepod species and make an initial progress toward the construction of a comprehensive DNA barcode database for copepods inhabiting the Korean Peninsula. PMID:27383475

  18. Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

    KAUST Repository

    Howard, Meredith D. A.

    2014-01-26

    Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

  19. Response of zooplankton to nutrient enrichment and fish in shallow lakes: a pan-European mesocosm experiment

    NARCIS (Netherlands)

    Vakkilainen, K.; Kairesalo, T.; Hietala, J.; Balayla, D.; Bécares, E.; van de Bund, W.; Van Donk, E.; Fernández-Aláez, M.; Gyllström, M.; Hansson, L-A.; Rosa Miracle, M.; Moss, B.; Romo, S.; Rueda, J.; Stephen, D.

    2004-01-01

    1. Responses of zooplankton to nutrient enrichment and fish predation were studied in 1998 and 1999 by carrying out parallel mesocosm experiments in six lakes across Europe. 2. Zooplankton community structure, biomass and responses to nutrient and fish manipulation showed geographical and year-to-ye

  20. ZOOPLANKTON COMMUNITY STRUCTURE OF THE SEA SURFACE MICROLAYER NEAR NUCLEAR POWER PLANTS AND MARINE FISH CULTURE ZONES IN DAYA BAY

    Institute of Scientific and Technical Information of China (English)

    杨宇峰; 王肇鼎; 潘明祥; 焦念志

    2002-01-01

    The authors' surveys in May-June 1999 (two cruises) at six sampling stations near nuclear power plants (NPP) and marine fish culture zones in Daya Bay, Guangdong, revealed species composition, densities and body-size of thesea surface microlayer (SM) zooplankton (>35 μm). Results showed that protozoans and copepod nauplii were the predominant components, accounting for 65.40% to95.56% of total zooplankton in abundance. The size-frequency distributions showed that the frequency of micro-zooplankton (0.02-0.2 mm) reached 0.8235. The SM zooplankton community structure revealed in the present study was quite different from that revealed by investigations in the 1980s in Daya Bay. Difference of sampling method has important influence on the obtained zooplankton community structure. SM zooplankton consisted of micro- and mesozooplankton (0.2-2.0 mm), with micro-zooplankton being predominant. Some possible cause-effect relations between the zooplankton community structure and mariculture, nuclear power plants cooling systems and sampling method are discussed.``

  1. Zooplankton community structure of the sea surface microlayer near nuclear power plants and marine fish culture zones in Daya Bay

    Science.gov (United States)

    Yang, Yu-Feng; Wang, Zhao-Ding; Pan, Ming-Xiang; Jiao, Nian-Zhi

    2002-06-01

    The authors' surveys in May June 1999 (two cruises) at six sampling stations near nuclear power plants (NPP) and marine fish culture zones in Daya Bay, Guangdong, revealed species composition, densities and body-size of the sea surface microlayer (SM) zooplankton (>35 μm). Results showed that protozoans and copepod nauplii were the predominant components, accounting for 65.40% to 95.56% of total zooplankton in abundance. The size-frequency distributions showed that the frequency of micro-zooplankton (0.02 0.2 mm) reached 0.8235. The SM zooplankton community structure revealed in the present study was quite different from that revealed by investigations in the 1980s in Daya Bay. Difference of sampling method has important influence on the obtained zooplankton community structure. SM zooplankton consisted of micro- and mesozooplankton (0.2 2.0 mm), with micro-zooplankton being predominant. Some possible cause-effect relations between the zooplankton community structure and mariculture, nuclear power plants cooling systems and sampling method are discussed.

  2. Variability of spatial and temporal distribution of zooplankton communities at Matrouh beaches, south-eastern Mediterranean Sea, Egypt

    Directory of Open Access Journals (Sweden)

    Sawsan M. Aboul Ezz

    2014-01-01

    Full Text Available The objectives of this work are to determine the main environmental drivers of zooplankton variability in water of Matrouh beach, south-eastern Mediterranean Sea and to evaluate the differences in zooplankton abundance and population structure in relation to chemical and biological parameters. Samples were collected seasonally from summer 2009 to summer 2010 at 10 sampling beaches. The zooplankton community was characterized by its high variability, and lower diversity. Zooplankton variability primarily responded to seasonal changes in water temperature and variation in salinity. In total, 49 zooplankton species were quantified; most of them were protozoans (22 species and copepods (14 species. The average zooplankton abundance was 36.0 × 103 ind. m−3, where copepods were dominant, making up 72.4% of the total population. Protozoa formed the second group, comprising 11.7%. Differences in species diversity were analysed in a zooplankton community, where the dominance of a single species was frequent. The Shannon–Wiener Diversity Index classified Matrouh water as being between moderately polluted and polluted, whereas the WQI demonstrated that it was between good and excellent. It can be concluded that, the index based on WQI is currently more suitable than the zooplankton species index for assessing the quality of water of Matrouh beaches.

  3. Hydrography and zooplankton off the central Oregon coast during the 1997-1998 El Nino event

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, W.T.; Emmett, B.; Jacobson, K. [NOAA, NMFS, NWFSC, Hatfield Marine Science Center, Newport, OR (United States); Schiewe, M.; Casillas, E. [NOAA, NWFSC Northwest Fisheries Science Center, Seattle, WA (United States)

    1998-12-31

    Hydrography and zooplankton were monitored at several ocean stations off the coast of Oregon to compare 1997 ocean conditions with conditions observed in the 1970s. It was shown that in the early spring of 1997, the Oregon upwelling zone began in a normal fashion and was followed by an increase in zooplankton production. In May, zooplankton numbers declined and continued to do so throughout the summer. The study, which also included sea surface temperature monitoring, showed that the sea surface temperature on the shelf was warmer by one degree than previous El Nino events. It was suggested that the warming in 1997 was due to onshore advection of warm offshore waters. The issue of how atmospheric pressure patterns and equatorial events influence coastal upwelling off the coast of Oregon was also explored. 1 tab., 3 figs.

  4. Diel variation and trophic structure in coral-reef zooplankton of Peninsular Malaysia

    OpenAIRE

    Nakajima, Ryota; Toda, Tatsuki; Yoshida, Teruaki; Othman, Bin Haji Ross

    2006-01-01

    Biomass in zooplankton (>100μm) and particulate organic matter (POM) (0.7-100μm) was investigated every 3 hours for two days at the fringing reef of Redang and Tioman Island, the east coast of Peninsular Malaysia. The zooplankton was size-fractionated into three fractions (100-200μm, 200-335μm, and >335μm) and POM was divided into two size-fractions (0.7-35 and 35-100μm). The POM (0.7-100μm) accounted for more than 95% of the total biomass (POM+zooplankton) in the water column. The largest si...

  5. Size and species diversity of zooplankton communities in fluctuating Mediterranean salt marshes

    Science.gov (United States)

    Brucet, Sandra; Boix, Dani; López-Flores, Rocío; Badosa, Anna; Quintana, Xavier D.

    2006-04-01

    Differences in size and species diversity were analysed in a zooplankton community of a Mediterranean salt marsh (Empordà wetlands, NE Iberian Peninsula), where the dominance of a single species was frequent. In the permanent salt marsh, species diversity and size diversity had similar patterns along zooplankton succession. In the temporary salt marsh species diversity was high after flooding and diminished once water inputs ceased. As species diversity declined size diversity increased. Eventually, one species of calanoid dominated the zooplankton community. The high size diversity in situations of calanoid dominance was possibly due to the co-occurrence of different developmental stages, each of which have different diets. Size diversity would thus indicate trophic niche segregation among different sizes. The combined use of species and size diversity values allows the identification of the successional phases.

  6. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    International Nuclear Information System (INIS)

    The WHAM-FTOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (FTOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H+ TOX to relate combined toxic effects of protons and metal cations towards lake crustacean zooplankton. • The fitted results give toxic potencies increasing in the order H+ TOX model has been applied to field data for pelagic lake crustacean zooplankton. The fitted results give metal toxic potencies increasing in the order H+ < Al < Cu < Zn < Ni

  7. The role of Callionymus lyra (L.) and C. reticulatus in the life cycle of Lernaeocera lusci in Belgian coastal waters (Southern Bight of the North Sea)

    NARCIS (Netherlands)

    Van Damme, P.A.; Maertens, D.; Arrumm, A.; Hamerlynck, O.; Ollevier, F.

    1993-01-01

    A survey of the dragonet Callionymus lyra and the reticulated dragonet C. reticulatus from Belgian coastal waters (Southern Bight of the North Sea) in June 1991 revealed 34% of dragonets infected with 1–7 Lernaeocera lusci. This same parasite infected 9% of the reticulated dragonets (mean intensity

  8. Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles

    Science.gov (United States)

    Le Quéré, Corinne; Buitenhuis, Erik T.; Moriarty, Róisín; Alvain, Séverine; Aumont, Olivier; Bopp, Laurent; Chollet, Sophie; Enright, Clare; Franklin, Daniel J.; Geider, Richard J.; Harrison, Sandy P.; Hirst, Andrew G.; Larsen, Stuart; Legendre, Louis; Platt, Trevor; Prentice, I. Colin; Rivkin, Richard B.; Sailley, Sévrine; Sathyendranath, Shubha; Stephens, Nick; Vogt, Meike; Vallina, Sergio M.

    2016-07-01

    Global ocean biogeochemistry models currently employed in climate change projections use highly simplified representations of pelagic food webs. These food webs do not necessarily include critical pathways by which ecosystems interact with ocean biogeochemistry and climate. Here we present a global biogeochemical model which incorporates ecosystem dynamics based on the representation of ten plankton functional types (PFTs): six types of phytoplankton, three types of zooplankton, and heterotrophic procaryotes. We improved the representation of zooplankton dynamics in our model through (a) the explicit inclusion of large, slow-growing macrozooplankton (e.g. krill), and (b) the introduction of trophic cascades among the three zooplankton types. We use the model to quantitatively assess the relative roles of iron vs. grazing in determining phytoplankton biomass in the Southern Ocean high-nutrient low-chlorophyll (HNLC) region during summer. When model simulations do not include macrozooplankton grazing explicitly, they systematically overestimate Southern Ocean chlorophyll biomass during the summer, even when there is no iron deposition from dust. When model simulations include a slow-growing macrozooplankton and trophic cascades among three zooplankton types, the high-chlorophyll summer bias in the Southern Ocean HNLC region largely disappears. Our model results suggest that the observed low phytoplankton biomass in the Southern Ocean during summer is primarily explained by the dynamics of the Southern Ocean zooplankton community, despite iron limitation of phytoplankton community growth rates. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean.

  9. Food habits of Juvenile American Shad and dynamics of zooplankton in the lower Columbia River

    Science.gov (United States)

    Haskell, C.A.; Tiffan, K.F.; Rondorf, D.W.

    2006-01-01

    As many as 2.4 million adult American shad annually pass John Day Dam, Columbia River to spawn upriver, yet food web interactions of juvenile shad rearing in John Day Reservoir are unexplored. We collected zooplankton and conducted mid-water trawls in McNary (June-July) and John Day reservoirs (August-November) from 1994 through 1996 during the outmigration of subyearling American shad and Chinook salmon. Juvenile American shad were abundant and represented over 98% of the trawl catch in late summer. The five major taxa collected in zooplankton tows were Bosmina longirostris, Daphnia, cyclopoid cope-pods, rotifers, and calanoid copepods. We evaluated total crustacean zooplankton abundance and Daphnia biomass in relation to water temperature, flow, depth, diel period, and cross-sectional location using multiple regression. Differences in zooplankton abundance were largely due to differences in water temperature and flow. Spatial variation in total zooplankton abundance was observed in McNary Reservoir, but not in John Day Reservoir. Juvenile American shad generally fed on numerically abundant prey, despite being less preferred than larger bodied zooplankton. A decrease in cladoceran abundance and size in August coupled with large percentages of Daphnia in juvenile American shad stomachs indicated heavy planktivory. Smaller juvenile American shad primarily fed on Daphnia in August, but switched to more evasive copepods as the mean size of fish increased and Daphnia abundance declined. Because Daphnia are particularly important prey items for subyearling Chinook salmon in mainstem reservoirs in mid to late summer, alterations in the cladoceran food base is of concern for the management of outmigrating salmonids and other Columbia River fishes. ?? 2006 by the Northwest Scientific Association. All rights reserved.

  10. 76 FR 1153 - Atlantic Grid Operations A LLC, Atlantic Grid Operations B LLC, Atlantic Grid Operations C LLC...

    Science.gov (United States)

    2011-01-07

    ... Energy Regulatory Commission Atlantic Grid Operations A LLC, Atlantic Grid Operations B LLC, Atlantic Grid Operations C LLC, Atlantic Grid Operations D LLC and Atlantic Grid Operations E LLC; Notice of... (Commission) Rules of Practice and Procedure, 18 CFR 385.207, and Order No. 679,\\1\\ Atlantic Grid Operations...

  11. Zooplankton diversity and abundance of mangrove ecosystem of Kali estuary, Karwar, west coast of India

    Directory of Open Access Journals (Sweden)

    V. Kumar

    2013-09-01

    Full Text Available The present study conducted at the mangrove ecosystem of Kali estuary. Samples were collected from the three fixed stations for the period of thirteen months from January 2008 to January 2009 at regular monthly interval to identify and quantify the abundance, taxonomy and relative ratio of phytoplankton and zooplankton. In the present study of species diversity of zooplankton groups in the mangrove area, composed of twelve groups comprising fifty two species major share comes from the copepods which comprises about seventeen species. Protozoa taxa comprised by five species, coelenterata and cladocera by two species each, ctenophore comprised by single species whereas the larval forms comprised by fourteen species.

  12. Trace metal concentrations in marine zooplankton from the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; Balachandran, K.K.; Nair, M.; Joseph, T.

    Rejomon et al.: Trace metal concentration in marine zooplankton from the Western Bay of Bengal - 107 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 6(1): 107-116. http://www.ecology.uni-corvinus.hu ● ISSN 1589 1623  2008, Penkala Bt., Budapest, Hungary....: Trace metal concentration in marine zooplankton from the Western Bay of Bengal - 108 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 6(1): 107-116. http://www.ecology.uni-corvinus.hu ● ISSN 1589 1623  2008, Penkala Bt., Budapest, Hungary 78 80 82 84...

  13. Evaluation of sound extinction and echo interference in densely aggregated zooplankton

    Directory of Open Access Journals (Sweden)

    Natalia Gorska

    2000-09-01

    Full Text Available The investigation of sound extinction and echo interference is important as regards the accurate assessment of the abundance of densely aggregated zooplankton. To study these effects,the analytical model describing sound backscattering by an aggregation of isotropic scatterers (Rytov et al. 1978, Sun & Gimenez 1992 has been extended to the case of densely aggregated elongated zooplankton. The evaluation of the effects in the case of a dense krill aggregation demonstrates that they can be significant and should be taken into account.

  14. Species diversity and community structure of zooplankton in the Zhubi Atoll, Nansha Islands, South China Sea

    OpenAIRE

    Jianqiang Yin; Liangmin Huang; Kaizhi Li; Lanlan Xiong

    2011-01-01

    Coral reefs contain the highest biodiversity ecosystem on Earth. In order to improve our understanding of the biodiversity and zooplankton communities, zooplankton was sampled using vertical trawls with 169 μm and 505 μm planktonic nets at 10 stations (5 within lagoon and 5 on reef flat) and one continuous observatory station from the 5th to the 15th of May, 2004 in the Zhubi Atoll of the Nansha Islands. A total of 96 species and 17 groups of planktonic larvae were identified, among which the...

  15. Zooplankton from OTEC sites in the Gulf of Mexico and the Caribbean

    Energy Technology Data Exchange (ETDEWEB)

    Commins, M.L.; Horne, A.J.

    1979-06-01

    The spatial and temporal variations in the abundance of major classes of zooplankton were measured using standard methods, between June and October 1978, at two OTEC sites in the Gulf of Mexico and in the Caribbean near Puerto Rico. The usual oceanic patterns were found with highest numbers near the surface, especially at night, and lowest numbers at 800 to 1000 m. Absolute numbers varied considerably from site to site. As expected, copepods (usually divided between calanoids and cyclopoids) dominated the zooplankton at all sites.

  16. Zooplankton abundance, species composition and ecology of tropical high-mountain crater lake Wonchi, Ethiopia

    Directory of Open Access Journals (Sweden)

    Fasil Degefu

    2014-11-01

    Full Text Available The highlands of Ethiopia represent some of the remnants of undisturbed aquatic ecosystems; they are however highly threatened by significant socio–economic developments and associated anthropogenic impacts. Lake Wonchi is one of the few remaining fairly pristine high–mountain crater lakes in the central highlands and has never been investigated in detail. We present a first study on zooplankton taxa composition, abundance and biomass conducted over more than one year including the underlying environmental drivers. The lake is basic (pH 7.9-8.9, dilute (specific conductivity 185-245 µS cm-1 and oligotrophic with mean trophic status index of 36. The zooplankton community composition showed low species richness comprising a total of fourteen taxa with six cladocerans, one copepod and seven rotifers. Simpson´s index of diversity with values between 0.6 and 0.8 pointed towards a homogenous taxa occurrence within the single sample units. The overall mean (±SD standing biomass of zooplankton was 62.02±25.76 mg dry mass m-3,which is low compared to other highland and rift valley lakes in Ethiopia. Cyclopoid copepods, in particular Thermocyclops ethiopiensis were the most abundant group and contributed 50% to the total zooplankton abundance followed by cladocerans (38% and rotifers (12%. Non-metric multi-dimensional scaling resulted in a 3-dimensional model, which revealed similar community composition on successive sampling dates except in December/January and May. Temperature, alkalinity, conductivity and nitrate-N had significant influence on this seasonal pattern. A weak, but significant positive correlation (r=0.482, N=20, P=0.037 between Chlorophyll a and zooplankton biomass mirrors a bottom-up effect of phytoplankton biomass on zooplankton dynamics. The zooplankton of Lake Wonchi displayed some degree of segregation along the epi– and metalimnion during this study, but diel vertical migration was not observed. The results show that fish

  17. Carbon intake by zooplankton. Importance and role of zooplankton grazing in the Indian sector of the Southern Ocean

    Science.gov (United States)

    Mayzaud, P.; Tirelli, V.; Errhif, A.; Labat, J. P.; Razouls, S.; Perissinotto, R.

    Ingestion by mesozooplankton and micronekton was monitored during two of the ANTARES cruises in the Indian sector of the Southern Ocean in spring and summer. The composition of the mesozooplankton populations varied in space and with season. Copepods always dominated in number and biomass, but salps and pteropods were present in the northern part of the transect in summer. Five species of large copepod ( Calanus simillimus, Calanoides acutus, Rhincalanus gigas, Calanus propinquus and Metridia gerlachei) dominated the biomass with a North-South gradient. Smaller species ( Oithona spp., Ctenocalanus citer, Clausocalanus laticeps) were also present. Biomass showed a definite trend with highest levels towards the polar front zone and permanent open-ocean area. Feeding activity was monitored either for the total population (summer) or specific individuals (spring). In summer, depending on the area considered, grazing rates by mesozooplankton appeared to have a significant impact on phytoplankton primary production. In the northern part of the transect (polar front zone or PFZ), salps and to a minor extent pteropods and copepods contributed mostly to the feeding pressure. Maximum intensity was observed in the Coastal Antarctic Zone (CCSZ) where Euphausia superba (adults and calyptopis larvae) could ingest more than 100% of the daily primary production. In spring, the impact of copepods dominated the zooplankton community. Small calanoids and young stages of large species of copepods rather than adult stages were the dominant contributors to grazing pressure. In summer, respiration rates of the dominant copepod species showed that energy expenditure exceeded by far chlorophyll ingestion. This is generally interpreted as the consequence of ingestion of alternate non-chlorophyll food source. The inverse correlation between the biomass of microzooplankton and the area of maximum difference between grazing and respiration confirmed that in summer the protozoans are strongly

  18. Species composition and distribution patterns of early life stages of cephalopods at Great Meteor Seamount (subtropical NE Atlantic)

    OpenAIRE

    Diekmann, Rabea; Piatkowski, Uwe

    2004-01-01

    The distribution of early life stages of cephalopods was studied during a cruise of RV Meteor in September 1998 at Great Meteor Seamount, an isolated flat-topped seamount in the subtropical eastern North Atlantic. Zooplankton sampling was conducted with a multi-opening-closing net (modified MOCNESS, 1 m² net opening, 335 µm mesh size) in seven depth strata between 290 m depth and the surface. 1180 early life stages of cephalopods were collected, representing at least 18 families and 31 mainly...

  19. Zooplankton and forage fish species off Peru: Large-scale bottom-up forcing and local-scale depletion

    Science.gov (United States)

    Ayón, Patricia; Swartzman, Gordon; Bertrand, Arnaud; Gutiérrez, Mariano; Bertrand, Sophie

    2008-10-01

    The Humboldt Current System, like all upwelling systems, has dramatic quantities of plankton-feeding fish, which suggested that their population dynamics may ‘drive’ or ‘control’ ecosystem dynamics. With this in mind we analysed the relationship between forage fish populations and their main prey, zooplankton populations. Our study combined a zooplankton sampling program (1961-2005) with simultaneous acoustic observations on fish from 40 pelagic surveys (1983-2005) conducted by the Peruvian Marine Research Institute (IMARPE) and landing statistics for anchoveta ( Engraulis ringens) and sardine ( Sardinops sagax) along the Peruvian coast from 1961 to 2005. The multi-year trend of anchoveta population abundance varied consistently with zooplankton biovolume trend, suggesting bottom-up control on anchovy at the population scale (since oceanographic conditions and phytoplankton production support the changes in zooplankton abundance). For a finer-scale analysis (km) we statistically modelled zooplankton biovolume as a function of geographical (latitude and distance from the 200-m isobath), environmental (sea surface temperature), temporal (year, month and time-of-day) and biological (acoustic anchovy and sardine biomass within 5 km of each zooplankton sample) covariates over all survey using both classification and regression trees (CART) and generalized additive models (GAM). CART showed local anchoveta density to have the strongest effect on zooplankton biovolume, with significantly reduced levels of biovolume for higher neighbourhood anchoveta biomass. Additionally, zooplankton biovolume was higher offshore than on the shelf. GAM results corroborated the CART findings, also showing a clear diel effect on zooplankton biovolume, probably due to diel migration or daytime net avoidance. Apparently, the observed multi-year population scale bottom-up control is not inconsistent with local depletion of zooplankton when anchoveta are locally abundant, since the

  20. Coastal observing and forecasting system for the German Bight - estimates of hydrophysical states

    Science.gov (United States)

    Stanev, E. V.; Schulz-Stellenfleth, J.; Staneva, J.; Grayek, S.; Seemann, J.; Petersen, W.

    2011-09-01

    A coastal observing system for Northern and Arctic Seas (COSYNA) aims at construction of a long-term observatory for the German part of the North Sea, elements of which will be deployed as prototype modules in Arctic coastal waters. At present a coastal prediction system deployed in the area of the German Bight integrates near real-time measurements with numerical models in a pre-operational way and provides continuously state estimates and forecasts of coastal ocean state. The measurement suite contributing to the pre-operational set up includes in situ time series from stationary stations, a High-Frequency (HF) radar system measuring surface currents, a FerryBox system and remote sensing data from satellites. The forecasting suite includes nested 3-D hydrodynamic models running in a data-assimilation mode, which are forced with up-to-date meteorological forecast data. This paper reviews the present status of the system and its recent upgrades focusing on developments in the field of coastal data assimilation. Model supported data analysis and state estimates are illustrated using HF radar and FerryBox observations as examples. A new method combining radial surface current measurements from a single HF radar with a priori information from a hydrodynamic model is presented, which optimally relates tidal ellipses parameters of the 2-D current field and the M2 phase and magnitude of the radials. The method presents a robust and helpful first step towards the implementation of a more sophisticated assimilation system and demonstrates that even using only radials from one station can substantially benefit state estimates for surface currents. Assimilation of FerryBox data based on an optimal interpolation approach using a Kalman filter with a stationary background covariance matrix derived from a preliminary model run which was validated against remote sensing and in situ data demonstrated the capabilities of the pre-operational system. Data assimilation significantly

  1. Current status of zooplankton in reservoir R-3 of the 'Mayak' production association

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, O.; Pryakhin, E. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Ivanov, I. [FSUE Mayak PA (Russian Federation)

    2014-07-01

    One of the commonly used objects for the study of human influence on aquatic ecosystems is zooplankton. Zooplankton community is a sensitive component of biota in reservoir which can change their functional parameters and species composition in response to exposure to different factors. The role of zooplankton in the transformation of energy and in the biotic cycling of the substance is very important. The study of the responses of this element in the water ecosystem with anthropogenic influences, including radioactive contamination, is an important task. The object of the study was the zooplankton in the reservoir R-3, Chelyabinsk region, Russia. R-3 is located in the buffer zone of the 'Mayak' PA and is the storage for low-level radioactive waste. In addition to the high content of radionuclides (the average specific activity of {sup 90}Sr in water was 2.8 kBq/l, {sup 137}Cs - 0.7 kBq/l), this reservoir is characterized by high values of dichromate oxidizability and phosphate contamination. Previously, the study of the zooplankton of this reservoir was conducted in 1952, regular observations were not organized. Assessment of the current status of the community, more than half a century residing in the conditions of radioactive and chemical contamination, seems highly interesting. Sampling was carried out in 2011-2012 at three stations: in the upper, middle, and near the dam of the reservoir by the method of weighted average of samples with bathometer. Analysis of samples showed that the zooplankton community consists of the following major groups: rotifers and cladocerans and copepods crustaceans. In total in R-3 27 species of zooplankton, including 19 species of rotifers, 3 species of copepod and 3 species of cladocerans, as well as two species of ciliates were discovered. Zooplankton abundance in 2011 was 9±9 million individuals/m{sup 3} (given the mean and standard deviation), in 2012 - 26.0±0.9 million individuals/m{sup 3}. The main contribution

  2. Current status of zooplankton in reservoir R-3 of the 'Mayak' production association

    International Nuclear Information System (INIS)

    One of the commonly used objects for the study of human influence on aquatic ecosystems is zooplankton. Zooplankton community is a sensitive component of biota in reservoir which can change their functional parameters and species composition in response to exposure to different factors. The role of zooplankton in the transformation of energy and in the biotic cycling of the substance is very important. The study of the responses of this element in the water ecosystem with anthropogenic influences, including radioactive contamination, is an important task. The object of the study was the zooplankton in the reservoir R-3, Chelyabinsk region, Russia. R-3 is located in the buffer zone of the 'Mayak' PA and is the storage for low-level radioactive waste. In addition to the high content of radionuclides (the average specific activity of 90Sr in water was 2.8 kBq/l, 137Cs - 0.7 kBq/l), this reservoir is characterized by high values of dichromate oxidizability and phosphate contamination. Previously, the study of the zooplankton of this reservoir was conducted in 1952, regular observations were not organized. Assessment of the current status of the community, more than half a century residing in the conditions of radioactive and chemical contamination, seems highly interesting. Sampling was carried out in 2011-2012 at three stations: in the upper, middle, and near the dam of the reservoir by the method of weighted average of samples with bathometer. Analysis of samples showed that the zooplankton community consists of the following major groups: rotifers and cladocerans and copepods crustaceans. In total in R-3 27 species of zooplankton, including 19 species of rotifers, 3 species of copepod and 3 species of cladocerans, as well as two species of ciliates were discovered. Zooplankton abundance in 2011 was 9±9 million individuals/m3 (given the mean and standard deviation), in 2012 - 26.0±0.9 million individuals/m3. The main contribution was that of rotifers: 88.5 % of the

  3. Hydrographic Conditions At The Carbonate Mound Locations In The NE Atlantic

    Science.gov (United States)

    van Weering, T.; de Hass, H.; White, M.; de Stigter, H.

    As part of the component 5th framework projects that form part of the OMARC clus- ter, hydrographic measurements have been made in the region of the deep water car- bonate mounds provinces of the NE Atlantic. These mounds are located at depths 600-1000m depth along the continental slopes of the Porcupine Sea Bight and Bank and the SE Rockall Bank. These regions correspond to the vertical and horizontal boundaries of the intermediate water masses that occupy the region, providing differ- ent hydrographic regimes between mound locations,. In addition there is a large vari- ability in temperature/salinity conditions and both characteristics have implications for the distribution of mound fauna. The deep water coral associated with carbonate mound structures coincide with strong benthic current activity and this is confirmed from benthic current measurements from landers and current meters at the SE Rockall and NW Porcupine Bank mound loca- tions. Near seabed currents are strong, with a typical mean speed of 20cm/s and a max- imum in excess of 50cm/s. At the SE Rockall Bank site, a mean SW along isobath flow is measured, whilst at the NW Porcupine mound location, a poleward slope current is measured. Bottom Ekman dynamics is apparent with a changes in near seabed verti- cal stratification related to changes to overlying slope current strength. Strong diurnal variability is found at the Rockall Bank site, providing strong cross-slope currents. The diurnal current forcing over both the Rockall and Porcupine Banks may result in enclosed circulation patterns over the banks and retention of organic material supplied to the mounds. In contrast, currents at the Hovland and Magellan mound sites in the northern Porcupine Sea Bight, where there are numerous buried mounds, are relatively low.

  4. Atlantic menhaden adult tagging study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atlantic menhaden are a schooling forage fish species, which are subject to a large commercial purse seine fishery. Atlantic menhaden are harvested for reduction...

  5. Taxonomic code, physical, and other data collected from DELAWARE II and other platforms in New York Bight from net casts and other instruments; 20 February 1973 to 16 December 1975 (NODC Accession 7601402)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Taxonomic Code, physical, and other data were collected using net casts and other instruments in the New York Bight from DELAWARE II and other platforms. Data were...

  6. HYDROCARBONS - TOTAL RESOLVED, CAS (CHEMICAL ABSTRACTS SERVICE) PARAMETER CODES and PCB, and other data from UNKNOWN in the New York Bight on 1901-01-01 (NODC Accession 8600271)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This submission contains the master data set assembled in a study called "Contaminant Body Burdens, Variability and Monitoring Implications for the New York Bight"....

  7. Physical, taxonomic code, and other data from current meter and other instruments in New York Bight from DOLPHIN and other platforms; 14 March 1971 to 03 August 1975 (NODC Accession 7601385)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, taxonomic code, and other data were collected using current meter and other instruments from DOLPHIN and other platforms in New York Bight. Data were...

  8. Water physics and chemistry data from moored current meter and bottle casts in the New York Bight as part of the North East Monitoring Program (NEMP) project, 10 April 1984 - 31 October 1984 (NODC Accession 8500225)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the New York Bight from April 10, 1984 to October 31, 1984. Data were...

  9. Zooplankton Linkages between Rivers and Great Lakes: Case Study from the St. Louis River

    Science.gov (United States)

    In this case study, we characterized the spatial and seasonal distribution and abundance of zooplankton within the hydrologically complex drowned river mouth of the St. Louis River, the second largest tributary to Lake Superior and an important fish nursery. We hypothesize that z...

  10. Vertical distribution of zooplankton: density dependence and evidence for an ideal free distribution with costs

    Directory of Open Access Journals (Sweden)

    Lampert Winfried

    2005-04-01

    Full Text Available Abstract Background In lakes with a deep-water algal maximum, herbivorous zooplankton are faced with a trade-off between high temperature but low food availability in the surface layers and low temperature but sufficient food in deep layers. It has been suggested that zooplankton (Daphnia faced with this trade-off distribute vertically according to an "Ideal Free Distribution (IFD with Costs". An experiment has been designed to test the density (competition dependence of the vertical distribution as this is a basic assumption of IFD theory. Results Experiments were performed in large, indoor mesocosms (Plankton Towers with a temperature gradient of 10°C and a deep-water algal maximum established below the thermocline. As expected, Daphnia aggregated at the interface between the two different habitats when their density was low. The distribution spread asymmetrically towards the algal maximum when the density increased until 80 % of the population dwelled in the cool, food-rich layers at high densities. Small individuals stayed higher in the water column than large ones, which conformed with the model for unequal competitors. Conclusion The Daphnia distribution mimics the predictions of an IFD with costs model. This concept is useful for the analysis of zooplankton distributions under a large suite of environmental conditions shaping habitat suitability. Fish predation causing diel vertical migrations can be incorporated as additional costs. This is important as the vertical location of grazing zooplankton in a lake affects phytoplankton production and species composition, i.e. ecosystem function.

  11. Patchy zooplankton grazing and high energy conversion efficiency: ecological implications of sandeel behavior and strategy

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Christensen, Asbjørn; Rindorf, Anna

    2013-01-01

    prey. Here we studied zooplankton consumption and energy conversion efficiency of lesser sandeel (Ammodytes marinus) in the central North Sea, using stomach data, length and weight-at-age data, bioenergetics, and hydrodynamic modeling. The results suggested: (i) Lesser sandeel in the Dogger area depend...

  12. Zooplankton standing stock assessment and fishery resources in the indian seas

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Sarupria, J.S.; Bhargava, R.M.S.

    .6 ml m sup(-3) (av. = 0.156 plus or minus 0.218 ml m sup(-3)) and 0.02 to 0.37 ml m sup(-3) (av. = 0.12 plus or minus 0.079 ml m sup(-3)) respectively. The general pattern of zooplankton distribution showed an increasing trend towards north...

  13. Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai, China

    Science.gov (United States)

    Yu, Na; Li, Erchao; Feng, Dexiang; Xiao, Baicai; Wei, Chaoqun; Zhang, Meiling; Chen, Liqiao

    2014-11-01

    Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton ( Brachionus calyciflorus, Microcyclops leuckarti, and Asplanchna priodonta) accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species ( Schmackeria forbesi and Lepadella ovalis) were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.

  14. Zooplankton grazing in a eutrophic lake: implications of diel vertical migration

    International Nuclear Information System (INIS)

    During summer and fall, depth profiles of zooplankton community grazing were determined in situ during day and night in the Schoehsee, a small eutrophic lake. Labeled algae of two different sizes were mixed with the natural suspension of phytoplankton in a grazing chamber. A small blue-green alga (Synechococcus, 1 μm) was labeled with 32P; a larger green alga (Scenedesmus, 4-15 μm) was labeled with 14C. During summer, grazing in the upper 5 m was negligible during day but strong at night. Hence, algae grow relatively unimpeded by grazing during daytime but are harvested at night. Vertical and diel differences in grazing rates disappeared when the vertical migration ceased in fall. Selectivity of grazing was controlled by the zooplankton species composition. Eudiaptomus showed a strong preference for Scenedesmus. Daphnia showed a slight preference for Scenedesmus, but Ceriodaphnia preferred Synechococcus. Cyclopoid copepodites did not ingest the small blue-green. Because Daphnia and Eudiaptomus were dominant, grazing rates on larger cells were usually higher than grazing rates on the small cells. Negative electivity indices for scenedesmus occurred only when the biomass of large crustaceans was extremely low (near the surface, during day). Zooplankton biomass was the main factor controlling both vertical and seasonal variations in grazing. Highest grazing rates (65%/d) were measured during fall when zooplankton abundance was high. Because differential losses can produce substantial errors in the results, it was necessary to process the samples on the boat immediately after collection, without preservation

  15. The variations of zooplankton biomass and their migration associated with the Yellow Sea Warm Current

    Science.gov (United States)

    Lü, Lian-Gang; Wang, Xiao; Wang, Huiwu; Li, Laoyu; Yang, Guangbing

    2013-08-01

    Multidisciplinary oceanographic investigations were carried out in the southern Yellow Sea (YS) from December 2006 to February 2007. The ship-based investigations provided spatial distributions of temperature, salinity, and zooplankton. The horizontal distributions of temperature and salinity indicate the location of the Yellow Sea Warm Current (YSWC), and the net-sampling results display low biomass of zooplankton in the YSWC area. The mooring observations show the temporal variability of the current, bottom temperature, and volume backscattering strength (Sv) at the mooring sites. The current and bottom temperature records illustrate the process of the arrival of the warm water advected by the YSWC. The time series of Sv measured with acoustic Doppler current profilers (ADCPs) indicate a distinct change in the diel vertical migration (DVM) pattern of the zooplankton. This change is associated with the arrival of the warm water. Our investigation suggests that the transport of low-biomass water by the YSWC causes the zooplankton biomass in the study area to decrease. The YSWC also causes the DVM to change due to enhanced vertical mixing.

  16. Zooplankton feeding ecology and the experimental acidification of Little Rock Lake

    International Nuclear Information System (INIS)

    There is considerable variety in both the selective behavior of suspension feeders and the quality of food available to them. The author reviews this variability and incorporate it in a simple model of particle selection that quantifies the consequences of selective feeding under various feeding conditions. To evaluate the concept that selective feeding enhances fitness, the author tests the hypothesis than an herbivorous zooplankton selects food items that best support its reproduction. Investigations of zooplankton herbivory in experimentally acidified Little Rock Lake indicate that acidification from pH 6.2 to pH 5.2 has not directly impaired feeding rates, while effects on selective feeding behavior are evident. Assessment of the effects of lake acidification on large predatory zooplankton indicate that Chaoborus spp. and water mite populations remain as yet unaffected, while Epischura lacustris and Leptodora kindtii have both declined in the acidified basin. Methodological tests show that preservation of labelled zooplankton by rapid freezing on dry ice minimizes loss of 14C and 32P. 14C retention approximates 100%, while 32P retention is more variable

  17. Zooplankton standing stock, community structure and diversity in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Srivastava, Y.

    station (lat. 22 degrees 07'N and long. 67 degrees 03'E) and was due to swarm of gammarid amphipods and shoal of sergestid shrimp Acetes johni. Herbivores dominated the zooplankton community and copepods were most abundant (36.9 to 71.7%). The other...

  18. Epizoic acoelomorph flatworms impair zooplankton feeding by the scleractinian coral Galaxea fascicularis

    NARCIS (Netherlands)

    Wijgerde, T.H.M.; Schots, P.; Onselen, van E.; Karruppannan, E.W.; Verreth, J.A.J.; Osinga, R.

    2013-01-01

    Many scleractinian coral species host epizoic acoelomorph flatworms, both in aquaculture and in situ. These symbiotic flatworms may impair coral growth and health through light-shading, mucus removal and disruption of heterotrophic feeding. To quantify the effect of epizoic flatworms on zooplankton

  19. Zooplankton community structure in the Yellow Sea and East China Sea in autumn

    Directory of Open Access Journals (Sweden)

    Hongju Chen

    2015-12-01

    Full Text Available Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface using a ring net (diameter 0.8 m, 505-μm mesh were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.

  20. Zooplankton of the Black Sea and the Eastern Mediterranean: Similarities and dissimilarities

    Directory of Open Access Journals (Sweden)

    A.V. KOVALEV

    2012-12-01

    Full Text Available A synthesis of data on abundance and biomass of zooplankton in the Eastern Mediterranean (EMED and the Black Sea shows major differences in the composition and structure of pelagic communities in the two basins. Few Mediterranean planktonic animals have invaded and acclimatised in the Black Sea. The great bulk of Black Sea species is represented by coastal inhabitants that spread throughout the whole basin. This process has been called “neritization” of the Black Sea fauna. Peculiarities in zooplankton assemblages of the Black Sea have been further strengthened over the last few decades due to increasing eutrophication and the massive invasion of the ctenophore Mnemiopsis leidyi. The relative contribution of copepods, cladocerans, chaetognaths, and appendicularians to total zooplankton biomass has notably decreased , whereas gelatinous groups (mainly represented by Mnemiopsis and Aurelia aurita contributed up to 99% of total wet weight in 1995 in the Black Sea.The basic features of planktonic fauna in the Black Sea are mainly due do the geo-morphological characters of the basin and the limited exchanges with the EMED, that are confined to the surface-subsurface layers in the Dardanelles and Bosphorus Straits. However, the dramatic changes that recently occurred in the structure of zooplankton assemblages seem to have been caused by heavy anthropogenic impact on the pelagic system.

  1. Incorporation of nitrogen from N2 fixation into amino acids of zooplankton

    DEFF Research Database (Denmark)

    Loick-Wilde, Natalie; Dutz, Jörg; Miltner, Anja; Gehre, Matthias; Montoya, Joseph P.; Voss, Maren

    2012-01-01

    Eurytemora affinis (Copepoda) were fed 15N-labeled Rhodomonas salina (Cryptophyta) or 15N-labeled Nodularia spumigena (Cyanobacteria) in excess under controlled laboratory conditions. Zooplankton collected from the Baltic Sea were fed natural phytoplankton amended with 15N-labeled N. spumigena. We...

  2. Zooplankton ecology in the Mandovi-Zuari estuarine system of Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Goswami, S.C.

    were influenced by the southwest monsoon. Salinity fluctuations were drastic (0.1 to 36.6 x 10 sup(-3)). This appeared to cause variations in plankton production and heterogeneity of various taxa. Zooplankton biomass and total numerical counts varied...

  3. Trace metal dynamics in zooplankton from the Bay of Bengal during summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; DineshKumar, P.K.; Nair, M.; Muraleedharan, K.R.

    Trace metal (Fe, Co, Ni, Cu, Zn, Cd, and Pb) concentrations in zooplankton from the mixed layer were investigated at 8 coastal and 20 offshore stations in the western Bay of Bengal during the summer monsoon of 2003. The ecotoxicological importance...

  4. The effect of zooplankton on the dynamics and molecular composition ofcarbohydrates during an experimental algal bloom

    DEFF Research Database (Denmark)

    Kragh, J. T.; Søndergaard, M.; Borch, N. H.

    2006-01-01

    The accumulation and degradation of carbohydrates (aldoses) were investigated during diatom blooms in two mesocosms. The effects of macrozooplankton were explored by addition of zooplankton to one mesocosm (+Z). Aldoses accumulated at a steady rate of 4.9 µM C d-1 from day 9 in the mesocosm without...

  5. Biochemical composition and caloric potential of zooplankton from Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sreepada, R.A.; Rivonker, C.U.; Parulekar, A.H.

    .62, 4.95, 1.54, 0.43, 4.4 and 4.16 respectively on wet weight basis. A good correlation of caloric potential with protein and lipid indicated to a certain extent that protein and lipid act as metabolic reserves of the zooplankton in the area...

  6. Relative abundance of resident versus oceanic zooplankton over an interisland reef

    International Nuclear Information System (INIS)

    Zooplankton were collected from various substrate types. Densities were determined and results indicated that demersal plankton were abundant on the Japtan reef flat. Behavioral mechanisms were exhibited by many organisms including swimming near the substrate or in the lees of coral heads. Demersal plankton may provide an important food source for nocturnally foraging fishes

  7. Biochemical composition of zooplankton of Bombay High (oil platform) area in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, K.L.; Wagh, A.B.

    Variations in the biochemical constituents and calorific values of zooplankton from an off-shore oil processing platform were estimated. Mean value of biomass was 0.35 ml.m/3 with relatively higher values during post-monsoon period. Copepods formed...

  8. Zooplankton biomass and potential fishery resources of the EEZ of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    An assessment of zooplankton biomass, secondary production and potential fishery resources of the EEZ of India was made from the data collected during a period of 15 years from 1976 to 1991. The areas studied included the Arabian Sea, Bay of Bengal...

  9. Annual cycle of zooplankton abundance and species composition in Izmit Bay (the northeastern Marmara Sea)

    Science.gov (United States)

    Isinibilir, Melek; Kideys, Ahmet E.; Tarkan, Ahmet N.; Yilmaz, I. Noyan

    2008-07-01

    The monthly abundance, biomass and taxonomic composition of zooplankton of Izmit Bay (the northeastern Marmara Sea) were studied from October 2001 to September 2002. Most species within the zooplankton community displayed a clear pattern of succession throughout the year. Generally copepods and cladocerans were the most abundant groups, while the contribution of meroplankton increased at inner-most stations and dominated the zooplankton. Both species number ( S) and diversity ( H') were positively influenced by the increase in salinity of upper layers ( r = 0.30 and r = 0.31, p < 0.001, respectively), while chlorophyll a was negatively affected ( r = -0.36, p < 0.001). Even though Noctiluca scintillans had a significant seasonality ( F11,120 = 8.45, p < 0.001, ANOVA), abundance was not related to fluctuations in temperature and only chlorophyll a was adversely correlated ( r = -0.35, p < 0.001). In general, there are some minor differences in zooplankton assemblages of upper and lower layers. A comparison of the species composition and abundance of Izmit Bay with other Black Sea bays reveals a high similarity between them.

  10. Atlantic Equatorial Deep Jets

    OpenAIRE

    Didwischus, Sven-Helge; Brandt, Peter; Greatbatch, Richard John

    2012-01-01

    The Equatorial Deep Jets (EDJ) are a dominant signal in the deep Atlantic at the equator. EDJs are vertical alternating zonal currents with a vertical wavelength of only a few hundred meters. They are found from below the Equatorial Undercurrent down to about 2500m. They were also observed in the Pacific and Indian Ocean. The EDJs are focused on the equator and have a meridional extent of about 1.5°S to 1.5°N. In the Atlantic, EDJs oscillate at a period of about 4.5 years as could be shown by...

  11. Impacts of algal blooms removal by chitosan-modified soils on zooplankton community in Taihu Lake,China

    Institute of Scientific and Technical Information of China (English)

    Jiajia Ni; Yuhe Yu; Weisong Feng; Qingyun Yan; Gang pan; Bo Yang; Xiang Zhang; Xuemei Li

    2010-01-01

    It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology,especially removing algal blooms,because algae were the major primary producer in algal lakes.The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study.Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE).A total of 44 zooplankton taxa (23 protozoa,17 rotifers,3 copepoda and 1 cladocera) were detected by microscope checkup,and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616,63 bands amplified by primers Fung-G-C and NS1) were detected by PCR-DGGE.The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites,and DGGE profiles could represent the biologic diversity.The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually.In addition,the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.

  12. Oceanographic profile Chlorophyll, zooplankton biomass and other measurements collected using net in the SE ATLANTIC in 1969 (NODC Accession 0000930)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hutchings, L. 1988. Horozontal distribution of mesozooplankton in the Southern Benguela Current, 1969-1974. Investigational Report of the Sea Fisheries Research...

  13. The Lake Ontario zooplankton community before (1987-1991) and after (2001-2005) invasion-induced ecosystem change

    Science.gov (United States)

    Stewart, T.J.; Johannsson, O.E.; Holeck, K.; Sprules, W.G.; O'Gorman, R.

    2010-01-01

    We assessed changes in Lake Ontario zooplankton biomass, production, and community composition before (1987–1991) and after (2001–2005) invasion-induced ecosystem changes. The ecosystem changes were associated with establishment of invasive dreissenid mussels and invasive predatory cladocerans (Bythotrephes and Cercopagis). Whole-lake total epilimnetic plus metalimnetic zooplankton production declined by approximately half from 42.45 (g dry wt∙m−2∙ year−1) during 1987–1991 to 21.91 (g dry wt∙m−2∙ year−1) in 2003 and averaged 21.01 (g dry wt∙m−2∙ year−1) during 2001–2005. Analysis of two independent data sets indicates that the mean biomass and biomass proportion of cyclopoid copepods declined while the same measures increased for the invasive predatory cladocerans. Changes in means and proportions of all other zooplankton groups were not consistent between the data sets. Cyclopoid copepod biomass and production declined by factors ranging from 3.6 to 5.7. Invasive predatory cladoceran biomass averaged from 5.0% to 8.0% of the total zooplankton biomass. The zooplankton community was otherwise resilient to the invasion-induced disruption as zooplankton species richness and diversity were unaffected. Zooplankton production was likely reduced by declines in primary productivity but may have declined further due to increased predation by alewives and invasive predatory cladocerans. Shifts in zooplankton community structure were consistent with increased predation pressure on cyclopoid copepods by alewives and invasive predatory cladocerans. Predicted declines in the proportion of small cladocerans were not evident. This study represents the first direct comparison of changes in Lake Ontario zooplankton production before and after the invasion-induced disruption and will be important to food web-scale investigations of invasion effects.

  14. Sulphur diagenesis in the sediments of the Kiel Bight, SW Baltic Sea, as reflected by multiple stable sulphur isotopes.

    Science.gov (United States)

    Strauss, Harald; Bast, Rebecca; Cording, Anja; Diekrup, David; Fugmann, Artur; Garbe-Schönberg, Dieter; Lutter, Andreas; Oeser, Martin; Rabe, Katharina; Reinke, Debora; Teichert, Barbara M A; Westernströer, Ulrike

    2012-01-01

    In this work, the biogeochemistry of marine sediments from the Kiel Bight, coastal SW Baltic Sea, is studied based on the abundance and isotopic composition of organic carbon and different forms of sedimentary sulphur. Active bacterial sulphate reduction, partly under sulphate-limiting conditions, is evident from paired δ(34)S and δ(18)O values of pore water sulphate. The resulting pore water sulphide is partly precipitated as acid-volatile iron sulphide and subsequently forms sedimentary pyrite, partly serves in later diagenetic sulphurisation of organic matter, or remains dissolved in the pore water, all evident from the respective δ(34)S values. Microbial sulphate turnover is associated with an apparent isotopic fractionation between dissolved sulphate and dissolved sulphide (Δ(34)S) that varies between 46 and 66‰. PMID:22303924

  15. Ecological evaluation of proposed reference sites in the New York Bight, Great South Bay, and Ambrose Light, New York

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, W.W.; Barrows, E.S.; Word, J.Q. [Battelle Marine Research Lab., Sequim, WA (United States)

    1996-10-01

    The current reference site used in evaluations of dredged material proposed for open water disposal in the New York Bight is the Mud Dump Reference Site. The sediment at this reference site is predominantly sand. The US Army Corps of Engineers New York District is considering designation of a new reference site that (1) includes a fine-grained component, believed to be necessary for adequate amphipod survival in laboratory tests, (2) better reflects the physical characteristics of the fine-grained sediment dredged from the New York/New Jersey Harbor and (3) is further removed from the Mud Dump Site than the current Mud Dump Reference Site. The Battelle Marine Science Laboratory was requested to characterize sediment collected from seven candidate reference sites during two study phases. This report presents the results of physical, chemical, and toxicological characterizations of sediment from these sites in comparisons with those of the original Mud Dump Reference Site.

  16. Evaluation of abiotic stresses of temperate estuaries by using resident zooplankton: A community vs. population approach

    Science.gov (United States)

    Paul, Sourav; Wooldridge, Tris; Perissinotto, Renzo

    2016-03-01

    By using permanently resident zooplankton, we assessed the ecological level (i.e. community and or population) that provides more in-depth indication of the stress related to salinity and temperature fluctuations in temperate estuaries. In the semi-arid warm temperate South Africa, the Gamtoos estuary experiences a full salinity gradient maintained by irregular but relatively frequent freshwater pulses, whereas the Kromme estuary is euhaline throughout its extent and receives only occasional freshwater inputs when the storage reservoir six km upstream overtops. Changes in the species evenness index of Pielou and the abundances of estuarine resident zooplankton species were modelled against salinity and temperature variations of respective estuaries. In the Gamtoos estuary, response of individual populations provided more in-depth information regarding zooplankton variability. However the most abundant resident zooplankton i.e. Acartia longipatella a copepod was not the best predictor of the salinity and temperature fluctuations. Conversely, the Kromme estuary study provided insights into the potential vulnerability of the resident estuarine zooplankton community to cold. Further, the population level study exposed responses of specific species against salinity changes. We discuss the pros and cons of designing ecological indicators of abiotic stress based on specific species, targeted to specific ecological level, and needs of considering the frequency and magnitude of fresh water inflow in an estuary. A suggestion is to use specific taxonomic group(s) (e.g. Copepods) to better understand the abiotic stress factors of specific set of estuaries (e.g. freshwater rich/starved) until a 'one size fits all' indicator is found for temperate estuaries.

  17. A global analysis of zooplankton in natural and artificial fresh waters

    Directory of Open Access Journals (Sweden)

    Faye L. Merrix-Jones

    2013-02-01

    Full Text Available Water-body size and location influence zooplankton diversity in freshwaters, but less is known about systematic variations in zooplankton community composition between natural and artificial waters on different continents. We used meta-analysis to assess how zooplankton in artificial water bodies across different biomes might differ from natural water bodies of similar size. Among 79 lakes, ponds and reservoirs (11 artificial and 68 natural, proximity to other water bodies apparently increased species richness in all lake types, probably reflecting dispersal. However, richness did not differ systematically between natural and artificial water bodies of comparable size. In contrast, community composition differed between artificial and natural waters after accounting for depth, productivity, longitude and conductivity, with models explaining up to 50% of the overall variance at genus level. Leptodiaptomus, Chydorus, Cyclops, Acanthocyclops, Skistodiaptomus, Epischura, Limnocalanus, Senecella, Heterocope, Arctodiaptomus and Aglaodiaptomus all occurred more frequently in natural waters, whilst Thermocyclops, Moina and Epischura occurred more frequently in artificial lakes. Rank-occurrence data revealed that Ceriodaphnia, Orthocyclops, Holopedium and Eucyclops were equitably distributed across water bodies of contrasting sizes, depths and climates. Other genera occurred under more specific conditions, typically where they had strong associations with natural lakes (e.g. Limnocalanus, Senecella, Heterocope, Arctodiaptomus and Aglaodiaptomus. These results are among the first to illustrate systematic differences in zooplankton composition between natural and artificial lakes at a global scale. Potential explanations require further evidence, but might include provision for niche specialists in natural lakes versus reduced heterogeneity, management or disturbance effects in artificial lakes; and effects of lake age, stability and habitat naturalness in

  18. Spatio-temporal variability of the North Sea cod recruitment in relation to temperature and zooplankton.

    Directory of Open Access Journals (Sweden)

    Delphine Nicolas

    Full Text Available The North Sea cod (Gadus morhua, L. stock has continuously declined over the past four decades linked with overfishing and climate change. Changes in stock structure due to overfishing have made the stock largely dependent on its recruitment success, which greatly relies on environmental conditions. Here we focus on the spatio-temporal variability of cod recruitment in an effort to detect changes during the critical early life stages. Using International Bottom Trawl Survey (IBTS data from 1974 to 2011, a major spatio-temporal change in the distribution of cod recruits was identified in the late 1990s, characterized by a pronounced decrease in the central and southeastern North Sea stock. Other minor spatial changes were also recorded in the mid-1980s and early 1990s. We tested whether the observed changes in recruits distribution could be related with direct (i.e. temperature and/or indirect (i.e. changes in the quantity and quality of zooplankton prey effects of climate variability. The analyses were based on spatially-resolved time series, i.e. sea surface temperature (SST from the Hadley Center and zooplankton records from the Continuous Plankton Recorder Survey. We showed that spring SST increase was the main driver for the most recent decrease in cod recruitment. The late 1990s were also characterized by relatively low total zooplankton biomass, particularly of energy-rich zooplankton such as the copepod Calanus finmarchicus, which have further contributed to the decline of North Sea cod recruitment. Long-term spatially-resolved observations were used to produce regional distribution models that could further be used to predict the abundance of North Sea cod recruits based on temperature and zooplankton food availability.

  19. Zooplankton distribution and behaviour in the Southern Ocean from surveys with a towed Optical Plankton Counter

    Science.gov (United States)

    Pollard, R. T.; Bathmann, U.; Dubischar, C.; Read, J. F.; Lucas, M.

    Spatial distributions of zooplankton with lengths between about 500 μm and 8 mm are described from surveys in the vicinity of the Antarctic Polar Front in austral summer 1995/6 using an Optical Plankton Counter mounted on a towed profiling SeaSoar. The distributions, split into several logarithmically spaced size classes, are compared and related to the physical environment south of the Polar Front in the Antarctic Zone and within the Polar Frontal Zone. They also are compared with phytoplankton distributions determined from surface chlorophyll data. Both phytoplankton and zooplankton carbon densities are low in the Antarctic Zone (2-3 g C m -2), but rise to larger values in the Polar Frontal Zone (5-7 g C m -2 for zooplankton and a maximum of 6 g C m -2 at fronts for phytoplankton). Calibration of OPC derived zooplankton biovolume to carbon was achieved by comparison with dry weights from multinet samples deployed in conjunction with CTD casts. The net data showed that over 98% of zooplankton counts were copepods. Diel behaviour also was examined. Only larger copepods (over 2 mm long) displayed significant diel migration, and then only 10-20% of the standing stock; the majority remained deeper than about 100 m and their distribution patterns suggest that they may be retained aside from the main frontal jets by ageostrophic circulations associated with the front. Copepods shorter than 2 mm rose from depth over the month-long survey to become concentrated in the surface layer (the top 70-100 m). The largest copepods that could be resolved, with lengths of about 4-8 mm (possibly Rhincalanus gigas), displayed unexpected behaviour in tending to migrate to the top 0-10 m by day, descending to 40-50 m each night.

  20. Atlantic City memories.

    Science.gov (United States)

    Epstein, Franklin H

    2008-04-01

    Fifty years ago, the Atlantic City meetings, held the first week in May of every year, were attended by all the elite of American academic medicine and all who wanted to join that group. Part of the magic of those meetings was that professors and neophytes took each other seriously and talked to each other. PMID:18382726

  1. Validation of Open-Sea CRYOSAT-2 Data in SAR Mode in the German Bight

    Science.gov (United States)

    Dinardo, Salvatore; Benveniste, Jérôme; Fenoglio-Marc, Luciana; Scharroo, Remko

    This work aims to generate and validate the altimetric geophysical parameters measured by the CryoSat-2 in SAR Mode in the temporal interval 2011-2012 in the area of the German Bight at distance to coast larger than 10 Kilometers (open-sea). Instantaneous sea surface height (SSH), significant wave height (SWH) and wind speed at 10 meter from sea surface (U10), measured by CryoSat-2, are compared to in-situ measurements at platforms, buoys and tide gauges and to results from an operational circulation model run by the German Federal Maritime and Hydrographic Agency (BSH). The in-situ data were made available by the Wasser- und Schifffahrtsverwaltung des Bundes (WSV). These stations are part of a network of tide gauges and offshore platforms equipped with continuously operation Global Navigation Satellite System (GNSS) receivers. Since the coordinates of the zero point of the tide gauge are computed in the International Terrestrial Reference Frame (ITRF) the absolute comparison between sea level from tide gauge and altimetry is possible. The relevant in-situ data are sea level, wave and wind data. The CryoSat-2 Data have been Delay-Doppler processed as from the FBR (Full Bit Rate) Level 1A to Level 1B and subsequently re-tracked using the SAMOSA's SAR Echo Model (full solution) and a curve-fitting scheme based on Levenberg-Marquard Least Square Minimization Algorithm. Sea surface height, significant wave height and wind speed at 20 Hz and 1 Hz have been derived. The Delay-Doppler processing (L1B) and the re-tracking processing (L2) has been carried out by the EOP-SER Altimetry Team at ESA/ESRIN. Pseudo pulse-limited (PLRM) data derived from CryoSat-2 in SAR mode and provided via the RADS database are compared with the same parameters derived from the CryoSat-2 SAR Data to estimate possible biases and trends between SAR mode and LRM mode and tune-up the SAR re-tracking scheme. Special attention will be paid to spot trends between SAR and PLRM with respect the orbital

  2. Atlantic tropical cyclones revisited

    Science.gov (United States)

    Mann, Michael E.; Emanuel, Kerry A.; Holland, Greg J.; Webster, Peter J.

    Vigorous discussions have taken place recently in Eos [e.g., Mann and Emanuel, 2006; Landsea, 2007] and elsewhere [Emanuel, 2005; Webster et al., 2005; Hoyos et al., 2006; Trenberth and Shea, 2006; Kossin et al., 2007] regarding trends in North Atlantic tropical cyclone (TC) activity and their potential connection with anthropogenic climate change. In one study, for example [Landsea, 2007], it is argued that a substantial underestimate of Atlantic tropical cyclone counts in earlier decades arising from insufficient observing systems invalidates the conclusion that trends in TC behavior may be connected to climate change. Here we argue that such connections are in fact robust with respect to uncertainties in earlier observations.Several recent studies have investigated trends in various measures of TC activity. Emanuel [2005] showed that a measure of total power dissipation by TCs (the power dissipation index, or PDI) is highly correlated with August-October sea surface temperatures (SST) over the main development region (MDR) for Atlantic TCs over at least the past half century. Some support for this conclusion was provided by Sriver and Ruber [2006]. Webster et al. [2005] demonstrated a statistically significant increase in recent decades in both the total number of the strongest category cyclones (categories 4 and 5) and the proportion of storms reaching hurricane intensity. Hoyos et al. [2006] showed that these increases were closely tied to warming trends in tropical Atlantic SST, while, for example, the modest decrease in vertical wind shear played a more secondary role. Kossin et al. [2007] called into question some trends in other basins, based on a reanalysis of past TC data, but they found the North Atlantic trends to be robust.

  3. Delineation of estuarine fronts in the German Bight using airborne laser-induced water Raman backscatter and fluorescence of water column constituents

    Science.gov (United States)

    Hoge, F. E.; Swift, R. N.

    1982-01-01

    The acquisition and application of airborne laser induced emission spectra from German Bight water during the 1979 MARSEN experiment is detailed for the synoptic location of estuarine fronts. The NASA Airborne Oceanographic Lidar (AOL) was operated in the fluorosensing mode. A nitrogen laser transmitter at 337.1 nm was used to stimulate the water column to obtain Gelbstoff or organic material fluorescence spectra together with water Raman backscatter. Maps showing the location and relative strength of estuarine fronts are presented. The distribution of the fronts indicates that mixing within the German Bight takes place across a relatively large area. Reasonable agreement between the patterns observed by the AOL and published results are obtained. The limitations and constraints of this technique are indicated and improvements to the AOL fluorosensor are discussed with respect to future ocean mapping applications.

  4. Concentrations of 137Cs and trace elements in zooplankton, and their vertical distributions off Rokkasho, Japan

    International Nuclear Information System (INIS)

    Zooplankton samples were collected at about 50 m depth with a large ring net (160-cm mouth diameter, 0.5-mm mesh) in May, June, October 2005 and June 2006 off Rokkasho, Japan where a nuclear fuel reprocessing plant will be in full-scale operation in the near future. Plankters in each sample were separated based on their species. Eight samples were used for the determination of 137Cs concentration and the other 21 samples were used for the determination of its stable isotope, Cs along with some other trace elements. All the samples were characterized by five dominant species, i.e. euphausiids, chaetognaths, copepods; Neocalanus spp., amphipods; Themisto spp. and Cyphocaris sp. Plankton samples were also taken at three to five discrete depths between the surface and ≤ 1,000 m in depth during daytime and nighttime for analysis of vertical distribution patterns of biomass, and for assessment of daily vertical migration activity. Integrated net zooplankton biomass at nighttime ranged from 0.85 to 8.74 g-DW m-2 in the 0-150 m layer without any appreciable day-night differences in the vertical distribution; below the layer, it decreased significantly. Only in spring, appreciable day-night differences in the vertical distribution were observed at the shallowest station. Concentrations of Cs and Co did not show significant difference among the five species. However, higher concentrations of Sr were observed in two amphipods. It is likely that amphipods had a different biological process in Sr metabolism from others. The concentration of 137Cs in zooplankton was usually very low and sometimes under the detection limit. In the present study, the highest concentration of 137Cs in zooplankton was 24 mBq kg-WW-1, corresponding to the concentration factor (CF) of 14, if the value of 1.7 mBq L-1 was given to the 137Cs concentration in seawater. The water-column inventory of 137Cs in a zooplankton community is calculated to be 0.29 to 1.95 mBq m-2, based on the data on biomass

  5. Syrticola flandricus n.g., n.sp., a harpacticoid copepod from the Southern Bight of the North Sea

    OpenAIRE

    Willems, K.A.; Claeys, D.

    1982-01-01

    During a comprehensive study of the macro- and meiobenthos of the Kwintebank, a sandbank in the Southern Bight of the North Sea, eleven female specimens of a cylindropsyllid, belonging to a new genus, were collected from one of the stations sampled. The station's coordinates are 51°18'00''N 2°40'10''E. The sediment at this stations is a pure, very well sorted, coarse sand (median grain size: 517 µm; sorting: 0.24; mud

  6. Ecological factors affecting the distribution of the zooplankton community in the Tigris River at Baghdad region, Iraq

    OpenAIRE

    Shayma Abdulwahab; Adel M. Rabee

    2015-01-01

    Biodiversity of zooplankton in the Tigris River running in Baghdad City, central Iraq, was investigated. Fourteen physical and chemical parameters, were analyzed, these parameters include water and air temperature, pH, EC, turbidity, TDS, DO, BOD5, total hardness, Ca+2, Mg+2, chloride, nitrate and reactive phosphate. Most of these values were within of the Iraqi and international standard limits. In all, 106 taxonomy units of zooplankton were identified, including 65 taxa belonging to rotifer...

  7. The Uday river’s littoral zooplankton in the region of the national nature park «Pyriatynskiy»

    OpenAIRE

    V. N. Trokhymets; M. V. Sydorenko; A. V. Podobaylo

    2011-01-01

    The ecological-faunistic analysis of the littoral zooplankton of the middle part of the Uday River has been performed for the first time. The research was conducted to confirm a reason to create the National Nature Park «Pyriatynskiy» in this region. The species diversity of the littoral zooplankton obtained from six scientific stations on the Uday River was established. The specific features of the zooplankton’s distribution in biotopes in summer days were revealed. The comparative descripti...

  8. Changes in abundance and community structure of the zooplankton population during the 2008 mucilage event in the northeastern Marmara Sea

    OpenAIRE

    OKYAR, Melek İŞİNİBİLİR; Üstün, Funda; ORUN, Deniz Ayşe

    2015-01-01

    The composition and abundance of zooplankton and the corresponding environmental conditions were investigated during the 2008 mucilage event (April-December 2008) in the Marmara Sea. As a result, 46 zooplanktonic taxa were identified. Copepods and cladocerans were generally the most abundant groups. Mnemiopsis leidyi had a significant seasonality, and abundance was related to fluctuations in temperature and salinity. The most important species were Acartia clausi and Penilia avirostris, but t...

  9. Effects of acidification and cadmium pollution on the populations and habitats of limnetic zooplankton; Effekter av forsuring og kadmium-forurensning paa populasjoner og samfunn av limnisk zooplankton

    Energy Technology Data Exchange (ETDEWEB)

    Schartau, A.K.L. [Norsk Inst. for Naturforskning, Trondheim (Norway)

    1996-01-01

    The conference paper deals with executed field tests on the adding of cadmium alone or combined with acidification of an enclosed space under different nutrient and predatory conditions. The addition of cadmium changed the biomass and the composition of the phytoplankton. In combination with the added nutrient salts, the biomass of special algae increased in the Cd loaded spaces, and the addition of acid changed the effect of Cd concentration by increased production of the same. The effect of a given Cd concentration on the zooplankton varied in a wide range of environmental conditions. 22 refs., 1 tab.

  10. Zooplankton spatial and diurnal variations in the Changjiang River estuary before operation of the Three Gorges Dam

    Institute of Scientific and Technical Information of China (English)

    GAO Xuelu; SONG Jinming; LI Xuegang

    2011-01-01

    Estuarine plankton communities can serve as indicators of ecosystem modification in response to anthropogenic influences. The main objectives of this study were to describe the spatial distribution and diurnal variability in zooplankton abundance and biomass over almost entire salinity gradient of the Changjiang (Yangtze) River estuary and to provide a background reference for future studies. To accomplish this, data were collected from 29 stations in the estuary from May 19 to 26, 2003,including two anchor stations. The spatial and diurnal variations in zooplankton characteristics, i.e.abundance, biomass, and gross taxonomic composition, were examined. Generally, both the abundance and biomass gradually increased seaward and presented distinct spatial variations. In addition, the spatial data revealed a significant correlation between abundance and biomass; however, there was no significant correlation between abundance and biomass for the diurnal data. Although the zooplankton composition indicated distinct spatial differences in terms of dominant groups, copepods accounted for >50% of the total zooplankton abundance in most regions and times. Three zooplankton assemblages were recognized through hierarchical cluster analysis. These assemblages existed along the salinity gradient from fresh water to seawater, and their positions coincided with those of the three principal water masses in the estuary. The assemblages were classified as: (1) true estuarine, (2) estuarine and marine, and (3) euryhaline marine, which were characterized by the copepods Sinocalanus dorrii, Labidocera euchaeta, and Calanus sinicus, respectively. Both spatial and diurnal data indicated that there was no significant correlation between zooplankton abundance/biomass and depth-integrated phytoplankton abundance.

  11. Experimental whole-lake increase of dissolved organic carbon concentration produces unexpected increase in crustacean zooplankton density.

    Science.gov (United States)

    Kelly, Patrick T; Craig, Nicola; Solomon, Christopher T; Weidel, Brian C; Zwart, Jacob A; Jones, Stuart E

    2016-08-01

    The observed pattern of lake browning, or increased terrestrial dissolved organic carbon (DOC) concentration, across the northern hemisphere has amplified the importance of understanding how consumer productivity varies with DOC concentration. Results from comparative studies suggest these increased DOC concentrations may reduce crustacean zooplankton productivity due to reductions in resource quality and volume of suitable habitat. Although these spatial comparisons provide an expectation for the response of zooplankton productivity as DOC concentration increases, we still have an incomplete understanding of how zooplankton respond to temporal increases in DOC concentration within a single system. As such, we used a whole-lake manipulation, in which DOC concentration was increased from 8 to 11 mg L(-1) in one basin of a manipulated lake, to test the hypothesis that crustacean zooplankton production should subsequently decrease. In contrast to the spatially derived expectation of sharp DOC-mediated decline, we observed a small increase in zooplankton densities in response to our experimental increase in DOC concentration of the treatment basin. This was due to significant increases in gross primary production and resource quality (lower seston carbon-to-phosphorus ratio; C:P). These results demonstrate that temporal changes in lake characteristics due to increased DOC may impact zooplankton in ways that differ from those observed in spatial surveys. We also identified significant interannual variability across our study region, which highlights potential difficulty in detecting temporal responses of organism abundances to gradual environmental change (e.g., browning). PMID:26919470

  12. Comparative studies on zooplankton community between the sea surface microlayer and the subsurface microlayer in Daya Bay, China

    Institute of Scientific and Technical Information of China (English)

    YANG Yufeng

    2005-01-01

    Characteristics of the zooplankton community inhabiting the sea surface microlayer (SM) and the sub-surface microlayer (SSM) are compared at six sampling stations in Daya Bay, near Shenzhen City of China during 2 cruises in 1999. This is the first study on zooplankton community in the SM in China. Results show that protozoans and nauplii are the most dominant components, accounting for 80.71% (SM) and 89.15% (SSM) of the total zooplankton in the average abundance, respectively. The densities of copepods (adult + copepodid) are higher in the SSM than in the SM. The size-frequency distributions indicate that the frequency of micro-zooplankton (<0.2mm) is higher in the SM (0.8235, n =290) than in the SSM (0.6768, n = 306). Enrichment phenomenon of zooplankton is detected in the SM at the sampling stations excluding two stations near nuclear power plants (NPP). The enrichment factor is from 1. 516to 3. 364 with the average value of 2. 267. The SM zooplankton community structure revealed in the present study is quite different from previous investigations in the Bay. Typical sea water characteristics such as turbidity, biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and chlorophyll a (Chl-a) indicate that the water quality is poorer in the SM than in the SSM.

  13. Experimental whole-lake increase of dissolved organic carbon concentration produces unexpected increase in crustacean zooplankton density

    Science.gov (United States)

    Kelly, Patrick T.; Craig, Nicola; Solomon, Christopher T.; Weidel, Brian C.; Zwart, Jacob A.; Jones, Stuart E.

    2016-01-01

    The observed pattern of lake browning, or increased terrestrial dissolved organic carbon (DOC) concentration, across the northern hemisphere has amplified the importance of understanding how consumer productivity varies with DOC concentration. Results from comparative studies suggest these increased DOC concentrations may reduce crustacean zooplankton productivity due to reductions in resource quality and volume of suitable habitat. Although these spatial comparisons provide an expectation for the response of zooplankton productivity as DOC concentration increases, we still have an incomplete understanding of how zooplankton respond to temporal increases in DOC concentration within a single system. As such, we used a whole-lake manipulation, in which DOC concentration was increased from 8 to 11 mg L−1 in one basin of a manipulated lake, to test the hypothesis that crustacean zooplankton production should subsequently decrease. In contrast to the spatially derived expectation of sharp DOC-mediated decline, we observed a small increase in zooplankton densities in response to our experimental increase in DOC concentration of the treatment basin. This was due to significant increases in gross primary production and resource quality (lower seston carbon-to-phosphorus ratio; C:P). These results demonstrate that temporal changes in lake characteristics due to increased DOC may impact zooplankton in ways that differ from those observed in spatial surveys. We also identified significant interannual variability across our study region, which highlights potential difficulty in detecting temporal responses of organism abundances to gradual environmental change (e.g., browning).

  14. Effects of natural banks of free-floating plants on zooplankton community in a shallow subtropical lake in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Vanessa Gazulha

    2011-08-01

    Full Text Available The aim of this study was to test the effects of natural free-floating plants on zooplankton distribution in a shallow subtropical lake. First, the hypothesis that free-floating plants have an effect on physico-chemicals, leading to a decrease on nutrient availability and influencing the phytoplankton biomass and zooplankton community was tested. Second, the hypothesis that free-floating plants act as a refuge for zooplankton was tested. Three microhabitats were selected: free-floating plants, littoral area and open water. Results demonstrated that the effects of different microhabitats on phytoplankton biomass and physico-chemicals were not significant, indicating a weak influence of the plants. Zooplankton densities were higher in free-floating plants and littoral area, although the effect of microhabitats was weak for most of the predominant genera. The absence of free-floating plant effects on phytoplankton and physico-chemicals showed that it was not a factor influencing the microcrustacean distribution in the microhabitats. Low differences in densities of zooplankton among microhabitats and low abundance of large-bodied cladocerans led to reject the hypothesis that free-floating plants act as a refuge for zooplankton.

  15. Evaluation of factors related to increased zooplankton biomass and altered species composition following impoundment of a Newfoundland reservoir

    International Nuclear Information System (INIS)

    An 11-year study of the zooplankton community in Cat Arm Hydroelectric Reservoir in Newfoundland was conducted to assess long-term zooplankton community dynamics in a subarctic system. Zooplankton biomass and species compositions were monitored from 1983 to 1993. The monitoring program documented the trophic evolution of the Cat Arm system as it changed from a shallow lake with short water retention time to a deep reservoir with a much lower flushing rate. Zooplankton biomass increased approximately 19-fold in the oligotrophic hydroelectric reservoir following impoundment in 1984, relative to biomass in the preexisting lake. During the first three years of impoundment, there were no increases in either phytoplankton biomass or primary productivity. Natality of the dominant cladoceran (Daphnia catawba) did not increase. Summer water retention time increased from pre-impoundment levels of 4 days in 1983 to 338 days in 1993. The study showed that zooplankton biomass was greatly correlated with water retention time, and showed no major correlation with phytoplankton biomass, primary productivity, nutrient concentrations, pH, colour, or epilimnetic temperature. It was concluded that changes in the zooplankton community in the hydroelectric reservoir were a result of decreases in losses due to washout. 41 refs., 2 tabs., 6 figs

  16. Temporal variability of vertical migration of zooplankton at deep-sea floor in the Amundsen Sea, Antarctica

    Science.gov (United States)

    Sul La, Hyoung; Ha, Ho Kyung; Kang, Chan Young; Wåhlin, Anna; Park, Jisoo; Lee, SangHoon; Shin, Hyoung Chul

    2014-05-01

    Vertical migration of zooplankton is ubiquitous behavior in marine plankton community. Observations on diel, seasonal, and interannual variation of zooplankton behavior can support the knowledge for understanding of marine ecosystems. However, daily and seasonal rhythms are little observed in the deep-sea with seasonally ice-covered water. We described the pattern of diel vertical distribution (DVM) above deep-sea floor in a seasonally ice-covered Amundsen Sea. Times series of acoustic backscatter was observed using a bottom-moored, upward-looking Acoustic Doppler current profiler (ADCP) in the depth of 250-550 m. Multi-frequency acoustic backscatter data (38 and 120 kHz, EK60) were collected to identify the composition of DVM between fish and zooplankton using a dB differencing technique. The seasonal vertical distribution of zooplankton was clearly governed by the seasonal phase of surface solar radiation (SSR) and sea ice condition (SIC), while water temperature did not affect on the DVM variation. The main depths of zooplankton were primarily distributed near 250 m with high SSR and low SIC period and found near bottom in the lowermost layers (>400 m) with low SSR and high SIC between mid-April and mid-November. The temporal variation of main depths of zooplankton was significantly correlated with both SSR and SIC (r = 0.87 and -0.70, respectively, ppump.

  17. Atlantic Basin refining profitability

    International Nuclear Information System (INIS)

    A review of the profitability margins of oil refining in the Atlantic Basin was presented. Petroleum refiners face the continuous challenge of balancing supply with demand. It would appear that the profitability margins in the Atlantic Basin will increase significantly in the near future because of shrinking supply surpluses. Refinery capacity utilization has reached higher levels than ever before. The American Petroleum Institute reported that in August 1997, U.S. refineries used 99 per cent of their capacity for several weeks in a row. U.S. gasoline inventories have also declined as the industry has focused on reducing capital costs. This is further evidence that supply and demand are tightly balanced. Some of the reasons for tightening supplies were reviewed. It was predicted that U.S. gasoline demand will continue to grow in the near future. Gasoline demand has not declined as expected because new vehicles are not any more fuel efficient today than they were a decade ago. Although federally-mandated fuel efficiency standards were designed to lower gasoline consumption, they may actually have prevented consumption from falling. Atlantic margins were predicted to continue moving up because of the supply and demand evidence: high capacity utilization rates, low operating inventories, limited capacity addition resulting from lower capital spending, continued U.S. gasoline demand growth, and steady total oil demand growth. 11 figs

  18. The dynamics of nutrient, toxic phytoplankton, nontoxic phytoplankton and zooplankton model

    Directory of Open Access Journals (Sweden)

    Hasnaa Fiesal Mohammed Hussien

    2016-02-01

    Full Text Available The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability conditions of all possible equilibrium points are established. The occurrence of local bifurcation and Hopf bifurcation are investigated. Finally, numerical simulation is used to study the global dynamics of this model.

  19. Structure, seasonal dynamics and distribution of zooplankton in lake Drukshiai in 1994

    International Nuclear Information System (INIS)

    Investigations on the zooplankton of Lake Drukshiai were carried out in 1994. There were registered 62 taxons of protozoa and 50 taxons of metazoa, and compared with the data of 1979 - 1986 the diversity of species composition decreased 2.1 times. Eurytermic and stenothermic thermophylic species prevailed in the plankton biocenosis. In protozooplankton dominated ciliates of subclasses teolotricha and spirotricha, in metazooplankton -planctonic crustacea (Copopeda and Cladocera). Rotifers (Rotaria) were abundant only in the shallow and heated water outlet area. Seasonal dynamics of protozooplankton indicated one maximum in spring and metazooplankton - in summer. High diferentiation in quantity and biomass of zooplankton in the lake revealed different level of eutrophication of some areas. (author). 7 refs., 5 figs

  20. Method for the in situ study of pollutant effects on natural zooplankton communities

    International Nuclear Information System (INIS)

    A new method was developed and tested for the in situ study of pollutant effects on zooplankton communities in large lakes which does not suffer the limitations of large enclosures. In each of five experiments conducted in northern Green Bay, Lake Michigan, two to four samples of lower epilimnion water for each of four levels of added pollutant (Cd) plus controls were incubated in situ in opaque, polyethylene carboys (2 to 5 gallon size) for 4 to 15 days. In each experiment 2 to 4 additional samples, which were not incubated, were also taken. This new method appears to overcome some of the limitations imposed by the use of large, transparent bags or open-top tubes in large lakes for studies of pollutant effects on zooplankton, at least for short- to intermediate-term effects

  1. Swimming in turbulence: zooplankton fitness in terms of foraging efficiency and predation risk

    DEFF Research Database (Denmark)

    Visser, Andre; Mariani, Patrizio; Pigolotti, Simone

    2009-01-01

    idealized descriptions of foraging and predation in a turbulent water column, we determine how fast a zooplankter should swim, if at all, and where should it position itself in the vertical to maximize its fitness given certain environmental conditions. Suspension feeding has an advantage over ambush......Turbulence impacts zooplankton fitness in opposing manners, by increasing contacts with prey but at the same time increasing contacts with predators. We investigate the fitness of individual zooplankton in terms of a trade-off between energetic gains and costs, and risk of predation. Through...... feeding at high turbulence levels, whereas cruise feeding becomes optimal at low turbulence levels. In general, behaviours that seek out low levels of turbulence increase an individual's fitness, a prediction that runs counter to turbulent encounter rate arguments, and exposes the fallacy of examining...

  2. Phytoplankton response to winter warming modified by large-bodied zooplankton: an experimental microcosm study

    Directory of Open Access Journals (Sweden)

    Hu He

    2015-03-01

    Full Text Available While several field investigations have demonstrated significant effects of cool season (winter or spring warming on phytoplankton development, the role played by large-bodied zooplankton grazers for the responses of phytoplankton to winter warming is ambiguous. We conducted an outdoor experiment to compare the effect of winter warming (heating by 3°C in combination with presence and absence of Daphnia grazing (D. similis on phytoplankton standing crops and community structure under eutrophic conditions. When Daphnia were absent, warming was associated with significant increases in phytoplankton biomass and cyanobacterial dominance. In contrast, when Daphnia were present, warming effects on phytoplankton dynamics were offset by warming-enhanced grazing, resulting in no significant change in biomass or taxonomic dominance. These results emphasize that large-bodied zooplankton like Daphnia spp. may play an important role in modulating the interactions between climate warming and phytoplankton dynamics in nutrient rich lake ecosystems.

  3. Estimates of zooplankton abundance and size distribution with the Optical Plankton Counter (OPC)

    DEFF Research Database (Denmark)

    Wieland, Kai; Petersen, D.; Schnack, D.

    1997-01-01

    The capability of the Optical Plankton Count er (OPC) to examine the abundance and size distribution of zooplankton was tested in Storfjorden, Norway, in June 1993. Selected material obtained from net sampling was measured with a laboratory version of the OPC and compared with microscope analysis...... in order to identify main species in the in situ size frequency distributions obtained by the submersible version of the OPC. Differences in the particle concentration between shallow and deep water layers were clearly resolved by the submersible OPC, but the high diversity of the zooplankton...... community and widely overlapping size ranges prevented a detailed analysis of the fine scale vertical distribution and the horizontal variability of abundance for distinct species. These results are used to discuss the limitations of the OPC for rapid and continuous surveying of spatial distribution and...

  4. Estimates of zooplankton abundance and size distribution with the Optical Plankton Counter (OPC)

    DEFF Research Database (Denmark)

    Wieland, Kai; Petersen, D.; Schnack, D.

    1997-01-01

    and widely overlapping size ranges prevented a detailed analysis of the fine scale vertical distribution and the horizontal variability of abundance for distinct species. These results are used to discuss the limitations of the OPC for rapid and continuous surveying of spatial distribution and abundance......The capability of the Optical Plankton Count er (OPC) to examine the abundance and size distribution of zooplankton was tested in Storfjorden, Norway, in June 1993. Selected material obtained from net sampling was measured with a laboratory version of the OPC and compared with microscope analysis...... in order to identify main species in the in situ size frequency distributions obtained by the submersible version of the OPC. Differences in the particle concentration between shallow and deep water layers were clearly resolved by the submersible OPC, but the high diversity of the zooplankton community...

  5. Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

    KAUST Repository

    Chust, Guillem

    2013-09-16

    In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was triggered by sea warming, using Generalized Additive Models. To this end, the population gravity centre of observed data was compared with that of a series of simulation experiments: (i) a model using only climate factors (i.e. niche-based model) to simulate species habitat suitability, (ii) a model using only temporal and spatial terms to reconstruct the population distribution, and (iii) a model using both factors combined, using a subset of observations as independent dataset for validation. Our findings show that only C. finmarchicus had a consistent poleward shift, triggered by sea warming, estimated in 8.1 km per decade in the North Atlantic (16.5 per decade for the northeast), which is substantially lower than previous works at the assemblage level and restricted to the Northeast Atlantic. On the contrary, C. helgolandicus is expanding in all directions, although its northern distribution limit in the North Sea has shifted northward. Calanus glacialis and C. hyperboreus, which have the geographic centres of populations mainly in the NW Atlantic, showed a slight southward shift, probably responding to cool water penetrating southward in the Labrador Current. Our approach, supported by high model accuracy, shows its power in detecting species latitudinal shifts and identifying its causes, since the trend of occurrence observed data is influenced by the sampling frequency, which has progressively concentrated to lower latitudes with time. © 2013 © 2013 International Council for

  6. NOAA TIFF Image - 10m Backscatter Mosaic, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2010), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the backscatter (intensity) of several deep coral priority areas off the South...

  7. Continental shelf processes effecting the oceanography of the South Atlantic Bight. Hydrography of Onslow Bay, North Carolina: September 1975 (OBIS II). Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, L P; Singer, J J; Dunstan, W M; Pietrafesa, L J

    1976-03-12

    Over the course of OBIS II, 3-14 September, two intrusion cores were observed. One was apparently trapped nearshore over much of the study period, but as time went on, it either dissipated, moved too far shoreward or moved too far laterally along the shelf to be detected by the existing observational grid. The other (later) intrusion was first detected on 5-7 September and was observed to be moving into the Bay from the southeast over the remainder of the study period. Plots of the horizontal temperature and salinity distribution were suggestive of these phenomenon by means of the higher salinity-lower temperature relationship. However, the real confirmation rests in the vertical distributions of sigma-t and chlorophyll presented in conjunction with the Bio and Hydrogrids, and the T--S plot which reveals slope waters on the shelf. The intruded waters were not of low enough temperature to carry high nutrient concentrations onto the shelf for study. However, the general results of this study tend to confirm the view that our basic grid array and methods are compatible with measurement of the processes we initially set out to study. Analyses of these data relative to the current meter data will allow a nearly complete description of the Onslow Bay system during the observational period.

  8. NOAA TIFF Image - 30m Slope, South Atlantic Bight - Deep Coral Priority Areas - USNS Pathfinder - (2003), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the slope (in degrees) of the 2003 multibeam bathymetry of the Charleston Bump off...

  9. NOAA TIFF Image - 30m Slope, South Atlantic Bight - Deep Coral Priority Areas - Thomas Jefferson - (2007), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the slope (in degrees) of the multibeam bathymetry of the Charleston Bump off of the...

  10. MAB_mobile_freq.SHP: recurrence interval of sediment mobility at select points in the Middle Atlantic Bight for May, 2010 - May, 2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has been characterizing the regional variation in shear stress on the sea floor and sediment mobility through statistical descriptors....

  11. NOAA TIFF Image - 4m Bathymetric Principal Component Analysis (PCA) of Red Snapper Research Areas in the South Atlantic Bight, 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains unified Bathymetric PCA GeoTiffs with 4x4 meter cell resolution describing the topography of 15 areas along the shelf edge off the South...

  12. Median of wave-current bottom shear stress in the Middle Atlantic Bight for May, 2010 - May, 2011 (MAB_median.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has been characterizing the regional variation in shear stress on the sea floor and sediment mobility through statistical descriptors....

  13. NOAA TIFF Image - 10m Backscatter Mosaic, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2009), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the backscatter (intensity) of several deep coral priority areas off the South...

  14. NOAA TIFF Image - 5m Backscatter Mosaic, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 5x5 meter cell size representing the backscatter (intensity) of several deep coral priority areas off the South...

  15. 95th percentile of wave-current bottom shear stress in the Middle Atlantic Bight for May, 2010 - May, 2011 (MAB_95th_perc.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has been characterizing the regional variation in shear stress on the sea floor and sediment mobility through statistical descriptors....

  16. Percentage of time sediment is mobile for May, 2010 - May, 2011 at select points in the Middle Atlantic Bight (MAB_mobile_perc.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has been characterizing the regional variation in shear stress on the sea floor and sediment mobility through statistical descriptors....

  17. Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C. Andersson

    2009-07-01

    Full Text Available The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6 ka. For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3 upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

  18. Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C. Andersson

    2010-03-01

    Full Text Available The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6000 years before present (6 ka. For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3 upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

  19. Zooplankton characterisation of Pampean saline shallow lakes, habitat of the Andean flamingoes

    OpenAIRE

    Yamila S. Battauz; Susana B. José de Paggi; Juan C. Paggi; Marcelo Romano; Ignacio Barberis

    2013-01-01

    The lowland saline shallow lakes in the Pampa de las Lagunas (Argentina), constitute an important habitat for flamingoes Phoenicopterus chilensis Molina and Phoenicoparrus andinus (Philippii). Little is known about the zooplankton communities of these systems, and their relationships with the temporal and spatial distribution of flamingoes. Ten shallow lakes in the Pampean region were studied in 2009 and 2010 winters, and in 2010 summer in order to assess the abundance, size and biomass of zo...

  20. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    Czech Academy of Sciences Publication Activity Database

    Stockdale, A.; Tipping, E.; Lofts, S.; Fott, J.; Garmo, Ø.; Hruška, Jakub; Keller, B.; Löfgren, S.; Maberlyh, S.; Majer, V.; Nierzwicki-Bauer, S. A.; Persson, G.; Schartau, A.; Thackeray, S. J.; Valois, A.; Vrba, Jaroslav; Walseng, B.; Yan, N.

    2014-01-01

    Roč. 186, MAR (2014), s. 115-125. ISSN 0269-7491 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA ČR GA206/07/1200 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : chemical speciation * bioavailability * recovery * crustacean zooplankton * lakes Subject RIV: EH - Ecology, Behaviour Impact factor: 4.143, year: 2014

  1. The combined influence of two agricultural contaminants on natural communities of phytoplankton and zooplankton.

    Science.gov (United States)

    Baker, Leanne F; Mudge, Joseph F; Thompson, Dean G; Houlahan, Jeff E; Kidd, Karen A

    2016-07-01

    Concentrations of glyphosate observed in the environment are generally lower than those found to exert toxicity on aquatic organisms in the laboratory. Toxicity is often tested in the absence of other expected co-occurring contaminants. By examining changes in the phytoplankton and zooplankton communities of shallow, partitioned wetlands over a 5 month period, we assessed the potential for direct and indirect effects of the glyphosate-based herbicide, Roundup WeatherMax(©) applied at the maximum label rate, both in isolation and in a mixture with nutrients (from fertilizers). The co-application of herbicide and nutrients resulted in an immediate but transient decline in dietary quality of phytoplankton (8.3 % decline in edible carbon content/L) and zooplankton community similarity (27 % decline in similarity and loss of three taxa), whereas these effects were not evident in wetlands treated only with the herbicide. Thus, even at a worst-case exposure, this herbicide in isolation, did not produce the acutely toxic effects on plankton communities suggested by laboratory or mesocosm studies. Indirect effects of the herbicide-nutrient mixture were evident in mid-summer, when glyphosate residues were no longer detectable in surface water. Zooplankton abundance tripled, and zooplankton taxa richness increased by an average of four taxa in the herbicide and nutrient treated wetlands. The lack of significant toxicity of Roundup WeatherMax alone, as well as the observation of delayed interactive or indirect effects of the mixture of herbicide and nutrients attest to the value of manipulative field experiments as part of a comprehensive, tiered approach to risk assessments in ecotoxicology. PMID:27112456

  2. Offshore Wind Farms in the North Sea: Is there an effect on the zooplankton community?

    Science.gov (United States)

    Auch, Dominik; Dudeck, Tim; Callies, Ulrich; Riethmüller, Rolf; Hufnagl, Marc; Eckhardt, André; Ove Möller, Klas; Haas, Bianca; Spreitzenbarth, Stefan; van Beusekom, Justus; Walter, Bettina; Temming, Axel; Möllmann, Christian; Floeter, Jens

    2016-04-01

    The climate conference in Paris 2015 has resulted in ambitious goals to mitigate the extent of global climate warming within this century. In Germany, the expansion of renewable energy sources is without any alternative to match the own aims of greenhouse gas reductions. Therefore, in the German EEZ of the North Sea around 10 offshore wind farms (OWFs) are already working and more are currently planned or already under construction. At this already substantial level of offshore wind energy production little is known about the effects of OWFs on the pelagic ecosystem. Earlier investigations have shown an increase of benthic organisms settling on hard substrates provided by the power plant foundations. However, the effects of offshore power plants on lower trophic level organisms within the water column are poorly understood. Thus, we investigated the abundance and distribution of zooplankton within and around OWFs. The analysis was based on optical data derived from a Video Plankton Recorder (VPR). The VPR was mounted on a TRIAXUS system including a suite of different sensors, hence allowing to combine zooplankton information with ambient hydrographic parameters. The combination of the VPR and the TRIAXUS system enabled us to analyse continuous zooplankton and hydrographic data with a high spatial resolution. In this study, we present results of transects through the OWFs Global Tech I, BARD Offshore 1, and Alpha Ventus. The analysis exhibits distinct pattern in the spatial distribution both of physical state variables and of plankton organisms within the vicinity of OWFs, especially of meroplankton, the larval phase of benthic organisms. Keywords: Offshore Wind Farms, Zooplankton, TRIAXUS, Video Plankton Recorder, Meroplankton Corresponding author: Dominik Auch, Institute for Hydrobiology and Fisheries Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany; auch.dominik@web.de

  3. Hydroxide stabilization as a new tool for ballast disinfection: efficacy of treatment on zooplankton

    Science.gov (United States)

    Moffitt, Christine M.; Watten, Barnaby J.; Barenburg, Amber; Henquinet, Jeffrey

    2016-01-01

    Effective and economical tools are needed for treating ship ballast to meet new regulatory requirements designed to reduce the introduction of invasive aquatic species from ship traffic. We tested the efficacy of hydroxide stabilization as a ballast disinfection tool in replicated, sequential field trials on board the M/V Ranger III in waters of Lake Superior. Ballast water was introduced into each of four identical 1,320 L stainless steel tanks during a simulated ballasting operation. Two tanks were treated with NaOH to elevate the pH to 11.7 and the remaining two tanks were held as controls without pH alteration. After retention on board for 14–18 h, CO2-rich gas recovered from one of two diesel propulsion engines was sparged into tanks treated with NaOH for 2 h to force conversion of NaOH ultimately to sodium bicarbonate, thereby lowering pH to about 7.1. Prior to gas sparging, the engine exhaust was treated by a unique catalytic converter/wet scrubber process train to remove unwanted combustion byproducts and to provide cooling. The contents of each tank were then drained and filtered through 35-µm mesh plankton nets to collect all zooplankton. The composition and relative survival of zooplankton in each tank were evaluated by microscopy. Zooplankton populations were dominated by rotifers, but copepods and cladocerans were also observed. Hydroxide stabilization was 100% effective in killing all zooplankton present at the start of the tests. Our results suggest hydroxide stabilization has potential to be an effective and practical tool to disinfect ship ballast. Further, using CO2 released from the ship engine reduces emissions and the neutralized by product, sodium bicarbonate, can have beneficial impacts on the aquatic environment.

  4. Zooplankton variability and larval striped bass foraging: Evaluating potential match/mismatch regulation

    Science.gov (United States)

    Chick, J.H.; Van Den Avyle, M.J.

    1999-01-01

    We quantified temporal and spatial variability of zooplankton in three potential nursery sites (river, transition zone, lake) for larval striped bass (Morone saxatilis) in Lake Marion, South Carolina, during April and May 1993-1995. In two of three years, microzooplankton (rotifers and copepod nauplii) density was significantly greater in the lake site than in the river or transition zone. Macrozooplankton (>200 ??m) composition varied among the three sites in all years with adult copepods and cladocerans dominant at the lake, and juvenile Corbicula fluminea dominant at the river and transition zone. Laboratory feeding experiments, simulating both among-site (site treatments) and within-site (density treatments) variability, were conducted in 1995 to quantify the effects of the observed zooplankton variability on foraging success of larval striped bass. A greater proportion of larvae fed in the lake than in the river or transition-zone treatments across all density treatments: mean (x), 10x and 100x. Larvae also ingested significantly more dry mass of prey in the lake treatment in both the mean and 10x density treatments. Field zooplankton and laboratory feeding data suggest that both spatial and temporal variability of zooplankton influence larval striped bass foraging. Prey density levels that supported successful foraging in our feeding experiments occurred in the lake during late April and May in 1994 and 1995 but were never observed in the river or transition zone. Because the rivers flowing into Lake Marion are regulated, it may be possible to devise flow management schemes that facilitate larval transport to the lake and thereby increase the proportion of larvae matched to suitable prey resources.

  5. Influence of zooplankton stoichiometry on nutrient sedimentation in a lake system

    OpenAIRE

    Darchambeau, François; Thys, I.; Leporcq, B.; Hoffmann, L.; Descy, J.-P.

    2005-01-01

    We explored rates and stoichiometry (C: N: P ratios) of sinking particles in a temperate reservoir during a 2-yr period. Plankton was sampled weekly, and a sediment trap placed below the metalimnion collected sinking particles. There were no significant relationships between the stoichiometry of entrapped material and seston or zooplankton stoichiometry. However the differences in the entrapped C: P and N: P ratios between consecutive trap samplings were negatively correlated with the time va...

  6. Cyprinid predation on zooplankton along the longitudinal profile of a canyon-shaped reservoir

    Czech Academy of Sciences Publication Activity Database

    Vašek, Mojmír; Kubečka, Jan; Seďa, Jaromír

    2003-01-01

    Roč. 156, č. 4 (2003), s. 535-550. ISSN 0003-9136 R&D Projects: GA AV ČR IAA6017201; GA ČR GA206/02/0520 Grant ostatní: GA FRVŠ(CZ) 346/2000 Institutional research plan: CEZ:AV0Z6017912 Keywords : fish predation * spatial heterogeneity * zooplankton Subject RIV: EH - Ecology, Behaviour Impact factor: 1.261, year: 2003

  7. The role of zooplankton in the pelagic-benthic coupling of the Southern Ocean

    OpenAIRE

    Schnack-Schiel, Sigrid B.; Isla, Enrique

    2005-01-01

    [EN] Zooplankton contributes in different ways to pelagic-benthic coupling: Their faecal material is a major route of energy flow and the vertical migrations of many species as well as the production of pelagic larvae by benthic organisms represent different paths to link the two subsystems. Antarctic particle fluxes have been shown to be highly variable in size and composition within a given region and even at the same site from year to year. There are also differences throughout the water c...

  8. Zooplankton (Cladocera, Copepoda) dynamics in the River Danube upstream and downstream of Budapest, Hungary

    OpenAIRE

    Vadadi-Fülöp, Cs.

    2009-01-01

    The spatial distribution and seasonal dynamics of zooplankton (Cladocera, Copepoda) were studied in the River Danube near Budapest, Hungary. The investigated river section was relatively poor in plankton, nauplii dominated. A total of 36 species was recorded of which Acanthocyclops robustus, Thermocyclops crassus, Bosmina longirostris were the most abundant. There was a downstream increase in copepod densities, however, no other remarkable differences could be observed between the profiles up...

  9. Changes in fish production effectivity in eutrophic fishponds of zooplankton structure

    Czech Academy of Sciences Publication Activity Database

    Potužák, J.; Hůda, J.; Pechar, Libor

    2007-01-01

    Roč. 15, - (2007), s. 201-210. ISSN 0967-6120 R&D Projects: GA MŽP(CZ) SM/640/18/03; GA MŽP(CZ) SL/1/6/04 Institutional research plan: CEZ:AV0Z60870520 Keywords : fishponds * zooplankton * eutrophic ation * fish management * primary production Subject RIV: GL - Fishing Impact factor: 0.828, year: 2007

  10. Ingestion by Japanese Eel Anguilla japonica Larvae on Various Minute Zooplanktons

    OpenAIRE

    Wullur, Stenly; Yoshimatsu, Takao; Tanaka, Hideki; Ohtani, Masataka; Sakakura, Yoshitaka; Kim, Hee-Jin; Hagiwara, Atsushi

    2013-01-01

    We observed the feeding incidence of Japanese eel Anguilla japonica larvae of 6, 7, 8 and 14 days after hatching (DAH) using various minute zooplanktons such as rotifer (Proales similis, Synchaeta sp., Keratella sp., Brachionus rotundiformis, B. angularis) and nauplii of copepod Paracyclopina nana, and compared those results to slurry type diets (i.e., shark eggs for control) to evaluate the usability of these planktons as primary food source for the mass culture of eel larvae. Feeding incid...

  11. Towards developing a general framework for modelling vertical migration in zooplankton.

    Science.gov (United States)

    Morozov, Andrew Yu; Kuzenkov, Oleg A

    2016-09-21

    Diel vertical migration (DVM) of zooplankton is a widespread phenomenon in both oceans and lakes, and is generally considered to be the largest synchronized movement of biomass on Earth. Most existing mathematical models of DVM are based on the assumption that animals maximize a certain criterion such as the expected reproductive value, the venturous revenue, the ratio of energy gain/mortality or some predator avoidance function when choosing their instantaneous depth. The major shortcoming of this general point of view is that the predicted DVM may be strongly affected by a subjective choice of a particular optimization criterion. Here we argue that the optimal strategy of DVM can be unambiguously obtained as an outcome of selection in the underlying equations of genotype/traits frequency dynamics. Using this general paradigm, we explore the optimal strategy for the migration across different depths by zooplankton grazers throughout the day. To illustrate our ideas we consider four generic DVM models, each making different assumptions on the population dynamics of zooplankton, and demonstrate that in each model we need to maximize a particular functional to find the optimal strategy. Surprisingly, patterns of DVM obtained for different models greatly differ in terms of their parameters dependence. We then show that the infinite dimensional trait space of different zooplankton trajectories can be projected onto a low dimensional space of generalized parameters and the genotype evolution dynamics can be easily followed using this low-dimensional space. Using this space of generalized parameters we explore the influence of mutagenesis on evolution of DVM, and we show that strong mutagenesis allows the coexistence of an infinitely large number of strategies whereas for weak mutagenesis the selection results in the extinction of most strategies, with the surviving strategies all staying close to the optimal strategy in the corresponding mutagenesis-free system. PMID

  12. Do the long-term changes in zooplankton biomass indicate changes in fish stock?

    Czech Academy of Sciences Publication Activity Database

    Hrbáček, Jaroslav; Brandl, Zdeněk; Straškraba, M.

    2003-01-01

    Roč. 504, - (2003), s. 203-213. ISSN 0018-8158. [Reservoir Limnology and Water Quality /4./. České Budějovice, 12.08.2002-16.08.2002] R&D Projects: GA ČR GA206/01/1113 Institutional research plan: CEZ:AV0Z6017912 Keywords : zooplankton biomass * long term changes * seasonal cycles Subject RIV: EG - Zoology Impact factor: 0.720, year: 2003

  13. Open water zooplankton communities in North African wetland lakes: the CASSARINA Project

    OpenAIRE

    Ramdani, Mohammed; Elkhiati, Najat; Flower, Roger J.; Birks, Hilary H.; Kraïem, Mejdidine M.; Adel A. Fathi; Patrick, Simon T.

    2001-01-01

    Zooplankton (Copepoda, Cladocera, Ostracoda, Rotifera and Diptera larvae) in nine North African lakes was collected from open water areas over twenty months during 1997/99. The results were used to monitor changes in the pelagic micro-invertebrate fauna of these sites with the purpose of exploring diversity structure and regional species occurrences. The studied sites formed three distinct groups based on hydrology and water quality criteria: (i) acid water with no marine connection (Megen...

  14. Epizoic acoelomorph flatworms impair zooplankton feeding by the scleractinian coral Galaxea fascicularis

    OpenAIRE

    Wijgerde, T.H.M.; Schots, P.; Onselen, van, E.; Karruppannan, E.W.; Verreth, J.A.J.; Osinga, R.

    2013-01-01

    Many scleractinian coral species host epizoic acoelomorph flatworms, both in aquaculture and in situ. These symbiotic flatworms may impair coral growth and health through light-shading, mucus removal and disruption of heterotrophic feeding. To quantify the effect of epizoic flatworms on zooplankton feeding, we conducted video analyses of single polyps of Galaxea fascicularis (Linnaeus 1767) grazing on Artemia nauplii in the presence and absence of symbiotic flatworms. 18S DNA analysis reveale...

  15. Epizoic acoelomorph flatworms impair zooplankton feeding by the scleractinian coral Galaxea fascicularis

    OpenAIRE

    Tim Wijgerde; Pauke Schots; Eline Van Onselen; Max Janse; Eric Karruppannan; Johan A.J. Verreth; Ronald Osinga

    2012-01-01

    Summary Many scleractinian coral species host epizoic acoelomorph flatworms, both in aquaculture and in situ. These symbiotic flatworms may impair coral growth and health through light-shading, mucus removal and disruption of heterotrophic feeding. To quantify the effect of epizoic flatworms on zooplankton feeding, we conducted video analyses of single polyps of Galaxea fascicularis (Linnaeus 1767) grazing on Artemia nauplii in the presence and absence of symbiotic flatworms. 18S DNA analysis...

  16. Zooplankton community occurrence in an area influenced by uranium mine, Caldas, MG, Brazil

    International Nuclear Information System (INIS)

    The Ore Treatment Unit (UTM), situated on the Pocos de Caldas - MG Plateau, is Brazil's first venture in uranium ore mining and chemical treatment and it belongs to Brazilian Nuclear Industries today. At UTM, radioactive effluents are generated due to the mine's acid drainage processes (MAD). Thus, due to the lack of scientific information with emphasis on Zooplankton Communities in areas impacted by uranium mine and MAD, the current study aimed to evaluate parameters such as electrical conductivity, pH, total phosphorus, total nitrogen, sulfate, fluoride, uranium, thorium, manganese, zinc and aluminum, as well as richness and density of the zooplankton organism's, all in samples from the Pit Mine. The electrical conductivity values observed were elevated (1976 to 2760 μS cm-1), while the pH values remained acidic (3.6 to 4.1). In respect to the SO4-2, elevated concentrations were observed (366.6 - 1832.0 mg L-1), as well as for F- (33.4 to 75.1 mg L-1). The U presented highest and lowest concentrations in Oct/08 and July/09, that is, 4.25 mg L-1 and 0.12 mg L-1, respectively. The Th concentrations remained constant (0.10 - 0.30 mg L-1). In respect to the Zooplankton Community low species richness and density were observed throughout the whole period. The low richness and density values of the zooplankton species can be related to the adverse environmental conditions, which are unfavorable to the development of this community: elevated values of electrical conductivity and acidic pH, both associated to the chemical composition of the effluent in natura. (author)

  17. Crustacean zooplankton species richness in Chilean lakes and ponds (23°-51°S)

    OpenAIRE

    Patricio De los Ríos-Escalante

    2013-01-01

    Chilean inland-water ecosystems are characterized by their low species-level biodiversity. This study analyses available data on surface area, maximum depth, conductivity, chlorophyll-α concentration, and zooplankton crustacean species number in lakes and ponds between 23° and 51°S. The study uses multiple regression analysis to identify the potential factors affecting the species number. The partial correlation analysis indicated a direct significant correlation between chlorophyll-α concent...

  18. OASIS in the sea: Measurement of the acoustic reflectivity of zooplankton with concurrent optical imaging

    Science.gov (United States)

    Jaffe, J. S.; Ohman, M. D.; De Robertis, A.

    A new instrument Optical-Acoustic Submersible Imaging System (OASIS) has been developed for three-dimensional acoustic tracking of zooplankton with concurrent optical imaging to verify the identity of the insonified organisms. OASIS also measures in situ target strengths (TS) of freely swimming zooplankton and nekton of known identity and 3-D orientation. The system consists of a three-dimensional acoustic imaging system (FishTV), a sensitive optical CCD camera with red-filtered strobe illumination, and ancillary oceanographic sensors. The sonar triggers the acquisition of an optical image when it detects the presence of a significant target in the precise location where the camera, strobe and sonar are co-registered. Acoustic TS can then be related to the optical image, which permits identification of the animal and its 3-D aspect. The system was recently deployed (August 1996) in Saanich Inlet, B.C., Canada. Motile zooplankton and nekton were imaged with no evidence of reaction to or avoidance of the OASIS instrument package. Target strengths of many acoustic reflectors were recorded in parallel with the optical images, triggered by the presence of an animal in the correct location of the sonar system. Inspection of the optical images, corroborated with zooplankton sampling with a MOCNESS net, revealed that the joint optically and acoustically sensed taxa at the site were the euphausiid Euphausia pacifica, the gammarid amphipod Orchomene obtusa, and a gadid fish. The simultaneous optical and acoustic images permitted an exact correlation of TS and taxa. Computer simulations from a model of the backscattered strength from euphausiids are in good agreement with the observed data.

  19. Trophic structure of zooplankton in the Fram Strait in spring and autumn 2003

    Science.gov (United States)

    Blachowiak-Samolyk, Katarzyna; Kwasniewski, Slawek; Dmoch, Katarzyna; Hop, Haakon; Falk-Petersen, Stig

    2007-11-01

    The trophic structure of zooplankton was investigated in Fram Strait (north western Svalbard) in spring and autumn of 2003. Depth-stratified zooplankton samples were collected at 12 stations on the shelf (˜200 m), across the shelf-slope (˜500 m) and over deep water (>750 m), using a Multiple Plankton Sampler equipped with 0.180-mm mesh size nets. Higher zooplankton abundance and estimated biomass were found in the shelf area. Abundance and biomass were two times higher in August, when sea-surface temperature was higher than in May. Herbivores dominated numerically in May, and omnivores in August, suggesting a seasonal sequence of domination by different trophic groups. Cirripedia nauplii and Fritillaria borealis prevailed in spring, whereas copepod nauplii and Calanus finmarchicus were numerically the most important herbivores in autumn. Small copepods, Oithona similis and Triconia borealis, were the most numerous omnivorous species in both seasons, but their abundances increased in autumn. Chaetognatha (mainly Eukrohnia hamata) accounted for the highest abundance and biomass among predatory taxa at all deep-water stations and during both seasons. Regarding vertical distribution, herbivores dominated numerically in the surface layer (0-20 m), and omnivores were concentrated somewhat deeper (20-50 m) during both seasons. Maximum abundance of predators was found in the surface layer (0-20 m) in spring, and generally in the 20-50 m layer in autumn. This paper presents the first comprehensive summary of the zooplankton trophic structure in the Fram Strait area. Our goals are to improve understanding of energy transfer through this ecosystem, and of potential climate-induced changes in Arctic marine food webs.

  20. Phytoplankton response to winter warming modified by large-bodied zooplankton: an experimental microcosm study

    OpenAIRE

    Hu He; Xiaolong Zhu; Xiaolan Song; Erik Jeppesen; Zhengwen Liu

    2015-01-01

    While several field investigations have demonstrated significant effects of cool season (winter or spring) warming on phytoplankton development, the role played by large-bodied zooplankton grazers for the responses of phytoplankton to winter warming is ambiguous. We conducted an outdoor experiment to compare the effect of winter warming (heating by 3°C) in combination with presence and absence of Daphnia grazing (D. similis) on phytoplankton standing crops and community structure under eutrop...

  1. Spatial variations in zooplankton diversity in waters contaminated with composite effluents

    Directory of Open Access Journals (Sweden)

    Asitava CHATTERJEE

    2007-08-01

    Full Text Available Zooplankton species are cosmopolitan in their clean freshwater habitat and are also found in industrial and municipal wastewaters. The present study records for the first time the aspects of zooplankton diversity in relation to physico-chemical environment of five selected sites of the East Calcutta wetlands, a Ramsar site of Kolkata city, India, heavily contaminated by industrial and municipal wastewaters. The study revealed the occurrence of 22 species of zooplankton, among these 3 species of Cladocera, 2 species of Copepoda, 15 species of Rotifera, and 2 species of Ostracoda were recorded. The copepod Mesocyclops leuckarti was found in all the five sites, rotifers Asplanchna brightwelli, Brachionus angularis, B. calyciflorus and Cladocera Ceriodaphnia cornuta were found in four sites; Moina micrura and Diaphanosoma sarsi were found at three sites. Site wise variation in dominance, diversity, evenness and richness were calculated. Site 1, a fish-pond that stabilized composite wastewater, showed the maximum species richness having 17 species, while Site 2, SWF wastewater carrying canal, showed only 4 species. The calculated Jack 1 values of Sites 1 to 5 were 21.78, 3.77, 18.63, 12.5 and 16.95 respectively. Shannon-Wiener species diversity index (H/ values were almost similar for all the three relatively less polluted sites viz, Site 1 (1.959, Site 4 (2.010, Site 5 (2.047. However, at highly polluted sites viz., 2 and 3, H/ value of 1.336 and 0.984 respectively, were calculated. Simpson’s Dominance index (Dsimp value was highest at Site 3 (0.618 indicating maximum dominance, whereas at Site 5 dominance was lowest (0.1680 and diversity was highest. We discuss the role of zooplankton in the amelioration of wastewater.

  2. Diel variations in zooplankton and their biochemical composition from Vengurla to Ratnagiri, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; KrishnaKumari, L.; Shrivastava, Y.

    of Marine Sciences Vol. 29, September, 2000, pp 277-280 Short Communication Diel variations in zooplankton and their biochemical composition from Vengurla to Ratnagiri, west coast of India S C Goswami, L.Krishna Kumari & Yashoshri Shrivastava National... population and their biochemical constituents from coastal areas is scanty. The present communication deals with diel variability of common groups including economically important fish and decapod larvae and their biochemical composition in the coastal...

  3. Gelatinous zooplankton biomass in the global oceans: geographic variation and environmental drivers

    OpenAIRE

    Lucas, Cathy H.; Jones, Daniel O. B.; Hollyhead, Catherine J.; Condon, Robert H.; Duarte, Carlos M.; Graham, William M.; Robinson, Kelly L.; Pitt, Kylie A.; Schildhauer, Mark; Regetz, Jim

    2014-01-01

    Aim: Scientific debate regarding the future trends, and subsequent ecological, biogeochemical and societal impacts, of gelatinous zooplankton (GZ) in a changing ocean is hampered by lack of a global baseline and an understanding of the causes of biogeographic patterns. We address this by using a new global database of GZ records to test hypotheses relating to environmental drivers of biogeographic variation in the multidecadal baseline of epipelagic GZ biomass in the world's oceans. Lo...

  4. Atlantic Oceanographic and Meteorological Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Atlantic Oceanographic and Meteorological Laboratory conducts research to understand the physical, chemical, and biological characteristics and processes of the...

  5. Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

    Science.gov (United States)

    Craig, Jessica; Youngbluth, Marsh; Jamieson, Alan J.; Priede, Imants G.

    2015-04-01

    The benthic boundary layer is a region often perceived to be high in faunal abundance and biomass. In this study, we investigated the distribution of near seafloor bioluminescent zooplankton (BL), macrozooplankton (>1 cm) and macroparticles (>430 μm) at the Northern Mid-Atlantic Ridge at ca. 2500 m depth. At sites south of 52°N, the Charlie Gibbs Fracture Zone, BL density increased weakly towards the seafloor. This trend was driven by small bioluminescent crustaceans, comprising ca. 90% of the total BL density. Macroparticle density was coherent with BL density, exhibiting a small increase towards the seafloor. Appendicularians (animals as well as occupied and discarded houses) were the most abundant macrozooplankton, and the only group to show a significant increase in density towards the seafloor. The absence of pronounced increases in BL and macroparticle density, and no increase in macrozooplankton (except appendicularians), towards the seafloor do not support the conventional view of high concentrations of particulate organic matter and zooplankton biomass in the benthic boundary layer relative to overlying waters.

  6. Estimating the geographic range of a threatened shark in a data-poor region:Cetorhinus maximus in the South Atlantic Ocean

    Institute of Scientific and Technical Information of China (English)

    Luis O LUCIFORA; Santiago A BARBINI; Edgardo E DI GICOMO; Juan A WAESSLE; Daniel E FIGUEROA

    2015-01-01

    The distribution of the planktivorous basking sharkCetorhinus maximus is influenced by zooplankton abundance at small scales and temperature at medium scales in the North Atlantic. Here, we estimate the distribution of basking sharks on South Atlantic continental shelves, and the relative importance of chlorophyll concentration, as a proxy for zooplankton abun-dance, and temperature in determining habitat suitability for basking sharks at large scales. We used maximum entropy (MaxEnt) and maximum likelihood (MaxLike) species distribution modelling to test three hypotheses: the distribution of basking sharks is determined by (1) temperature, (2) chlorophyll concentration, or (3) both chlorophyll and temperature, while considering other factors, such as oxygen and salinity. Off South America, basking shark habitat included subtropical, temperate and cool-temperate waters between approximately 20°S and 55°S. Off Africa, basking shark habitat was limited to cool-temperate waters off Nami-bia and southern South Africa. MaxLike models had a better fit than MaxEnt models. The best model included minimum chloro-phyll concentration, dissolved oxygen concentration, and sea surface temperature range, supporting hypothesis 3. However, of all variables included in the best model, minimum chlorophyll concentration had the highest influence on basking shark distribution. Unlike the North Atlantic distribution, the South Atlantic distribution of basking sharks includes subtropical and cool-temperate waters. This difference is explained by high minimum chlorophyll concentration off southern Brazil as compared to North Atlan-tic subtropical areas. Observations in other regions of the world support this conclusion. The highest habitat suitability for bask-ing sharks is located close to nearshore areas that experience high anthropogenic impact [Current Zoology 61 (5): 811–826, 2015].

  7. Determinants of community structure of zooplankton in heavily polluted river ecosystems

    Science.gov (United States)

    Xiong, Wei; Li, Jie; Chen, Yiyong; Shan, Baoqing; Wang, Weimin; Zhan, Aibin

    2016-02-01

    River ecosystems are among the most affected habitats globally by human activities, such as the release of chemical pollutants. However, it remains largely unknown how and to what extent many communities such as zooplankton are affected by these environmental stressors in river ecosystems. Here, we aim to determine major factors responsible for shaping community structure of zooplankton in heavily polluted river ecosystems. Specially, we use rotifers in the Haihe River Basin (HRB) in North China as a case study to test the hypothesis that species sorting (i.e. species are “filtered” by environmental factors and occur at environmental suitable sites) plays a key role in determining community structure at the basin level. Based on an analysis of 94 sites across the plain region of HRB, we found evidence that both local and regional factors could affect rotifer community structure. Interestingly, further analyses indicated that local factors played a more important role in determining community structure. Thus, our results support the species sorting hypothesis in highly polluted rivers, suggesting that local environmental constraints, such as environmental pollution caused by human activities, can be stronger than dispersal limitation caused by regional factors to shape local community structure of zooplankton at the basin level.

  8. Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    Eliane Maria de Souza Nogueira

    2011-08-01

    Full Text Available The zooplankton of aquatic environments is composed mostly of protozoans, rotifers, cladocerans and copepods, which play an important role in the food chain, transferring mass and energy from primary producers to higher trophic levels. This work was prepared with the objective of contributing to the knowledge of zooplankton biodiversity that occurs in the Sub-basin of Rio Poxim. Water samples were taken at monthly intervals at four sampling stations located along the sub-basin in the period August 2009 to July 2010. To obtain the zooplankton community, 100 L of water were filtered on nylon net with an aperture of 50 mm. Were identified 72 taxa distributed in the following taxonomic categories Rotifera, Protozoa, Porifera, Nematoda, Anellida, Cladocera, Copepoda, Ostracoda, Isopoda and Insecta. In terms of species richness, the phylum Rotifera followed by the Protoctista were the most relevant with forty and fifteen taxa, respectively. The most representative taxa in numerical terms were Arcella vulgaris, Notholca sp. Rotary sp. and nematodes. Regarding the community diversity index, the community was characterized as low diversity, but the taxa were distributed evenly in all monitoring points.

  9. Zooplankton (Cladocera, Copepoda dynamics in the River Danube upstream and downstream of Budapest, Hungary

    Directory of Open Access Journals (Sweden)

    Vadadi-Fülöp, Cs.

    2009-11-01

    Full Text Available The spatial distribution and seasonal dynamics of zooplankton (Cladocera, Copepoda were studied in the River Danube near Budapest, Hungary. The investigated river section was relatively poor in plankton, nauplii dominated. A total of 36 species was recorded of which Acanthocyclops robustus, Thermocyclops crassus, Bosmina longirostris were the most abundant. There was a downstream increase in copepod densities, however, no other remarkable differences could be observed between the profiles upstream and downstream of the capital. Generally, the streamline was characterized by lower densities and lower number of taxa as compared to the river bank; nevertheless, there were differences between the left and the right banks both upstream or downstream as well. Seasonal dynamics was defined by a marked late winter–spring aspect and abundance peaks were found to be characteristic for Danube with high densities in May–June and August–September. Examining the relationship between zooplankton density and the hydrological regime, it can be concluded that zooplankton production in the main channel is of minor importance, rather floodplain areas and adjacent water bodies seem to be important sources of plankton biomass.

  10. Evidence of microplastics in samples of zooplankton from Portuguese coastal waters.

    Science.gov (United States)

    Frias, J P G L; Otero, V; Sobral, P

    2014-04-01

    Records of high concentrations of plastic and microplastic marine debris floating in the ocean have led to investigate the presence of microplastics in samples of zooplankton from Portuguese coastal waters. Zooplankton samples collected at four offshore sites, in surveys conducted between 2002 and 2008, with three different sampling methods, were used in this preliminary study. A total of 152 samples were processed and microplastics were identified in 93 of them, corresponding to 61% of the total. Costa Vicentina, followed by Lisboa, were the regions with higher microplastic concentrations (0.036 and 0.033 no. m⁻³) and abundances (0.07 and 0.06 cm³ m⁻³), respectively. Microplastic: zooplankton ratios were also higher in these two regions, which is probably related to the proximity of densely populated areas and inputs from the Tejo and Sado river estuaries. Microplastics polymers were identified using Micro Fourier Transformed Infrared Spectroscopy (μ-FTIR), as polyethylene (PE), polypropylene (PP) and polyacrylates (PA). The present work is the first report on the composition of microplastic particles collected with plankton nets in Portuguese coastal waters. Plankton surveys from regular monitoring campaigns conducted worldwide may be used to monitor plastic particles in the oceans and constitute an important and low cost tool to address marine litter within the scope of the Marine Strategy Framework Directive (2008/56/EC). PMID:24461782

  11. Predator evasion in zooplankton is suppressed by polyunsaturated fatty acid limitation.

    Science.gov (United States)

    Brzeziński, Tomasz; von Elert, Eric

    2015-11-01

    Herbivorous zooplankton avoid size-selective predation by vertical migration to a deep, cold water refuge. Adaptation to low temperatures in planktonic poikilotherms depends on essential dietary lipids; the availability of these lipids often limits growth and reproduction of zooplankton. We hypothesized that limitation by essential lipids may affect habitat preferences and predator avoidance behavior in planktonic poikilotherms. We used a liposome supplementation technique to enrich the green alga Scenedesmus obliquus and the cyanobacterium Synecchococcus elongatus with the essential lipids, cholesterol and eicosapentaenoic acid (EPA), and an indoor system with a stratified water-column (plankton organ) to test whether the absence of these selected dietary lipids constrains predator avoidance (habitat preferences) in four species of the key-stone pelagic freshwater grazer Daphnia. We found that the capability of avoiding fish predation through habitat shift to the deeper and colder environment was suppressed in Daphnia unless the diet was supplemented with EPA; however, the availability of cholesterol did not affect habitat preferences of the tested taxa. Thus, their ability to access a predator-free refuge and the outcome of predator-prey interactions depends upon food quality (i.e. the availability of an essential fatty acid). Our results suggest that biochemical food quality limitation, a bottom-up factor, may affect the top-down control of herbivorous zooplankton. PMID:26232092

  12. Mechanisms of compensatory dynamics in zooplankton and maintenance of food chain efficiency under toxicant stress.

    Science.gov (United States)

    Mano, Hiroyuki; Tanaka, Yoshinari

    2016-03-01

    Communities with species that are tolerant to environmental stresses may be able to maintain the ecosystem functions under the stress, because the tolerant species can compensate for the loss of sensitive species. In this study, we focused on the food chain efficiency (FCE), the trophic transfer across three trophic levels, as an important process for ecosystem function, and examined the conditions under which such compensation could occur with aquarium experiments using an insecticide (methomyl) as the stressor. Our aquariums included one of two pairs of insecticide-tolerant and insecticide-sensitive cladoceran species, and a fish as the predator. The response of FCE to the insecticide stress, as indicated by the fish biomass production, depended on the zooplankton species combinations. FCE and total zooplankton biomass were maintained in the pair in which the compensatory changes of species abundances were clear, whereas they decreased in the pair in which the compensatory changes were not clear. This indicated the compensatory dynamics in the zooplankton community responsible for the observed resistance to the stress. We inferred the driving factors for the compensatory dynamics and the community resistance with respect to species traits of ecological importance, and concluded that a dissimilarity between species as regards the tolerance trait and a clear trade-off between the tolerance and the competitive ability was required to drive the compensatory dynamics, and a similarity or a superiority of the tolerant species as regards the functional effect trait (the predator avoidance and the reproductive potential) were required to maintain FCE. PMID:26683817

  13. Estimation of the toxicity of pollutants to marine phytoplanktonic and zooplanktonic organisms

    International Nuclear Information System (INIS)

    One of the basic components of the action plans sponsored by UNEP in the framework of the Regional Seas Programme is the assessment of the state of the marine environment and of its resources, and of the sources and trends of the pollution, and the impact of pollution on human health, marine ecosystems, and amenities. In order to ensure that the data obtained through this assessment can be compared on a world-wide basis and thus contribute to the Global Environment Monitoring System (GEMS) of UNEP, a set of Reference Methods and Guidelines for marine pollution studies are being developed as part of a programme of comprehensive technical support which includes the provision of expert advice, reference methods and materials, training and data quality assurance. This reference method describes procedures for estimating the toxicity of pollutants to marine phytoplankton and zooplankton. Procedures are given for estimating the media effective concentrations (EC50) of toxicants to phytoplankton, and the minimum algistatic concentration (MAC-5). For zooplankton, procedures are given for determining median lethal concentrations. Organisms are exposed to each of a range of concentrations of the test substance. For phytoplankton, the median effective concentration (EC50) is estimated in terms of the number of individuals surviving, the biomass of individuals surviving, or the chlorophyll content of the individuals surviving. For zooplankton, the media lethal concentration (LC50) is estimated by conventional log-probit analysis of the mortality data

  14. Zooplankton variation in relation to hydrology in an enclosed hypoxic bay (Amvrakikos Gulf, Greece

    Directory of Open Access Journals (Sweden)

    G. KEHAYIAS

    2014-09-01

    Full Text Available This study investigated the temporal and spatial variation of the zooplankton community of a hypoxic coastal embayment (Amvrakikos Gulf, western Greece in relation to hydrological characteristics during an annual cycle. The main hydrological feature was the prolonged water stratification, which determined hypoxic conditions in the deeper layers that became anoxic close to the bottom in September, while vertical mixing occurred for a very short period (October-November. The total zooplankton abundance fluctuated between 44.6 and 159.7 ind l-1. Fourteen groups were recorded, among which copepods dominated accounting on average for 86.4 %. Most of the groups presented higher abundance values in winter and spring when increased chlorophyll-α concentrations were found. Oxygen depletion affects the vertical distribution of most zooplankton groups and the vertical habitat partitioning between copepod orders and their ontogenetic stages. Several taxa were recorded even in the deep, anoxic layers, but only the polychaete larvae increased in abundance with depth. Calanoids, appendicularians and bivalve larvae presented eastward decrease of abundance in the deepest layers following the same pattern of oxygen decrease. Notwithstanding hypoxic conditions in its deepest layers, Amvrakikos Gulf was accounted for a mesotrophic ecosystem, with the nutrient concentration being lower than in the past. Several biotic elements indicate that the gulf is in a transitional phase towards a better quality state and these results reinforce the need for consistent monitoring of this ecosystem.

  15. Effect of planktivores, zooplankton, and macrobenthos on material flow in a small lake

    International Nuclear Information System (INIS)

    Planktivores, zooplankton grazers, and macrobenthos were studied to determine how changes in animal community structure may alter the flow of material in Dunham Pond, CT. Chaoborus and chironomid larvae were studied to determine how they affect the flux of matter across the sediment/water interface. This was done by incubating undisturbed cores in situ and relating changes in water chemistry to larval density. The log-transformed flux rates of iron, manganese, and phosphorus were linearly related to larval biomass. Functional groups may be successfully used to predict rates of material flow. Changes in the mass of macroinvertebrates affect the flux rates of redox-active substances across the sediment/water interface. The use of population densities and feeding characteristics to estimate trophic transfer in Dunham Pond indicate that (1) visual planktivory by larval perch may result in overutilization of prey, (2) ambush planktivory by univoltine Chaoborus appears to under utilize prey, and (3) zooplankton grazing tracks net primary productivity, regardless of zooplankton community structure. Animal groups cycle 30-100% of the phosphorus required for 14C productivity in Dunham Pond

  16. Imazethapyr and imazapic, bispyribac-sodium and penoxsulam: Zooplankton and dissipation in subtropical rice paddy water

    Energy Technology Data Exchange (ETDEWEB)

    Reimche, Geovane B., E-mail: geovane_reimche@yahoo.com.br [Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS (Brazil); Machado, Sérgio L.O. [Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS (Brazil); Oliveira, Maria Angélica [Department of Biology, Federal University of Santa Maria, Santa Maria, RS (Brazil); Zanella, Renato; Dressler, Valderi Luiz; Flores, Erico M.M. [Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS (Brazil); Gonçalves, Fábio F. [School of Chemistry and Food, Federal Foundation University of Rio Grande (FURG), 95500-000 Santo Antônio da Patrulha, RS (Brazil); Donato, Filipe F.; Nunes, Matheus A.G. [Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS (Brazil)

    2015-05-01

    Herbicides are very effective at eliminating weed and are largely used in rice paddy around the world, playing a fundamental role in maximizing yield. Therefore, considering the flooded environment of rice paddies, it is necessary to understand the side effects on non-target species. Field experiment studies were carried out during two rice growing seasons in order to address how the commonly-used herbicides imazethapyr and imazapic, bispyribac-sodium and penoxsulam, used at recommended dosage, affect water quality and the non-target zooplankton community using outdoor rice field microcosm set-up. The shortest (4.9 days) and longest (12.2 days) herbicide half-life mean, estimated of the dissipation rate (k) is shown for imazethapyr and bispyribac-sodium, respectively. Some water quality parameters (pH, conductivity, hardness, BOD{sub 5}, boron, potassium, magnesium, phosphorus and chlorides) achieved slightly higher values at the herbicide treatment. Zooplankton community usually quickly recovered from the tested herbicide impact. Generally, herbicides led to an increase of cladocera, copepods and nauplius population, while rotifer population decreased, with recovery at the end of the experiment (88 days after herbicide treatment). - Highlights: • Selective herbicides in paddy rice fields, do not affect water quality. • Zooplankton communities show good response with herbicide dissipation. • The use of commercial herbicide mixture has strong effects on freshwater Rotifers.

  17. Two Distinct Roles of Atlantic SSTs in ENSO Variability: North Tropical Atlantic SST and Atlantic Nino

    Science.gov (United States)

    Ham, Yoo-Geun; Kug, Jong-Seong; Park, Jong-Yeon

    2013-01-01

    Two distinct roles of the Atlantic sea surface temperatures (SSTs), namely, the North Tropical Atlantic (NTA) SST and the Atlantic Nino, on the El Nino-Southern Oscillation (ENSO) variability are investigated using the observational data from 1980 to 2010 and coupled model experiments. It appears that the NTA SST and the Atlantic Nino can be used as two independent predictors for predicting the development of ENSO events in the following season. Furthermore, they are likely to be linked to different types of El Nino events. Specifically, the NTA SST cooling during February, March, and April contributes to the central Pacific warming at the subsequent winter season, while the negative Atlantic Nino event during June, July, and August contributes to enhancing the eastern Pacific warming. The coupled model experiments support these results. With the aid of a lagged inverse relationship, the statistical forecast using two Atlantic indices can successfully predict various ENSO indices.

  18. Zooplanktonic community of six reservoirs in northeast Brazil Comunidade zooplanctônica de seis reservatórios no nordeste do Brasil

    OpenAIRE

    VLS. Almeida; ÊW. Dantas; M. Melo-Júnior; MC. Bittencourt-Oliveira; AN Moura

    2009-01-01

    The aim of the present study was to investigate the zooplankton community at six reservoirs in the state of Pernambuco (Brazil). Zooplankton assemblages were identified using current literature and quantitatively analysed under a microscope and stereomicroscope. Concurrently to the sampling of zooplanktonic and phytoplanktonic communities, in situ measurements of abiotic variables, such as water temperature, dissolved oxygen and pH, were determined using field probes and transparency was dete...

  19. Effect of Water Hyacinth (Eichornia crassippes) Infestation on Zooplankton Populations in Awba Reservoir, Ibadan South-West Nigeria

    OpenAIRE

    K.S. Chukwuka; U.N. Uka

    2007-01-01

    The effects of water hyacinth infestation on the distribution, abundance and species composition of zooplankton in Awba reservoir were investigated. Samples were collected in each of the sampling areas (water hyacinth infested and open water) by vertical zooplankton hauls using 64 um bolting silk net. The samples were immediately fixed in 4% formalin for preservation. The species composition of the zooplankton from the sampled areas consisted of 3 taxa, comprising of 6 species of Cladocera (M...

  20. Cyanobacteria as a carbon source for zooplankton in eutrophic Lake Taihu, China, measured by 13C labeling and fatty acid biomarkers

    OpenAIRE

    de Kluijver, A.; Yu, J.L.; Houtekamer, M.; Middelburg, J. J.; Liu, Z.W.

    2012-01-01

    Using a combined stable-isotope and fatty-acid approach, we examined carbon-transfer routes from the cyanobacterium Microcystis to zooplankton in eutrophic Lake Taihu, China. Microcystis is generally considered poor food for zooplankton, and we hypothesized that most Microcystis carbon flows to zooplankton via dissolved organic matter (DOM)-bacteria and detritus-bacteria pathways rather than via direct grazing. The hypothesis was tested by analyzing C-13 isotopes at natural abundance in field...