Turtle bycatch in the pelagic longline fishery off southern Africa ...

African Journals Online (AJOL)

Capture by pelagic longline fisheries has been identified as a key threat to turtle populations. This study is the first assessment of turtle bycatch in the South African pelagic longline fishery for tunas Thunnus spp. and swordfish Xiphias gladius. A total of 181 turtles was caught on observed sets between 1998 and 2005, at a ...

77 FR 34334 - Western Pacific Pelagic Fisheries; Revised Limits on Sea Turtle Interactions in the Hawaii...

Science.gov (United States)

2012-06-11

... Interactions in the Hawaii Shallow-Set Longline Fishery AGENCY: National Marine Fisheries Service (NMFS... occur between the Hawaii-based shallow-set pelagic longline fishery and leatherback and loggerhead sea... Fisheries, NMFS PIR, 808-944-2248. SUPPLEMENTARY INFORMATION: The Hawaii-based shallow-set pelagic longline...

75 FR 56017 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

Science.gov (United States)

2010-09-15

.... 0910131362-0087-02] RIN 0648-XZ06 Fisheries of the Exclusive Economic Zone Off Alaska; Shallow- Water Species... closure. SUMMARY: NMFS is opening directed fishing for shallow-water species by vessels using trawl gear... of the 2010 Pacific halibut bycatch allowance specified for the trawl shallow-water species fishery...

Assessing and mitigating of bottom trawling. Final BENTHIS project Report (Benthic Ecosystem Fisheries Impact Study)

DEFF Research Database (Denmark)

Rijnsdorp, Adriaan D; Eigaard, Ole Ritzau; Kenny, Andrew

2017-01-01

the fuel cost without affecting the catch rate of the target species. Replacing mechanical stimulation by tickler chains with electrical stimulation In the beam trawl fishery for sole, reduced footprint and penetration depth as well as the fuel cost. Electrical stimulation is also a promising innovation...... to reduce the bycatch and bottom contact in the beam trawl fishery for brown shrimps. Sea trials to replace bottom trawls with pots were inconclusive. Results suggest that creels may offer an alternative for small Nephrops fishers in the Kattegat. In waters off Greece, the catch rates were very low. Sea...... trials with the blue mussel fishery showed that fishers could reduce their footprint by deploying acoustic equipment to detect mussel concentrations that allow the fishers to more precisely target the mussel beds and hence reduce fishing in areas with low mussel density. A review of the various case...

78 FR 7371 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

Science.gov (United States)

2013-02-01

... Rationalization Program; Cost Recovery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... Office rule goes final before the cost recovery program rule and if it would affect the appeals process... would implement a cost recovery program for the Pacific coast groundfish trawl rationalization program...

Deep-Sea Mega-Epibenthic Assemblages from the SW Portuguese Margin (NE Atlantic Subjected to Bottom-Trawling Fisheries

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Sofia P. Ramalho

2017-11-01

Full Text Available Bottom-trawling fisheries are a common threat to the health of continental margins worldwide. Together with numerous environmental and biological processes, physical disturbance induced by trawlers can largely shape the benthic habitats and their associated assemblages. At the SW Portuguese Margin, crustacean bottom trawlers have exploited deep-sea habitats for a few decades, but its effects on the benthic biodiversity are practically unknown. During the spring-summer of 2013 and 2014, several Remotely Operated Vehicle (ROV video transects were used to investigate mega-epibenthic abundance, composition, and diversity in soft-sediment areas subjected to varying trawling pressures off Sines and Setúbal (200–800 m. Differences in mega-epibenthic assemblages were linked with environmental changes (depth, grain size, primary productivity and trawling disturbance. The effect of trawling was assessed between segments with similar habitat characteristics, i.e., muddy-sand bottoms between 300 and 500 m. Areas subjected to intensive trawling pressure showed a generally flattened seabed, with abundant recent trawl marks (up to 3 scars.100 m−1, indicating that the seabed physical integrity was compromised. Significant negative correlations were detected between various mega-epibenthic diversity indices [S, H′, and ET(20] and trawling pressure (h.cell−1.y−1. Furthermore, the distinct mega-epibenthic assemblages and absence of several sessile erect morphospecies at both low and highly disturbed locations by trawling off Sines, namely all seapen morphospecies found in non-trawled areas, demonstrates the negative influence of trawling fisheries on the benthic component of the study area. Also, low dissimilarity between assemblages from the main fishing grounds and the adjacent low-disturbance locations, suggests that the potentially negative influence of trawling can extend beyond the targeted areas (e.g., by the plumes of re-suspended sediments. The

Identification and evaluation of shark bycatch in Georgia's commercial shrimp trawl fishery with implications for management

Science.gov (United States)

Belcher, C.N.; Jennings, C.A.

2011-01-01

Many US states have recreational and commercial fisheries that occur in nursery areas occupied by subadult sharks and can potentially affect their survival. Georgia is one of few US states without a directed commercial shark fishery, but the state has a large, nearshore penaeid shrimp trawl fishery in which small sharks occur as bycatch. During our 1995–1998 investigation of bycatch in fishery-dependent sampling events, 34% of 127 trawls contained sharks. This bycatch totalled 217 individuals from six species, with Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson), the most common and finetooth shark, Carcharhinus isodon (Müller & Henle) and spinner shark, Carcharhinus brevipinna (Müller & Henle), the least common. The highest catch rates for sharks occurred during June and July and coincided with the peak months of the pupping season for many species. Trawl tow speed and tow time did not significantly influence catch rates for shark species. Gear configurations [net type, turtle excluder device (TED), bycatch reduction device] affected catch rates for shark species. Results of this study indicate gear restrictions, a delayed season opening, or reduced bar spacing on TEDs may reduce shark bycatch in this fishery.

Bell-shaped size selection in a bottom trawl: A case study for Nephrops directed fishery with reduced catches of cod

DEFF Research Database (Denmark)

Lövgren, Johan; Herrmann, Bent; Feekings, Jordan P.

2016-01-01

and size selectivity have motivated the development of selective systems in trawl fisheries that utilize more than one selective device simultaneously. An example can be found in the Swedish demersal trawl fishery targeting Norway lobster (Nephrops norvegicus), which simultaneously aims at avoiding catches...

The Pelagics Habitat Analysis Module (PHAM): Decision Support Tools for Pelagic Fisheries

Science.gov (United States)

Armstrong, E. M.; Harrison, D. P.; Kiefer, D.; O'Brien, F.; Hinton, M.; Kohin, S.; Snyder, S.

2009-12-01

PHAM is a project funded by NASA to integrate satellite imagery and circulation models into the management of commercial and threatened pelagic species. Specifically, the project merges data from fishery surveys, and fisheries catch and effort data with satellite imagery and circulation models to define the habitat of each species. This new information on habitat will then be used to inform population distribution and models of population dynamics that are used for management. During the first year of the project, we created two prototype modules. One module, which was developed for the Inter-American Tropical Tuna Commission, is designed to help improve information available to manage the tuna fisheries of the eastern Pacific Ocean. The other module, which was developed for the Coastal Pelagics Division of the Southwest Fishery Science Center, assists management of by-catch of mako, blue, and thresher sharks along the Californian coast. Both modules were built with the EASy marine geographic information system, which provides a 4 dimensional (latitude, longitude, depth, and time) home for integration of the data. The projects currently provide tools for automated downloading and geo-referencing of satellite imagery of sea surface temperature, height, and chlorophyll concentrations; output from JPL’s ECCO2 global circulation model and its ROM California current model; and gridded data from fisheries and fishery surveys. It also provides statistical tools for defining species habitat from these and other types of environmental data. These tools include unbalanced ANOVA, EOF analysis of satellite imagery, and multivariate search routines for fitting fishery data to transforms of the environmental data. Output from the projects consists of dynamic maps of the distribution of the species that are driven by the time series of satellite imagery and output from the circulation models. It also includes relationships between environmental variables and recruitment. During

Identification and evaluation of shark bycatch in Georgia’s commercial shrimp trawl fishery with implications for management

Science.gov (United States)

Belcher, C.N.; Jennings, Cecil A.

2011-01-01

Many US states have recreational and commercial fisheries that occur in nursery areas occupied by subadult sharks and can potentially affect their survival. Georgia is one of few US states without a directed commercial shark fishery, but the state has a large, nearshore penaeid shrimp trawl fishery in which small sharks occur as bycatch. During our 1995-1998 investigation of bycatch in fishery-dependent sampling events, 34% of 127 trawls contained sharks. This bycatch totalled 217 individuals from six species, with Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson), the most common and finetooth shark, Carcharhinus isodon (Müller & Henle) and spinner shark, Carcharhinus brevipinna (Müller & Henle), the least common. The highest catch rates for sharks occurred during June and July and coincided with the peak months of the pupping season for many species. Trawl tow speed and tow time did not significantly influence catch rates for shark species. Gear configurations [net type, turtle excluder device (TED), bycatch reduction device] affected catch rates for shark species. Results of this study indicate gear restrictions, a delayed season opening, or reduced bar spacing on TEDs may reduce shark bycatch in this fishery.

Bycatch of crustacean and fish bottom trawl fisheries from southern Portugal (Algarve

Directory of Open Access Journals (Sweden)

Maria Esmeralda Costa

2008-12-01

Full Text Available As part of two research projects for analysing bycatch and discards, we quantified catch composition, catch rates, bycatch and discards in two important commercial bottom trawl fisheries (crustacean and fish trawls off the southern coast of Portugal (Algarve. Stratified sampling by onboard observers took place from February 1999 to March 2001 and data were collected from 165 tows during 52 fishing trips. Commercial target species included crustaceans: blue and red shrimp (Aristeus antennatus, deep-water rose shrimp (Parapenaeus longirostris, Norway lobster (Nephrops norvegicus; and fishes: seabreams (Diplodus spp. and Pagellus spp., horse mackerels (Trachurus spp. and European hake (Merluccius merluccius. The trawl fisheries are characterised by considerable amounts of bycatch: 59.5% and 80.4% of the overall total catch for crustacean and fish trawlers respectively. A total of 255 species were identified, which belonged to 15 classes of organisms (137 vertebrates, 112 invertebrates and 6 algae. Crustacean trawlers had higher bycatch biodiversity. Bony fish (45.6% and 37.8% followed by crustaceans (14.6% and 11.5% were the dominant bycatch components of both crustacean and fish trawlers respectively. The influence of a number of factors (e.g. depth, fishing gear, tow duration and season on bycatch and discards is discussed.

Use of a fishery-independent trawl survey to evaluate distribution patterns of subadult sharks in Georgia

Science.gov (United States)

Belcher, C.N.; Jennings, Cecil A.

2009-01-01

We investigated the utility of a fishery-independent trawl survey for assessing a potential multispecies shark nursery in Georgia's nearshore and inshore waters. A total of 234 subadult sharks from six species were captured during 85 of 216 trawls. Catch rates and size distributions for subadult sharks and the ratio of neonates to juveniles were consistent among areas. The highest concentrations of subadult sharks occurred in creeks and sounds. Species composition varied among areas. The Atlantic sharpnose shark Rhizoprionodon terraenovae was the most abundant species in sound and nearshore stations, whereas the bonnethead Sphyrna tiburo was the most abundant species in creeks. The aggregate of other species occurred with higher frequency in the sounds and nearshore. Sampling characteristics of the trawl survey were compared with those from a fishery-independent longline survey of subadult sharks to assess the similarity of the two gears. A total of 193 subadult sharks from seven species were captured during 57 of 96 longline sets, whereas 52 subadults from four species were captured during 20 of 48 trawls. Selectivity and efficiency differed between the two gears. The trawl had lower catch rates, caught smaller sharks, and encountered a different suite of species than the longline. General seasonal trends in relative abundance also differed between the two gears; the longline showed an increasing trend in abundance, whereas the trawl showed a stable trend. Although trawls were not found to be efficient for sampling subadult sharks from most species, they can be a useful source of supplemental data.

76 FR 57679 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

Science.gov (United States)

2011-09-16

.... 101126522-0640-02] RIN 0648-XA704 Fisheries of the Exclusive Economic Zone Off Alaska; Shallow- Water... closure. SUMMARY: NMFS is opening directed fishing for shallow-water species by vessels using trawl gear... apportionment of the 2011 Pacific halibut bycatch allowance specified for the trawl shallow-water species...

Job satisfaction in the shrimp trawl fisheries of Chennai, India

OpenAIRE

Bavinck, M.

2012-01-01

Shrimp trawling represents an important fishing métier in South India, generating high levels of employment and economic value. It is also a contested métier, ostensibly contributing to environmental degradation and social inequality. This paper investigates the job satisfaction of crew members (captains and workers) on board the shrimp trawlers of Chennai (former Madras). Research took place in 2007 and 2008 (N = 137). Results suggest a general satisfaction with being in the fishery. However...

76 FR 52888 - Western Pacific Pelagic Fisheries; American Samoa Longline Gear Modifications To Reduce Turtle...

Science.gov (United States)

2011-08-24

... Modifications To Reduce Turtle Interactions AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... Pacific Region (Pelagics FEP), including an environmental assessment, that presents background information on this rule. The Pelagics FEP and Amendment 5 are available from the Council, 1164 Bishop St., Suite...

78 FR 79388 - Western Pacific Pelagic Fisheries; Catch and Effort Limits for the U.S. Participating Territories

Science.gov (United States)

2013-12-30

... Hawaii longline fisheries: The deep-set fishery that targets bigeye tuna, and the shallow-set fishery... a management framework and process for specifying fishing catch and effort limits and accountability... process for specifying catch or fishing effort limits and accountability measures for pelagic fisheries in...

The Ecuadorian Artisanal Fishery for Large Pelagics: Species Composition and Spatio-Temporal Dynamics.

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Jimmy Martínez-Ortiz

Full Text Available The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt (about 15.5 million fish were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the "oceanic-artisanal" fleet component, which consists of mother-ship (nodriza boats with their towed fiber-glass skiffs (fibras operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips. The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C from the south and offshore. During this season, dolphinfish (Coryphaena hippurus dominates the catches. However, in warmer waters, the fishery changes to tuna

The Ecuadorian Artisanal Fishery for Large Pelagics: Species Composition and Spatio-Temporal Dynamics.

Science.gov (United States)

Martínez-Ortiz, Jimmy; Aires-da-Silva, Alexandre M; Lennert-Cody, Cleridy E; Maunder, Mark N

2015-01-01

The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the "oceanic-artisanal" fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna

Deep-water fisheries at the Atlantic Frontier

Science.gov (United States)

Gordon, J. D. M.

2001-05-01

The deep sea is often thought of as a cold, dark and uniform environment with a low-fish biomass, much of which is highly adapted for life in a food-poor environment. While this might be true of the pelagic fish living in the water column, it is certainly not true of the demersal fish which live on or close to the bottom on the continental slopes around the British Isles (the Atlantic Frontier). These fish are currently being commercially exploited. There is growing evidence to support the view that success of the demersal fish assemblages depends on the pelagic or benthopelagic food sources that impinge both vertically and horizontally onto the slope. There are several quite separate and distinct deep-water fisheries on the Atlantic Frontier. It is a physical barrier, the Wyville-Thomson Ridge, which results in the most significant division of the fisheries. The Ridge, which has a minimum depth of about 500 m, separates the warmer deep Atlantic waters from the much colder Norwegian Sea water and as a result, the deep-water fisheries to the west of the Hebrides and around the offshore banks are quite different from those of the Faroe-Shetland Channel (West of Shetland). The fisheries to the West of the Hebrides can be further divided by the fishing method used into bottom trawl, semipelagic trawl and longline. The bottom-trawl fisheries extend from the shelf-slope break down to about 1700 m and the target species varies with depth. The smallest vessels in the fleet fish on the upper slope, where an important target species is the anglerfish or monkfish ( Lophius spp.). On the mid-slope the main target species are blue ling ( Molva dypterygia) and roundnose grenadier ( Coryphaenoides rupestris), with bycatches of black scabbardfish ( Aphanopus carbo) and deep-water sharks. On the lower slope orange roughy ( Hoplostethus atlanticus) is an important target species. The major semipelagic trawl fishery is a seasonal fishery on spawning aggregations of blue whiting

Hydrodynamic characteristics of the oval cambered double slotted otter board in bottom trawl fisheries

Science.gov (United States)

Liu, J.; Huang, H. L.; Li, L. Z.; Qu, T. C.; Wu, Y.; Chen, S.; Yang, J. L.; Rao, X.

2017-07-01

The otter board is one of the main components of single boat trawl fisheries. An oval cambered double slotted otter board was developed for improving the expansion performance of trawl net in bottom trawl fisheries. A flume model experiment was conducted to measure the lift coefficient (C L), drag coefficient (C D), and lift to drag ratio (K) in different angles of attack (α). The experimental results are as follows : (1) The C L and K value show a trend of increasing at the beginning and then decreasing with the increase of angle of attack, the C D value reflects an upward trend as the angle of attack increases; (2) The D3 otter board (front flow deflector angle at 29°) showed a better hydrodynamic performance. When α=30°, the max lift coefficient (C Lmax) was 1.464, in this case C D = 0.554 and K=2.643. When α=15°, the max lift to drag ratio (K max) was 4.165, C L =0.633, and C D = 0.152. This suggests that the best working scope for the angle of attack is between 15°~30°, in which case, C L>0.633 and K>2.643. The mean value of the lift coefficient was 1.071 and the mean of the lift to drag ratio was 3.482. Comparative analysis of the hydrodynamic performance of different types of otter boards showed that the D3 otter board both had good expansion performance and efficiency, which can provide a reference basis for further optimization of the bottom trawl otter board.

Impact of El Niño events on pelagic fisheries in Peruvian waters

Science.gov (United States)

Ñiquen, Miguel; Bouchon, Marilú

2004-03-01

Using data from stock assesment surveys on pelagic resources during El Niño events of 1972/73, 1982/83, 1997/98, we analyze biological changes on pelagic ecosystems and pelagic fisheries during different stages of development of El Niño phenomenon: emergence, full, final and post-Niño. Results indicate changes in spatial distribution of resources, their concentration and size structure. In anchovy (Engraulis ringens) a decrease in biomass was observed, which was estimated at 1.2 million tons in September 1998, the lowest throughout the 1990s. This resource showed an asymmetric distribution towards the south of Peru. Other pelagic resources increased their biomass during or after Niño events, primarily sardine (Sardinops sagax), jack mackerel (Trachurus murphyi), pacific mackerel (Scomber japonicus), and longnose anchovy (Anchoa nasus). At the end of the El Niño phenomenon we found less productivity but more diversity in the pelagic ecosystem. During the 1997/98 El Niño, the diversity index (Manual de Ecologia, 1a Edition, Editorial Trillas, Mexico, 267pp) increased from 0.87 to 1.23-1.70. In both the emergence stage and fully developed stages of El Niño we found large numbers of sardine and longnose anchovy present simultaneously. Size structure of sardine, jack mackerel, and pacific mackerel showed an increase in juveniles. Anchovy during El Niño showed a single modal group composed of adults, but the post-Niño phase indicated an increase in juveniles with an average length of 6-7 cm. In El Niño conditions spawning among anchovy was low, but among sardine and pacific mackerel it was high. We observed, for the first time during full spawning, juvenile sardines with a total length of 18-20 cm. The anchovy spawning season during the post-Niño phase was considerably lengthened, from April to December 1998. Drastic change occurred in fisheries when monospecific fisheries, based on anchovy before El Niño, became multispecific fisheries based on sardine, jack

Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

Directory of Open Access Journals (Sweden)

Alana Grech

Full Text Available BACKGROUND: The Queensland East Coast Otter Trawl Fishery (ECOTF for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA. The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation. METHODOLOGY AND RESULTS: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions. CONCLUSIONS/SIGNIFICANCE: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

50 CFR 660.337 - Trawl rationalization program - data collection requirements.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Trawl rationalization program - data... COAST STATES West Coast Groundfish Fisheries § 660.337 Trawl rationalization program - data collection... guarantee that they will qualify for quota share under a future trawl rationalization program. The following...

50 CFR 600.725 - General prohibitions.

Science.gov (United States)

2010-10-01

.... Longline. F. Recreational fishery F. Hook and line, rod and reel, spear. 9. Atlantic Bluefish Fishery (FMP.... Purse seine, seine. C. Mixed species pot and trap fishery C. Pot, trap. D. Bluefish, croaker, flounder... Bluefish Fishery (FMP): A. Bluefish, croaker, and flounder trawl fishery A. Trawl. B. Pelagic longline and...

Behaviour of fish by-catch in the mouth of a crustacean trawl.

Science.gov (United States)

Queirolo, D; Gaete, E; Montenegro, I; Soriguer, M C; Erzini, K

2012-06-01

The behaviour of fish by-catch was recorded and characterized by in situ observations in the mouth of a crustacean trawl using an underwater camera system with artificial light, at depths between 106 and 461 m, along the central coast of Chile. The groups or species studied were rattails (family Macrouridae), Chilean hake Merluccius gayi gayi, sharks (orders Carcharhiniformes and Squaliformes), skates (family Rajidae), flatfishes (genus Hippoglossina) and small benthopelagic and demersal fishes (orders Osmeriformes, Stomiiformes, Gadiformes, Ophidiiformes and Perciformes). The fish behaviour was categorized in terms of (1) position in the water column, (2) initial orientation with respect to the trawl, (3) locomotion and (4) swimming speed with respect to the trawl. Rattails, sharks, skates and flatfishes were passive in response to the trawl and showed similar behavioural patterns, with most fishes observed sitting or touching the bottom with no swimming or other activity. Merluccius gayi gayi was the most active species, displaying a wide combination of behavioural responses when the trawl approached. This species showed several behavioural patterns, mainly characterized by swimming forward at variable speed. A fraction of small bentho-pelagic and demersal fishes also showed an active behaviour but always at lower speed than the trawl. The species-specific differences in behaviour in the mouth of the trawl suggest that improvements at the level of the footrope can be made to reduce by-catch, especially of passive species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Common dolphin (Delphinus delphis bycatch in New Zealand commercial trawl fisheries.

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Finlay N Thompson

Full Text Available Marine mammals are regularly reported as bycatch in commercial and artisanal fisheries, but data are often insufficient to allow assessment of these incidental mortalities. Observer coverage of the mackerel trawl fishery in New Zealand waters between 1995 and 2011 allowed evaluation of common dolphin Delphinus delphis bycatch on the North Island west coast, where this species is the most frequently caught cetacean. Observer data were used to develop a statistical model to estimate total captures and explore covariates related to captures. A two-stage Bayesian hurdle model was used, with a logistic generalised linear model predicting whether any common dolphin captures occurred on a given tow of the net, and a zero-truncated Poisson distribution to estimate the number of dolphin captures, given that there was a capture event. Over the 16-year study period, there were 119 common dolphin captures reported on 4299 observed tows. Capture events frequently involved more than one individual, with a maximum of nine common dolphin observed caught in a single tow. There was a peak of 141 estimated common dolphin captures (95% c.i.: 56 to 276; 6.27 captures per 100 tows in 2002-03, following the marked expansion in annual effort in this fishery to over 2000 tows. Subsequently, the number of captures fluctuated although fishing effort remained relatively high. Of the observed capture events, 60% were during trawls where the top of the net (headline was <40 m below the surface, and the model determined that this covariate best explained common dolphin captures. Increasing headline depth by 21 m would halve the probability of a dolphin capture event on a tow. While lack of abundance data prevents assessment of the impact of these mortalities on the local common dolphin population, a clear recommendation from this study is the increasing of headline depth to reduce common dolphin captures.

2014 Small Pelagics Survey (GU1406, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Objectives of the 2013 Small Pelagics Acoustic/Trawl Survey were to sample the northern Gulf of Mexico with a 90-ft high opening trawl to facilitate assessments of...

Can pelagic forage fish and spawning cisco (Coregonus artedi) biomass in the western arm of Lake Superior be assessed with a single summer survey?

Science.gov (United States)

Yule, D.L.; Stockwell, J.D.; Schreiner, D.R.; Evrard, L.M.; Balge, M.; Hrabik, T.R.

2009-01-01

Management efforts to rehabilitate lake trout Salvelinus namaycush in Lake Superior have been successful and the recent increase in their numbers has led to interest in measuring biomass of pelagic prey fish species important to these predators. Lake Superior cisco Coregonus artedi currently support roe fisheries and determining the sustainability of these fisheries is an important management issue. We conducted acoustic and midwater trawl surveys of the western arm of Lake Superior during three periods: summer (July-August), October, and November 2006 to determine if a single survey can be timed to estimate biomass of both prey fish and spawning cisco. We evaluated our methods by comparing observed trawl catches of small (cisco increased substantially in November, while small bloater Coregonus hoyi biomass was lower. We compared our summer 2006 estimates of total fish biomass to the results of a summer survey in 1997 and obtained similar results. We conclude that the temporal window for obtaining biomass estimates of pelagic prey species in the western arm of Lake Superior is wide (July through October), but estimating spawning cisco abundance is best done with a November survey.

Bycatch and release of pelagic megafauna in industrial trawler fisheries off Northwest Africa

NARCIS (Netherlands)

Zeeberg, J.J.; Corten, A.A.H.M.; Graaf, de E.

2006-01-01

The accidental capture of large animals such as sharks, manta rays, sea turtles, and dolphins in pelagic trawler fisheries remains controversial because it threatens biological diversity in many biogeographical regions, including the subtropical eastern North Atlantic. Bycatch rates observed during

Life Cycle Inventory Analysis for a Small-Scale Trawl Fishery in Sendai Bay, Japan

Directory of Open Access Journals (Sweden)

Kazuhito Watanabe

2016-04-01

Full Text Available A reduced environmental burden, while maintaining high quality and low cost, has become an important factor for achieving sustainability in the fisheries sector. The authors performed life cycle inventory (LCI analysis targeting the fish production for a small-scale trawl fishery including small trawlers operating in Sendai Bay, Japan. The average annual cumulative CO2 emissions for the small trawlers were 4.7 ton-CO2/ton-product and 8.3 ton-CO2/million Japanese yen (JPN. Total fuel consumption contributed to 97% of the global warming potential. The range of variation in the basic unit of CO2 for each small trawler was also elucidated. Energy conservation through lower fuel consumption is shown to be an effective measure for reducing CO2 in a small trawler fishery. Moreover, the authors examined the system boundary, the determination of the functional unit, and the allocation method of applying LCI analysis to fisheries. Finally, the economy and environment of small trawler fisheries are discussed as important factors for sustainable fisheries, and the life cycle approach is applied to a new fishery type in Japan.

Species selectivity in different sized topless trawl designs: Does size matter?

DEFF Research Database (Denmark)

Krag, Ludvig Ahm; Herrmann, Bent; Karlsen, Junita Diana

2015-01-01

-specific quotas. The toplesstrawl design was developed to improve species-specific selectivity in such fisheries. In a topless trawl,the foot rope is located more forward than the headline to allow fish to escape upwards, whereas theheadline is located in front in traditional trawl designs. In this study we...... Atlantic, topless trawls have been introducedas legal cod-selective trawl designs. However, this study demonstrates that identical gear modificationsmade to similar trawls of different sizes and used in the same fishery can lead to different results....

Using marine reserves to manage impact of bottom trawl fisheries requires consideration of benthic food-web interactions

DEFF Research Database (Denmark)

van Denderen, Pieter Daniël; Rijnsdorp, Adriaan D.; van Kooten, Tobias

2016-01-01

Marine protected areas (MPAs) are widely used to protect exploited fish species as well as to conserve marine habitats and their biodiversity. They have become a popular management tool also for bottom trawl fisheries, a common fishing technique on continental shelves worldwide. The effects of bo...

Influence of twin and multi-rig trawl systems on CPUE in the Danish Norway lobster (Nephrops norvegicus) fishery

DEFF Research Database (Denmark)

Feekings, Jordan P.; Berg, Casper Willestofte; Krag, Ludvig Ahm

2016-01-01

analyse catchrates of four target species, Norway lobster (Nephrops norvegicus), cod (Gadus morhua), plaice (Pleuronectesplatessa) and haddock (Melanogrammus aeglefinus), to try and understand how the use of multi-rig trawlshave altered catch rates within the Danish demersal trawl fishery over the last 16...

Fisheries in the Mediterranean

Directory of Open Access Journals (Sweden)

C. PAPACONSTANTINOU

2000-06-01

Full Text Available The aim of this paper is to give a description of the Mediterranean fisheries, and its level of exploitation and to address the main questions dealing with its management. The Mediterranean is a semi-enclosed marine area with generally narrow continental shelves. The primary production of the Mediterranean is among the lowest in the world (26-50g C m-2 y-1. The Mediterranean fisheries can be broken down into three main categories: small scale fisheries, trawling and seining fisheries, which operated on demersal, small pelagic and large pelagic resources. After a general description of the state of the resources in the different areas of the Mediterranean it is concluded that (a the overall pictures from the western to the eastern Mediterranean are not considerably different, (b the total landings in the Mediterranean have been increased the last decades, and (c from the perspective of stock assessment, the very few available time series data show stable yield levels. In general fisheries management in the Mediterranean is at a rela- tively early stage of development, judging by the criteria of North Atlantic fisheries. Quota systems are generally not applied, mesh-size regulations usually are set at low levels relative to scientific advice, and effort limitation is not usually applied or, if it is, is not always based on a formal resource assessment. The conservation/management measures applied by the Mediterranean countries can be broadly separated into two major categories: those aiming to keep the fishing effort under control and those aiming to make the exploitation pattern more rational. The most acute problems in the management of the Mediterranean resources are the multispecificity of the catches and the lack of reliable official statistics.

Cooperative Research Paired Trawl Sweep Comparison Study

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In the spring of 2009, Northeast Fisheries Science Center (NEFSC) replaced the previous standard bottom trawl gear (Yankee 36) with a new standard survey trawl...

Improving the effectiveness of escape windows in directed Norway lobster Nephrops norvegicus trawl fisheries

DEFF Research Database (Denmark)

Madsen, Niels; Holst, René; Frandsen, Rikke

2012-01-01

A substantial improvement in the bycatch selectivity of Norway lobster Nephrops norvegicus trawls is required, particularly with respect to cod Gadus morhua , whose stocks are at low levels in several areas. Conventional escape windows are not adequate to properly release cod and other bycatch...... species caught in the trawls. To address this issue, we developed a novel sorting box concept consisting of a four-panel section with a window on the top in order to improve the escape of cod and other bycatch species through an escape window while retaining the target catch of Norway lobster. The concept....... The reduction in bycatch decreased with decreasing mesh size and increasing height of the sorting box. Escape of Norway lobster through the escape window was limited. A modified version of the sorting box concept was implemented in the Kattegat fishery from 2009 onwards...

Integrating the provision of ecosystem services and trawl fisheries for the management of the marine environment.

Science.gov (United States)

Muntadas, Alba; de Juan, Silvia; Demestre, Montserrat

2015-02-15

The species interaction and their biological traits (BT) determine the function of benthic communities and, hence, the delivery of ecosystem services. Therefore, disturbance of benthic communities by trawling may compromise ecosystem service delivery, including fisheries' catches. In this work, we explore 1) the impact of trawling activities on benthic functional components (after the BTA approach) and 2) how trawling impact may affect the ecosystem services delivered by benthic communities. To this aim, we assessed the provision of ecosystem services by adopting the concept of Ecosystem Service Providers (ESP), i.e. ecological units that perform ecosystem functions that will ultimately deliver ecosystem services. We studied thirteen sites subjected to different levels of fishing effort in the Mediterranean. From a range of environmental variables included in the study, we found ESPs to be mainly affected by fishing effort and grain size. Our results suggested that habitat type has significant effects on the distribution of ESPs and this natural variability influences ESP response to trawling at a specific site. In order to summarize the complex relationships between human uses, ecosystem components and the demand for ecosystem services in trawling grounds, we adapted a DPSIR (Drivers-Pressures-State Change-Impact-Response) framework to the study area, emphasizing the role of society as Drivers of change and actors demanding management Responses. This integrative framework aims to inform managers about the interactions between all the elements involved in the management of trawling grounds, highlighting the need for an integrated approach in order to ensure ecosystem service provision. Copyright © 2014 Elsevier B.V. All rights reserved.

STATUS OF SMALL PELAGIC FISHERY IN THE MAKASSAR STRAIT BASED AT THE NORTHERN PART OF JAVA

Directory of Open Access Journals (Sweden)

Sri Turni Hartati

2016-12-01

Full Text Available The coastal of Makassar Strait is one of main fishing grounds for purse seine vessels from northern part of Java which based at the following landing sites, i.e. Pekalongan, Tegal and Juwana. The purse seine fishery predominantly targets small pelagic fish. This paper attempts to present the current condition of small pelagic fishery in the Makassar Strait. Catch and effort (trip data between 2004 and 2011 from the three landing sites were used to estimate Maximum Sustainable Yield (MSY using Schaefer & Fox models. The results showed a decreasing trend in the catch rate, from 30.83 tons/trip in 2004 to 12.27 tons/trip in 2011. The estimated MSY is at the range of 34,705- 37,930 tons with optimum efforts for 2,234-2,500 purse seine trips. Thus the level of purse seine fishing effort in 2011, i.e. 3,078 trips, was exceeding the optimum effort. The decreasing trend in the catch rate may indicate overfishing is occurring between 2004 and 2011. For management of the small pelagic fisheries in the waters of Makassar Strait, important action recommended is fishing effort restrictions. The effort allowed would be only in the range of 2,234-2,500 purse seine trips, and the fishing capacity needs to be controled.

Testing Nordmøre grids on the target and by-catch species of the commercial bottom trawl fishery in the Gulf of Cadiz

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Mariángeles Gamaza

2015-12-01

Full Text Available Sorting grids have been tested worldwide in trawl fisheries. Here we report upon the first trials performed using Nordmøre sorting grids with four different bar spacings in the trawl fisheries of the Gulf of Cadiz targeting crustaceans as the main resource. A total of 288 valid hauls and 67 commercial species were caught. Escapement and escape size selectivity were evaluated for the most important target and by-catch species. A decrease in the percentage of biomass escape was recorded with increasing grid spacing for the two target species, deep-water rose shrimp (Parapenaeus longirostris and Norway lobster (Nephrops norvegicus, from 24% to 8% for the former and from 86 to 9% for the latter, with a 15-mm and 30-mm grid respectively. In general, high escape rates were found for most finfish and cephalopods. For hake (Merluccius merluccius, as the main by-catch species, the results showed an escape rate decreasing from 96% to 71% as the bar spacing increased. Our findings suggest the 30-mm grid would be effective for the deep-water crustacean trawlers but different mitigation measures will be required for other métiers in the multispecies trawl fishery of the Gulf of Cadiz.

Discarding Discards: Identification of influential factors and possible mitigation tools in demersal trawl fisheries

DEFF Research Database (Denmark)

Feekings, Jordan P.

Discarding of aquatic organisms is a global problem in the world’s fisheries, where more than 7 million tonnes are caught and subsequently discarded each year. The understanding of what drives discarding can help provide mitigation measures in the future. Altering management measures which result...... in high discard rates/ratios may prove beneficial not only to the economic viability of the fishery but also to the biological functioning of the ecosystem. The present Ph.D. thesis, titled “Discarding Discards: Identification of influential factors and possible mitigation tools in demersal trawl...... an examination of the efficiency of technical regulations currently in force and retrospective analyses of the efficiency of such measures in the past. The thesis consists of a review and 4 papers. Paper I is an investigation of the factors that can potentially influence the discarding of commercial species...

The footprint of bottom trawling in European waters

NARCIS (Netherlands)

Eigaard, Ole R.; Bastardie, Francois; Hintzen, Niels T.; Buhl-Mortensen, Lene; Buhl-Mortensen, Pål; Catarino, Rui; Dinesen, Grete E.; Egekvist, Josefine; Fock, Heino O.; Geitner, Kerstin; Gerritsen, Hans D.; González, Manuel Marín; Jonsson, Patrik; Kavadas, Stefanos; Laffargue, Pascal; Lundy, Mathieu; Gonzalez-Mirelis, Genoveva; Nielsen, J.R.; Papadopoulou, Nadia; Posen, Paulette E.; Pulcinella, Jacopo; Russo, Tommaso; Sala, Antonello; Silva, Cristina; Smith, Christopher J.; Vanelslander, Bart; Rijnsdorp, Adriaan D.

2017-01-01

Mapping trawling pressure on the benthic habitats is needed as background to support an ecosystem approach to fisheries management. The extent and intensity of bottom trawling on the European continental shelf (0-1000 m) was analysed from logbook statistics and vessel monitoring system data for

Summer Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Sampling the coastal waters of the Gulf of Maine using the Northeast Fishery Science Center standardized bottom trawl has been problematic due to large areas of hard...

From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

DEFF Research Database (Denmark)

Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard

2015-01-01

Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes....... A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide...... with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the test codend compared with the standard codend. The decrease in damages may also improve quality indirectly by inflicting...

Escape windows to improve the size selectivity in the Baltic cod trawl fishery

DEFF Research Database (Denmark)

Madsen, Niels; Holst, René; Foldager, L.

2002-01-01

A rapid decrease of the stock of Baltic cod (Gadus morhua) has provided the incentive to improve the size selectivity in the trawl fishery. Use of escape windows is permitted in the legislation to give means of improving the size selectivity of cod as an alternative to a traditional standard codend....... The history of the use of escape windows in the Baltic Sea cod fishery is reviewed. The present escape windows do not function optimally. The objective of this new experiment was to compare an improved design of escape window, which is placed in the upper panel, with that of standard codend. Three standard...... of the codend selectivity was formulated to analyse the results and determine the effects of codend type, mesh size and other recorded variables. L50 and SR increased significantly with the mesh size. L50 was significantly increased and SR significantly reduced for a window codend with the same window mesh size...

Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

DEFF Research Database (Denmark)

Krag, Ludvig Ahm

have been published in scientific journals and Paper 3 has been submitted to Fisheries Research. This review will take a broader perspective and will examine the capturing process, which is the basis for the selection process. Moreover, it discusses the existing methods and knowledge in the fields...... different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the highest discard rates of juvenile fish, including cod. The focus of this work was on improving......, and openings. The results show that the morphology-based simulations of size selectivity of cod can be used to explain a large part of both the within-haul and the between-haul variations previously reported from sea trials. The method can further predict the selection parameters (L50 and SR) for cod...

Recreational fishery catch and effort estimates for large pelagic species from Maine through Virginia from 2002-06-01 to 2014-10-31 (NCEI Accession 0137959)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — On the Atlantic Coast from Maine to Virginia, NOAA Fisheries uses the Large Pelagics Survey (LPS) to measure the total recreational catch of large pelagics fish...

77 FR 51709 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

Science.gov (United States)

2012-08-27

... Migratory Species; Bigeye Tuna Catch Limit in Longline Fisheries for 2012 AGENCY: National Marine Fisheries... Fisheries of the Western Pacific Region (Pelagics FEP) developed by the Western Pacific Fishery Management... Pelagics FEP. Section 113(a) further directs the Secretary of Commerce, for the purposes of annual...

Dolphinfish Bycatch in Spanish Mediterranean Large Pelagic Longline Fisheries, 2000–2010

Directory of Open Access Journals (Sweden)

David Macías

2012-01-01

Full Text Available The aim of this paper is to describe the dolphinfish bycatch rates in the longline fisheries of the Western Mediterranean and modelling the nominal bycatch abundance and distribution of dolphinfish from the Spanish Mediterranean as a function of technical, geographical, and seasonality factors. Our results indicate that the impact of the pelagic and semipelagic longline on the dolphinfish population is relatively low (1.083 fishes per 1000 hooks, in contrast with the greater effect on the target species population. We obtained a statistically significant logistic model, with the following factors: technical characteristics of the fishery, geographical location, and seasonality. Drifting surface longliners targeting albacore is the gear with the highest effect on Mediterranean dolphinfish population. The technical characteristics of the fishery and seasonality factors have an important role in explaining the absence or presence of dolphinfish bycatch in the different boat strata, gear types, and seasons. Moreover, sea surface temperature and lunar phases also present additional explanations. Lunar phase as SST has been frequently used as an explanatory variable affecting catch rates of dolphinfish.

Distribution of Bottom Trawling Effort in the Yellow Sea and East China Sea.

Directory of Open Access Journals (Sweden)

Shengmao Zhang

Full Text Available Bottom trawling is one of the most efficient fishing activities, but serious and persistent ecological issues have been observed by fishers, scientists and fishery managers. Although China has applied the Beidou fishing vessel position monitoring system (VMS to manage trawlers since 2006, little is known regarding the impacts of trawling on the sea bottom environments. In this study, continuous VMS data of the 1403 single-rig otter trawlers registered in the Xiangshan Port, 3.9% of the total trawlers in China, were used to map the trawling effort in 2013. We used the accumulated distance (AD, accumulated power distance (APD, and trawling intensity as indexes to express the trawling efforts in the Yellow Sea (YS and East China Sea (ECS. Our results show that all three indexes had similar patterns in the YS and ECS, and indicated a higher fishing effort of fishing grounds that were near the port. On average, the seabed was trawled 0.73 times in 2013 over the entire fishing region, and 51.38% of the total fishing grounds were with no fishing activities. Because of VMS data from only a small proportion of Chinese trawlers was calculated fishing intensity, more VMS data is required to illustrate the overall trawling effort in China seas. Our results enable fishery managers to identify the distribution of bottom trawling activities in the YS and ECS, and hence to make effective fishery policy.

NEFSC 2002 Winter Bottom Trawl Survey (AL0203, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2002 Fall Bottom Trawl Survey (AL0210, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2011 Fall Bottom Trawl Survey (HB1105, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2008 Spring Bottom Trawl Survey (AL0801, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2008 Spring Bottom Trawl Survey (HB0802, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2015 Fall Bottom Trawl Survey (HB1506, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2011 Spring Bottom Trawl Survey (HB1102, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2007 Bottom Trawl Survey Calibration (HB0711, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2003 Spring Bottom Trawl Survey (DE0303, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2008 Fall Bottom Trawl Survey (AL0803, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2004 Winter Bottom Trawl Survey (AL0401, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2005 Fall Bottom Trawl Survey (AL0508, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 1998 Fall Bottom Trawl Survey (AL9811, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2009 Spring Bottom Trawl Survey (HB0901, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2012 Spring Bottom Trawl Survey (HB1201, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2015 Spring Bottom Trawl Survey (HB1501, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2004 Spring Bottom Trawl Survey (AL0403, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 1999 Fall Bottom Trawl Survey (AL9911, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2005 Fall Bottom Trawl Survey (AL0509, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2012 Fall Bottom Trawl Survey (HB1206, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2013 Fall Bottom Trawl Survey (HB1304, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2010 Spring Bottom Trawl Survey (HB1002, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2016 Fall Bottom Trawl Survey (HB1604, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2000 Fall Bottom Trawl Survey (Al0006, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2000 Fall Bottom Trawl Survey (AL0007, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2005 Winter Bottom Trawl Survey (AL0502, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2009 Fall Bottom Trawl Survey (HB0905, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2004 Fall Bottom Trawl Survey (AL0409, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2013 Spring Bottom Trawl Survey (HB1301, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2014 Fall Bottom Trawl Survey (HB1405, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2014 Spring Bottom Trawl Survey (HB1401, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2007 Bottom Trawl Survey Calibration (HB0710, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2005 Spring Bottom Trawl Survey (AL0504, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2016 Spring Bottom Trawl Survey (HB1601, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

NEFSC 2008 Fall Bottom Trawl Survey (HB0807, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

West Coast Groundfish Bottom Trawl Survey Data - Annual West Coast time series groundfish trawl data collection survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Members of the Fishery Resource Analysis and Monitoring Division Survey Team conduct an annual West Coast Groundfish Bottom Trawl Survey from May - October each...

Warming shelf seas drive the subtropicalization of European pelagic fish communities.

Science.gov (United States)

Montero-Serra, Ignasi; Edwards, Martin; Genner, Martin J

2015-01-01

Pelagic fishes are among the most ecologically and economically important fish species in European seas. In principle, these pelagic fishes have potential to demonstrate rapid abundance and distribution shifts in response to climatic variability due to their high adult motility, planktonic larval stages, and low dependence on benthic habitat for food or shelter during their life histories. Here, we provide evidence of substantial climate-driven changes to the structure of pelagic fish communities in European shelf seas. We investigated the patterns of species-level change using catch records from 57,870 fisheries-independent survey trawls from across European continental shelf region between 1965 and 2012. We analysed changes in the distribution and rate of occurrence of the six most common species, and observed a strong subtropicalization of the North Sea and Baltic Sea assemblages. These areas have shifted away from cold-water assemblages typically characterized by Atlantic herring and European sprat from the 1960s to 1980s, to warmer-water assemblages including Atlantic mackerel, Atlantic horse mackerel, European pilchard and European anchovy from the 1990s onwards. We next investigated if warming sea temperatures have forced these changes using temporally comprehensive data from the North Sea region. Our models indicated the primary driver of change in these species has been sea surface temperatures in all cases. Together, these analyses highlight how individual species responses have combined to result in a dramatic subtropicalization of the pelagic fish assemblage of the European continental shelf. © 2014 John Wiley & Sons Ltd.

The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

Directory of Open Access Journals (Sweden)

Francesco Colloca

Full Text Available The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%. This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006 aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy

The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

Science.gov (United States)

Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J; Spedicato, Maria Teresa

2015-01-01

The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem

Interannual Variability of Fisheries Economic Returns and Energy Ratios Is Mostly Explained by Gear Type

Science.gov (United States)

Trenkel, Verena M.; Daurès, Fabienne; Rochet, Marie-Joëlle; Lorance, Pascal

2013-01-01

According to portfolio theory applied to fisheries management, economic returns are stabilised by harvesting in a portfolio stocks of species whose returns are negatively correlated and for which the portfolio economic return variance is smaller than the sum of stock specific return variances. Also, variability is expected to decrease with portfolio width. Using a range of indicators, these predictions were tested for the French fishing fleets in the Bay of Biscay (Northeast Atlantic) during the period 2001–2009. For this, vessels were grouped into eight fishing fleets based on the gears used and exploited species were grouped into five functional groups. The portfolio width of fleets ranged from 1–3 functional groups, or 4–19 species. Economic fleet returns (sale revenues minus fishing costs) varied strongly between years; the interannual variability was independent of portfolio width (species or functional groups). Energy ratio expressed by the ratio between fuel energy used for fishing and energy contained in landings varied from 0.3 for purse seines to 9.7 for trawlers using bottom trawls alone or in combination with pelagic trawls independent of portfolio width. Interannual variability in total sale revenues was larger than the sum of species specific sales revenue variability, except for fleets using hooks and pelagic trawlers; it increased with the number of species exploited. In conclusion, the interannual variability of economic returns or energy ratios of French fisheries in the Bay of Biscay did not decrease with the number of species or functional groups exploited, though it varied between fleets. PMID:23922951

Modeled distribution and abundance of a pelagic seabird reveal trends in relation to fisheries

Science.gov (United States)

Renner, Martin; Parrish, Julia K.; Piatt, John F.; Kuletz, Kathy J.; Edwards, Ann E.; Hunt, George L.

2013-01-01

The northern fulmar Fulmarus glacialis is one of the most visible and widespread seabirds in the eastern Bering Sea and Aleutian Islands. However, relatively little is known about its abundance, trends, or the factors that shape its distribution. We used a long-term pelagic dataset to model changes in fulmar at-sea distribution and abundance since the mid-1970s. We used an ensemble model, based on a weighted average of generalized additive model (GAM), multivariate adaptive regression splines (MARS), and random forest models to estimate the pelagic distribution and density of fulmars in the waters of the Aleutian Archipelago and Bering Sea. The most important predictor variables were colony effect, sea surface temperature, distribution of fisheries, location, and primary productivity. We calculated a time series from the ratio of observed to predicted values and found that fulmar at-sea abundance declined from the 1970s to the 2000s at a rate of 0.83% (± 0.39% SE) per annum. Interpolating fulmar densities on a spatial grid through time, we found that the center of fulmar distribution in the Bering Sea has shifted north, coinciding with a northward shift in fish catches and a warming ocean. Our study shows that fisheries are an important, but not the only factor, shaping fulmar distribution and abundance trends in the eastern Bering Sea and Aleutian Islands.

Spatial Overlap of Grey Seals and Fisheries in Irish Waters, Some New Insights Using Telemetry Technology and VMS.

Directory of Open Access Journals (Sweden)

M Cronin

Full Text Available Seals and humans often target the same food resource, leading to competition. This is of mounting concern with fish stocks in global decline. Grey seals were tracked from southeast Ireland, an area of mixed demersal and pelagic fisheries, and overlap with fisheries on the Celtic Shelf and Irish Sea was assessed. Overall, there was low overlap between the tagged seals and fisheries. However, when we separate active (e.g. trawls and passive gear (e.g. nets, lines fisheries, a different picture emerged. Overlap with active fisheries was no different from that expected under a random distribution, but overlap with passive fisheries was significantly higher. This suggests that grey seals may be targeting the same areas as passive fisheries and/or specifically targeting passive gear. There was variation in foraging areas between individual seals suggesting habitat partitioning to reduce intra-specific competition or potential individual specialisation in foraging behaviour. Our findings support other recent assertions that seal/fisheries interactions in Irish waters are an issue in inshore passive fisheries, most likely at the operational and individual level. This suggests that seal population management measures would be unjustifiable, and mitigation is best focused on minimizing interactions at nets.

Cooperation between scientists, NGOs and industry in support of sustainable fisheries: the South African hake Merluccius spp. trawl fishery experience.

Science.gov (United States)

Field, J G; Attwood, C G; Jarre, A; Sink, K; Atkinson, L J; Petersen, S

2013-10-01

This paper examines the increasingly close interaction between natural and social scientists, non-governmental organizations (NGO) and industry, in pursuit of responsible ecosystem-based management of fisheries. South Africa has committed to implementing an ecosystem approach to fisheries management. Management advice stems from multi-stakeholder representation on government-led scientific and management working groups. In the hake Merluccius capensis and Merluccius paradoxus fishery, the primary management measure is an annual total allowable catch (TAC), the level of which is calculated using a management procedure (MP) that is revised approximately every 4 years. Revision of the MP is a consultative process involving most stakeholders, and is based on simulation modelling of projected probable scenarios of resource and fishery dynamics under various management options. NGOs, such as the Worldwide Fund for Nature in South Africa (WWF-SA), have played an important role in influencing consumers, the fishing industry and government to develop responsible fishing practices that minimize damage to marine ecosystems. Cooperation between industry, government and scientists has helped to improve sustainability and facilitated the meeting of market-based incentives for more responsible fisheries. Research includes ecosystem modelling, spatial analysis and ecosystem risk assessment with increasing research focus on social and economic aspects of the fishery. A four-year cooperative experiment to quantify the effect of trawling on benthic community structure is being planned. The food requirements of top predators still need to be included in the TAC-setting formulae and more social and economic research is needed. This paper also demonstrates how NGO initiatives such as Marine Stewardship Council certification and the Southern African Sustainable Seafood Initiative, a traffic light system of classifying seafood for consumers, have contributed to responsible fishing

NEFSC Small Pelagics Acoustic/Midwater Trawl Survey (DE9903, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The small pelagics cruise will map the distribution of small pelagic species such as Atlantic mackerel, Atlantic herring, silver hake, butterfish, and squid, in the...

A dataset from bottom trawl survey around Taiwan

Directory of Open Access Journals (Sweden)

Kwang-tsao Shao

2012-05-01

Full Text Available Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000–2003, in the waters around Taiwan and Penghu (Pescadore Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw. They have also been published through TaiBIF (http://taibif.tw, FishBase and GBIF (website see below. This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

The economic and financial performance of Bahrain's Fisheries Sector

International Nuclear Information System (INIS)

Abdulqader, E.A.A.

2007-01-01

This work is based on an extensive socio-economic survey conducted at all Bahrain landing sites in the period July-November, 2002. Based on boat size and the type of fishing gear used, eight fisheries sectors were determined, these included small boats using wire traps, shrimp trawls, gillnets, hooks and lines and barrier traps. It also included large boats using wire traps, shrimp trawls and gillnets. The economic and financial performances of these sectors were evaluated. The ratio of net catch flow to total earnings was used to measure the economic performance, while the return over investment was used to measure the financial performance. Higher economic returns (except for gillnet and shrimp trawl fisheries) were found in the case of small boats where smaller investments are found. This indicated that an over-fishing condition exists in Bahrain's fisheries, which is clearly found in the case of the shrimp trawl fishery. (author)

75 FR 55745 - Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2010-09-14

... Pacific Fishery Management Council's (Pacific Council) Coastal Pelagic Species Management Team (CPSMT) and... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... sardine stock assessment for 2010. Other issues relevant to Coastal Pelagic Species fisheries management...

A knowledge platform to inform on the effects of trawling on benthic communities

Science.gov (United States)

Muntadas, Alba; Lample, Michel; Demestre, Montserrat; Ballé-Béganton, Johanna; de Juan, Silvia; Maynou, Francesc; Bailly, Denis

2018-02-01

For a successful implementation of an Ecosystem Approach to Fisheries (EAF) management, it is necessary that all stakeholders involved in fisheries management are aware of the implications of fishing impacts on ecosystems and agree with the adopted measures to mitigate these impacts. In this context, there is a need for tools to share knowledge on the ecosystem effects of fisheries among these stakeholders. When managing bottom trawl fisheries under an EAF framework, one of the main concerns is the direct and indirect consequences of trawling impacts on benthic ecosystems. We developed a platform using the ExtendSim® software with a user-friendly interface that combines a simulation model based on existing knowledge, data collection and representation of predicted trawling impacts on the seabed. The platform aims to be a deliberation support tool for fisheries' stakeholders and, simultaneously, raise public awareness of the need for good benthic community knowledge to appropriately inform EAF management plans. The simulation procedure assumes that trawling affects benthic communities with an intensity that depends on the level of fishing effort exerted on benthic communities and on the habitat characteristics (i.e. sediment grain size). Data to build the simulation comes from epifaunal samples from 18 study sites located in Mediterranean continental shelves subjected to different levels of fishing effort. In this work, we present the simulation outputs of a 50% fishing effort increase (and decrease) in four of the study sites which cover different habitats and different levels of fishing effort. We discuss the platform strengths and weaknesses and potential future developments.

Bio-economic evaluation of implementing trawl fishing gear with different selectivity

DEFF Research Database (Denmark)

Grønbæk Kronbak, Lone; Nielsen, J. Rasmus; Jørgensen, Ole A.

2009-01-01

The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...... for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and byratches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...

Bio-economic evaluation of implementing trawl fishing gear with different selectivity

DEFF Research Database (Denmark)

Kronbak, Lone Grønbæk; Nielsen, J. Rasmus; Jørgensen, Ole A.

2009-01-01

The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...... for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and bycatches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...

Identifying pelagic ecosystem indicators for management

DEFF Research Database (Denmark)

Trenkel, Verena; Hintzen, Niels; Rindorf, Anna

2013-01-01

When exploiting fish populations under the ecosystem approach, aiming for MSY is not necessarily sufficient to ensure wider ecosystem sustainability. All of the large stocks of pelagic fish are managed through harvest control rules based on an MSY approach. Ensuring good environmental status...... will probably require further constraints to be imposed by management. Most of the current paradigm with regards to GES for fisheries has been based on demersal fish. Pelagic fisheries and fish are operationally and biologically respectively different. We use the example of applying the ecosystem approach...... between objectives and indicators were explored for a range of examples highlighting the importance of the biology and the interaction between the pelagic ecosystem and humans. Considering MSY targets alone will not fulfil GES objectives with regards to e.g. genetic, phenotypic, and behavioural dimensions...

76 FR 14378 - Fisheries of the South Atlantic; South Atlantic Fishery Management Council; Public Meeting

Science.gov (United States)

2011-03-16

... the South Atlantic; South Atlantic Fishery Management Council; Public Meeting AGENCY: National Marine... the Coastal Migratory Pelagics Fishery Management Plan (FMP) for the South Atlantic and Gulf of Mexico... AP will also review Amendment 19 to the Coastal Migratory Pelagics FMP regarding alternatives for bag...

NEFSC 2008 Spring Bottom Trawl Survey - Site Specific Calibration (HB0803, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

trawl bycatch in the fishing grounds of Bus

African Journals Online (AJOL)

ajl yemi

2011-11-30

. Biol. 86: 1455-1462. Watson RA, Dredge MLC, Mayer DG (1990). Spatial and seasonal variation in demersal trawl fauna associated with a prawn fishery on the CentralGreat Barrier Reef, Australia. Aust. J. Mar. Freshw. Res.

The use of at‐sea‐sampling data to dissociate environmental variability in Norway lobster (Nephrops norvegicus) catches to improve resource exploitation efficiency within the Skagerrak/Kattegat trawl fishery

DEFF Research Database (Denmark)

Feekings, Jordan P.; Christensen, Asbjørn; Jonsson, Patrik

2015-01-01

Research into the influence of environmental variables on the behaviour of Norway lobster (Nephrops norvegicus), and hence catch rates, dates back to the 1960s (e.g., Höglund and Dybern, Diurnal and seasonal variations in the catch‐composition of Nephrops norvegicus (L.) at the Swedish west coast...... on commercial trawl catches of Nephrops norvegicus (L.). ICES J. Mar. Sci. 58:1318). Here, we aimed to dissociate environmental variability in Norway lobster catches to improve resource exploitation efficiency within the Skagerrak and Kattegat trawl fisheries by utilising data collected as part of an extensive...

Modelling and simulation of size selectivity in diamond mesh trawl cod-ends

DEFF Research Database (Denmark)

Herrmann, Bent

of the fishing gear. The cod-end is the rearmost part of a trawl where catch accumulates and in which most of the size selection is known to take place. To date, the main method used to assess the selectivity of trawl cod-ends has been to run sea trials followed by statistical analysis of the obtained......Within many fisheries there is a widespread discard of fish. Furthermore, there are several fisheries where fish are caught before reaching the optimal size, leading to an adverse exploitation of the resources. One way to achieve a more optimal exploitation is to improve the size selectivity...

Spring Coastal Pelagic Species Acoustic Trawl Survey (SH1404, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — 14 Acoustic transects were run offshore of Southern California between San Francisco and Cape Mendocino, CA with CTD casts conducted daily and trawls nightly based...

50 CFR Figure 6 to Part 223 - TED Extension in Summer Flounder Trawl

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false TED Extension in Summer Flounder Trawl 6 Figure 6 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 6 Figure 6 to Part 223—TED...

Genetic isolation between coastal and fishery-impacted, offshore bottlenose dolphin (Tursiops spp.) populations.

Science.gov (United States)

Allen, Simon J; Bryant, Kate A; Kraus, Robert H S; Loneragan, Neil R; Kopps, Anna M; Brown, Alexander M; Gerber, Livia; Krützen, Michael

2016-06-01

The identification of species and population boundaries is important in both evolutionary and conservation biology. In recent years, new population genetic and computational methods for estimating population parameters and testing hypotheses in a quantitative manner have emerged. Using a Bayesian framework and a quantitative model-testing approach, we evaluated the species status and genetic connectedness of bottlenose dolphin (Tursiops spp.) populations off remote northwestern Australia, with a focus on pelagic 'offshore' dolphins subject to incidental capture in a trawl fishery. We analysed 71 dolphin samples from three sites beyond the 50 m depth contour (the inshore boundary of the fishery) and up to 170 km offshore, including incidentally caught and free-ranging individuals associating with trawl vessels, and 273 dolphins sampled at 12 coastal sites inshore of the 50 m depth contour and within 10 km of the coast. Results from 19 nuclear microsatellite markers showed significant population structure between dolphins from within the fishery and coastal sites, but also among dolphins from coastal sites, identifying three coastal populations. Moreover, we found no current or historic gene flow into the offshore population in the region of the fishery, indicating a complete lack of recruitment from coastal sites. Mitochondrial DNA corroborated our findings of genetic isolation between dolphins from the offshore population and coastal sites. Most offshore individuals formed a monophyletic clade with common bottlenose dolphins (T. truncatus), while all 273 individuals sampled coastally formed a well-supported clade of Indo-Pacific bottlenose dolphins (T. aduncus). By including a quantitative modelling approach, our study explicitly took evolutionary processes into account for informing the conservation and management of protected species. As such, it may serve as a template for other, similarly inaccessible study populations. © 2016 John Wiley & Sons Ltd.

76 FR 56985 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

Science.gov (United States)

2011-09-15

... to estimate total haddock catch by the herring midwater trawl fleet in these herring management areas.... 110627355-1539-02] RIN 0648-BB08 Magnuson-Stevens Fishery Conservation and Management Act Provisions... the NE Multispecies Fishery Management Plan (FMP), which increases the haddock incidental catch cap...

78 FR 20616 - Western Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2013-04-05

... Pacific Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS.... SUMMARY: The Western Pacific Fishery Management Council (Council) will hold meeting of its Pelagics Plan... the Council Pelagics Conference Room to discuss the following agenda items: Tuesday, April 23, 2013, 8...

Acoustic-Trawl Survey of Walleye Pollock on the Eastern Bering Sea Shelf (DY1407, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey on the eastern Bering Sea...

77 FR 22286 - Western Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2012-04-13

... Pacific Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS.... SUMMARY: The Western Pacific Fishery Management Council (Council) will hold a meeting of its Pelagics Plan... pelagics annual report module changes 4. American Samoa annual report module changes 5. Summary of current...

The fish and fisheries of Jones Bank and the wider Celtic Sea

Science.gov (United States)

Martinez, I.; Ellis, J. R.; Scott, B.; Tidd, A.

2013-10-01

The Celtic Sea is a diverse fishing ground that supports important commercial fisheries for a range of demersal fish, large and small-bodied pelagic fish and a variety of cephalopods and other shellfish. A regional overview of the main commercial fish stocks of the Celtic Sea and of the fish that occur in the vicinity of Jones Bank are provided through analyses of landings data from English and Welsh vessels, and from scientific trawl surveys. Dedicated smaller scale sampling via trawl surveys combined with baited cameras on and around the Jones Bank were also analysed to investigate the importance of sandbank habitats with attention paid to the differences in the species occurring on the top of the bank in comparison to adjacent off-bank habitats. Official landing statistics for UK (English and Welsh) vessels indicated that the predominant commercial demersal species in ICES Divisions VIIg,h (in terms of quantities landed) were anglerfish, megrim, pollack and skates (Rajidae). There were, however, regional differences in the distribution of fish and fisheries, and the area surrounding Jones Bank (ICES Rectangles 28E1 and 28E2) supports fisheries for megrim, anglerfish, skates, hake, ling and turbot, with otter trawl, gillnet and beam trawl the main gears used. Recent survey data collected with GOV (Grande Ouverture Verticale) trawl from the Celtic Sea (ICES Divisions VIIe-h, 2007-2010) were used to highlight the broad scale distribution of the main fish assemblages in the Celtic Sea. Analyses of the fish and cephalopod catches from these surveys indicated that there were four broad assemblages in the area, including (i) a region around the Cornwall (which will also be partly influenced by the necessity to use rockhopper ground gear on these rough grounds), (ii) the shallower regions of the north-western Celtic Sea (including parts of the Bristol Channel), (iii) the deeper parts of the outer shelf and (iv) the central Celtic Sea. These data also provided

Microbiological assessment along the fish production chain of the Norwegian pelagic fisheries sector--Results from a spot sampling programme.

Science.gov (United States)

Svanevik, Cecilie Smith; Roiha, Irja Sunde; Levsen, Arne; Lunestad, Bjørn Tore

2015-10-01

Microbes play an important role in the degradation of fish products, thus better knowledge of the microbiological conditions throughout the fish production chain may help to optimise product quality and resource utilisation. This paper presents the results of a ten-year spot sampling programme (2005-2014) of the commercially most important pelagic fish species harvested in Norway. Fish-, surface-, and storage water samples were collected from fishing vessels and processing factories. Totally 1,181 samples were assessed with respect to microbiological quality, hygiene and food safety. We introduce a quality and safety assessment scheme for fresh pelagic fish recommending limits for heterotrophic plate counts (HPC), thermos tolerant coliforms, enterococci and Listeria monocytogenes. According to the scheme, in 25 of 41 samplings, sub-optimal conditions were found with respect to quality, whereas in 21 and 9 samplings, samples were not in compliance concerning hygiene and food safety, respectively. The present study has revealed that the quality of pelagic fish can be optimised by improving the hygiene conditions at some critical points at an early phase of the production chain. Thus, the proposed assessment scheme may provide a useful tool for the industry to optimise quality and maintain consumer safety of pelagic fishery products. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

75 FR 17902 - Western Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2010-04-08

... Components Species for Pelagics Fishery Ecosystem Plan 8. Longline fishery meeting 9. Other business 10.... SUMMARY: The Western Pacific Fishery Management Council (Council) will hold meetings of its Pelagics Plan... requirements for operational-level catch and effort data 5. Catch and bycatch effects of large circle hooks in...

SEAMAP Groundfish/Shrimp Trawl Red Snapper Analytical Dataset Provided to NRDA

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories has conducted standardized groundfish trawl surveys in the Gulf of Mexico since 1987. Prior to 1987,...

76 FR 65155 - Fisheries Off West Coast States; Highly Migratory Species Fisheries; Swordfish Retention Limits

Science.gov (United States)

2011-10-20

...; Swordfish Retention Limits AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... consistent with regulations implementing the Western Pacific Fishery Management Council's Pacific Pelagics...

Diamond vs. square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards

OpenAIRE

Ordines, F. (Francesc); Massutí, E. (Enric); Guijarro, B. (Beatriz); Mas, R. (Ramon)

2006-01-01

Selectivity studies usually describe the effects on target species, whereas information on by-catch and discards is scarce. Nevertheless, large quantities of undersized individuals and invertebrates are discarded in the Mediterranean multi-species bottom trawl fishery. The present work analyses the data from two surveys carried out on the shallow and deep continental shelf (50–78 m, and 147–189 m, respectively) off the Balearic Islands (western Mediterranean). In these surveys, the traditiona...

Climate variability and change scenarios for a marine commodity: Modelling small pelagic fish, fisheries and fishmeal in a globalized market

Science.gov (United States)

Merino, Gorka; Barange, Manuel; Mullon, Christian

2010-04-01

The world's small pelagic fish populations, their fisheries, fishmeal and fish oil production industries and markets are part of a globalised production and consumption system. The potential for climate variability and change to alter the balance in this system is explored by means of bioeconomic models at two different temporal scales, with the objective of investigating the interactive nature of environmental and human-induced changes on this globalised system. Short-term (interannual) environmental impacts on fishmeal production are considered by including an annual variable production rate on individual small pelagic fish stocks over a 10-year simulation period. These impacts on the resources are perceived by the fishmeal markets, where they are confronted by two aquaculture expansion hypotheses. Long-term (2080) environmental impacts on the same stocks are estimated using long-term primary production predictions as proxies for the species' carrying capacities, rather than using variable production rates, and are confronted on the market side by two alternative fishmeal management scenarios consistent with IPCC-type storylines. The two scenarios, World Markets and Global Commons, are parameterized through classic equilibrium solutions for a global surplus production bioeconomic model, namely maximum sustainable yield and open access, respectively. The fisheries explicitly modelled in this paper represent 70% of total fishmeal production, thus encapsulating the expected dynamics of the global production and consumption system. Both short and long-term simulations suggest that the sustainability of the small pelagic resources, in the face of climate variability and change, depends more on how society responds to climate impacts than on the magnitude of climate alterations per se.

Stable isotopes reveal the effect of trawl fisheries on the diet of commercially exploited species.

Science.gov (United States)

Hinz, Hilmar; Moranta, Joan; Balestrini, Stephen; Sciberras, Marija; Pantin, Julia R; Monnington, James; Zalewski, Alex; Kaiser, Michel J; Sköld, Mattias; Jonsson, Patrik; Bastardie, Francois; Hiddink, Jan Geert

2017-07-24

Bottom trawling can change food availability for benthivorous demersal species by (i) changing benthic prey composition through physical seabed impacts and (ii) by removing overall benthic consumer biomass increasing the net availability of benthic prey for remaining individuals. Thus trawling may both negatively and positively influence the quantity and quality of food available. Using δ 13 C and δ 15 N we investigated potential diet changes of three commercially exploited species across trawling gradients in the Kattegat (plaice, dab and Norway lobster (Nephrops)) and the Irish Sea (Nephrops). In the Kattegat, trawling affected primarily the biomass of benthic consumers, lowering competition. Nephrops showed significant positive relationships for δ 13 C and a domed relationship for δ 15 N with trawling. In the Irish Sea, intense trawling had a negative effect on benthic prey. δ 13 C and δ 15 N thus showed the inverse relationships to those observed in the Kattegat. Plaice from the Kattegat, showed a significant relationship with trawling intensity for δ 13 C, but not for δ 15 N. No relationship was found for dab. Changes of δ 13 C and δ 15 N correlated with changes in condition of species. The results show that the removal of demersal competitors and benthos by trawling can change the diets of commercial species, ultimately affecting their body condition.

AFSC/RACE/MACE: Results of 2014 acoustic trawl survey Bogoslof DY1402

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center (AFSC) regularly conduct acoustic-trawl...

NWFSC Observer Trawl Data, off West Coast of US, 2002-2006

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Observer Trawl Data collected during 2002-2006 off West Coast of US. This data product originates from data collected by fishery observers in the West Coast...

Shelikof Strait Acoustic-Trawl Survey of Walleye Pollock (DY1203, ME70)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Midwater Assessment and Conservation Engineering (MACE) program of the Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment...

Shumagin Islands Acoustic-Trawl Survey of Walleye Pollock (DY1201, ME70)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Midwater Assessment and Conservation Engineering (MACE) program of the Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment...

76 FR 23964 - Fisheries in the Western Pacific; Pelagic Fisheries; Purse Seine Prohibited Areas Around American...

Science.gov (United States)

2011-04-29

... are managed under the Pelagics FEP. The Council prepared Amendment 3 to the Pelagics FEP to address... animals, such as pelagic fishes and sea turtles, tend to congregate to naturally-occurring floating..., vessel monitoring system (VMS), and the use of safe sea turtle handling techniques. BILLING CODE 3510-22...

Bayesian spatio-temporal discard model in a demersal trawl fishery

Science.gov (United States)

Grazia Pennino, M.; Muñoz, Facundo; Conesa, David; López-Quílez, Antonio; Bellido, José M.

2014-07-01

Spatial management of discards has recently been proposed as a useful tool for the protection of juveniles, by reducing discard rates and can be used as a buffer against management errors and recruitment failure. In this study Bayesian hierarchical spatial models have been used to analyze about 440 trawl fishing operations of two different metiers, sampled between 2009 and 2012, in order to improve our understanding of factors that influence the quantity of discards and to identify their spatio-temporal distribution in the study area. Our analysis showed that the relative importance of each variable was different for each metier, with a few similarities. In particular, the random vessel effect and seasonal variability were identified as main driving variables for both metiers. Predictive maps of the abundance of discards and maps of the posterior mean of the spatial component show several hot spots with high discard concentration for each metier. We argue how the seasonal/spatial effects, and the knowledge about the factors influential to discarding, could potentially be exploited as potential mitigation measures for future fisheries management strategies. However, misidentification of hotspots and uncertain predictions can culminate in inappropriate mitigation practices which can sometimes be irreversible. The proposed Bayesian spatial method overcomes these issues, since it offers a unified approach which allows the incorporation of spatial random-effect terms, spatial correlation of the variables and the uncertainty of the parameters in the modeling process, resulting in a better quantification of the uncertainty and accurate predictions.

78 FR 79673 - South Atlantic Fishery Management Council; Public Meetings

Science.gov (United States)

2013-12-31

... Atlantic Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS... the Joint Coastal Migratory Pelagics Framework Amendment for 2014; [email protected] for... the Coastal Migratory Pelagics FMP; [email protected] for Joint Amendment 26 to the Coastal...

The Danish Experience with Transferable Fishing Concessions

DEFF Research Database (Denmark)

Højrup, Thomas

2012-01-01

The task of the concise chapter is to describe the Danish experiences with a basic regulation based upon the principle of Transferable Fisheries Concessions, TFC - at the backgruund of the introduction of Transfreable Quotas in 2003 (pelagic fisheries) and 2007 (demersal fisheries). To do this th...... dependent upon the struggles on the financial markets, replacing sustainable fishing methods with heavy buttom trawling and undermining the future of young people in the fishing industry....

STUDY ON OCEANGRAFHIC AND WEATHER CONDITIONS RELATED TO THE ABUNDANCE OF SMALL PELAGIC FISHERY IN NATUNA SEA USING REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

Teguh Prayogo

2012-11-01

Full Text Available Indonesian waters have abundance of natural resources; the potential of small pelagic fish in Natuna Sea and SouthChina Sea have not been optimized yet explores. Unfortunately, it was caused by lacking in the data of environmentalconditions that have been changed and the information of appropriate fishing ground. Hence, dynamical oceanographicinformation and weather condition is necessary to optimize small pelagic fish exploitation.Research location in Natuna Sea and its surrounding with geographical position is 08°N–03°S; 103°–111°E. Theoceanographic condition representative by monthly SST, Chl-a, SSH that derived from satellite data and Dipole ModeIndex for 2002-2007 from FRCGC website. Monthly wind data is variable for weather condition. Small pelagic fishabundance representative by annual fish production (2002-2005 and monthly Catch Per Unit Effort (CPUE ofGoldstripe sardinella, Bigeye scad and Indian scad (2006. It was data collected from Directorate General of CaptureFisheries (Ministry of Marine Affairs and Fisheries and daily fishing operation (2007 used to calculate match-up ratiothat was collected from Pemangkat fishing port in West Kalimantan. Research process consists of image processing,descriptive correlation analysis and GIS analysis to predict fishing ground map and match-up ratio calculation.Result of this research is the annual fish catch production of Bigeye scad and Indian scad (2002-2005 is tend toincrease and the monthly CPUE of both species is high during SE Monsoon (May-Sep that is condition contrarily in NWMonsoon (Nov-Apr. Meanwhile, the annual fish catch production of Goldstripe sardinella production is tend to decreasefrom 2002-2005, it has CPUE is high in early SE Monsoon (May. During the SE Monsoon (May-Sep when DM Index ispositive (+ the Indian scad and Bigeye scad production is high, for Goldstripe sardinella the fish production is highwhen DM Index is positive (+ in May. The accuracy of prediction map of

78 FR 31519 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-05-24

... Mexico Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS... the Coastal Migratory Pelagics (CMP) Advisory Panel (AP) via webinar. DATES: The meeting will convene... Migratory Pelagics (CMP) Advisory Panel (AP). The CMP AP will review materials related to the development...

78 FR 59656 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-09-27

... Mexico Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS.... Framework Action to Define Charter Fishing b. Coastal Migratory Pelagics Amendment 19 (permit req. and sale of bag limit fish) c. Coastal Migratory Pelagics Amendment 20 (trip limits, seasons, transit...

78 FR 61842 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-10-04

... Mexico Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS... Mackerel Amendments 20A--Coastal Migratory Pelagics Sale and Permit Provisions and Final Amendment 20B--Modifications to the Coastal Migratory Pelagics Zone Management, and on Final Action--Reef Fish Amendment 39...

Job Satisfaction in the Shrimp Trawl Fisheries of Vietnam

Science.gov (United States)

Sinh, Le Xuan

2012-01-01

This paper investigates the job satisfaction of small-scale shrimp trawl fishers in the vicinity of Camau National Park in southern Vietnam. The research sample consisted of 77 fishers who belong to a growing population of shrimp fishers in the region. The results suggest that 60% would change their fishing metier, 78% would leave fishing for…

78 FR 25255 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-04-30

... Mexico Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS... Pelagics Advisory Panel. DATES: The meeting will convene at 8:30 a.m. and conclude by 4 p.m. on Wednesday.... SUPPLEMENTARY INFORMATION: The Coastal Migratory Pelagics (CMP) Advisory Panel will meet to discuss CMP...

78 FR 41914 - South Atlantic Fishery Management Council (Council); Public Meetings

Science.gov (United States)

2013-07-12

... Atlantic Fishery Management Council (Council); Public Meetings AGENCY: National Marine Fisheries Service... as well as Framework actions to the Coastal Migratory Pelagics FMP. DATES: The meetings will be held... and Framework Actions to the Coastal Migratory Pelagics (CMP) FMP 1. Amendment 19 is a joint Gulf of...

Environmental DNA from Seawater Samples Correlate with Trawl Catches of Subarctic, Deepwater Fishes.

Directory of Open Access Journals (Sweden)

Philip Francis Thomsen

Full Text Available Remote polar and deepwater fish faunas are under pressure from ongoing climate change and increasing fishing effort. However, these fish communities are difficult to monitor for logistic and financial reasons. Currently, monitoring of marine fishes largely relies on invasive techniques such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA metabarcoding of seawater samples from continental slope depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were found with both trawling and eDNA, while three families were found only with eDNA and two families were found only with trawling. Key commercial fish species for Greenland were the most abundant species in both eDNA reads and biomass catch, and interpolation of eDNA abundances between sampling sites showed good correspondence with catch sizes. Environmental DNA sequence reads from the fish assemblages correlated with biomass and abundance data obtained from trawling. Interestingly, the Greenland shark (Somniosus microcephalus showed high abundance of eDNA reads despite only a single specimen being caught, demonstrating the relevance of the eDNA approach for large species that can probably avoid bottom trawls in most cases. Quantitative detection of marine fish using eDNA remains to be tested further to ascertain whether this technique is able to yield credible results for routine application in fisheries. Nevertheless, our study demonstrates that eDNA reads can be used as a qualitative and quantitative proxy for marine fish assemblages in deepwater oceanic

Final report of the Working Group on electrical Trawling

NARCIS (Netherlands)

Haan, de D.; Molenaar, P.; Rijnsdorp, A.D.; Steenbergen, J.; Marlen, van B.

2017-01-01

WGELECTRA met three times (22–24/10/2014; 10–12/11/2015, and 17–19/01/2017) to discuss the ongoing research projects in Belgium, the Netherlands, and Germany and provide an overview of the state of the art knowledge of the ecological effects. Pulse trawls are used in the North Sea fishery for

50 CFR 660.512 - Limited entry fishery.

Science.gov (United States)

2010-10-01

... ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Coastal Pelagics Fisheries.... The Regional Administrator's action shall constitute final action for the agency for the purposes of...

75 FR 49890 - Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2010-08-16

... Pacific Fishery Management Council's (Pacific Council) Coastal Pelagic Species Management Team (CPSMT) and... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... will be available at the following location: Pacific Fishery Management Council, Small Conference Room...

Job satisfaction in the shrimp trawl fisheries of Chennai, India

NARCIS (Netherlands)

Bavinck, M.

2012-01-01

Shrimp trawling represents an important fishing métier in South India, generating high levels of employment and economic value. It is also a contested métier, ostensibly contributing to environmental degradation and social inequality. This paper investigates the job satisfaction of crew members

Incidental catches of pelagic megafauna by the EU pelagic fleet in the Mauritanian exclusive economic zone during the year 2001 : results extracted from the scientific observer program

NARCIS (Netherlands)

Hofstede, ter R.

2003-01-01

The joint project between the Netherlands Institute for Fisheries Research (RIVO) and the Mauritanian Institute for Oceanography and Fisheries Research (IMROP) has been initiated in 1998 in order to strengthen Mauritania’s capacity for research on stocks of small pelagic fish. Part of this project

The NSW Steam Trawl Fishery on the South-East Continental Shelf of Australia, 1915-1961

DEFF Research Database (Denmark)

Jacobsen, A. Lif Lund

2014-01-01

How was modern fishing methods, in the form of steam trawling, introduced in Australia? And what were the consequences for the fish stocks found on the South-East Continental Shelf? Through historical catch records and archival resources, the history of the NSW Steam Trawl Industry from 1915...... that flathead biomass on the South-East Continental shelf was permanently reduced. The study furthermore reveals how the trawl industry was influenced by government policy, market conditions, war and fishing effort with little understanding of the marine resources which they relied on....

Vertical ecology of the pelagic ocean: classical patterns and new perspectives.

Science.gov (United States)

Sutton, T T

2013-12-01

Applications of acoustic and optical sensing and intensive, discrete-depth sampling, in concert with collaborative international research programmes, have substantially advanced knowledge of pelagic ecosystems in the 17 years since the 1996 Deepwater Fishes Symposium of the Fisheries Society of the British Isles. Although the epipelagic habitat is the best-known, and remote sensing and high-resolution modelling allow near-synoptic investigation of upper layer biophysical dynamics, ecological studies within the mesopelagic and deep-demersal habitats have begun to link lower and upper trophic level processes. Bathypelagic taxonomic inventories are far from complete, but recent projects (e.g. MAR-ECO and CMarZ, supported by the Census of Marine Life programme) have quantitatively strengthened distribution patterns previously described for fishes and have provided new perspectives. Synthesis of net and acoustic studies suggests that the biomass of deep-pelagic fishes may be two to three orders of magnitude greater than the total global commercial fisheries landings. Discrete-depth net sampling has revealed relatively high pelagic fish biomass below 1000 m in some regions, and that gelatinous zooplankton may be key energy vectors for deep-pelagic fish production. Lastly, perhaps, the most substantive paradigm shift is that vertical connectivity among fishes across classical depth zones is prevalent- suggesting that a whole-water column approach is warranted for deep ocean conservation and management. © 2013 The Fisheries Society of the British Isles.

Job Satisfaction in the Shrimp Trawl Fisheries of Chennai, India

Science.gov (United States)

Bavinck, Maarten

2012-01-01

Shrimp trawling represents an important fishing metier in South India, generating high levels of employment and economic value. It is also a contested metier, ostensibly contributing to environmental degradation and social inequality. This paper investigates the job satisfaction of crew members (captains and workers) on board the shrimp trawlers…

Assessing the suitability of commercial fisheries data for local-scale ...

African Journals Online (AJOL)

... are suitable for systematic spatial planning on a local scale and can be used for future spatial management and conservation. Keywords: chokka-squid, conservation planning, demersal trawl, linefish, logbooks, observer data, shark longline, small pelagic, vessel monitoring system. African Journal of Marine Science 2014, ...

Co-location of passive gear fisheries in offshore wind farms in the German EEZ of the North Sea: A first socio-economic scoping

DEFF Research Database (Denmark)

Stelzenmüller, V.; Diekmann, Rabea; Bastardie, Francois

2016-01-01

and size selectivityhave motivated the development of selective systems in trawl fisheries that utilize more than one selec-tive device simultaneously. An example can be found in the Swedish demersal trawl fishery targetingNorway lobster (Nephrops norvegicus), which simultaneously aims at avoiding catches...

Pacific halibut bycatch in Pacific cod fisheries in the Bering Sea: an analysis to evaluate area-time management

Science.gov (United States)

Adlerstein, Sara A.; Trumble, Robert J.

1998-03-01

Mortality of discarded Pacific halibut bycatch from Pacific cod fisheries in the Bering Sea leads to significant losses in the halibut setline and in the Pacific cod fisheries. The commercial halibut fishery loses yield because of catch limit reductions to compensate the resource for lost spawning potential and because halibut killed as bycatch will not be available for subsequent harvest, and the cod fisheries may lose harvest if they reach a bycatch mortality limit before reaching allowed catch. In this study, significant differences in Pacific halibut bycatch rates and associated yield losses were found among months and areas of the Bering Sea in the longline and trawl fisheries for Pacific cod in 1990-1992. Bycatch rates were usually highest in late spring and early summer and in areas close to the Unimak Pass. With the exception of 1992, yield loss in the longline fishery was around 1 kg per kg of bycatch mortality, irrespective of where or when bycatch occurred. In the trawl fishery, loss of halibut yield varied from 1 to 4 kg per kg of bycatch mortality. Highest halibut net yield losses per tonne of groundfish harvest usually coincided with highest bycatch rates. When both fisheries operated in one area, trawl bycatch often imposed higher yield losses than longline bycatch, despite lower bycatch rates. Bycatch was affected by the strong 1987 halibut year class. Highest bycatch and yield loss rates occurred in the trawl fishery in 1990 and 1991 when the population was dominated by halibut age-3 and -4, and in the longline fishery in 1992 as fish reached age-5.

AFSC/REFM: Digitized 2005 GOA Trawl Logbooks merged with Fish Ticket and Observer data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data include a full year of logbook forms for vessels 60-124 feet in length (the partial coverage fleet) that had participated in the trawl flatfish fishery of...

Influence of the hydrodynamic conditions on the accessibility of Aristeus antennatus and other demersal species to the deep water trawl fishery off the Balearic Islands (western Mediterranean)

OpenAIRE

Amores, Ángel; Rueda, Lucía; Monserrat, Sebastià; Guijarro, Beatriz; Pasqual, Catalina; Massutí, Enric

2013-01-01

Monthly catches per unit of effort (CPUE) of adult red shrimp (. Aristeus antennatus), reported in the deep water bottom trawl fishery developed on the Sóller fishing ground off northern Mallorca (Western Mediterranean), and the mean ocean surface vorticity in the surrounding areas are compared between 2000 and 2010. A good correlation is found between the rises in the surrounding surface vorticity and the drops in the CPUE of the adult red shrimp. This correlation could be explained by assum...

76 FR 35409 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fisheries of the Gulf of...

Science.gov (United States)

2011-06-17

... Atlantic States AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric..., red drum, coastal migratory pelagics, stone crab, and lobsters in the Gulf, and snapper-grouper, coastal migratory pelagics, dolphin and wahoo, and lobsters in the South Atlantic. The EFP exempts...

Demersal trawling on the South African south and east coasts for the ...

African Journals Online (AJOL)

spamer

ralis was initiated in 1878, initially using a steam tug ... species composition, catch seasonality, catch per unit effort (cpue) and size-at-recruitment over the time ... Changes in the Eastern Cape demersal inshore trawl fishery operating out of Port ... MATERIAL AND METHODS ... The model parameters were estimated by mini-.

50 CFR 660.381 - Limited entry trawl fishery management measures.

Science.gov (United States)

2010-10-01

... or tied along the length of the footrope). Other lines or ropes that run parallel to the footrope may... gear must have unprotected footropes at the trawl mouth, and must not have rollers, bobbins, tires... gear may not be enlarged by encircling it with chains or by any other means. Ropes or lines running...

75 FR 971 - Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2010-01-07

... Pacific Fishery Management Council's (Council) Scientific and Statistical Committee, Coastal Pelagic Species Management Team, and Groundfish Management Team will hold a working meeting, which is open to the... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National...

Pelagic fish stock assessment by acoustic methods at Ifremer

OpenAIRE

Doray, Mathieu; Masse, Jacques; Petitgas, Pierre; Doray, Mathieu; Masse, Jacques; Petitgas, Pierre

2010-01-01

The main objective of Ifremer's pelagic sea surveys (Pelgas in the Bay of Biscay and Pelmed in the Gulf of Lion) is to assess the biomass of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) populations, based on fisheries acoustic data. Complementary data on the whole pelagic ecosystem (hydrology, plankton, fish eggs and larvae, other fish species, seabirds and marine mammals) are also collected during the cruises. This document describes the procedures used to derive stock a...

78 FR 56217 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fisheries of the Gulf of...

Science.gov (United States)

2013-09-12

... Atlantic States AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... specified in 50 CFR part 622, Subparts A through R for reef fish, red drum, coastal migratory pelagics, and spiny lobster in the Gulf of Mexico, and snapper-grouper, coastal migratory pelagics, dolphin and wahoo...

78 FR 23708 - List of Fisheries for 2013

Science.gov (United States)

2013-04-22

.... 121024581-3333-01] RIN 0648-BC71 List of Fisheries for 2013 AGENCY: National Marine Fisheries Service (NMFS....S. Atlantic Ocean, Caribbean, Gulf of Mexico large pelagics longline vessels operating in special..., through state agencies, or through the fishery summary documents available on the NMFS Office of Protected...

Bottom trawl assessment of Lake Ontario prey fishes

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy

2018-01-01

Managing Lake Ontario fisheries in an ecosystem-context requires prey fish community and population data. Since 1978, multiple annual bottom trawl surveys have quantified prey fish dynamics to inform management relative to published Fish Community Objectives. In 2017, two whole-lake surveys collected 341 bottom trawls (spring: 204, fall: 137), at depths from 8-225m, and captured 751,350 fish from 29 species. Alewife were 90% of the total fish catch while Deepwater Sculpin, Round Goby, and Rainbow Smelt comprised the majority of the remaining total catch (3.8, 3.1, and 1.1% respectively). The adult Alewife abundance index for US waters increased in 2017 relative to 2016, however the index for Canadian waters declined. Adult Alewife condition, assessed by the predicted weight of a 165 mm fish (6.5 inches), declined in 2017 from record high values observed in spring 2016. Spring 2017 Alewife condition was slightly less than the 10-year average, but the fall value was well below the 10-year average, likely due to increased Age-1 Alewife abundance. The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of 2016 likely contributed to the large year class. In contrast the relatively cool 2017 spring and cold winter may result in a lower than average 2017 year class. Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in 2017. Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in 2017 because Round Goby abundance declined sharply from 2016. Slimy Sculpin density continued to decline and the 2017 biomass index for US waters was the lowest ever observed. Prior to Round Goby proliferation, juvenile Slimy Sculpin comprised ~10% of the Slimy Sculpin catch, but

The NSW Steam Trawl Fishery on the South-East Continental Shelf of Australia, 1915–1961

DEFF Research Database (Denmark)

Lund Jacobsen, A. Lif

2014-01-01

How was modern fishing methods, in the form of steam trawling, introduced in Australia? And what were the consequences for the fish stocks found on the South-East Continental Shelf? Through historical catch records and archival resources, the history of the NSW Steam Trawl Industry from 1915...

Comparative technical aspects of the Nephrops norvegicus (L. fishery in the northern Mediterranean Sea

Directory of Open Access Journals (Sweden)

Francesc Sarda

1998-12-01

Full Text Available A comparative study of the technical characteristics of the Norway lobster fishery in the Mediterranean Sea is presented. The different trawl vessels, trawl gears, trawling manoeuvres, and status of the statistics compiled by the administrations are described. The main conclusions are that catchability has increased with technological advances, official landings statistics are flawed in most of the Mediterranean, and fishing methods differed from country to country.

From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality.

Directory of Open Access Journals (Sweden)

Junita D Karlsen

Full Text Available Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus. In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i aboard the fishing vessel; ii at the Fishermen's Collection Central, and iii in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper

77 FR 34024 - Western Pacific Fishery Management Council; Public Meetings

Science.gov (United States)

2012-06-08

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Western Pacific Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and.... and 4 p.m. on June 28, 2012. Pelagics and International Fisheries is scheduled on the agenda for the...

Energy consumption in the Danish fishery

DEFF Research Database (Denmark)

Thrane, Mikkel

2003-01-01

Previous studies based on Life Cycle Assessment (LCA) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals...... that there are great differences in the fuel consumption between fisheries targeting ground or shellfish and those targeting pelagic or industrial fish....

Improving the selectivity of beam trawls in The Netherlands: the effect of large mesh top panels on the catch rates of sole, plaice, cod and whiting

NARCIS (Netherlands)

Marlen, van B.

2003-01-01

This paper presents the results of experiments aimed to improve the selectivity of beam trawls in the North Sea for roundfish whilst minimizing losses on target flatfish. Large-meshed top panels were designed for the tickler chain type of beam trawls used in this fishery. The design process involved

76 FR 60004 - Western Pacific Fishery Management Council; Public Meetings

Science.gov (United States)

2011-09-28

... Pacific Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS.... Species with MSY, Existing Quota, or Reference Points (Tier 3 and 4). a. Coastal Pelagics in Hawaii. b...'s Report. 5. Agency Reports. A. National Marine Fisheries Service. 1. Pacific Islands Regional...

Fishery potential of the Gulf of Kachchh

Digital Repository Service at National Institute of Oceanography (India)

Nair, V.R.; Govindan, K.; Ramaiah, Neelam; Gajbhiye, S.N.

Fishery potential of the interior Gulf of Kachchh and adjacent creek regions was reported for the first time as baseline data for future ecological assessment. The experimental trawling and gill netting indicated that the inner Gulf (av. 7.8 kg...

The Omani Coastal Traditional Sardine Fishery 1994-2007: A Review

Directory of Open Access Journals (Sweden)

Saud Al-Jufaili

2011-01-01

Full Text Available The Omani coastal fishery is categorized into small pelagics, large pelagics, demersals, shellfishes, and sharks and rays. During the period 1994-2007 the small pelagics contributed 39 and 21% to the total Omani fisheries landings and values respectively. During 1994-2007 sardines alone contributed 76 and 51% to the total small pelagics landings and values, respectively. Al-Batina and Muscat regions contributed the highest to the total landings; among other Omani regions, Musandam, Muscat, and Sharqiya and Al-Wusta regions. Total sardines prices ranges from 114 to 225 Omani Rials per ton depending on where the sardines are coming from. On the other hand, Al-Batina and Muscat regions contributed the most in the total sardine values. Few gonadosomatic index studies indicated two major spawning peaks: a major one occurred during March-April and a minor one in September-October.

Pelagic shark fisheries of Indonesia's Eastern Indian Ocean ...

African Journals Online (AJOL)

Sharks are commonly caught in Indonesian waters both by target fisheries and as bycatch. Fishers targeting sharks mostly employ drift longlines, whereas tuna longlines and gillnets are the gear mostly responsible for shark bycatch. Our studies on shark fisheries have been conducted since 2006 and have focused on the ...

78 FR 21114 - Magnuson-Stevens Act Provisions; General Provisions for Domestic Fisheries; Application for...

Science.gov (United States)

2013-04-09

... for Sustainable Fisheries, Northeast Region, NMFS (Assistant Regional Administrator), has made a... University Cooperative Extension of Suffolk County, NY. Regulations under the Magnuson-Stevens Fishery... limits to conduct onboard sampling. This project proposes to evaluate bottom trawl modifications as a...

76 FR 30107 - Western Pacific Fishery Management Council; Public Meetings

Science.gov (United States)

2011-05-24

.... Pelagic Fisheries A. Action Items 1. Options Paper on Shallow-Set Longline Fishery for Swordfish 2... Management Uncertainty iii. ACL Specifications for MHI Deep 7 Bottomfish 2. Report on Kona Crab Fishery 3... Development Program (CDP) Process Development L. Advisory Group Recommendations M. SSC Recommendations N...

Identification of fish populations with particular reference to the pelagic fish stocks of the Indian Ocean region

Digital Repository Service at National Institute of Oceanography (India)

Dwivedi, S.N.

The most essential step in any fishery management is the identification of discrete fish populations. This is particularly important for the development of Indian Ocean pelagic fisheries. The simple signal character analysis of meristic or metric...

Influence of the hydrodynamic conditions on the accessibility of the demersal species to the deep water trawl fishery off the Balearic Islands (western Mediterranean)

Science.gov (United States)

Amores, A.; Rueda, L.; Monserrat, S.; Guijarro, B.; Pasqual, C.; Massutí, E.

2013-12-01

Ocean mean surface vorticity from gridded multi-mission satellite altimetry data was explored in the Western Mediterranean basin for the period 2000-2010, with the aim of comparing its variability with several species of the deep water fishery in the area. Monthly catches per unit of effort (CPUE) of adult red shrimp (Aristeus antennatus), reported in the deep water bottom trawl fishery developed off northern Mallorca Island displayed a good correlation with surface vorticity. This correlation could be explained by assuming that most of the surface vorticity episodes could reach the bottom, increasing the seabed velocities and producing sediment resuspensions, which could affect the near bottom water turbidity. A. antennatus would respond to this increased turbidity by moving downwards to the deeper waters. This massive displacement of red shrimp specimens away from the fishing grounds would consequently decrease their accesibility to fishing exploitation. This relationship between vorticity and catches also holds for other species , considered as by-catch of the deep water fishery in the area. Results appear to support the suggestion that the water turbidity generated by the vorticy episodes is significant enough to affect the dynamics of the demersal species. The way the surface vorticity observed can affect the bottom sediments is also investigated using a year-long moored near-bottom currentmeter and a sediment trap sited in the fishing grounds.

Fisheries management and the value chain

DEFF Research Database (Denmark)

Nielsen, Max; Andersen, Peder; Ravensbeck, Lars

2017-01-01

management. The purpose of this paper is to address this gap. The model is applied to the pelagic fisheries of the Northeast Atlantic and considers the whole value chain, identifying resource rent and consumer and producer surpluses. The results show that the sum of the resource rent and the producer surplus...... in the harvest sector in 2007 was 32% of the landing value, compared with the maximum economic yield of 49%. Hence, the fisheries were quite well managed. To achieve the maximum sum of the resource rent and the producer surplus in the harvest sector, the fleet must be reduced from 156 vessels to 80 vessels....... However, it must only be reduced to 93 vessels if the objective is to maximize economic welfare. The analysis shows that the main source of welfare improvement through the improved management of the North Atlantic pelagic fisheries is linked to the harvest sector (rent and producer surplus gains) and...

Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

Science.gov (United States)

Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

2015-10-01

Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

Analyses of Trawling Track and Fishing Activity Based on the Data of Vessel Monitoring System (VMS)：A Case Study of the Single Otter Trawl Vessels in the Zhoushan Fishing Ground

Institute of Scientific and Technical Information of China (English)

WANG Yang; WANG Yingbin; ZHENG Ji

2015-01-01

The original purpose of Vessel Monitoring System (VMS) is for enforcement and control of vessel sailing. With the ap-plication of VMS in fishing vessels, more and more population dynamic studies have used VMS data to improve the accuracy of fisheries stock assessment. In this paper, we simulated the trawl trajectory under different time intervals using the cubic Hermite spline (cHs) interpolation method based on the VMS data of 8 single otter trawl vessels (totally 36000 data items) fishing in Zhou-shan fishing ground from September 2012 to December 2012, and selected the appropriate time interval. We then determined vessels’ activities (fishing or non-fishing) by comparing VMS speed data with the corresponding speeds from logbooks. The results showed that the error of simulated trajectory greatly increased with the increase of time intervals of VMS data when they were longer than 30 minutes. Comparing the speeds from VMS with those from the corresponding logbooks, we found that the vessels’ speeds were be-tween 2.5kn and 5.0kn in fishing. The cHs interpolation method is a new choice for improving the accuracy of estimation of sailing trajectory, and the VMS can be used to determine the vessels’ activities with the analysis of their trajectories and speeds. Therefore, when the fishery information is limited, VMS can be one of the important data sources for fisheries stock assessment, and more at-tention should be paid to its construction and application to fisheries stock assessment and management.

76 FR 17107 - Fisheries of the Exclusive Economic Zone Off Alaska; Application for an Exempted Fishing Permit

Science.gov (United States)

2011-03-28

... development and testing of a salmon excluder device for the Bering Sea pollock trawl fishery. This activity is... salmon bycatch by the pollock trawl industry during the EFP period could potentially approach or exceed... experimental design requires this quantity of salmon to ensure statistically valid results. The applicant also...

NPRB711 Quantification of unobserved injury and mortality of Bering Sea crabs due to encounters with trawls on the seafloor

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The potential for unobserved mortality of crabs encountering bottom trawls, but not captured, has long been a concern in the management of Bering Sea fisheries. We...

75 FR 31321 - Fisheries of the Exclusive Economic Zone Off Alaska; Rock Sole, Flathead Sole, and “Other...

Science.gov (United States)

2010-06-03

.... 0910131363-0087-02] RIN 0648-XW74 Fisheries of the Exclusive Economic Zone Off Alaska; Rock Sole, Flathead... participating in the Amendment 80 limited access fishery in the Bering Sea and Aleutian Islands management area... the trawl rock sole, flathead sole, and ``other flatfish'' fishery category by vessels participating...

Fishery potential along the Indian coastal waters between Porbandar and Ratnagiri

Digital Repository Service at National Institute of Oceanography (India)

Gajbhiye, S.N.; Mehta, P.; Mustafa, S.; Nair, V.R.

As part of the ongoing marine pollution monitoring programme the coastal stretch between Porbandar and Ratnagiri was considered to assess the fishery potential. Regular experimental trawling was done off Porbandar, Veraval, Diu, Hazira, Daman...

78 FR 13161 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Final 2013 and 2014 Harvest...

Science.gov (United States)

2013-02-26

... halibut PSC trawl limits between the trawl gear deep-water and the shallow-water species fishery... specifications set forth in Tables 1 through 31 of this document reflect the outcome of this process, as required... for pollock, sablefish, deep-water flatfish, rex sole, Pacific ocean perch, northern rockfish...

78 FR 43146 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-07-19

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC763 Gulf of Mexico Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS... d. Recommendation of ABC 4. Overview of ongoing Coastal Migratory Pelagics Amendments a. CMP...

50 CFR 229.36 - Atlantic Pelagic Longline Take Reduction Plan (PLTRP).

Science.gov (United States)

2010-10-01

... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS AUTHORIZATION FOR COMMERCIAL FISHERIES UNDER THE MARINE MAMMAL PROTECTION ACT OF 1972 Take Reduction Plan Regulations and Emergency... the U.S. east coast, a component of the Atlantic Ocean, Caribbean, Gulf of Mexico large pelagics...

Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters

Directory of Open Access Journals (Sweden)

Pål Buhl-Mortensen

2018-02-01

Full Text Available Bottom trawling and seabed littering are two serious threats to seabed integrity. We present an overview of the distribution of seabed litter and bottom trawling in Norwegian waters (the Norwegian Sea and the southern Barents Sea. Vessel Monitoring System (VMS records and trawl marks (TM on the seabed were used as indicators of pressure and impact of bottom trawling, respectively. Estimates of TM density and litter abundance were based on analyses of seabed videos from 1,778 locations, surveyed during 23 cruises, part of the Norwegian seabed mapping programme MAREANO. The abundance and composition of litter and the density of TM varied with depth, and type of sediments and marine landscapes. Lost or discarded fishing gear (especially lines and nets, and plastics (soft and hard plastic and rubber were the dominant types of litter. The distribution of litter reflected the distribution of fishing intensity (density of VMS records and density of TM at a regional scale, with highest abundance close to the coast and in areas with high fishing intensity, indicated from the VMS data. However, at a local scale patterns were less clear. An explanation to this could be that litter is transported with currents and accumulates in troughs, canyons, and local depressions, rather than reflecting the fisheries footprints directly. Also, deliberate dumping of discarded fishing gear is likely to occur away from good fishing grounds. Extreme abundance of litter, observed close to the coast is probably caused by such discarded fishing gear, but the contribution from aggregated populations on land is also indicated from the types of litter observed. The density of trawl marks is a good indicator of physical impact in soft sediments where the trawl gear leaves clear traces, whereas on harder substrates the impacts on organisms is probably greater than indicated by the hardly visible marks. The effects of litter on benthic communities is poorly known, but large litter

Planktonic stages of small pelagic fishes (Sardinella aurita and Engraulis encrasicolus) in the central Mediterranean Sea: The key role of physical forcings and implications for fisheries management

Science.gov (United States)

Torri, Marco; Corrado, Raffaele; Falcini, Federico; Cuttitta, Angela; Palatella, Luigi; Lacorata, Guglielmo; Patti, Bernardo; Arculeo, Marco; Mifsud, Roberta; Mazzola, Salvatore; Santoleri, Rosalia

2018-03-01

Multidisciplinary studies are recently aiming to define diagnostic tools for fishery sustainability by coupling ichthyoplanktonic datasets, physical and bio-geochemical oceanographic measurements, and ocean modelling. The main goal of these efforts is to understand those processes that control the dispersion and fate of fish larvae and eggs, and thus tuning the inter-annual variability of the biomass of small pelagic fish species. In this paper we analyse the distribution of eggs and larvae as well as the biological features of the two species of pelagic fish, Engraulis encrasicolus and Sardinella aurita in the north-eastern sector of the Sicily Channel (Mediterranean Sea) from ichthyoplanktonic data collected during the 2010 and 2011 summer cruises. We use Lagrangian simulations and satellite data (i.e., sea surface temperature, wind, and chlorophyll-a concentration) to recognize the main oceanographic patterns that mark eggs and larvae transport processes. We provide a mechanistic explanation of a cross-shore transport process by using a potential vorticity (PV) model that takes into account the role of wind stress in generating cold filaments. Our results show that the strong offshore transport towards Malta occurred in 2010 was likely due to a persistent Mistral wind forcing that generated high-PV cold filaments. This phenomenon was not found in the 2011 analysis, which indeed showed an along-shore transport towards the retention area of Capo Passero. Since, for the first time, we describe the spatial distribution of the early life stage of Sardinella aurita in the northern part of the Sicily Channel and we clarify the link between the ocean dynamics and the fate of small pelagic fish larvae, this work provides a useful, diagnostic tool for the sustainable management of fishery resources.

Time-zoning for the safe-guarding of capture fisheries: a closed season in Tamil Nadu, India

NARCIS (Netherlands)

Bavinck, M.; de Klerk, L.; van Dijk, D.; Rothuizen, J.V.; Blok, A.N.; Bokhorst, J.R.; van Haastrecht, E.K.; van de Loo, T.J.C.; Quaedvlieg, J.G.J.; Scholtens, J.

2008-01-01

A closed fishing season is arguably the most important fisheries regulation measure implemented by the government of India in the new millennium. Applied mainly to the inshore trawl fishing fleet, the planners’ intention was a safe-guarding of capture fisheries. This article, which is based on

78 FR 44539 - Mid-Atlantic Fishery Management Council (MAFMC); Public Meetings

Science.gov (United States)

2013-07-24

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC777 Mid-Atlantic Fishery Management Council (MAFMC); Public Meetings AGENCY: National Marine Fisheries Service (NMFS... Amendment, Amendment 5 to Dolphin/Wahoo, Amendment 19 and 20 to the Joint Coastal Migratory Pelagics (CMP...

Criteria for sustainable fisheries on juveniles illustrated for Mediterranean hake: control the juvenile harvest, and safeguard spawning refugia to rebuild population fecundity

Directory of Open Access Journals (Sweden)

John F. Caddy

2015-09-01

Full Text Available The paper provides a broad overview of issues relevant to management of fisheries for juvenile fish in contrast to the many stock assessments following Beverton and Holt’s (1957 approach for rational exploitation of mature fishes. A perspective on assessing these fisheries is illustrated for juvenile European hake, Merluccius merluccius, in the northwestern Mediterranean. Here, a constant natural mortality (M assumption is incorrect, as is the assumption that high fecundities are necessarily adequate for stock replacement. The high Ms-at-age for juveniles generated by the reciprocal model are shown to be a logical counterpart to the high fecundity of hake. Charnov’s criterion of intergenerational reproductive replacement is used to test for a sustainable population, analogous to a limit reference point warning of the dangers of overfishing beyond population replacement. Once peak mortality rates of age 2 hake exceed F(2=1.1-1.2, which is currently the case, reproductive replacement may be at risk. Adult exploitation by inshore trawls is low, and maturing hake surviving the fine-mesh trawl fishery migrate offshore with a reduced vulnerability to fine-mesh gears. Early research suggested that rough bottom near the shelf edge once formed a refugium protecting offshore spawners from trawling, and led to abundant recruitment of juveniles nearer shore. It may not do so if offshore fishing effort by reinforced bottom trawls, gill nets and longlines is uncontrolled. Restoring offshore refugia to protect spawners and controlling peak fishing mortality of juveniles would be a precautionary strategy aimed at restoring previous levels of recruitment to the small-mesh trawl fishery.

Fish bycatch of the laulao catfish Brachyplatystoma vaillantii (Valenciennes, 1840 trawl fishery in the Amazon Estuary

Directory of Open Access Journals (Sweden)

Erica Antunes Jimenez

2013-06-01

Full Text Available This study aimed to analyse the composition and seasonal variation in the fish bycatch of the Brachyplatystoma vaillantii trawl fishery in the Amazon Estuary in 2009 by monitoring the trips of 48 vessels. The bycatch represented 29% of the catches, totalling 22,228 specimens and 52 taxa, distributed in 22 families (the principal families were Ariidae, Pimelodidae, and Sciaenidae. Brachyplatystoma rousseauxii, Plagioscion squamosissimus, and Sciades herzbergii together contributed 69% of the bycatch and were considered consistent bycatch species. Although a higher proportion of bycatch was captured during the rainy season, the seasonal difference was not significant. A multidimensional scaling (MDS ordination analysis and an analysis of similarity (ANOSIM indicated that the species composition of the bycatch was similar across the seasons. However, larger numbers of B. rousseauxii and P. squamosissimus were captured during the rainy season, whereas S. herzbergii predominated during the dry season. The marine migrants and estuarine species guilds showed the greatest richness, whereas freshwater migrants were the most numerous. Among the feeding guilds, the zoobenthivores were the most diverse, whereas the piscivores were the most abundant. The results indicate that fishing pressure primarily affects small- (20-30 cm and medium-sized (30-50 cm individuals, although the catch of P. squamosissimus was composed primarily of adults. However, the catches of both B. rousseauxii and B. vaillantii were composed primarily of juveniles.

Groundfish/Shrimp and Red Snapper trawl surveys conducted in the Gulf of Mexico from 1990-01-01 to 2014-12-30 (NCEI Accession 0147703)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories has conducted standardized groundfish trawl surveys in the Gulf of Mexico since 1987. Prior to 1987,...

Steam trawling on the south-east continental shelf of Australia. An environmental history of fishing, management and science in NSW, 1865 -1961

DEFF Research Database (Denmark)

Jacobsen, A. Lif Lund

2010-01-01

. Motivated by Sydney’s insufficient supplies of fish, the objective of early fisheries management in the state of New South Wales (NSW) was to improve the industry. Driven by state developmentalism, efforts were focused on increasing the productivity of already existing coastal fisheries through fisheries......As many of the world’s fish stocks are fully or over-exploited there is an urgent need for governments to provide robust fisheries management. However, governments are often slow to implement necessary changes to fisheries practices. The will to govern is an essential factor in successful marine...... resource management. Studies of historical documents from State and Commonwealth fisheries authorities involved in the steam trawl fishery on the south-east continental shelf of Australia illustrate different expressions of intentional management and how a more ecological responsible view has emerged...

A junk-food hypothesis for gannets feeding on fishery waste

Science.gov (United States)

Grémillet, David; Pichegru, Lorien; Kuntz, Grégoire; Woakes, Anthony G; Wilkinson, Sarah; Crawford, Robert J.M; Ryan, Peter G

2008-01-01

Worldwide fisheries generate large volumes of fishery waste and it is often assumed that this additional food is beneficial to populations of marine top-predators. We challenge this concept via a detailed study of foraging Cape gannets Morus capensis and of their feeding environment in the Benguela upwelling zone. The natural prey of Cape gannets (pelagic fishes) is depleted and birds now feed extensively on fishery wastes. These are beneficial to non-breeding birds, which show reduced feeding effort and high survival. By contrast, breeding gannets double their diving effort in an attempt to provision their chicks predominantly with high-quality, live pelagic fishes. Owing to a scarcity of this resource, they fail and most chicks die. Our study supports the junk-food hypothesis for Cape gannets since it shows that non-breeding birds can survive when complementing their diet with fishery wastes, but that they struggle to reproduce if live prey is scarce. This is due to the negative impact of low-quality fishery wastes on the growth patterns of gannet chicks. Marine management policies should not assume that fishery waste is generally beneficial to scavenging seabirds and that an abundance of this artificial resource will automatically inflate their populations. PMID:18270155

Ecologically Important Areas for Pacific Fishery Management Council's June 2005 Preferred Alternative, Groundfish EFH Final EIS

Data.gov (United States)

Pacific States Marine Fisheries Commission — These data depict ecologically important areas that were developed through a collaborative process involving Oceana; groundfish trawl fishermen, organized by the...

Sustainable Fisheries in Southeast Asia

Directory of Open Access Journals (Sweden)

Melda Kamil Ariadno

2011-09-01

Full Text Available Fisheries activity has increased significantly in number. As a result, we might see high investment in fisheries is due to the high demand for fish and fisheries products. Therefore, marine resources as well as other living resources are at risk in being harmed by excessive fisheries activities, for example: the use of trawl. Indonesia, as a Maritime State, need to impose sustainable fisheries because the principle of utilizing sustainable fisheries resources as adopted in the Law on Fisheries (Law No. 31 Year 2004 as amended by Law No. 45 Year 2009 to control fishery activities.Fishery activities are regulated not only by the Law on Fisheries but also international regulation adopted worldwide such as the Code of Conduct for Responsible Fisheries (CCRF. CCRF was prepared to include primary principles to elaborate the mechanism of fishery activities which is designated not to cost harmful damages in fisheries activities. CCRF is also accompanied by several technical guidelines that provide certain procedures to be applied to (1 fishing operations; (2 the precautionary approach as applied to capture fisheries and species introductions; (3 integrating fisheries into coastal area management; (4 fisheries management; (5 aquaculture development; and (6 inland fisheries. Consequently, CCRF is intended to cover any kind of fishery anywhere in the world not just marine capture fisheries, but also freshwater fisheries as well as aquaculture both marine and freshwater aquaculture. Excessive fishery activities would then not be harmful if Indonesia is willing to impose regulation which is significantly and effectively to manage these kind of fishery activities. Along with the fact that Indonesia is recognized as a Marine State, there is no reason to hold back in addressing this situation.

75 FR 52478 - Fisheries of the Exclusive Economic Zone Off Alaska; Reallocation of Pacific Cod in the Bering...

Science.gov (United States)

2010-08-26

... a timely fashion and would delay the reallocation of Pacific cod specified from trawl catcher... catcher vessel Pacific cod fishery is currently open, it is important to immediately inform the industry... and efficient operation of this fishery, to allow the industry to plan for the fishing season, and to...

Deep Trawl Dataset

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Otter trawl (36' Yankee and 4-seam net deepwater gear) catches from mid-Atlantic slope and canyons at 200 - 800 m depth. Deep-sea (200-800 m depth) flat otter trawls...

Prenatal stress from trawl capture affects mothers and neonates: a case study using the southern fiddler ray (Trygonorrhina dumerilii)

Science.gov (United States)

Guida, L.; Awruch, C.; Walker, T. I.; Reina, R. D.

2017-04-01

Assessing fishing effects on chondrichthyan populations has predominantly focused on quantifying mortality rates. Consequently, sub-lethal effects of capture stress on the reproductive capacity of chondrichthyans are largely unknown. We investigated the reproductive consequences of capture on pregnant southern fiddler rays (Trygonorrhina dumerilii) collected from Swan Bay, Australia, in response to laboratory-simulated trawl capture (8 h) followed immediately by air exposure (30 min). Immediately prior to, and for up to 28 days post trawling, all females were measured for body mass (BM), sex steroid concentrations (17-β estradiol, progesterone, testosterone) and granulocyte to lymphocyte (G:L) ratio. At parturition, neonates were measured for total length (TL), BM and G:L ratio. Trawling reduced maternal BM and elevated the G:L ratio for up to 28 days. Trawling did not significantly affect any sex steroid concentrations relative to controls. Neonates from trawled mothers were significantly lower in BM and TL than control animals, and had an elevated G:L ratio. Our results show that capture of pregnant T. dumerilii can influence their reproductive potential and affect the fitness of neonates. We suggest other viviparous species are likely to be similarly affected. Sub-lethal effects of capture, particularly on reproduction, require further study to improve fisheries management and conservation of chondrichthyans.

Bottom trawling and oxygen minimum zone influences on continental slope benthic community structure off Vancouver Island (NE Pacific)

Science.gov (United States)

De Leo, Fabio C.; Gauthier, Maéva; Nephin, Jessica; Mihály, Steven; Juniper, S. Kim

2017-03-01

Understanding responses of benthic ecosystems to cumulative impacts of natural stressors, long-term ocean change and increasing resource exploitation is an emerging area of interest for marine ecologists and environmental managers. Few, if any, studies have quantitatively addressed cumulative effects in the deep sea. We report here on a study from the continental slope off Vancouver Island (Canada) in the northeast Pacific Ocean, where the Oxygen Minimum Zone impinges on seabed habitats that are subjected to widespread bottom trawling, primarily by the fishery for thornyhead (Sebastolobus ssp.). We examined how the benthic megafauna in this area was influenced by varying levels of dissolved oxygen and trawling activity, along a depth gradient that was also likely to shape community composition. Continuous video and sonar records from two ROV surveys (50 linear km total; depth range 300-1400 m) respectively provided data on faunal attributes (composition, abundance and diversity) and the frequency of trawl door marks on the seabed. Faunal and trawl data were compiled in a geo-referenced database along with corresponding dissolved oxygen data, and pooled into 500 m segments for statistical analysis. Trawl mark occurrence peaked between 500 and 1100 m, corresponding to areas of slope subjected to hypoxia (PERMANOVA analyses, with characterizing taxa identified for all three factors. Depth, dissolved oxygen and trawl mark density accounted for 21% to 52% of the variability in benthic community structure according to multiple regression (DISTLM) models. Species richness was highest at intermediate depths and in areas subject to intermediate levels of trawling, and higher under hypoxia than under severe hypoxia. These statistically significant trends demonstrate that the structuring influences of bottom trawling on deep-sea benthic communities can be observed even where communities are being shaped by strong environmental gradients.

Stakeholder participation in the management of North East Atlantic pelagic fish stocks

DEFF Research Database (Denmark)

Coers, Aukje; Raakjær, Jesper; Olesen, Christian

2012-01-01

When the Regional Advisory Councils (RACs) were created during the last reform of the Common Fisheries Policy (CFP) in 2002, it was recognised that in addition to the five geographically orientated stakeholder lead advisory bodies, a separate RAC dedicated exclusively to pelagic fisheries...... floor. For this reason, as well as the fact that they are usually widely distributed, researching and managing this dynamic group of fishes across the borders of many countries requires a unique approach. Fortunately, despite these complexities, policy makers have succeeded to establish a reasonably...

78 FR 9024 - Sea Turtle Conservation; Shrimp Trawling Requirements

Science.gov (United States)

2013-02-07

... restriction and require all skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) rigged for... purposes of this notice, skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) will be... trawls, pusher-head trawls, and wing nets (butterfly trawls) in the Gulf of Mexico to use TEDs in their...

The size selectivity of the main body of a sampling pelagic pair trawl in freshwater reservoirs during the night

Czech Academy of Sciences Publication Activity Database

Říha, Milan; Jůza, Tomáš; Prchalová, Marie; Mrkvička, Tomáš; Čech, Martin; Draštík, Vladislav; Muška, Milan; Kratochvíl, Michal; Peterka, Jiří; Tušer, Michal; Vašek, Mojmír; Kubečka, Jan

2012-01-01

Roč. 127, September (2012), s. 56-60 ISSN 0165-7836 R&D Projects: GA MZe(CZ) QH81046 Institutional support: RVO:60077344 Keywords : quantitative sampling * gear selectivity * trawl * reservoirs Subject RIV: GL - Fishing Impact factor: 1.695, year: 2012

Microplastic sampling with the AVANI trawl compared to two neuston trawls in the Bay of Bengal and South Pacific.

Science.gov (United States)

Eriksen, Marcus; Liboiron, Max; Kiessling, Tim; Charron, Louis; Alling, Abigail; Lebreton, Laurent; Richards, Heather; Roth, Barent; Ory, Nicolas C; Hidalgo-Ruz, Valeria; Meerhoff, Erika; Box, Carolynn; Cummins, Anna; Thiel, Martin

2018-01-01

Many typical neuston trawls can only be used during relatively calm sea states and slow tow speeds. During two expeditions to the Bay of Bengal and the eastern South Pacific we investigated whether the new, high-speed AVANI trawl (All-purpose Velocity Accelerated Net Instrument) collects similar amounts and types of microplastics as two established scientific trawl designs, the manta trawl and the DiSalvo neuston net. Using a 335 μm net, the AVANI trawl can collect microplastics from the sea surface at speeds up to 8 knots as it "skis" across the surface, whereas the manta and DiSalvo neuston trawls must be towed slowly in a less turbulent sea state and often represent shorter tow lengths. Generally, the AVANI trawl collected a greater numerical abundance and weight of plastic particles in most size classes and debris types than the manta trawl and DiSalvo neuston net, likely because these trawls only skim the surface layer while the AVANI trawl, moving vertically in a random fashion, collects a "deeper" sample, capturing the few plastics that float slightly lower in the water column. However, the samples did not differ enough that results were significantly affected, suggesting that studies done with these different trawls are comparable. The advantage of the AVANI trawl over traditional research trawls is that it allows for collection on vessels underway at high speeds and during long transits, allowing for a nearly continuous sampling effort over long distances. As local surface currents make sea surface abundance widely heterogeneous, widely spaced short-tow trawls, such as the manta and DiSalvo trawls, can catch or miss hotspots or meso-scale variability of microplastic accumulations, whereas the AVANI trawl, if utilized for back-to-back tows of intermediate distances (5-10 km), can bridge variable wind conditions and debris concentrations potentially reducing variance and provide a greater resolution of spatial distribution. Copyright © 2017 Elsevier Ltd

Trawling disturbance on benthic ecosystems and consequences on commercial species: a northwestern Mediterranean case study

Directory of Open Access Journals (Sweden)

Alba Muntadas

2014-03-01

Full Text Available Trawling is known to disturb benthic communities and habitats, which may in turn indirectly affect populations of commercial species that live in close association with the seabed. The degree of impact on both benthic communities and demersal species depends on the fishing effort level. This may vary over the year because of the fleet dynamics, which are in turn normally driven by the main target species’ life cycle. In this study we describe changes in benthic functional components of a northwestern Mediterranean fishing ground that represents a recruitment area for an important target species (red mullet, Mullus barbatus. This fishing ground experiences a varying intensity of fishing effort over the year and benthic functional components under different levels of trawling were compared with an unfished, control area. Traits related to sexual maturity and life span for infauna and body size and life span for epifauna were found to vary with fishing activity. Potential effects of these changes on ecological functioning and the impact on red mullet population are discussed. The development of fisheries management plans under an ecosystem based fisheries management (EBFM requires the links between target species and benthic communities’ disturbance due to fishing practices to be explicitly considered.

Recovery of Seamount Precious Coral Beds From Heavy Trawling Disturbance with Links to Carbonate Chemistry Changes

Science.gov (United States)

Roark, E. B.; Baco-Taylor, A.; Morgan, N. B.; Shamberger, K.; Miller, K.; Brooks, J.

2016-12-01

Increasing anthropogenic impacts in the deep sea make studies of resilience and recovery time critical, with deep-sea hard-substrate habitats and large-scale disturbances having received little attention. Seamount hard-substrate habitats in particular are thought to have low resilience due to the slow growth rates and recruitment limitations of key structure-forming taxa. Seamounts of the far Northwestern Hawaiian Islands and Emperor Chain have had some of the heaviest trawl impacts in the world, from both fish and precious coral fisheries, and include sites that are still trawled and recovering ones that have been protected since establishment of the EEZ in 1977. To test the hypothesis of low resilience we compare these impacted seamounts to untrawled sites. We used the AUV Sentry in 2014 and 2015 to image nine features (three per "treatment") and analyze for substrate and visible megafauna. Sites in the "still trawled" treatment were characterized by extensive areas of bare substrate with abundant trawl scars. Sites in the "recovering" and "never trawled" locations had abundant megafauna in hard substrate areas. Initial comparisons of transects at 700m depth for three sites indicate that Yuryaku in the "still trawled" treatment had lower diversity and abundance of megafauna compared to the "recovering" and "never trawled" locations with a dominance of sea urchins. The "recovering" and "never trawled" sites were dominated by cnidarians, fishes, and echinoderms, but differed in dominant species, diversity, abundances and occurrence of dead coral skeletons. These preliminary results suggest that the recovering sites have not returned to a pre-impact community type in the 38 years since they were trawled. The megafauna distribution, in particular that of deep-sea corals, was compared to environmental water column variables at the study sites across the Northwestern Hawaiian Islands. Deep-sea corals with calcium carbonate skeletons were found living below the

Energy consumption in the Danish fishery

DEFF Research Database (Denmark)

Thrane, Mikkel

2004-01-01

Previous studies based on life-cycle assessment (LCA) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of certain fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals...... that there are great differences in fuel consumption between fisheries targeting groundfish or shellfish and those targeting pelagic fish or industrial fish. Here, I show that fuel consumption per kilogram of caught fish varies considerably as a function of fishing gear and vessel size, even considering the same......) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of certain fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals that there are great differences in fuel consumption between...

Stable isotopes reveal the effect of trawl fisheries on the diet of commercially exploited species

DEFF Research Database (Denmark)

Hinz, Hilmar; Moranta, Joan; Balestrini, Stephen

2017-01-01

both negatively and positively influence the quantity and quality of food available. Using δ 13C and δ 15N we investigated potential diet changes of three commercially exploited species across trawling gradients in the Kattegat (plaice, dab and Norway lobster (Nephrops)) and the Irish Sea (Nephrops...

A study of fish behaviour in the extension of a demersal trawl using a multi-compartment separator frame and SIT camera system

DEFF Research Database (Denmark)

Krag, Ludvig Ahm; Madsen, Niels; Karlsen, Junita

2009-01-01

A rigid separator frame with three vertically stacked codends was used to study fish behaviour in the extension piece of a demersal trawl. A video camera recorded fish as they encountered the separator frame. Ten hauls were conducted in a mixed species fishery in the northern North Sea. Fish...

AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service 2012 Chukchi Sea Bottom Trawl Surveys

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the 2012 NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the Chukchi Sea. 71 survey stations were...

Using small meshed collecting bags on trawls to quantify trawls seabed disturbance of aquatic organisms

DEFF Research Database (Denmark)

Krag, Ludvig Ahm

impact on commercial fishing grounds. In this study we develop and test small-meshed collecting bags designed to retain juvenile fish and benthic megafauna. The collecting bags are mounted in the wings and body of the trawl. The catches in the collection bags provide information of the species and size...... in the mechanical effect, such as penetration depth of the ground gear of different trawl designs. Collecting bags are also mounted to the different sections of the trawl in pairs, one to collect the organisms that pass through the trawl meshes and one to collect the population. Standard selectivity analyses...

75 FR 2197 - Western Pacific Fisheries; Regulatory Restructuring

Science.gov (United States)

2010-01-14

... AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA..., and Western Pacific Pelagics), and the Final Programmatic Environmental Impact Statement (PEIS) that... Section 3507 of the PRA requires that agencies inventory and display a current control number assigned by...

Multispecies fisheries management in the Mediterranean Sea: application of the Fcube methodology

DEFF Research Database (Denmark)

Maravelias, C.D.; Damalas, D.; Ulrich, Clara

2012-01-01

The ecosystem approach (EA) advocates that advice should be given based on a holistic management of the entire marine ecosystem and all fisheries and fleets involved. Recent developments have advanced to multi‐species, multi‐fisheries advice, rather than on a single‐species/fleet/area stock basis...... and socioeconomic parameters were used for coastal and trawl fisheries in the Aegean Sea. Results pointed out the strengths and weaknesses of alternative management strategies from both a biological and socioeconomic perspective. Fcube revealed the importance of effort control in the coastal fisheries...... that are still managed with no effort restrictions. The present findings, although preliminary, revealed that stringent cuts to effort and catch levels are required if EA management goals are to be met. The Fcube methodology, initially developed for mixed fisheries advice in northern European waters...

75 FR 5950 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper and Grouper Off the...

Science.gov (United States)

2010-02-05

... States AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration... United States. This would include reef fish, red drum, coastal migratory pelagics, stone crab, and lobsters in the Gulf of Mexico, and snapper-grouper, coastal migratory pelagics, dolphin and wahoo, and...

77 FR 45508 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Trawl...

Science.gov (United States)

2012-08-01

... for species caught incidentally in the whiting fishery (including lingcod, Pacific cod, canary... allocations. The process of ``holding'' back sufficient QP is similar to the current process of starting the...

Fisheries Online Information System - Fishing vessel based survey of young-of-year groundfish along the Newport Hydrographic Line

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Northwest Fisheries Science Center (NWFSC) conducts a comprehensive groundfish bottom trawl survey encompassing the U.S. West Coast between the borders with...

Marine fisheries review, Vol. 54, No. 1, 1992. Quarterly report

International Nuclear Information System (INIS)

Hobart, W.L.

1992-01-01

Contents: characteristics of billfish anglers in the u.s. atlantic ocean; effects of the santa barbara, calif., oil spill on the apparent abundance of pelagic fishery resources; remote camera and trapping survey of the deep-water shrimps heterocarpus laevigatus and h. ensifer and the geryon crab chaceon granulatus in palau; and on the distribution and fishery potential of the japanese red crab chaceon granulatus in the palauan archipelago, western caroline islands

Catch of pelagic hauls in Mediterranean acoustic surveys: Is it the same between day and night?

Directory of Open Access Journals (Sweden)

Athanassios Machias

2013-03-01

Full Text Available Fish sampling is a critical aspect of acoustic surveys, because it is directly related to the “transformation” of echo into species biomass and subsequently affects the accuracy of acoustic estimates. In the present study, we investigated the differences between day and night sampling in a the catch composition through certain diversity indices and b the length frequency distribution of anchovy and sardine using catch data of pelagic hauls collected from four different regions of the European Mediterranean waters. In addition, the possible bias in trawl efficiency due to sampling time and the possible error introduced in acoustic estimates were investigated. No statistically significant differences were found between day and night in any of the parameters examined. The results showed that a more flexible strategy can be adopted to reduce the duration and the cost of acoustic sampling for small pelagic species. The advantages and disadvantages of the two sampling strategies are discussed.

Studies on food organisms of pelagic fishes as revealed by the 1979 North Atlantic Eel Expedition

Science.gov (United States)

Appelbaum, S.

1982-09-01

The extent to which pelagic fishes occurring in the Sargasso Sea and adjacent parts of the Atlantic prey on leptocephali (Anguilliformes) was investigated. Most of the fishes examined (c. 95%) were collected using a commercial pelagical trawl. The stomach contents of about 1000 fishes (25 species of 10 families), mostly belonging to the suborders Myctophoidei, Stomiatoidei and the order Anguilliformes, were examined. The remains of invertebrates, mainly crustaceans, molluscs, tunicates, chaetognaths, and siphonophores were found in 28.8 % of the stomachs. Fishes, mostly myctophids or fish remains, were observed in 11.2 % of the stomachs; 18.7 % contained unidentified items and 40.6 % were empty. Leptocephali ( Ariosoma spp. and Gnathophis sp.) were found in the alimentary tract of 0.5 % of the fishes examined, exclusively represented by the myctophid, Ceratoscopelus warmingii. This report indicates that the Sargasso Sea population of Anguilla leptocephali, economically the most important eel, is not seriously affected by predation of oceanic fish species considered in this study.

75 FR 5541 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands; Final 2009...

Science.gov (United States)

2010-02-03

...\\ BSAI trawl limited access fisheries Red king crab C. opilio C. bairdi (animals) Halibut mortality (mt..., skates, and octopus. Classification This action is authorized under 50 CFR 679.20 and is exempt from...

Application of a bioeconomic model for supporting the management process of the small pelagic fishery in the Veneto Region, northern Adriatic Sea, Italy

Directory of Open Access Journals (Sweden)

Silvia Silvestri

2009-09-01

Full Text Available We explore the sustainability of the small pelagics fishery in the northern Adriatic sea, northeastern Italy, by means of a bioeconomic simulation model. This model reproduces the biological and economic conditions in which the fisheries occur. Starting from an initial condition (2004, the simulation model incorporates the biological and economic processes of the resources and the fishing fleet and computes the most probable future trajectory of the system under different management conditions. We analysed the projection of selected indicators (biomass, recruitment, catches, profits under four different management scenarios based on effort control, and we assessed the performance of these management measures against the current situation. The four scenarios were: i increase in fuel price, ii reduction in fuel price, iii limiting the number of days at sea, and iv extending the fishing period. Each management event was introduced in the third year of the simulation. For each scenario a stochastic simulation was carried out. Our results show that the impact of each management measure tested was not homogeneous across the fleet. In particular, comparatively smaller vessels generally display narrower profit margins and tend to be more sensitive to negative shocks, reinforcing the idea that management measures should be calibrated by stratifying the fleet before implementation.

Building a knowledge base for management of a new fishery: Boarfish (Capros aper) in the Northeast Atlantic

NARCIS (Netherlands)

Stange, K.

2016-01-01

This paper examines recent collaborative efforts by fisheries scientists and representatives from the pelagic fishing industry in Europe to generate a knowledge base to support management of a new fishery for boarfish (Capros aper) in the Northeast Atlantic. The forms of knowledge used and produced

Influence of fleet renewal and trawl development on landings per unit effort of the Danish northern shrimp (Pandalus borealis) fishery

DEFF Research Database (Denmark)

Eigaard, Ole Ritzau; Munch-Petersen, Sten

2011-01-01

Recent stock assessments of the Pandalus stock in the Skagerrak (ICES Division IIIa) and the Norwegian Deep (Division IVa east) have relied largely on a time-series of landings per unit effort (lpue) calculated from Danish logbook data. Because of fleet renewal and trawl-size changes, the relatio......Recent stock assessments of the Pandalus stock in the Skagerrak (ICES Division IIIa) and the Norwegian Deep (Division IVa east) have relied largely on a time-series of landings per unit effort (lpue) calculated from Danish logbook data. Because of fleet renewal and trawl-size changes...

How effective is electronic monitoring in mixed bottom-trawl fisheries?

NARCIS (Netherlands)

Helmond, van A.T.M.; Chen, C.; Poos, J.J.

2015-01-01

In the context of the landing obligation under the European Common Fisheries Policy, electronic monitoring (EM) is often presented as one of the solutions to fully document catches. EM includes video monitoring to record the catch handling process on board the vessels. This study evaluated the

75 FR 33531 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Science.gov (United States)

2010-06-14

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 RIN 0648-XW79 Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine..., recent Large Pelagics Survey estimates indicate that charter/headboat BFT landings constitute...

Reflex impairment, physiological stress, and discard mortality of European plaice Pleuronectes platessa in an otter trawl fishery

DEFF Research Database (Denmark)

Methling, Caroline; Skov, Peter Vilhelm; Madsen, Niels

2017-01-01

whether reflex impairment can predict short-term mortality in commercially trawled European plaice upon landing and after air exposure of up to 90 min. Sub-lethal stress was assessed by a suite of physiological variables. Over a 10-day period, mortality was monitored for a total of 199 plaice following...... trawl and air exposure of varying duration, and for 50 control fish scored for reflex impairment on board the vessel. Mortality was only observed in fish exposed to air for >60 min, and averaged 11.1% (95% CI = 7.1–16.3%). Reflex impairment was found to be a significant (P ... of mortality in a generalized linear model, excluding other initially included variables by using a stepwise method. Plasma cortisol, haematocrit, and plasma osmolality all indicated a profound and increasing level of stress with air exposure, accompanied by a near depletion of muscle phosphocreatine...

77 FR 29955 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Trawl...

Science.gov (United States)

2012-05-21

..., and for species caught incidentally in the whiting fishery (including lingcod, Pacific cod, canary..., depending on the formula used, there may be new QS permit owners, while some current QS permit owners who.... The current regulations give QS permit owners with excess QS two years after QS transfer begins to...

Energy density of marine pelagic fish eggs

DEFF Research Database (Denmark)

Riis-Vestergaard, J.

2002-01-01

Analysis of the literature on pelagic fish eggs enabled generalizations to be made of their energy densities, because the property of being buoyant in sea water appears to constrain the proximate composition of the eggs and thus to minimize interspecific variation. An energy density of 1.34 J mul......(-1) of total egg volume is derived for most species spawning eggs without visible oil globules. The energy density of eggs with oil globules is predicted by (σ) over cap = 1.34 + 40.61 x (J mul(-1)) where x is the fractional volume of the oil globule. (C) 2002 The Fisheries Society of the British...

Fisheries and conflicts in Guanabara Bay, Rio de Janeiro, Brazil

OpenAIRE

Jablonski, Silvio; Azevedo, Alexandre de Freitas; Moreira, Luiz Henrique Arantes

2006-01-01

Despite the magnitude of domestic and industrial pollution, fishery yield registered in several landing points at Guanabara Bay, between April 2001 and March 2002 was slightly over 19,000 tons, corresponding to a value of US$ 4.8 million. When considered only the fish directed to the food market, the total catch amounted to about 6,300 tons and a value of US$ 3.7 million. Only a few fish species reached expressive densities compatible with commercial fisheries. Among small pelagic fish, Atlan...

Job Satisfaction in the Coastal Pelagic Fisheries of Senegal

Science.gov (United States)

Sall, Aliou

2012-01-01

The marine fishery in Senegal, West Africa, is a major source of employment and food security. It currently faces the consequences of ecological degradation. This paper examines job satisfaction among small-scale purse seine fishers, who constitute one of the dominant fishing metiers in Senegal. The research sample consists of 80 purse seine…

Ocean warming expands habitat of a rich natural resource and benefits a national economy

DEFF Research Database (Denmark)

Jansen, Teunis; Post, Søren Lorenzen; Kristiansen, Trond

2016-01-01

Geographic redistribution of living natural resources changes access and thereby harvesting opportunities between countries. Internationally shared fish resources can be sensitive to shifts in the marine environment and this may have great impact on the economies of countries and regions that rely...... northwest in the Atlantic. This change in migration pattern was followed by a rapid development of a large-scale fishery of substantial importance for the national economy of Greenland (23% of Greenland's export value of all goods in 2014). A pelagic trawl survey was conducted in mid-summer 2014...

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

NARCIS (Netherlands)

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

2013-01-01

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

Fish Catch Composition of Artisanal and Bottom Trawl Fisheries in ...

African Journals Online (AJOL)

1Kenya Marine and Fisheries Research Institute, PO Box 81651 – 80100, Mombasa, Kenya;. 2University ... bay dates back to the 9th century, coinciding with the rise ... Bay remains under review. Initiatives to ..... be less selective than artisanal gear (i.e. higher. S and H' .... sufficient attention, and their testing and successful ...

75 FR 7443 - Western Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2010-02-19

... definition of shortline fishing gear 5. Non-commercial fishing for Pelagic Management Unit Species in Rose.... The PPT will meet as late as necessary to complete scheduled business. Although non-emergency issues... emergency action under section 305(c) of the Magnuson-Stevens Fishery Conservation and Management Act...

76 FR 79620 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Proposed 2012 and 2013...

Science.gov (United States)

2011-12-22

.... Apportionment of trawl PSC limits between the deep-water and shallow-water fisheries, limits for non-exempt... specifications. The draft 2011 SAFE reports indicate that the biomass trend for shallow-water flatfish, deep... inshore and offshore processing components in the [[Page 79621

77 FR 21015 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Science.gov (United States)

2012-04-09

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 [Docket No. 110210132-1275-02] RIN 0648-XB116 Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries AGENCY... to their ability to attract customers. In addition, 2011 Large Pelagics Survey estimates indicate...

76 FR 18416 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Science.gov (United States)

2011-04-04

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 [Docket No. 100317152-0176-01] RIN 0648-XA327 Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries AGENCY... ability to attract customers. In addition, recent Large Pelagics Survey estimates indicate that charter...

Long-term, Ecosystem-Scale Changes in the Southern Benguela Marine Pelagic Social-Ecological System: Interaction of Natural and Human Drivers

Directory of Open Access Journals (Sweden)

Astrid Jarre

2013-12-01

Full Text Available South Africa's small pelagics fishery is currently the largest in volume and second largest in value in the southern Benguela. It exploits short-lived, small pelagic fishes such as anchovy (for reduction into fish meal and oil and sardine (for reduction as well as human consumption through canned products, and to a lesser extent redeye round herring and mesopelagics, largely for reduction. We explore the recent history (1940s to present of the social-ecological system around this fishery. The natural subsystem, at the scales of the ocean environment and the ecosystem, is characterized by high interannual and documented decadal-scale variability. We characterize the human social subsystem at the scales of the fishing industry, legislation, and west coast fishing towns, and demonstrate interdependencies between the natural and social subsystems by following system-scale changes. The pelagic fishing industry has evolved to deal with variability through consolidation, diversification, and range expansion. Legislation has increasingly looked for conservation of the resource while ensuring economic viability of the industry, and hence factory- and vessel-related jobs. Fishing communities under apartheid stayed largely dependent on company-generated infrastructure, combining seasonal employment in the fishing factories with inshore fishing, targeting rock lobster and line fish. While the pelagic industry persisted and communities survived, the resource base for both offshore and inshore fisheries gradually eroded. The advent of democracy in the mid-1990s brought allocation of long-term fishing rights to individuals or companies under conditions of depleted inshore resources aggravated by a shift in the distribution of pelagic fish away from the west coast towards the Cape south coast in the second half of the 1990s. The resultant loss of employment and fishing rights in the inshore has generated community coping strategies that include poaching and

Vulnerability of oceanic sharks as pelagic longline bycatch

Directory of Open Access Journals (Sweden)

A.J. Gallagher

2014-08-01

Full Text Available Bycatch (the unintentional catch of non-target species or sizes is consistently ranked as one of the greatest threats to marine fish populations; yet species-specific rates of bycatch survival are rarely considered in risk assessments. Regulations often require that bycatch of threatened species be released; but, if animals are already dead, their release serves no conservation purpose. We examined the survival of 12 shark species caught as bycatch in the US Atlantic pelagic longline fishery. Shark survival was evaluated in relation to fishery target (swordfish versus tuna and four operational, environmental, and biological variables to evaluate the underlying mechanisms affecting mortality. Survival estimates ranged from 33% (night shark to 97% (tiger shark with seven of the 12 species being significantly affected by at least one variable. We placed our survival results within a framework that assessed each species’ relative vulnerability by integrating survival estimates with reproductive potential and found that the bigeye thresher, dusky, night, and scalloped hammerhead shark exhibited the highest vulnerabilities to bycatch. We suggest that considering ecological and biological traits of species shows promise for designing effective conservation measures, whereas techniques that reduce fisheries interactions in the first place may be the best strategy for highly vulnerable species.

Benthic marine debris, with an emphasis on fishery-related items, surrounding Kodiak Island, Alaska, 1994-1996

Science.gov (United States)

Hess, N.A.; Ribic, C.A.; Vining, I.

1999-01-01

Composition and abundance of benthic marine debris were investigated during three bottom trawl surveys in inlet and offshore locations surrounding Kodiak Island, Alaska, 1994-1996. Debris items were primarily plastic and metal regardless of trawl location. Plastic bait jars, fishing line, and crab pots were the most common fishery-related debris items and were encountered in large amounts in inlets (20-25 items km-2), but were less abundant outside of inlets (4.5-11 items km-2). Overall density of debris was also significantly greater in inlets than outside of inlets. Plastic debris densities in inlets ranged 22-31.5 items km-2, 7.8-18.8 items km-2 outside of inlets. Trawls in inlets contained almost as much metal debris as plastic debris. Density of metal debris ranged from 21.2 to 23.7 items km-2 in inlets, a maximum of 2.7 items km-2 outside of inlets. Inlets around the town of Kodiak had the highest densities of fishery-related and total benthic debris. Differences in benthic debris density between inlets and outside of inlets and differences by area may be due to differences in fishing activity and water circulation patterns. At the current reduced levels of fishing activity, however, yearly monitoring of benthic debris appears unnecessary. Copyright (C) 1999.

Seabird bycatch in the demersal longline fishery off southern Africa ...

African Journals Online (AJOL)

Differences in catch rates between trips were investigated and moon phase, area and gear type were all found to be significant. All birds were caught using light gear, which sank significantly slower than heavier gear. The South African hake longline fishery has a relatively small impact on pelagic seabird populations ...

78 FR 20258 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Science.gov (United States)

2013-04-04

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 [Docket No. 120306154-2241-02] RIN 0648-XC593 Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries AGENCY... retention limit is vital to their ability to attract customers. In addition, 2012 Large Pelagics Survey...

Assessment of Marine Litter in the Barents Sea, a Part of the Joint Norwegian–Russian Ecosystem Survey

Directory of Open Access Journals (Sweden)

Bjørn E. Grøsvik

2018-03-01

Full Text Available This study presents a large-scale monitoring of marine litter performed in the joint Norwegian–Russian ecosystem monitoring surveys in the period from 2010 to 2016 and contribute to documentation of the extent of marine litter in the Barents Sea. The distribution and abundance of marine litter were calculated by recordings of bycatch from the pelagic trawling in upper 60 m, from bottom trawling close to the sea floor, and floating marine debris at surface by visual observations. The study is comprehensive regarding coverage and number with registrations from 2,265 pelagic trawls and 1,860 bottom trawls, in addition to surface registration between the stations. Marine litter has been recorded from 301 pelagic and 624 of the bottom trawl catches. In total, 784 visual observations of floating marine debris were recorded during the period. Marine litter has been categorized according to volume or weight of the material types plastic, wood, metal, rubber, glass, paper, and textile. Marine litter is observed in the entire Barents Sea and distribution vary with material densities, ocean currents and depth. Plastic dominated number of observations with marine litter, as 72% of surface observations, 94% of pelagic trawls, and 86% of bottom trawls contained plastic. Observations of wood constituted 19% of surface observations, 1% of pelagic trawls, and 17% of bottom trawls with marine litter. Materials from other categories such as metal, rubber, paper, textile, and glass were observed sporadically. Recordings of wood dominated surface observations (61.9 ± 21.6% by volume and on seafloor (59.4 ± 35.0% by weight, while plastic dominated marine litter observations in upper 60 m depth (86.4 ± 16.5% by weight over these 7 years. Based on recordings and volume or area covered, mean levels of plastic in the upper 60 m of the Barents Sea were found to 0.011 mg m−3 (pelagic and 2.9 kg km−2 at sea floor over the study period. Average levels of marine

Integer-valued trawl processes

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole E.; Lunde, Asger; Shephard, Neil

2014-01-01

the probabilistic properties of such processes in detail and, in addition, study volatility modulation and multivariate extensions within the new modelling framework. Moreover, we describe how the parameters of a trawl process can be estimated and obtain promising estimation results in our simulation study. Finally......This paper introduces a new continuous-time framework for modelling serially correlated count and integer-valued data. The key component in our new model is the class of integer-valued trawl processes, which are serially correlated, stationary, infinitely divisible processes. We analyse...

77 FR 69796 - Fisheries of the Exclusive Economic Zone Off Alaska; Application for an Exempted Fishing Permit

Science.gov (United States)

2012-11-21

... concentrations of salmon and pollock for addressing experimental design criteria. The activities under the EFP... test a salmon excluder device for the Central Gulf of Alaska pollock trawl fishery. This activity is... approach the Central GOA Chinook salmon PSC limits of 18,316 Chinook salmon. If the EFP Chinook salmon were...

Responsible fisheries summary: 2000-2001 annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-05-01

The energy required to harvest fish from the sea is greater than that required for the production of any other primary food product. Increasing energy efficiency in the fishing industry makes sense, especially in light of the recent increases in fossil fuel prices and the increased concern expressed about greenhouse gas emissions. As a result, Fisheries and Oceans Canada collaborated with partners from the fishing industry, and with support provided by Natural Resources Canada, Program of Energy Research and Development (PERD) to initiate several projects aimed at improving the energy efficiency of fishing gear and related components. During the period April 2000 to March 2001, five projects were completed and two more were initiated. The goals were the determination of the effectiveness of new gear prototypes and fishing techniques towards a reduction in energy consumption. Detailed experimental protocols, gear prototypes, flume tank testing, at-sea trials, analysis of results, and reporting to industry and stakeholders are some of the facets common to most of the projects. Potential fuel savings, in the range of 2,330,000 liters annually for the shrimp trawler fleet were identified by testing new composite trawl netting. Potential fuel savings of 850,000 liters in Silver Hake could be realized by using new small diameter high tenacity braided polyethylene twines in trawl netting, when compared to standard polyethylene. A reduction of approximately 13 per cent in fuel consumption per kilogram of fish harvested is possible, as demonstrated by the testing of new Triplex Trawl design, with three codends rather than one. Operational costs and fuel consumption are both reduced through the use of the new Millennium trawl design using small mesh size in forepart and body of trawl, as shown by the Greenland Halibut (Turbot) selectivity experiments. Meshing is reduced, as is the by-catch of small Turbot. Potential benefits of lighter weight materials of construction were

Cooperative Research Twin Trawl Sweep Comparison Study

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The "Twin-Trawl Sweep Efficiency Study" was intended to compare the sweep efficiency and selectivity of the NEFSC standardized bottom trawl to that of a standardized...

75 FR 55689 - Fisheries of the Exclusive Economic Zone Off Alaska; Reallocation of Yellowfin Sole in the Bering...

Science.gov (United States)

2010-09-14

... fisheries data in a timely fashion and would delay the reallocation of yellowfin sole from the BSAI trawl... is important to immediately inform the industry as to the revised allocations. Immediate notification... industry to plan for the fishing season, and to avoid potential disruption to the fishing fleet as well as...

DIAGNOSIS OF SHRIMP TRAWLING IN THE STATE OF PERNAMBUCO, BRAZIL

Directory of Open Access Journals (Sweden)

Carlos Eduardo Rangel Andrade

2016-09-01

Full Text Available With a technical approach, this diagnosis aims to fill a gap in the overview of the activity, considering its technical aspects that manage the fishing effort of shrimping of Penambuco. From October 2013 to August 2014, the fishing grounds were identified used in this activity, as well as the fishing method, the number of boats and fishermen acting, type of boat and gears used. Analyses were performed with the major communities operating in this fishery (Recife, Jaboatão dos Guararapes, Barra de Sirinhaém and São Jose da Coroa Grande. The analyzes of the catch were tested using one-way ANOVA (α 5%. They observed two traditional types: the beach seining and trawing. It was cataloged about 50 vessels in the activity, with approximately 100 fishermen. They are caught mainly three types of shrimp: pink (Farfantepenaeus spp., Seabob (Xiphopenaeus kroyeri and white (Lithopenaeus schmitii. Statistical data concentrated in the metropolitan area of Recife and Barra de Sirinhaém. There seems to be a direct relationship rainfall with shrimp production because with increased rainfall, there is a higher volume of landing fishery. Barra de Sirinhaém is the main area used in the State. Keywords: ‘mangote’; trawling fishing; pink shrimp; Farfantepenaeus spp.

AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service Annual Eastern Bering Sea Summer Bottom Trawl Surveys 1975 - 2015

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the annual NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the eastern Bering Sea continental...

Assessing broad life cycle impacts of daily onboard decision-making, annual strategic planning, and fisheries management in a northeast Atlantic trawl fishery

NARCIS (Netherlands)

Ziegler, F.; Groen, E.A.; Hornborg, S.; Bokkers, E.A.M.; Karlsen, K.M.; Boer, de I.J.M.

2015-01-01

Purpose: Capture fisheries are the only industrial-scale harvesting of a wild resource for food. Temporal variability in environmental performance of fisheries has only recently begun to be explored, but only between years, not within a year. Our aim was to better understand the causes of temporal

Pelagic Habitat Analysis Module (PHAM) for GIS Based Fisheries Decision Support

Science.gov (United States)

Kiefer, D. A.; Armstrong, Edward M.; Harrison, D. P.; Hinton, M. G.; Kohin, S.; Snyder, S.; O'Brien, F. J.

2011-01-01

We have assembled a system that integrates satellite and model output with fisheries data We have developed tools that allow analysis of the interaction between species and key environmental variables Demonstrated the capacity to accurately map habitat of Thresher Sharks Alopias vulpinus & pelagicus. Their seasonal migration along the California Current is at least partly driven by the seasonal migration of sardine, key prey of the sharks.We have assembled a system that integrates satellite and model output with fisheries data We have developed tools that allow analysis of the interaction between species and key environmental variables Demonstrated the capacity to accurately map habitat of Thresher Sharks Alopias vulpinus nd pelagicus. Their seasonal migration along the California Current is at least partly driven by the seasonal migration of sardine, key prey of the sharks.

Fisheries oceanography of northern pelagic fish species

DEFF Research Database (Denmark)

Tsoukali, Stavroula

for marine organisms. One of the impacts will be the time that species start to spawn, and there is already evidence for earlier spawning in some North Sea fish species. A change like that may likely have a chain reaction, affecting larval stages and whether they will live in environments with high food...... of the species they consume now and increased availability of new species. In addition, there will likely be economic impacts on the local fishing communities. How species respond to climate change is a field of research that receives great attention because the responses will affect the management of fisheries......People are familiar with marine fish species and the great variety of different species that are available in the market, such as herring, cod and sole. What may not be well known is that every individual fish goes through a long, risky journey during its life before reaching maturity. Most...

Small is beautiful: Marine small-scale fisheries catches from the South-West Maluku Regency

Science.gov (United States)

Hutubessy, BG; Mosse, JW; Hayward, P.

2017-10-01

The fisheries data supplied by fisheries agency have served as the primary tool for regional fisheries statistics. However, it is recognized these data are incomplete and often underestimate actual catches, particularly for small-scale fisheries. There is no widely accepted definition of small-scale fisheries or global data on number of small-scale fishers and their catches. This study reconstructed total marine catches from 1980 to 2015 for South-west Maluku (MBD) regency, by applying an established catch construction approach utilizing all available quantitative and qualitative data, combined with assumption-based estimations and interpolations. As newly established regency since 2009, there is lack of fisheries data available which is needed for fisheries management. Fishers’ knowledge is important information taken from to construct long-term fisheries data. Estimated total fish withdrawal from MBD waters was 86,849.66 tonnes during 1980 - 2015, dominated by pelagic fishes. Consistency of estimated total removal and total landings at MBD regency play important role in small-scale fisheries management and this method of visualizing the history of fishery from poor-data condition might be an optimistic effort.

BIO-EXPLOITATION STATUS OF BOMBAY DUCK (Harpadon nehereus HAMILTON, 1822 ON TRAWL FISHERY IN TARAKAN WATERS

Directory of Open Access Journals (Sweden)

Duto Nugroho

2015-06-01

Full Text Available North Kalimantan Province, notably Tarakan City marine waters, is one of the important fishing ground in boundary area among Sulu Sulawesi Marine Ecoregion. It produces approximately 100 mt/annum of Bombay duck (Harpadon nehereus with valued of US$ 750,000. The sustainability of this fishery is a crucially concern given the following: substantial economic contribution, significant dependence of small-scale fishers on this species for their livelihoods. The fishing intensities considerable and growing threats to their habitats. To evaluate the vulnerability of individual species to over exploitation, the spawning potential ratio (SPR approach applied to describe the status of its existing fisheries. This approach provides the ability to determine fishing mortality as reference points to enhance its sustainability. The objective of this study is to understand this fish biomass resilience to harvesting. The calculated SPR based on the value of estimated length of first capture or Lc at 208 mm is equivalent to the SPR of 28%. With a base line of stocks are generally thought to risk recruitment declining when SPR <20%, recent finding indicated that the existing fishery can be generally described as nearly fully exploited. In recognition of this sector’s has an ecological importance and socio-economic significance, the sustainable development of Bombay duck fisheries should be initiated through developing local fishery committee to provide a their local fishery management plan.

Experimental investigation and numerical analysis to develop low-energy large-midwater trawls

Science.gov (United States)

Lee, Jihoon; Kim, Taeho; Lee, Chun-Woo; Park, Subong

2017-12-01

Fuel consumption in fisheries is a primary concern because of its effects on the environment and the costs incurred by fishermen. Many studies have been conducted to reduce the fuel consumption in fishing operations. Fuel consumption due to fishing gear during a fishing operation is generally related to the hydrodynamic resistance on the gear. This means that fuel consumption is proportional to the drag created by the towing speed. Based on numerical methods, this study suggests a new approach to reduce fuel consumption in fisheries. The results of the simulation are in good agreement with those of model experiments. The total as well as partial resistance forces on the gear are calculated by simulation. The simulation results suggest improved materials and gear structure for reducing the hydrodynamic forces on the gear while maintaining gear performance. The method for assessing the gear performance involves measuring the height and width of the net mouth. Furthermore, this study investigates the efficiency of a low-energy trawl from an economic point of view. The findings of this study will be useful in reducing greenhouse gas (GHG) emissions in fishing operations, and thereby contribute toward lowering fishing costs by saving fuel.

Fishery Development and Exploitation in South East Australia

Directory of Open Access Journals (Sweden)

Camilla Novaglio

2018-04-01

Full Text Available Understanding the full extent of past ecological changes in human-influenced marine systems is needed to inform present management policies, but is often hampered by the scarcity of information about exploitation practices and population status over the entire history of fishing. The history of commercial fishing in South East Australia is relatively recent and thus easier to document. Our aim is to reconstruct such history and to use this information to understand general patterns and consequences of fishing exploitation. Intense exploitation of marine resources arrived in South East Australia with European colonization in the early 1800s, and unregulated sealing, whaling and oyster dredging resulted in the first documented significant impact on local marine populations. Exploitation extended to demersal resources in 1915 when the trawl fishery developed. Between the early 1800s and the 1980s, some of the exploited stocks collapsed, but fishing moved further offshore and in deeper waters as technology improved and new resources became available or were discovered. This phase of fisheries expansion masked the unsustainable nature of some fishing industries, such as trawling and whaling, and postponed the need for management regulations. From the 1990s onward, an increasing awareness of the depleted nature of some fisheries led to the establishment of management strategies aiming at a more sustainable exploitation of target stocks and, from the mid-2000s onwards, management strategies were revised and improved to better address the effect of fishing on multiple components of marine ecosystems. This led to the recovery of some depleted populations and to increased habitat protection. The relatively short history of fishing exploitation and the small scale of the fishing industry in South East Australia played a significant role in limiting the magnitude of fishing impacts on local populations and helped to achieve recoveries when fisheries

76 FR 60444 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

Science.gov (United States)

2011-09-29

..., cobia, cero, little tunny, dolphin, and bluefish (Gulf only). At present, only king mackerel, Spanish... bluefish from the Coastal Migratory Pelagic FMP. The Councils and NMFS have determined these species are...

Harvest Strategies for an Ecosystem Approach to Fisheries Management in Western Mediterranean Demersal Fisheries

Directory of Open Access Journals (Sweden)

Antoni Quetglas

2017-04-01

Full Text Available The serious overfishing of most Mediterranean stocks demands urgent reforms of the management measures aiming to guarantee the sustainability of resources, notably when compared with the improvement observed in other European areas. The new EU Common Fisheries Policy (CFP constitutes an excellent opportunity to introduce the changes needed for such a reform. According to this CFP, all European fish stocks should be brought to a state where they can produce at MSY by 2020 at the latest. The CFP also establishes that the objective of sustainable exploitation should be achieved through multiannual plans (MAPs adopted in consultation with relevant stakeholders having fisheries management interests such as fishermen, non-governmental organizations, and policy makers. Together with the MSY and MAP approaches, the new CFP contains several other measures, directed to guarantee the ecological and socio-economic sustainability of fisheries by means of the implementation of the ecosystem approach to fisheries management (EAFM. With this new perspective, the CFP wants to avoid past failures of fisheries management based on monospecific approaches. This study is a first step toward the application of the EAFM in the Balearic Islands by means of the development of a harvest strategy with defined objectives, targets, limits, and clear management control rules aimed at optimizing socioeconomic and ecological objectives in the framework of the new CFP. Different management scenarios designed to achieve that goal were modeled for the main demersal commercial fisheries from the study area, the bottom trawl, and small-scale fisheries. The work begins with a general description of those fisheries, their main fishing grounds, and assessments of the exploitation status of the main target stocks in order to establish the current situation. Secondly, alternative management scenarios to maximize catch and profits while considering societal objectives were evaluated by

Influence of the hydrodynamic conditions on the accessibility of Aristeus antennatus and other demersal species to the deep water trawl fishery off the Balearic Islands (western Mediterranean)

Science.gov (United States)

Amores, Angel; Rueda, Lucía; Monserrat, Sebastià; Guijarro, Beatriz; Pasqual, Catalina; Massutí, Enric

2014-10-01

Monthly catches per unit of effort (CPUE) of adult red shrimp (Aristeus antennatus), reported in the deep water bottom trawl fishery developed on the Sóller fishing ground off northern Mallorca (Western Mediterranean), and the mean ocean surface vorticity in the surrounding areas are compared between 2000 and 2010. A good correlation is found between the rises in the surrounding surface vorticity and the drops in the CPUE of the adult red shrimp. This correlation could be explained by assuming that most of the surface vorticity episodes could reach the bottom, increasing the seabed velocities and producing sediment resuspension, which could affect the near bottom water turbidity. A. antennatus would respond to this increased turbidity disappearing from the fishing grounds, probably moving downwards to the deeper waters. This massive displacement of red shrimp specimens away from the fishing grounds would consequently decrease their accessibility to fishing exploitation. Similar although more intense responses have been observed during the downslope shelf dense water current episodes that occurred in a submarine canyon, northeast of the Iberian peninsula. The proposed mechanism suggesting how the surface vorticity observed can affect the bottom sediments is investigated using a year-long moored near-bottom current meter and a sediment trap moored near the fishing grounds. The relationship between vorticity and catches is also explored for fish species (Galeus melastomus, Micromesistius poutassou, Phycis blennoides) and other crustacean (Geryon longipes and Nephrops norvegicus), considered as by-catch of the deep water fishery in the area. Results appear to support the suggestion that the water turbidity generated by the vorticity episodes is significant enough to affect the dynamics of the demersal species.

77 FR 38266 - Sea Turtle Conservation; Shrimp Trawling Requirements; Public Hearing

Science.gov (United States)

2012-06-27

... withdraw the alternative tow time restriction and require all skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) rigged for fishing to use turtle excluder devices (TEDs) in their nets, which...

Vertical structure, biomass and topographic association of deep-pelagic fishes in relation to a mid-ocean ridge system

Science.gov (United States)

Sutton, T. T.; Porteiro, F. M.; Heino, M.; Byrkjedal, I.; Langhelle, G.; Anderson, C. I. H.; Horne, J.; Søiland, H.; Falkenhaug, T.; Godø, O. R.; Bergstad, O. A.

2008-01-01

The assemblage structure and vertical distribution of deep-pelagic fishes relative to a mid-ocean ridge system are described from an acoustic and discrete-depth trawling survey conducted as part of the international Census of Marine Life field project MAR-ECO . The 36-station, zig-zag survey along the northern Mid-Atlantic Ridge (MAR; Iceland to the Azores) covered the full depth range (0 to >3000 m), from the surface to near the bottom, using a combination of gear types to gain a more comprehensive understanding of the pelagic fauna. Abundance per volume of deep-pelagic fishes was highest in the epipelagic zone and within the benthic boundary layer (BBL; 0-200 m above the seafloor). Minimum fish abundance occurred at depths below 2300 m but above the BBL. Biomass per volume of deep-pelagic fishes over the MAR reached a maximum within the BBL, revealing a previously unknown topographic association of a bathypelagic fish assemblage with a mid-ocean ridge system. With the exception of the BBL, biomass per volume reached a water column maximum in the bathypelagic zone between 1500 and 2300 m. This stands in stark contrast to the general "open-ocean" paradigm that biomass decreases exponentially from the surface downwards. As much of the summit of the MAR extends into this depth layer, a likely explanation for this mid-water maximum is ridge association. Multivariate statistical analyses suggest that the dominant component of deep-pelagic fish biomass over the northern MAR was a wide-ranging bathypelagic assemblage that was remarkably consistent along the length of the ridge from Iceland to the Azores. Integrating these results with those of previous studies in oceanic ecosystems, there appears to be adequate evidence to conclude that special hydrodynamic and biotic features of mid-ocean ridge systems cause changes in the ecological structure of deep-pelagic fish assemblages relative to those at the same depths over abyssal plains. Lacking terrigenous input of

Effects of Climate Change and Fisheries Bycatch on Shy Albatross (Thalassarche cauta) in Southern Australia.

Science.gov (United States)

Thomson, Robin B; Alderman, Rachael L; Tuck, Geoffrey N; Hobday, Alistair J

2015-01-01

The impacts of climate change on marine species are often compounded by other stressors that make direct attribution and prediction difficult. Shy albatrosses (Thalassarche cauta) breeding on Albatross Island, Tasmania, show an unusually restricted foraging range, allowing easier discrimination between the influence of non-climate stressors (fisheries bycatch) and environmental variation. Local environmental conditions (rainfall, air temperature, and sea-surface height, an indicator of upwelling) during the vulnerable chick-rearing stage, have been correlated with breeding success of shy albatrosses. We use an age-, stage- and sex-structured population model to explore potential relationships between local environmental factors and albatross breeding success while accounting for fisheries bycatch by trawl and longline fisheries. The model uses time-series of observed breeding population counts, breeding success, adult and juvenile survival rates and a bycatch mortality observation for trawl fishing to estimate fisheries catchability, environmental influence, natural mortality rate, density dependence, and productivity. Observed at-sea distributions for adult and juvenile birds were coupled with reported fishing effort to estimate vulnerability to incidental bycatch. The inclusion of rainfall, temperature and sea-surface height as explanatory variables for annual chick mortality rate was statistically significant. Global climate models predict little change in future local average rainfall, however, increases are forecast in both temperatures and upwelling, which are predicted to have detrimental and beneficial effects, respectively, on breeding success. The model shows that mitigation of at least 50% of present bycatch is required to offset losses due to future temperature changes, even if upwelling increases substantially. Our results highlight the benefits of using an integrated modeling approach, which uses available demographic as well as environmental data

Effects of Climate Change and Fisheries Bycatch on Shy Albatross (Thalassarche cauta in Southern Australia.

Directory of Open Access Journals (Sweden)

Robin B Thomson

Full Text Available The impacts of climate change on marine species are often compounded by other stressors that make direct attribution and prediction difficult. Shy albatrosses (Thalassarche cauta breeding on Albatross Island, Tasmania, show an unusually restricted foraging range, allowing easier discrimination between the influence of non-climate stressors (fisheries bycatch and environmental variation. Local environmental conditions (rainfall, air temperature, and sea-surface height, an indicator of upwelling during the vulnerable chick-rearing stage, have been correlated with breeding success of shy albatrosses. We use an age-, stage- and sex-structured population model to explore potential relationships between local environmental factors and albatross breeding success while accounting for fisheries bycatch by trawl and longline fisheries. The model uses time-series of observed breeding population counts, breeding success, adult and juvenile survival rates and a bycatch mortality observation for trawl fishing to estimate fisheries catchability, environmental influence, natural mortality rate, density dependence, and productivity. Observed at-sea distributions for adult and juvenile birds were coupled with reported fishing effort to estimate vulnerability to incidental bycatch. The inclusion of rainfall, temperature and sea-surface height as explanatory variables for annual chick mortality rate was statistically significant. Global climate models predict little change in future local average rainfall, however, increases are forecast in both temperatures and upwelling, which are predicted to have detrimental and beneficial effects, respectively, on breeding success. The model shows that mitigation of at least 50% of present bycatch is required to offset losses due to future temperature changes, even if upwelling increases substantially. Our results highlight the benefits of using an integrated modeling approach, which uses available demographic as well as

Stable Isotope Food Web Analysis of a Large Subtropical Lake: Alternative Explanations for 15N Enrichment of Pelagic vs. Littoral Fisheries

Directory of Open Access Journals (Sweden)

Karl E. Havens

2003-01-01

Full Text Available The food webs of littoral, pelagic, and littoral-pelagic ecotone (interface regions of a large subtropical lake were investigated using stable isotope ratio methods, expanding the focus of a previous fish-only study to include other food web components such as primary producers and invertebrates. In these food webs, δ13C increased ~4o/oo and δ15N increased ~10o/oo from primary producers to fish. The δ15N of fish was ~9o/oo in the littoral zone, ~10 o/oo in the ecotone, and ~12o/oo in the pelagic zone. The cross-habitat enrichment in fish 15N corresponded with both an increase in the size of fish and an increase in the δ15N of primary consumers (mollusks. Despite larger body size in the pelagic zone, fish in all three habitats appear to occur at the same average trophic level (TL = 4, assuming an enrichment factor of 3.4o/oo per trophic level, and normalizing to the δ15N of primary consumers.

Banning is not enough: The complexities of oceanic shark management by tuna regional fisheries management organizations

Directory of Open Access Journals (Sweden)

Mariana Travassos Tolotti

2015-07-01

Full Text Available Recently, declining populations of several pelagic shark species have led to global conservation concerns surrounding this group. As a result, a series of species-specific banning measures have been implemented by Regional Fishery Management Organizations (RFMOs in charge of tuna fisheries, which include retention bans, finning bans and trading bans. There are both positive and negative aspects to most management measures, but generally, the positive aspects outweigh the negatives, ensuring the measure is beneficial to the resource and its users in the long term. Banning measures are a good first step towards the conservation of pelagic shark species, especially since they improve conservation awareness among fishers, managers and the public. Measures that impose total bans, however, can lead to negative impacts that may jeopardize the populations they were intended to protect. The majority of pelagic shark catches are incidental and most sharks die before they reach the vessel or after they are released. The legislation set out by RFMOs only prevents retention but not the actual capture or the mortality that may occur as a result. Managers should be fully aware that the development and implementation of mitigation measures are critical for a more effective conservation strategy.

SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

Directory of Open Access Journals (Sweden)

Tommaso Russo

Full Text Available Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries, a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1 spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2 an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3 a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in

SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

Science.gov (United States)

Russo, Tommaso; Parisi, Antonio; Garofalo, Germana; Gristina, Michele; Cataudella, Stefano; Fiorentino, Fabio

2014-01-01

Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries), a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1) spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2) an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3) a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in the Strait of

Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

KAUST Repository

Bachiller, E

2015-08-27

Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

KAUST Repository

Bachiller, E; Irigoien, Xabier

2015-01-01

Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

Fisheries monitoring in Babel: fish ethnotaxonomy in a hotspot of common names

Directory of Open Access Journals (Sweden)

Marilia Previero

Full Text Available The lack of a long term, comprehensive and reliable fisheries statistics system is a major impediment to fisheries management in Brazil. Fishing is one of the main activities throughout the country's coast, with predominance of small-scale, artisanal, multigear, and multispecies captures that are landed in a pulverized network of coastal villages. Brazil is also a hotspot of common names, another feature that challenges artisanal fisheries' monitoring. We combined taxonomic and ethnobiological information to support the implementation of an artisanal fisheries' monitoring program under the co-management framework of a Marine Extractive Reserve in Bahia State, Northeastern Brazil. We surveyed 141 fishing landings, recording 86 fish species (43 families and 52 correspondences 1:1 between local and scientific names. Broad folk categories had an average of 5.1 specific names, with "cação" (shark being the category with more specific names (24 names to six biological species. With the exception of species that make up the bycatch captured by shrimp trawling, fisherfolks are able to identify commercially important species from both fresh specimens and photos. Common names can be reliably used in fisheries monitoring programs, and their usage facilitates the participation of fisherfolks in surveys based on voluntary or compulsory declarations of captures

76 FR 37287 - Western Pacific Pelagic Fisheries; Prohibiting Longline Fishing Within 30 nm of the Northern...

Science.gov (United States)

2011-06-27

... fleets. This rule also makes several administrative clarifications to the pelagic fishing regulations... in the area. Also, an EEZ closure will disadvantage the United States in its negotiations to renew... recommended prohibited area for longline fishing around the CNMI. This final rule also makes administrative...

Optimisation of trawl energy efficiency under fishing effort constraint

OpenAIRE

Priour, Daniel; Khaled, Ramez

2009-01-01

Trawls energy efficiency is greatly affected by the drag, as well as by the swept area. The drag results in an increase of the energy consumption and the sweeping influences the catch. Methods of optimisation of the trawl design have been developed in order to reduce the volume of carburant per kg of caught fish and consequently the drag per swept area of the trawl. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For e...

Fall Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Fall Bottom Trawl Survey was initiated in 1963 and covered an area from Hudson Canyon, NY to Nova Scotia, Canada. Throughout the years,...

Winter Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

Spring Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

Large Pelagics Intercept Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Intercept Survey (LPIS) is a dockside survey of private and charterboat captains who have just completed fishing trips directed at large pelagic...

75 FR 32993 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Amendments 20...

Science.gov (United States)

2010-06-10

.../processor (C/P) trawl fleets. The trawl rationalization program is intended to increase net economic benefits, create individual economic stability, provide full utilization of the trawl sector allocation..., creates individual economic stability, provides for full utilization of the trawl sector allocation...

Quantifying changes in abundance, biomass and spatial distribution of Northeast Atlantic (NEA) mackerel (Scomber scombrus) in the Nordic Seas from 2007 to 2014

DEFF Research Database (Denmark)

Nøttestad, Leif; Utne, Kjell Rong; Óskarsson, Gudmundur .J.

2016-01-01

The Northeast Atlantic (NEA) mackerel (Scomber scombrus) is a widely distributed pelagic fish species that plays a key role in the marine ecosystem. In recent years, there has been a large fishery targeting mackerel in the NEA. At the same time as the geographic range of the mackerel fishery has...... on coordinated and standardized swept-area surface trawling in July–August from IESSNS increased from 1.96 million t [relative standard error (RSE) ¼ 30.35%] in 2007 to 8.77 million t (RSE ¼ 7.95%) in 2014. Simultaneously, the mackerel stock expanded its geographic range during the feeding season from 1......%). Furthermore, evaluation of the performance of the estimated abundance indices by age for this time-series, based on internal consistency and catch curves, suggest that the abundance indices of ages 3–12 track the temporal variation in abundance reasonably, and thus is applicable for stock assessments...

Food consumption and daily feeding periodicity : comparison between pelagic and demersal whiting in the North Sea

DEFF Research Database (Denmark)

Pedersen, Jens

2000-01-01

composition and energy density of the prey and spatial distribution of the whiting, demonstrates the need for a sampling design that includes both pelagic and demersal layers when quantifying the food consumption of whiting.(C) 2000 The Fisheries Society of the British Isles.......Pelagic North Sea whiting Merlagius merlangus fed at night, while demersal whiting fed by day. The estimated specific daily ration ranged from 4.38 to 7.84% in 1992 and from 3.99 to 10.31% in 1993 using the in situ rate of gastric evacuation. Using Anderson's evacuation model the specific daily...... ration ranged from 0.41 to 1.66% in 1992 and from 0.78 to 1.75% in 1993. The specific daily rations were significantly different where energy density of stomach content by length class of whiting was significantly different between the two layers and years. The fact that daily ration was related to prey...

A fuzzy-logic tool for multi-criteria decision making in fisheries: the case of the South African pelagic fishery

DEFF Research Database (Denmark)

Paterson, B.; Jarre, Astrid; Moloney, C.L.

2007-01-01

The present study presents an electronic decision-support tool that uses a fuzzy-logic model of expert knowledge to assist in multi-criteria decision-making in the context of an Ecosystem Approach to Fisheries (EAF). The prototype model integrates the multiple goals and objectives related...... to the evaluation of the ecosystem performance of the South African sardine Sardinops sagax fishery into a NetWeaver knowledge base and provides intuitive visual outputs to communicate results to managers and stakeholders. The software tool was developed in a consultative process with key experts and follows...... on expert opinion. Results show that the model is robust and conservative. The strength of the approach lies in the ability to include variables that are difficult to measure. It provides a means of rendering value judgements explicit and transparent. The tool synthesises a large amount of information...

AFSC/ABL: Lynn Canal Echo-Integrated Trawl Surveys, 2001-2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance.

Science.gov (United States)

Hiddink, Jan Geert; Jennings, Simon; Sciberras, Marija; Szostek, Claire L; Hughes, Kathryn M; Ellis, Nick; Rijnsdorp, Adriaan D; McConnaughey, Robert A; Mazor, Tessa; Hilborn, Ray; Collie, Jeremy S; Pitcher, C Roland; Amoroso, Ricardo O; Parma, Ana M; Suuronen, Petri; Kaiser, Michel J

2017-08-01

Bottom trawling is the most widespread human activity affecting seabed habitats. Here, we collate all available data for experimental and comparative studies of trawling impacts on whole communities of seabed macroinvertebrates on sedimentary habitats and develop widely applicable methods to estimate depletion and recovery rates of biota after trawling. Depletion of biota and trawl penetration into the seabed are highly correlated. Otter trawls caused the least depletion, removing 6% of biota per pass and penetrating the seabed on average down to 2.4 cm, whereas hydraulic dredges caused the most depletion, removing 41% of biota and penetrating the seabed on average 16.1 cm. Median recovery times posttrawling (from 50 to 95% of unimpacted biomass) ranged between 1.9 and 6.4 y. By accounting for the effects of penetration depth, environmental variation, and uncertainty, the models explained much of the variability of depletion and recovery estimates from single studies. Coupled with large-scale, high-resolution maps of trawling frequency and habitat, our estimates of depletion and recovery rates enable the assessment of trawling impacts on unprecedented spatial scales.

The Distribution of Capture Fisheries Based Small Pelagic - Mackerel Fish Species In Balikpapan Waters, East Kalimantan

Directory of Open Access Journals (Sweden)

Said Abdusysyahid

2014-04-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE In the utilization of common property resource, long term balance in aquaculture is difficult to maintain as people trying to maximize their profit leading to considerable extensification. The objective of this research was to analyze the number of stock, production, and effort of Mackerel fish (Scomberomorus commersonii resource based on bio-economic approach. Primary data was collected based on purposive sampling method where the respondents in this research were Small Pelagic fishers which determined deliberately due to specific consideration. Secondary data used in this research was obtained from several sources. Data production and effort (input or effort was arranged in a time sequence according to the type of fishing gears and their targets of fishery resource being studied and then determined the value of CPUE (catch per unit effort. Mathematically, the input gear to be standardized is calculated from fishing power index multiplies with input (effort of standardized gear. The result shows that the renewable capacity begins to decrease leading to a condition of biologically over fishing. Aside from that, the Mackerel fish resource in this area also experiences economically over fishing condition which indicated by higher economic calculation value and lower capture yield. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New

Characterisation and standardisation of a red shrimp Aristeus antennatus, (Risso, 1816 fishery off the Alicante gulf (SE Spain

Directory of Open Access Journals (Sweden)

Mariano García Rodríguez

2003-03-01

Full Text Available The red shrimp (Aristeus antennatus is a target species of a deep trawl fishery in the Gulf of Alicante. This paper describes the fishery by following the activity of this trawl fleet between 1992 and 1999. Principal Components Analysis (PCA of specific catch compositions identified five main components that explained 92% of the variability, and the catches were grouped into three main species: red shrimp, hake and blue whiting. Hierarchical Clustering Grouping of the percentage species catch composition allowed the fleet to be considered as two main groups, according to monthly landings and by differentiating the origin of the catches (slope or shelf. The species composition of the catch and the red shrimp catch rates (CPUE differed between the two fleet groups. The application of Generalised Linear Modelling (GLM to the CPUE series gave consistent indices of abundance. The fleet group, year and season had significant effects on shrimp catch rates, with the fleet group being the most important, and these models explained up to 62% of the total deviance. The abundance indices showed little variation from 1992, although 1994 had the highest value and 1997-1998 the lowest. Comparison with survey indices showed similar trends, while mean uncorrected CPUE differed. Monthly variations of shrimp indices showed a lower abundance in summer, which was attributed to the reproductive patterns of the species. As a result, the use of some fleet grouping techniques is recommended before standardising CPUEs to obtain trends or to calibrate assessment in a fishery.

Best practices for assessing forage fish fisheries-seabird resource competition

Science.gov (United States)

Sydeman, William J.; Thompson, Sarah Ann; Anker-Nilssen, Tycho; Arimitsu, Mayumi L.; Bennison, Ashley; Bertrand, Sophie; Boersch-Supan, Philipp; Boyd, Charlotte; Bransome, Nicole C.; Crawford, Robert J.M.; Daunt, Francis; Furness, Robert W.; Gianuca, Dimas; Gladics, Amanda; Koehn, Laura; Lang, Jennifer W.; Loggerwell, Elizabeth; Morris, Taryn L.; Phillips, Elizabeth M.; Provencher, Jennifer; Punt, André E..; Saraux, Claire; Shannon, Lynne; Sherley, Richard B.; Simeone, Alejandro; Wanless, Ross M.; Wanless, Sarah; Zador, Stephani

2017-01-01

Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass central to pelagic food webs. In particular, fisheries targeting forage fish and euphausiids may be in competition with seabirds, likely the most sensitive of marine vertebrates given limitations in their foraging abilities (ambit and gape size) and high metabolic rate, for food resources. Lately, apparent competition between fisheries and seabirds has led to numerous high-profile conflicts over interpretations, as well as the approaches that could and should be used to assess the magnitude and consequences of fisheries-seabird resource competition. In this paper, we review the methods used to date to study fisheries competition with seabirds, and present “best practices” for future resource competition assessments. Documenting current fisheries competition with seabirds generally involves addressing two major issues: 1) are fisheries causing localized prey depletion that is sufficient to affect the birds? (i.e., are fisheries limiting food resources?), and 2) how are fisheries-induced changes to forage stocks affecting seabird populations given the associated functional or numerical response relationships? Previous studies have been hampered by mismatches in the scale of fisheries, fish, and seabird data, and a lack of causal understanding due to confounding by climatic and other ecosystem factors (e.g., removal of predatory fish). Best practices for fisheries-seabird competition research should include i) clear articulation of hypotheses, ii) data collection (or summation) of fisheries, fish, and seabirds on matched spatio-temporal scales, and iii) integration of observational and experimental

76 FR 5326 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; King and Spanish Mackerel Coastal...

Science.gov (United States)

2011-01-31

... Spanish Mackerel Coastal Migratory Pelagic Fishery Off the Southern Atlantic States; Control Date AGENCY... that it is establishing a new control date to control future access to the king and Spanish mackerel... September 17, 2010, for king and Spanish mackerel. The Council requested a new control date for the king and...

AFSC/ABL: Frederick Sound Echo-integrated Trawl Survey, 2001 to 2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Frederick Sounds echo-trawl survey was conducted from 2001 to 2004. The surveys were conducted throughout most of the southern part...

Status of rainbow smelt in the U.S. waters of Lake Ontario, 2013

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.

2014-01-01

Rainbow Smelt Osmerus mordax are the second most abundant pelagic prey fish in Lake Ontario after Alewife Alosa psuedoharengus. The 2013, USGS/NYSDEC bottom trawl assessment indicated the abundance of Lake Ontario age-1 and older Rainbow Smelt decreased by 69% relative to 2012. Length frequency-based age analysis indicated that age-1 Rainbow Smelt constituted approximately 50% of the population, which is similar to recent trends where the proportion of age-1 has ranged from 95% to 42% of the population. While they constituted approximately half of the catch, the overall abundance index for age 1 was one of the lowest observed in the time series, potentially a result of cannibalism from the previous year class. Combined data from all bottom trawl assessments along the southern shore and eastern basin indicate the proportion of the fish community that is Rainbow Smelt has declined over the past 30 years. In 2013 the proportion of the pelagic fish catch (only pelagic species) that was Rainbow Smelt was the second lowest in the time series at 3.1%. Community diversity indices, based on bottom trawl catches, indicate that Lake Ontario fish community diversity, as assessed by bottom trawls, has sharply declined over the past 36 years and in 2013 the index was the lowest value in the time series. Much of this community diversity decline is driven by changes in the pelagic fish community and dominance of Alewife.

Migration and fisheries of North East Atlantic mackerel (Scomber scombrus) in autumn and winter

DEFF Research Database (Denmark)

Jansen, Teunis; Campbell, A.; Kelly, C.

2012-01-01

It has been suggested that observed spatial variation in mackerel fisheries, extending over several hundreds of kilometers, is reflective of climate-driven changes in mackerel migration patterns. Previous studies have been unable to clearly demonstrate this link. In this paper we demonstrate...... correlation between temperature and mackerel migration/distribution as proxied by mackerel catch data from both scientific bottom trawl surveys and commercial fisheries. We show that mackerel aggregate and migrate distances of up to 500 km along the continental shelf edge from mid-November to early March....... The path of this migration coincides with the location of the relatively warm shelf edge current and, as a consequence of this affinity, mackerel are guided towards the main spawning area in the south. Using a simulated time series of temperature of the shelf edge current we show that variations...

Antarctic krill; assessment of mesh size selectivity and escape mortality from trawls

DEFF Research Database (Denmark)

Krafft, Bjørn A.; Krag, Ludvig Ahm; Herrmann, Bent

2015-01-01

Marine AS. The project will examine krill escape mortality from the codend during a full scale field experiment, model size selectivity and escape mortality in codends including different designs and assess the size selectivity in the trawl body forward of the codend. Based on end results from the preceding...... examinations we will be able to predict size selectivity and escape mortality from the entire trawl body with the appurtenant mortality for different trawl designs......This working paper presents the aims and methodology for a three-year-project (commenced in 2015) assessing size selectivity and escape mortality of Antarctic krill from trawl nets. The project is widely based on acquired experiences from a completed study Net Escapement of Antarctic krill...

Postrelease survival, vertical and horizontal movements, and thermal habitats of five species of pelagic sharks in the central Pacific Ocean

DEFF Research Database (Denmark)

Musyl, Michael K.; Brill, Richard W.; Curran, Daniel S.

2011-01-01

]) in the central Pacific Ocean to determine speciesspecific movement patterns and survival rates after release from longline fishing gear. Only a single postrelease mortality could be unequivocally documented: a male blue shark which succumbed seven days after release. Meta-analysis of published reports......From 2001 to 2006, 71 pop-up satellite archival tags (PSATs) were deployed on five species of pelagic shark (blue shark [Prionace glauca]; shortfin mako [Isurus oxyrinchus]; silky shark [Carcharhinus falciformis]; oceanic whitetip shark [C. longimanus]; and bigeye thresher [Alopias superciliosus...... and the current study (n=78 reporting PSATs) indicated that the summary effect of postrelease mortality for blue sharks was 15% (95% CI, 8.5-25.1%) and suggested that catch-and-release in longline fisheries can be a viable management tool to protect parental biomass in shark populations. Pelagic sharks displayed...

Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

DEFF Research Database (Denmark)

Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng

2016-01-01

such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...... depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were...... found with both trawling and eDNA, while three families were found only with eDNA and two families were found only with trawling. Key commercial fish species for Greenland were the most abundant species in both eDNA reads and biomass catch, and interpolation of eDNA abundances between sampling sites...

Life cycle ecophysiology of small pelagic fish and climate-driven changes in populations

Science.gov (United States)

Peck, Myron A.; Reglero, Patricia; Takahashi, Motomitsu; Catalán, Ignacio A.

2013-09-01

opinion, the continued development of biophysical models that close the life cycle (depict all life stages) offers the best chance of revealing processes causing historical fluctuations on the productivity and distribution of small pelagic fishes and to project future climate-driven impacts. Correctly representing physiological-based mechanisms will increase confidence in the outcomes of models simulating the potential impacts of bottom-up processes, a first step towards evaluating the mixture of factors and processes (e.g. intra-guild dynamics, predation, fisheries exploitation) which interact with climate to affect populations of small pelagic fishes. Understand the impacts of reduced growth rates during the juvenile stage on the process of maturation and spawning condition of small pelagic fishes. Examine the effects of changes in prey quality on the duration and magnitude of spawning by small pelagic fishes to capture how climate-driven changes in zooplankton species composition might act as a “bottom-up” regulator of fish productivity. Identify the drivers for spawning location and timing to better understand how spawning dynamics may be influenced by climate change (e.g. changes in water salinity or turbidity resulting from changes in river discharges or wind-driven turbulence, respectively).

Epibenthic diversity and productivity on a heavily trawled Barents Sea bank (Tromsøflaket

Directory of Open Access Journals (Sweden)

Monika Kędra

2017-04-01

Full Text Available Shallow Arctic banks have been observed to harbour rich communities of epifaunal organisms, but have not been well-studied with respect to composition or function due to sampling challenges. In order to determine how these banks function in the Barents Sea ecosystem, we used a combination of video and trawl/dredge sampling at several locations on a heavily trawled bank, Tromsøflaket – located at the southwestern entrance to the Barents Sea. We describe components of the benthic community, and calculate secondary production of dominant epifaunal organisms. Forty-six epibenthic taxa were identified, and sponges were a significant part of the surveyed benthic communities. There were differences in diversity and production among areas, mainly related to the intensity of trawling activities. Gamma was the most diverse and productive area, with highest species abundance and biomass. Trawled areas had considerably lower species numbers, and significant differences in epifaunal abundance and biomass were found between all trawled and untrawled areas. Trawling seems to have an impact on the sponge communities: mean individual poriferan biomass was higher in untrawled areas, and, although poriferans were observed in areas subjected to more intensive trawling, they were at least five times less frequent than in untrawled areas.

Impact and distribution of bottom trawl fishing on mud-bottom communities in the Kattegat

DEFF Research Database (Denmark)

Pommer, Christina Dahl; Olesen, Michael; Hansen, Jorgen L. S.

2016-01-01

The Kattegat in the inner Danish waters has been trawled for at least 80 yr, but so far only few attempts have been made to quantify the trawl effort, its spatial distribution and its potential ecological impact on the benthic fauna. GIS-analyses of VMS-data from trawling in the Kattegat by both ...

A bio-economic appraisal of pair trawl fisheries off southeastern Brazil Uma análise bio-econômica da pesca de parelhas no sudeste do Brasil

Directory of Open Access Journals (Sweden)

Luiz Arnaud Britto de Castro

2001-01-01

Full Text Available A study of the pair trawl fisheries was made in an attempt to introduce bio-economic models into fishery management in southern and southeastern Brazil. The biological parameters of demersal fishes found in the literature were used to mount the bio-economic model. Since there are no historical data on the economics of the fishery industry, the present market values of fish and of the diverse items that compose the costs of the catch have been used. The results show that the fleet was oversized in the period 1976-1981. The number of boats was reduced from 28 pairs to only 11 in 1996, but was still considered too big. The size of the fleet is reflected in the economic results of the analysis which shows negative returns. However, the fact that some of the fixed costs are not actually spent by the owners of the boats, as many of them have no insurance and most of the boats are already completely paid off and do not accrue costs on the capital invested must all be taken into account. On the other hand, the income figures used in this analysis did not take into account the value of the by-catch landed.Numa primeira tentativa de introduzir modelos bio-econômicos no gerenciamento pesqueiro no sudeste e sul do Brasil realizou-se um estudo da pesca de parelhas. Para isso construiu-se um modelo utilizando os parâmetros biológicos disponíveis na literatura. Como não há registros históricos de dados econômicos da pesca, foram utilizados os valores atuais do pescado e dos diversos insumos utilizados nessa atividade. Os resultados indicam que a frota estava superdimensionada no período de 1976-1981. De fato, daquela época até 1996, essa frota reduziu-se de 28 parelhas para apenas 11, um número ainda excessivo. O superdimensionamento da frota reflete-se nos resultados econômicos da análise, na forma de retornos financeiros negativos. Entretanto, deve-se levar em conta que alguns dos custos fixos não representam efetivo desembolso por parte dos

Pelagic Project Mauritania 2005-2006

NARCIS (Netherlands)

Heessen, H.J.L.; Tjoe-Awie, P.J.; Haan, de D.; Ybema, M.S.

2007-01-01

The Pelagic Project Mauritania 2005-2006 was the continuation of two earlier, but similar, projects for the years 1998-2001 and 2002-2004. The project was carried out in cooperation between IMARES and IMROP and had as most important objectives to further the assessment of small pelagic species,

Status and trends of the major roundfish, flatfish, and pelagic fish stocks in the North Sea : Thirty-year overview

DEFF Research Database (Denmark)

Serchuk, F.M.; Kirkegaard, Eskild; Daan, N.

1996-01-01

Changes in the status of the major roundfish, flatfish, and pelagic stocks in the North Sea over the past 30 years are reviewed. Synopses are presented on trends in catches, fishing mortality, spawning-stock biomass, and recruitment for eight stocks (cod, haddock, whiting, saithe, plaice, sole......, herring, and mackerel), together with an evaluation of the current state of these resources and the most resent management advice provided by the ICES Advisory, Committee on Fishery Management. (C) 1996 International Council for the Exploration of the Sea...

Prioritizing fishery management for loggerhead turtle (Caretta caretta) conservation in the northern Adriatic Sea from reproductive value analysis

OpenAIRE

Lazar, Bojan; Heppell, Selina S.

2013-01-01

Fisheries bycatch often affects particular size classes of turtles. Because of the late age at maturity, the reproductive value (RV) of small juvenile, large juvenile and adult loggerheads vary by orders of magnitude. RV provides a relative measure of value for individuals, thereby allowing us to estimate the effects of different stressors based on the number of animals killed. Using RV as a comparative index, we assessed the relative impact of trawl and gillnet fi sheries operating in the no...

Beyond duplicity and ignorance in global fisheries

Directory of Open Access Journals (Sweden)

Daniel Pauly

2009-06-01

Full Text Available The three decades following World War II were a period of rapidly increasing fishing effort and landings, but also of spectacular collapses, particularly in small pelagic fish stocks. This is also the period in which a toxic triad of catch underreporting, ignoring scientific advice and blaming the environment emerged as standard response to ongoing fisheries collapses, which became increasingly more frequent, finally engulfing major North Atlantic fisheries. The response to the depletion of traditional fishing grounds was an expansion of North Atlantic (and generally of northern hemisphere fisheries in three dimensions: southward, into deeper waters and into new taxa, i.e. catching and marketing species of fish and invertebrates previously spurned, and usually lower in the food web. This expansion provided many opportunities for mischief, as illustrated by the European Union’s negotiated ‘agreements’ for access to the fish resources of Northwest Africa, China’s agreement-fee exploitation of the same, and Japan blaming the resulting resource declines on the whales. Also, this expansion provided new opportunities for mislabelling seafood unfamiliar to North Americans and Europeans, and misleading consumers, thus reducing the impact of seafood guides and similar effort toward sustainability. With fisheries catches declining, aquaculture—despite all public relation efforts—not being able to pick up the slack, and rapidly increasing fuel prices, structural changes are to be expected in both the fishing industry and the scientific disciplines that study it and influence its governance. Notably, fisheries biology, now predominantly concerned with the welfare of the fishing industry, will have to be converted into fisheries conservation science, whose goal will be to resolve the toxic triad alluded to above, and thus maintain the marine biodiversity and ecosystems that provide existential services to fisheries. Similarly, fisheries

Trophic interactions and distribution of some Squaliforme sharks, including new diet descriptions for Deania calcea and Squalus acanthias.

Science.gov (United States)

Dunn, Matthew R; Stevens, Darren W; Forman, Jeffrey S; Connell, Amelia

2013-01-01

Squaliforme sharks are a common but relatively vulnerable bycatch in many deep water fisheries. Eleven species of squaliforme shark are commonly caught at depths of 200-1200 m on Chatham Rise, New Zealand, and their diversity suggests they might occupy different niches. The diets of 133 Deania calcea and 295 Squalus acanthias were determined from examination of stomach contents. The diet of D. calcea was characterised by mesopelagic fishes, and S. acanthias by benthic to pelagic fishes, but was more adaptive and included likely scavenging. Multivariate analyses found the most important predictors of diet variability in S. acanthias were year, bottom temperature, longitude, and fish weight. The diet of the nine other commonly caught squaliforme sharks was reviewed, and the spatial and depth distribution of all species on Chatham Rise described from research bottom trawl survey catches. The eleven species had a variety of different diets, and depth and location preferences, consistent with niche separation to reduce interspecific competition. Four trophic groups were identified, characterised by: mesopelagic fishes and invertebrates (Centroselachus crepidater, D. calcea, and Etmopterus lucifer); mesopelagic and benthopelagic fishes and invertebrates (Centroscymnus owstoni, Etmopterus baxteri); demersal and benthic fishes (Centrophorus squamosus, Dalatias licha, Proscymnodon plunketi); and a generalist diet of fishes and invertebrates (S. acanthias). The trophic levels of the species in each of the four groups were estimated as 4.18-4.24, 4.20-4.23, 4.24-4.48, and 3.84 respectively. The diet of Oxynotus bruniensis and Squalus griffini are unknown. The different niches occupied by different species are likely to influence their vulnerability to bottom trawl fisheries. Some species may benefit from fisheries through an increased availability of scavenged prey.

Risk assessment and uncertainty of the shrimp trawl fishery in the Gulf of California considering environmental variability

Directory of Open Access Journals (Sweden)

Luis César Almendarez-Hernández

2015-09-01

Full Text Available The shrimp fishery off the Mexican Pacific coast is the country's most important fishery from the economic standpoint. However, it faces serious problems, including the fleet's overcapitalization and age, in addition to the environmental variability that affects the size of catches. Thus, this activity depends on a variety of factors that add uncertainty to the profitability of fishing vessels. This study aims to estimate the probability of success and economic risk of "type vessels" under two different environmental variability scenarios in the Gulf of California. The results from the economic simulation pointed to the vessel type used in Guaymas (Sonora as the most efficient one under a neutral climate change scenario, showing a homogeneous behaviour in physical characteristics and mode of operation. By contrast, under a scenario of a monotonic rise in sea surface temperature, the shrimp fishery faces a greater risk of incurring economic losses. The simulated climate behaviour scenarios revealed that the activity involves a moderate economic profitability under the neutral scenario; however, under the warming scenario, profitability may be low or even nil due to the risks and uncertainty resulting from the influence of environmental phenomena.

A 'simple anterior fish excluder' (SAFE for mitigating penaeid-trawl bycatch.

Directory of Open Access Journals (Sweden)

Matthew J McHugh

Full Text Available Various plastic strips and sheets (termed 'simple anterior fish excluders'-SAFEs were positioned across the openings of penaeid trawls in attempts at reducing the unwanted bycatches of small teleosts. Initially, three SAFEs (a single wire without, and with small and large plastic panels were compared against a control (no SAFE on paired beam trawls. All SAFEs maintained targeted Metapenaeus macleayi catches, while the largest plastic SAFE significantly reduced total bycatch by 51% and the numbers of Pomatomus saltatrix, Mugil cephalus and Herklotsichthys castelnaui by up to 58%. A redesigned SAFE ('continuous plastic' was subsequently tested (against a control on paired otter trawls, significantly reducing total bycatch by 28% and P. saltatrix and H. castelnaui by up to 42%. The continuous-plastic SAFE also significantly reduced M. macleayi catches by ~7%, but this was explained by ~5% less wing-end spread, and could be simply negated through otter-board refinement. Further work is required to refine the tested SAFEs, and to quantify species-specific escape mechanisms. Nevertheless, the SAFE concept might represent an effective approach for improving penaeid-trawl selectivity.

Long-term changes in deep-water fish populations in the northeast Atlantic: a deeper reaching effect of fisheries?

OpenAIRE

Bailey, D.M.; Collins, M.A.; Gordon, J.D.M.; Zuur, A.F.; Priede, I.G.

2009-01-01

A severe scarcity of life history and population data for deep-water fishes is a major impediment to successful fisheries management. Long-term data for non-target species and those living deeper than the fishing grounds are particularly rare. We analysed a unique dataset of scientific trawls made from 1977 to 1989 and from 1997 to 2002, at depths from 800 to 4800 m. Over this time, overall fish abundance fell significantly at all depths from 800 to 2500 m, considerably deeper than the maximu...

Spatio-temporal patterns and environmental controls of small pelagic fish body condition from contrasted Mediterranean areas

Science.gov (United States)

Brosset, Pablo; Fromentin, Jean-Marc; Van Beveren, Elisabeth; Lloret, Josep; Marques, Virginie; Basilone, Gualtiero; Bonanno, Angelo; Carpi, Piera; Donato, Fortunata; Čikeš Keč, Vanja; De Felice, Andrea; Ferreri, Rosalia; Gašparević, Denis; Giráldez, Ana; Gücü, Ali; Iglesias, Magdalena; Leonori, Iole; Palomera, Isabel; Somarakis, Stylianos; Tičina, Vjekoslav; Torres, Pedro; Ventero, Ana; Zorica, Barbara; Ménard, Frédéric; Saraux, Claire

2017-02-01

Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we studied anchovy and sardine body condition variability, a key index of population health and its response to environmental and anthropogenic changes. Wide temporal and spatial patterns were investigated by analyzing separately data from scientific surveys and fisheries in eight Mediterranean areas between 1975 and 2015. Results showed that anchovy and sardine body condition as well as maximum size in some areas sharply decreased in most Mediterranean areas along years (except in the Northern Alboran Sea). Despite this general pattern, well-marked environmental differences between sub-regions were highlighted by several analyses and variations in body condition were not found to be homogeneous over all the Mediterranean Sea. Further, other analyses revealed that except for the Adriatic where major changes towards a lower body condition were concomitant with a decrease in river runoffs and chl-a concentration, no concomitant environmental regime shift was detected in other areas. Together, these analyses highlighted the current poor body condition of almost all small pelagic fish populations in the Mediterranean. Yet, global environmental indices could not explain the observed changes and the general decrease in condition might more likely come from regional environmental and/or anthropogenic (fishing) effects. A prolonged state of poor fish body condition, together with an observed reduced size and early age-at-maturity may have strong ecological, economic and social consequences all around the Mediterranean Sea.

Aspects of the biology of the Atlantic Midshipman, Porichthys porosissimus (Teleostei, Batrachoididae: an important by-catch species of shrimp trawling off southern Brazil

Directory of Open Access Journals (Sweden)

Marcelo Vianna

2000-01-01

Full Text Available Trawl fishing for pink shrimp (Farfantepenaeus brasiliensis and F. paulensis catches large quantities of by-catch fish, discarded due to their having no commercial vaue. As these species have rarely been studied, the impact of fisheries on these populations is not known. This contribution studies the biology of a species of no commercial value, the Atlantic midshipman Porichthys porosissimus. The last haul /Tom a commercial trawler, operating on the northern coast of São Paulo State and the southern coast of Rio de Janeiro State, was preserved (/Tom being discarded and identified at the species leveI. It was observed that this fishery affects the juvenile population which is intluenced by the seasonal variation of the water masses. Growth parameters were estimated: L∞ = 37.0 cm, K = 0.285 year-1. Instantaneous mortality coefficients were estimated: 2=2.14, M=0.63, F= 1.51, S= 11.8 and E=0.71. Considering the intensive activity of the shrimp trawl tleet operating in this area, the deleterious action of trawling is considered as of high impact. The stock management measures applied for pink shrimp are without effect regarding P. porosissimus. which has its spawning period before the closed season and its recruitment peak after it. The results show overfishing and the need to apply measures to reduce trawling action, such as adequate policies, introduction of selectivity devices and the creation of exclusion zones for trawl fishing.A pesca de arrasto para a captura do camarão-rosa (Fm:fantepenaeus brasi/iensis e F. paulensis captura grande quantidade de peixes considerados fauna acompanhante que são descartados por não possuírem valor comercial. Assim, pouco aparecem em trabalhos de biologia pesqueira com dados de desembarque, sendo a ação pesqueira sobre estas populações pouco conhecida. Neste estudo, um arrasto mensal de um barco de pesca foi desembarcado sem que nada do material capturado fosse descartado. Analisou-se Porichthys

Improving fishing effort descriptors: Modelling engine power and gear-size relations of five European trawl fleets

DEFF Research Database (Denmark)

Eigaard, Ole Ritzau; Rihan, Dominic; Graham, Norman

2011-01-01

Based on information from an international inventory of gears currently deployed by trawlers in five European countries, the relationship between vessel engine power and trawl size is quantified for different trawl types, trawling techniques and target species. Using multiplicative modelling it i...

Incidental catches of pelagic megafauna by the Dutch pelagic fleet in the Mauritanian Exclusive Economic Zone during the years 1999 - 2003

NARCIS (Netherlands)

Hofstede, ter R.; Zeeberg, J.J.; Haan, de D.; Couperus, A.S.; Mantingh, I.T.

2004-01-01

This report presents all registered catches of pelagic megafauna by the Dutch pelagic fleet in the Mauritanian Exclusive Economic Zone during the years 1999-2003. ‘By-catches’ incidentally include large species, notably cetaceans, sea turtles, sharks, rays, and some large pelagic fish such as

ASSESSING THE STATE OF THE PELAGIC HABITAT: A CASE STUDY OF PLANKTON AND ITS ENVIRONMENT IN THE WESTERN IRISH SEA

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Cordula Scherer

2016-11-01

Full Text Available Much work had been undertaken on tracking change in the condition of marine pelagic ecosystems and on identifying regime shifts. However, it is also necessary to relate change to states of good ecosystem health or what the European Marine Strategy Framework Directive (MSFD calls 'Good Environmental Status' (GES. Drawing on existing scientific and legislative principles, including those of OSPAR's 'Strategy to Combat Eutrophication', we propose a framework for assessing the status of what the MSFD calls the 'pelagic habitat' in temperate coastal seas. The framework uses knowledge of local ecohydrodynamic conditions, especially those relating to the stratification and optical environment, to guide expectations of what would be recognised as healthy in terms of ecosystem 'organisation' and 'vigour'. We apply this framework to the seasonally stratified regime of the Western Irish Sea, drawing on published and new work on stratification, nutrient and phytoplankton seasonal cycles, zooplankton, and the implications of plankton community structure and production for higher trophic levels. We conclude that, despite human pressures including nutrient enrichment, and the food-web effects of fisheries, the pelagic ecosystem here is in GES, and hence may be used as a reference for the 'Plankton Index' method of tracking change in state space in seasonally stratified waters.

Evaluation of three levels of selective devices relevant to management of the Danish Kattegat-Skagerrak Nephrops fishery

DEFF Research Database (Denmark)

Frandsen, Rikke; Holst, René; Madsen, Niels

2009-01-01

This study illuminates a range of technological options relevant to present legislation for regulating fish by-catch in a small-meshed Nephrops fishery. The selection of cod, haddock, hake, lemon sole, Nephrops, plaice, saithe, witch, and whiting were evaluated using the twin-trawl technique for...... parameters by species and confidence bands to compare the selective properties of different gear types. For cod, haddock, hake, Nephrops, plaice, and whiting we obtained estimates for all three gear variants, whereas we obtained estimates for lemon sole and witch only with the standard and the SMP codends...

Determination of effective effort on hake Merluccius merluccius in a Mediterranean trawl fishery

Directory of Open Access Journals (Sweden)

Francisco Alemany

2003-12-01

Full Text Available The direct control of fishing effort as a management tool is of special interest in the Mediterranean, where the lack of effective international management systems and the high diversity of the catches significantly increases the complexity of implementing TAC´s as an indirect control of fishing effort. However, its enforcement should be based on the precise knowledge of the relationship between the fishing effort and its corresponding fishing mortality. In this sense, the general aim of this study was to develop an approach for analysing this relationship. In order to estimate the annual effective fishing effort on hake, a relational data base including daily landings by vessel and species of trawl fleet based on the port of Palma, Mallorca island (western Mediterranean during the period 1983-1991 was built. Fishing mortalities were available from VPA. Fishing effort and fishing mortality were split by subfleets or métiers which were identified by cluster analysis. Significant linear relationships between the two parameters were obtained when fishing effort was considered as the number of days in which hake catch was higher than 10 kg multiplied by GRT of correspondent vessels. These CPUE values are mainly obtained when trawlers operate in the muddy bottoms of the shelf and on the upper slope, where hake populations are mostly distributed. On the other hand, no clear trends in catchability by métier were found during the period analysed.

Infectious diseases affect marine fisheries and aquaculture economics

Science.gov (United States)

Lafferty, Kevin D.; Harvell, C. Drew; Conrad, Jonathan M.; Friedman, Carolyn S.; Kent, Michael L.; Kuris, Armand M.; Powell, Eric N.; Rondeau, Daniel; Saksida, Sonja M.

2015-01-01

Seafood is a growing part of the economy, but its economic value is diminished by marine diseases. Infectious diseases are common in the ocean, and here we tabulate 67 examples that can reduce commercial species' growth and survivorship or decrease seafood quality. These impacts seem most problematic in the stressful and crowded conditions of aquaculture, which increasingly dominates seafood production as wild fishery production plateaus. For instance, marine diseases of farmed oysters, shrimp, abalone, and various fishes, particularly Atlantic salmon, cost billions of dollars each year. In comparison, it is often difficult to accurately estimate disease impacts on wild populations, especially those of pelagic and subtidal species. Farmed species often receive infectious diseases from wild species and can, in turn, export infectious agents to wild species. However, the impact of disease export on wild fisheries is controversial because there are few quantitative data demonstrating that wild species near farms suffer more from infectious diseases than those in other areas. The movement of exotic infectious agents to new areas continues to be the greatest concern.

Configuring the Mesh Size, Side Taper and Wing Depth of Penaeid Trawls to Reduce Environmental Impacts

Science.gov (United States)

Broadhurst, Matt K.; Sterling, David J.; Millar, Russell B.

2014-01-01

The effects of reducing mesh size while concomitantly varying the side taper and wing depth of a generic penaeid-trawl body were investigated to improve engineering performance and minimize bycatch. Five trawl bodies (with the same codends) were tested across various environmental (e.g. depth and current) and biological (e.g. species and sizes) conditions. The first trawl body comprised 41-mm mesh and represented conventional designs (termed the ‘41 long deep-wing'), while the remaining trawl bodies were made from 32-mm mesh and differed only in their side tapers, and therefore length (i.e. 1N3B or ‘long’ and ∼28o to the tow direction vs 1N5B or ‘short’ and ∼35o) and wing depths (‘deep’–97 T vs ‘shallow’–60 T). There were incremental drag reductions (and therefore fuel savings – by up to 18 and 12% per h and ha trawled) associated with reducing twine area via either modification, and subsequently minimizing otter-board area in attempts to standardize spread. Side taper and wing depth had interactive and varied effects on species selectivity, but compared to the conventional 41 long deep-wing trawl, the 32 short shallow-wing trawl (i.e. the least twine area) reduced the total bycatch by 57% (attributed to more fish swimming forward and escaping). In most cases, all small-meshed trawls also caught more smaller school prawns Metapenaeus macleayi but to decrease this effect it should be possible to increase mesh size slightly, while still maintaining the above engineering benefits and species selectivity. The results support precisely optimizing mesh size as a precursor to any other anterior penaeid-trawl modifications designed to improve environmental performance. PMID:24911786

trawl codends for blue whiting (Micromesistius

African Journals Online (AJOL)

Administrator

2010-12-27

Dec 27, 2010 ... Page 1 ... landing size; PE, polyethylene; PA, polyamide; LSMTPC, large square mesh top panel codend; SR, selection range. taceans by traditional Mediterranean trawls in seasonal .... Size structure of the population indicated retaining (thin line), escaping. (broken line) and entering (thick line) from the ...

An Improved Backstepping-Based Controller for Three-Dimensional Trajectory Tracking of a Midwater Trawl System

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Zhao Yan

2016-01-01

Full Text Available An improved backstepping control method for three-dimensional trajectory tracking of a midwater trawl system is investigated. A new mathematical model of the trawl system while considering the horizontal expansion effect of two otter boards is presented based on the Newton Euler method. Subsequently, an active path tracking strategy of the trawl system based on the backstepping method is proposed. The nonstrict feedback characteristic of the proposed model employs a control allocation method and several parallel nonlinear PID (Proportion Integration Differentiation controllers to eliminate the high-order state variables. Then, the stability analysis by the Lyapunov Stability Theory shows that the proposed controller can maintain the stability of the trawl system even with the presence of external disturbances. To validate the proposed controller, a simulation comparison with a linear PID controller was conducted. The simulation results illustrate that the improved backstepping controller is effective for three-dimensional trajectory tracking of the midwater trawl system.

Roles of density-dependent growth and life history evolution in accounting for fisheries-induced trait changes.

Science.gov (United States)

Eikeset, Anne Maria; Dunlop, Erin S; Heino, Mikko; Storvik, Geir; Stenseth, Nils C; Dieckmann, Ulf

2016-12-27

The relative roles of density dependence and life history evolution in contributing to rapid fisheries-induced trait changes remain debated. In the 1930s, northeast Arctic cod (Gadus morhua), currently the world's largest cod stock, experienced a shift from a traditional spawning-ground fishery to an industrial trawl fishery with elevated exploitation in the stock's feeding grounds. Since then, age and length at maturation have declined dramatically, a trend paralleled in other exploited stocks worldwide. These trends can be explained by demographic truncation of the population's age structure, phenotypic plasticity in maturation arising through density-dependent growth, fisheries-induced evolution favoring faster-growing or earlier-maturing fish, or a combination of these processes. Here, we use a multitrait eco-evolutionary model to assess the capacity of these processes to reproduce 74 y of historical data on age and length at maturation in northeast Arctic cod, while mimicking the stock's historical harvesting regime. Our results show that model predictions critically depend on the assumed density dependence of growth: when this is weak, life history evolution might be necessary to prevent stock collapse, whereas when a stronger density dependence estimated from recent data is used, the role of evolution in explaining fisheries-induced trait changes is diminished. Our integrative analysis of density-dependent growth, multitrait evolution, and stock-specific time series data underscores the importance of jointly considering evolutionary and ecological processes, enabling a more comprehensive perspective on empirically observed stock dynamics than previous studies could provide.

Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats

NARCIS (Netherlands)

Denderen, van Daniel; Bolam, Stefan G.; Hiddink, Jan Geert; Jennings, Simon; Kenny, Andrew; Rijnsdorp, Adriaan D.; Kooten, Van Tobias

2015-01-01

Bottom trawl fishing has widespread impacts on benthic habitats and communities. The benthic response to trawling seems to be smaller or absent in areas exposed to high natural disturbance, leading to the hypothesis that natural and trawl disturbance affect benthic communities in a similar way.

Keeping Food on the Table: Human Responses and Changing Coastal Fisheries in Solomon Islands.

Science.gov (United States)

Albert, Simon; Aswani, Shankar; Fisher, Paul L; Albert, Joelle

2015-01-01

Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region's fisheries in the future.

Keeping Food on the Table: Human Responses and Changing Coastal Fisheries in Solomon Islands.

Directory of Open Access Journals (Sweden)

Simon Albert

Full Text Available Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort, and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region's fisheries in the future.

Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

DEFF Research Database (Denmark)

Krag, Ludvig Ahm

reduce the catch of cod without simultaneously reduce the catch of the target species. To optimise the trade-off between discard and loss of marketable catch, solutions have to be specific to particular fisheries or populations of fish. Papers 1 and 3 provide specific examples of how size- and species...

Corpus Christi EFH Trawling Effects 2001-2002

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — We compared sediments and benthos of two adjacent zones of the middle Texas coast, one of which was closed to shrimp trawling for 7 months. Findings indicated that...

Catch rates as indicators of ecosystem health and exploitation status in the shrimp fishery in the South China sea

DEFF Research Database (Denmark)

Christensen, Steen; van Thi, Dang

2008-01-01

that might reflect seasonality in shrimp recruitment was found, making this resource potentially suitable for a fishery management system based on closed seasons. Further, the data indicate that the major part of the catches are comprised of low value species belonging to the genera Parapenaeopsis; whereas......Based on catch and effort data analyses covering the period 1996-2002, time series of catch rates in the trawl fisheries in the South China Sea along the coasts of Bac Lieu and Ca Mau in South East Vietnam were estimated. The indicators include catch rates for total shrimp catch, five major shrimp...... the most valuable species, i.e. the Penaeus and Metapenaeus catch groups have been significantly depleted during the period investigated. Based on the experiences from the present analysis, recommendations are presented with regard to adjustments of the enumerator data collection programme to fulfil...

Bycatch in 36 and 40 mm PA Turkish twin rigged beam trawl codends

African Journals Online (AJOL)

The Turkish twin rigged beam trawl which has two identical nets rigged side by side on the same beam targets mainly the Parapenaeus longirostris, although some bycatch fish species have also become target species. Thus, landings of the shrimp beam trawling fleet also include some commercially valuable fishes.

Quantity and biochemical composition of particulate organic matter in a highly trawled area (Thermaikos Gulf, Eastern Mediterranean Sea

Directory of Open Access Journals (Sweden)

Antonio Pusceddu

2015-11-01

Full Text Available Bottom trawling represents nowadays one of the most severe anthropogenic disturbances at sea, and determines large impacts on benthic communities and processes. Bottom trawling determines also local sediment resuspension and the effects of the injection of large amounts of surface sediments into the water column have been repeatedly investigated. Few studies have assessed the consequences of sediment resuspension caused by bottom trawling on the quantity, biochemical composition and bioavailability of suspended organic particles and how these eventually rival those exerted by natural storms. To provide insights on this poorly addressed issue, we investigated concentrations and biochemical composition of total and enzymatically digestible pools of particulate organic matter (POM in the Thermaikos Gulf (Mediterranean Sea under calm sea conditions, during intensive trawling activities, and after a severe storm. We show here that sediment resuspension caused by trawling can cause large effects on POM quantity, biochemical composition and bioavailability. Both during trawling and after the storm, the relative importance of the carbohydrate pools increased (in the upper water column and the total lipid concentrations decreased (in the intermediate and bottom layers when compared to values measured during calm conditions. These results would suggest that bottom trawling could inject in the upper water column POM pools more refractory in nature (e.g., carbohydrates than those present in calm or after-storm conditions. By contrast, we show also that the bioavailable fraction of biopolymeric C increased significantly during trawling in the upper water column of the shallowest stations and in the bottom water column layer of the deepest ones. These results provide evidence that bottom trawling can influence the overall trophic status of coastal waters, exerting effects similar or stronger than those caused by natural storms, though of variable amplitude

Trophic interactions and distribution of some Squaliforme sharks, including new diet descriptions for Deania calcea and Squalus acanthias.

Directory of Open Access Journals (Sweden)

Matthew R Dunn

Full Text Available Squaliforme sharks are a common but relatively vulnerable bycatch in many deep water fisheries. Eleven species of squaliforme shark are commonly caught at depths of 200-1200 m on Chatham Rise, New Zealand, and their diversity suggests they might occupy different niches. The diets of 133 Deania calcea and 295 Squalus acanthias were determined from examination of stomach contents. The diet of D. calcea was characterised by mesopelagic fishes, and S. acanthias by benthic to pelagic fishes, but was more adaptive and included likely scavenging. Multivariate analyses found the most important predictors of diet variability in S. acanthias were year, bottom temperature, longitude, and fish weight. The diet of the nine other commonly caught squaliforme sharks was reviewed, and the spatial and depth distribution of all species on Chatham Rise described from research bottom trawl survey catches. The eleven species had a variety of different diets, and depth and location preferences, consistent with niche separation to reduce interspecific competition. Four trophic groups were identified, characterised by: mesopelagic fishes and invertebrates (Centroselachus crepidater, D. calcea, and Etmopterus lucifer; mesopelagic and benthopelagic fishes and invertebrates (Centroscymnus owstoni, Etmopterus baxteri; demersal and benthic fishes (Centrophorus squamosus, Dalatias licha, Proscymnodon plunketi; and a generalist diet of fishes and invertebrates (S. acanthias. The trophic levels of the species in each of the four groups were estimated as 4.18-4.24, 4.20-4.23, 4.24-4.48, and 3.84 respectively. The diet of Oxynotus bruniensis and Squalus griffini are unknown. The different niches occupied by different species are likely to influence their vulnerability to bottom trawl fisheries. Some species may benefit from fisheries through an increased availability of scavenged prey.

Fisheries economics and fisheries management

DEFF Research Database (Denmark)

Andersen, Peder

2013-01-01

spent too much time on fundamentals in fisheries economics at the expense of the development of applicable models for fisheries managers? Of course, this question is relevant only IF fisheries economics and fisheries economists have a role to play in fisheries management.......Professor Rögnvaldur Hannesson's influence on the development and history of fisheries economics is unquestionable. Also, he has strongly pointed out the potential gains from a more active use of fisheries economics in fisheries management. In light of this, one may ask if fisheries economists have...

Larval assemblages of large and medium-sized pelagic species in the Straits of Florida

Science.gov (United States)

Richardson, David E.; Llopiz, Joel K.; Guigand, Cedric M.; Cowen, Robert K.

2010-07-01

Critical gaps in our understanding of the distributions, interactions, life histories and preferred habitats of large and medium-size pelagic fishes severely constrain the implementation of ecosystem-based, spatially structured fisheries management approaches. In particular, spawning distributions and the environmental characteristics associated with the early life stages are poorly documented. In this study, we consider the diversity, assemblages, and associated habitat of the larvae of large and medium-sized pelagic species collected during 2 years of monthly surveys across the Straits of Florida. In total, 36 taxa and 14,295 individuals were collected, with the highest diversity occurring during the summer and in the western, frontal region of the Florida Current. Only a few species (e.g. Thunnus obesus, T. alalunga, Tetrapturus pfluegeri) considered for this study were absent. Small scombrids (e.g. T. atlanticus, Katsuwonus pelamis, Auxis spp.) and gempylids dominated the catch and were orders of magnitude more abundant than many of the rare species (e.g. Thunnus thynnus,Kajikia albida). Both constrained (CCA) and unconstrained (NMDS) multivariate analyses revealed a number of species groupings including: (1) a summer Florida edge assemblage (e.g. Auxis spp., Euthynnus alleterattus, Istiophorus platypterus); (2) a summer offshore assemblage (e.g. Makaira nigricans, T. atlanticus, Ruvettus pretiosus, Lampris guttatus); (3) an ubiquitous assemblage (e.g. K. pelamis, Coryphaena hippurus, Xiphias gladius); and (4) a spring/winter assemblage that was widely dispersed in space (e.g. trachipterids). The primary environmental factors associated with these assemblages were sea-surface temperature (highest in summer-early fall), day length (highest in early summer), thermocline depth (shallowest on the Florida side) and fluorescence (highest on the Florida side). Overall, the results of this study provide insights into how a remarkable diversity of pelagic species

Bottom trawling affects fish condition through changes in the ratio of prey availability to density of competitors

DEFF Research Database (Denmark)

Hiddink, Jan Geert; Moranta, Joan; Balestrini, Stephen

2016-01-01

pressure. 2. We assessed the impact of bottom trawling on the food availability, condition and stomach contents of three flatfishes and the Norway lobster in an area in the Kattegat hat is characterized by a steep commercial bottom-trawling gradient due to the establishment of an area closed to all....... This pattern was mirrored in both the condition and stomach contents of plaice and for long-rough dab. 4. No effect of trawling on dab prey and condition was found. Conversely, the condition of the main target species – Norway lobster – increased as its biomass decreased with increased trawling intensities. 5...

Gear Selectivity of a Longfin Squid Bottom Trawl

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Loligo pealeii (longfin inshore squid) co-occurs with Atlantic butterfish (Peprilus triacanthus) throughout the year and discarding in the L. pealeii bottom trawl...

75 FR 78343 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Amendments 20...

Science.gov (United States)

2010-12-15

... increase net economic benefits, create individual economic stability, provide full utilization of the trawl... economic benefits and create individual economic stability. Response. Start dates for the Pacific whiting... net economic benefits, create economic stability, provide full utilization of the trawl sector...

76 FR 59064 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

Science.gov (United States)

2011-09-23

.... 101126522-0640-02] RIN 0648-XA722 Fisheries of the Exclusive Economic Zone Off Alaska; Shallow- Water... closure. SUMMARY: NMFS is opening directed fishing for shallow-water species by [[Page 59065

HF radar and drifter observing system in the Adriatic for fishery management and security

DEFF Research Database (Denmark)

Corgnati, Lorenzo; Carlson, Daniel Frazier; Mantovani, Carlo

2014-01-01

A HF radar system has been operating since May 2013 in the Southern Adriatic between the Gargano Cape and the Manfredonia Gulf. The system, that has been tested and complemented with drifter launchings during three experiments, produces maps of surface ocean velocities at 2 km resolution every hour....... These data support fishery management as well as search and rescue and pollution mitigation operations. The Manfredonia Gulf is a known nursery area for small pelagic fish (anchovies and sardines), and its dynamics and connectivity properties are very relevant to the study of population dynamics. HF radar...

Net escapement of Antartic krill in trawls

DEFF Research Database (Denmark)

Krafft, B.A.; Krag, Ludvig Ahm; Herrmann, Bent

This document describes the aims and methodology of a three year project (commenced in 2012) entitled Net Escapement of Antarctic krill in Trawls (NEAT). The study will include a morphology based mathematical modeling (FISHSELECT) of different sex and maturity groups of Antarctic krill (Euphausia...

Habitat use and diel vertical migration of bigeye thresher shark: Overlap with pelagic longline fishing gear.

Science.gov (United States)

Coelho, Rui; Fernandez-Carvalho, Joana; Santos, Miguel N

2015-12-01

Pelagic longliners targeting swordfish and tunas in oceanic waters regularly capture sharks as bycatch, including currently protected species as the bigeye thresher, Alopias superciliosus. Fifteen bigeye threshers were tagged with pop-up satellite archival tags (PSATs) in 2012-2014 in the tropical northeast Atlantic, with successful transmissions received from 12 tags for a total of 907 tracking days. Marked diel vertical movements were recorded on all specimens, with most of the daytime spent in deeper colder water (mean depth = 353 m, SD = 73; mean temperature = 10.7 °C, SD = 1.8) and nighttime spent in warmer water closer to the surface (mean depth = 72 m, SD = 54; mean temperature = 21.9 °C, SD = 3.7). The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders (TDRs), and the overlap with habitat utilization was calculated. Overlap is taking place mainly during the night and is higher for juveniles. The results presented herein can be used as inputs for Ecological Risk Assessments for bigeye threshers captured in oceanic tuna fisheries, and serve as a basis for efficient management and conservation of this vulnerable shark species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lost in translation? Multi-metric macrobenthos indicators and bottom trawling

DEFF Research Database (Denmark)

Gislason, Henrik; Bastardie, Francois; Dinesen, Grete E.

2017-01-01

trawling. We use linear mixed effects models to analyze how bottom trawling intensity affects the indicators used in the Danish (Danish Quality Index, DKI) and Swedish (Benthic Quality Index, BQI) environmental monitoring programs in the Kattegat, the sea area between Sweden and Denmark. Using year...... of individuals per sample (density), we expect species density and density to be positively correlated. This correlation was confirmed by a simulation model and by statistical analysis of the bottom samples in which log species density was highly significantly related to log density (r = 0.75, df = 144, p ...

Large Pelagics Telephone Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Telephone Survey (LPTS) collects fishing effort information directly from captains holding Highly Migratory Species (HMS) permits (required by...

Bottom Trawl Survey Protocol Development (HB0706, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Cruise objectives include: 1) Investigate performance characteristics of new research bottom trawl; 2) Develop standard operating procedures for the NEFSC Bottom...

Patterns of variations in large pelagic fish: A comparative approach between the Indian and the Atlantic Oceans

Science.gov (United States)

Corbineau, A.; Rouyer, T.; Fromentin, J.-M.; Cazelles, B.; Fonteneau, A.; Ménard, F.

2010-07-01

Catch data of large pelagic fish such as tuna, swordfish and billfish are highly variable ranging from short to long term. Based on fisheries data, these time series are noisy and reflect mixed information on exploitation (targeting, strategy, fishing power), population dynamics (recruitment, growth, mortality, migration, etc.), and environmental forcing (local conditions or dominant climate patterns). In this work, we investigated patterns of variation of large pelagic fish (i.e. yellowfin tuna, bigeye tuna, swordfish and blue marlin) in Japanese longliners catch data from 1960 to 2004. We performed wavelet analyses on the yearly time series of each fish species in each biogeographic province of the tropical Indian and Atlantic Oceans. In addition, we carried out cross-wavelet analyses between these biological time series and a large-scale climatic index, i.e. the Southern Oscillation Index (SOI). Results showed that the biogeographic province was the most important factor structuring the patterns of variability of Japanese catch time series. Relationships between the SOI and the fish catches in the Indian and Atlantic Oceans also pointed out the role of climatic variability for structuring patterns of variation of catch time series. This work finally confirmed that Japanese longline CPUE data poorly reflect the underlying population dynamics of tunas.

Large Pelagics Biological Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Biological Survey (LPBS) collects additional length and weight information and body parts such as otoliths, caudal vertebrae, dorsal spines, and...

Population parameters of the Pacific flagfin mojarra Eucinostomus currani (Perciformes: Gerreidae captured by shrimp trawling fishery in the Gulf of California

Directory of Open Access Journals (Sweden)

Juana López-Martínez

2011-06-01

Full Text Available Shrimp trawling fishery in the Gulf of California captures a wide variety of non-target species of fish, crustaceans, and mollusks that are relatively unknown. The Pacific flagfin mojarra Eucinostomus currani is a frequently found species in these catches, nevertheless, nothing is currently known about its population dynamics. To contribute to the knowledge on this fish species, we studied the size structure, growth, mortality, and the recruitment pattern during the 2004-2005 seasons. A total of 6 078 mojarra were captured from 350 samples, with minimum and maximum lengths of 4.5cm and a maximum of 21.0cm. The average total length of the four major cohorts was 11.4, 13.7, 15.6 and 18.0cm, corresponding to ages 0.9, 1.2, 1.6 and 2.2 years, respectively, being the most abundant the 1.2 year-old group. The instant growth coefficient indicated moderate growth rates (K S=0.81/year, K E=0.85/year, corresponding to individuals living between 3.5 to 3.7 years. The estimated asymptotic lengths was L∞=21.8cm. In general, the population could be considered healthy: natural mortality (M=1.53/year; total mortality (Z=2.73 /year; condition factor (K=0.01072; fishery mortality (F=1.2/ year and exploitation rate (E=0.43/year. The maximum reproduction period almost coincided with the closed season for shrimp fishing (March to August, thus we concluded that survival of the species is ensured because reproduction is indirectly protected. Rev. Biol. Trop. 59 (2: 887-897. Epub 2011 June 01.La pesquería de camarón del Golfo de California captura una amplia variedad de especies incidentales, relativamente no conocidas que incluye peces, crustáceos y moluscos. La mojarra bandera del Pacífico Eucinostomus currani es frecuentemente encontrada en las capturas del camarón y no hay información sobre su dinámica poblacional. La estructura de tallas, crecimiento, mortalidad y patrón de reclutamiento fueron determinados durante la temporada 2004-2005. De manera que

Impact of bottom trawling on sediment characteristics - A study along inshore waters off Veraval coast, India

Digital Repository Service at National Institute of Oceanography (India)

Bhagirathan, U.; Meenakumari, B.; Jayalakshmy, K.V.; Panda, S.K.; Madhu, V.R.; Vaghela, D.T.

The present communication is a study on the impact of bottom trawling on the sediment characteristics along Veraval coast, which is the largest trawler port of India. Experimental bottom trawling was conducted from MFV Sagarkripa at five transects...

Analysis of habitat characteristics of small pelagic fish based on generalized additive models in Kepulauan Seribu Waters

Science.gov (United States)

Rivai, A. A.; Siregar, V. P.; Agus, S. B.; Yasuma, H.

2018-03-01

One of the required information for sustainable fisheries management is about the habitat characteristics of a fish species. This information can be used to map the distribution of fish and map the potential fishing ground. This study aimed to analyze the habitat characteristics of small pelagic fishes (anchovy, squid, sardine and scads) which were mainly caught by lift net in Kepulauan Seribu waters. Research on habitat characteristics had been widely done, but the use of total suspended solid (TSS) parameters in this analysis is still lacking. TSS parameter which was extracted from Landsat 8 along with five other oceanographic parameters, CPUE data and location of fishing ground data from lift net fisheries in Kepulauan Seribu were included in this analysis. This analysis used Generalized Additive Models (GAMs) to evaluate the relationship between CPUE and oceanographic parameters. The results of the analysis showed that each fish species had different habitat characteristics. TSS and sea surface height had a great influence on the value of CPUE from each species. All the oceanographic parameters affected the CPUE of each species. This study demonstrated the effective use of GAMs to identify the essential habitat of a fish species.

High post-capture survival for sharks, rays and chimaeras discarded in the main shark fishery of Australia?

Science.gov (United States)

Braccini, Matias; Van Rijn, Jay; Frick, Lorenz

2012-01-01

Most sharks, rays and chimaeras (chondrichthyans) taken in commercial fisheries are discarded (i.e. returned to the ocean either dead or alive). Quantifying the post-capture survival (PCS) of discarded species is therefore essential for the improved management and conservation of this group. For all chondrichthyans taken in the main shark fishery of Australia, we quantified the immediate PCS of individuals reaching the deck of commercial shark gillnet fishing vessels and applied a risk-based method to semi-quantitatively determine delayed and total PCS. Estimates of immediate, delayed and total PCS were consistent, being very high for the most commonly discarded species (Port Jackson shark, Australian swellshark, and spikey dogfish) and low for the most important commercial species (gummy and school sharks). Increasing gillnet soak time or water temperature significantly decreased PCS. Chondrichthyans with bottom-dwelling habits had the highest PCS whereas those with pelagic habits had the lowest PCS. The risk-based approach can be easily implemented as a standard practice of on-board observing programs, providing a convenient first-step assessment of the PCS of all species taken in commercial fisheries.

76 FR 65662 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

Science.gov (United States)

2011-10-24

... mackerel, and cobia. The intent of this rule is to specify ACLs for species not undergoing overfishing... overfishing, ACLs and AMs must be established at a level that prevents overfishing and helps to achieve OY... mechanism for specifying ACLs at a level such that overfishing does not occur in a fishery and AMs to...

Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots.

Science.gov (United States)

Queiroz, Nuno; Humphries, Nicolas E; Mucientes, Gonzalo; Hammerschlag, Neil; Lima, Fernando P; Scales, Kylie L; Miller, Peter I; Sousa, Lara L; Seabra, Rui; Sims, David W

2016-02-09

Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.

A comparison between benthic gillnet and bottom trawl for assessing fish assemblages in a shallow eutrophic lake near the Changjiang River estuary

Science.gov (United States)

Li, Yalei; Liu, Qigen; Chen, Liping; Zhao, Liangjie; Wu, Hao; Chen, Liqiao; Hu, Zhongjun

2018-03-01

Two fishing methods including gillnetting and trawling to estimate attributes of fish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition differed significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as different polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more effective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator of fish density depends on fishing season in the lake.

Precision in systematic trawl surveys as assessed from replicate ...

African Journals Online (AJOL)

Local variability was analysed as random noise, modelled and later reapplied ... The main statistical techniques applied were less susceptible to outlier catches ... be used to estimate the vessel factor when intercalibrating trawl survey vessels.

Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

DEFF Research Database (Denmark)

Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng

2016-01-01

depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were......Remote polar and deepwater fish faunas are under pressure from ongoing climate change and increasing fishing effort. However, these fish communities are difficult to monitor for logistic and financial reasons. Currently, monitoring of marine fishes largely relies on invasive techniques...... such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...

2013-2014 California Current Ecosystem (CCE14): Acoustic-Trawl Survey of Coastal Pelagic Fishes (Legs I and II); and Investigations of hake survey methods, life history, and associated ecosystem (Legs III and IV) (SH1405, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The 2014 acoustic-trawl method (ATM) project aboard Bell M. Shimada represents a joint effort between the SWFSC and the NWFSC in investigating elements of the...

2013-2014 California Current Ecosystem (CCE14): Acoustic-Trawl Survey of Coastal Pelagic Fishes (Legs I and II); and Investigations of hake survey methods, life history, and associated ecosystem (Legs III and IV) (SH1405, ME70)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The 2014 acoustic-trawl method (ATM) project aboard Bell M. Shimada represents a joint effort between the SWFSC and the NWFSC in investigating elements of the...

Temporal and Spatial Distribution of Catches of Tiger Sharks, Galeocerdo cuvier, in the Pelagic Longline Fishery Around the Hawaiian Islands

OpenAIRE

Polovina, Jeffrey J.; Lau, Boulderson B.

1993-01-01

Thirty-five tiger sharks, Galeocerdo cuvier, have been reported caught in pelagic longline gearfrom 25 to 265 n.mi. off the Hawaiian Archipelago during December 1990-May 1993. Fifteen sharks were caught farther than 50 n.mi. offshore, indicating that tiger sharks do occur well offshore and removed from benthic topography. About 89% of the sharks were caught during October-March, while only 56% of the fishing effort occurred during that period.

Metodologia para a monitorização e gestão da pesca de arrasto em Portugal. O exemplo do SIG GEOCRUST 1.0

Directory of Open Access Journals (Sweden)

Joana Simões

2003-12-01

Full Text Available A METHODOLOGY FOR THE MONITORING AND MANAGEMENT OF TRAWL FISHERIES IN PORTUGAL. THE SIG EXAMPLE OF GEOCRUST 1.0. This paper aims to present the Geographical Information System GEOCRUST 1.0, a computer programme developed within the fishery research project DGXIV 99/059, Use of Satellite GPS data to map effort and landings of the Portuguese crustacean fleet (GEOCRUST, in the University of Algarve. This stand-alone application was developed essentially to map fishing effort and catch per unit effort (CPUE information for the Portuguese crustacean trawl fleet, operating off the Southwest and South coasts of Portugal. The data available for this study included GPS vessels’ geographical positions and speed, transmitted via satellite to the Portuguese fisheries inspection authorities, and their catch reported to the Portuguese Directorate-General of Fisheries. GEOCRUST 1.0 was developed in ®VISUAL BASIC 6.0 using two ActiveX control: ADODB, to connect with the ®MSACCESS 2000 database and ®MAPOBJECTS 2.0 PRO, to communicate with the maps and provide GIS facilities. The application includes seven modules with the following objectives: Module 1 – to map and edit the original VMS data for a single vessel or group of vessels, for different periods of time; Module 2 – to analyse the trawl speed of each vessel; Module 3 – to define the boundaries of all fishing trips performed by vessel along the year; Module 4 – to identify and define the trawl hauls, within each fishing trip; Module 5 – to issue maps of fishing effort and CPUE; Module 6 – for exploratory data analysis and to extract data from the DB for further use in other computer packages and Module 7 – to recreate the activity of a single vessel, group of vessels or the total fleet, for a fixed period of time. This GIS application, fully developed by programming, has the advantage of being able to be used on its own without any need for external software support. The system developed

Pan-Atlantic analysis of the overlap of a highly migratory species, the leatherback turtle, with pelagic longline fisheries

Science.gov (United States)

Fossette, S.; Witt, M. J.; Miller, P.; Nalovic, M. A.; Albareda, D.; Almeida, A. P.; Broderick, A. C.; Chacón-Chaverri, D.; Coyne, M. S.; Domingo, A.; Eckert, S.; Evans, D.; Fallabrino, A.; Ferraroli, S.; Formia, A.; Giffoni, B.; Hays, G. C.; Hughes, G.; Kelle, L.; Leslie, A.; López-Mendilaharsu, M.; Luschi, P.; Prosdocimi, L.; Rodriguez-Heredia, S.; Turny, A.; Verhage, S.; Godley, B. J.

2014-01-01

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters. PMID:24523271

Comparative ecology of widely distributed pelagic fish species in the North Atlantic: Implications for modelling climate and fisheries impacts

Science.gov (United States)

Trenkel, V. M.; Huse, G.; MacKenzie, B. R.; Alvarez, P.; Arrizabalaga, H.; Castonguay, M.; Goñi, N.; Grégoire, F.; Hátún, H.; Jansen, T.; Jacobsen, J. A.; Lehodey, P.; Lutcavage, M.; Mariani, P.; Melvin, G. D.; Neilson, J. D.; Nøttestad, L.; Óskarsson, G. J.; Payne, M. R.; Richardson, D. E.; Senina, I.; Speirs, D. C.

2014-12-01

This paper reviews the current knowledge on the ecology of widely distributed pelagic fish stocks in the North Atlantic basin with emphasis on their role in the food web and the factors determining their relationship with the environment. We consider herring (Clupea harengus), mackerel (Scomber scombrus), capelin (Mallotus villosus), blue whiting (Micromesistius poutassou), and horse mackerel (Trachurus trachurus), which have distributions extending beyond the continental shelf and predominantly occur on both sides of the North Atlantic. We also include albacore (Thunnus alalunga), bluefin tuna (Thunnus thynnus), swordfish (Xiphias gladius), and blue marlin (Makaira nigricans), which, by contrast, show large-scale migrations at the basin scale. We focus on the links between life history processes and the environment, horizontal and vertical distribution, spatial structure and trophic role. Many of these species carry out extensive migrations from spawning grounds to nursery and feeding areas. Large oceanographic features such as the North Atlantic subpolar gyre play an important role in determining spatial distributions and driving variations in stock size. Given the large biomasses of especially the smaller species considered here, these stocks can exert significant top-down pressures on the food web and are important in supporting higher trophic levels. The review reveals commonalities and differences between the ecology of widely distributed pelagic fish in the NE and NW Atlantic basins, identifies knowledge gaps and modelling needs that the EURO-BASIN project attempts to address.

NPRB 1117 Cooperative research to develop new trawl footrope designs to reduce mortality of southern Tanner and snow crabs (Chionoecetes bairdi and C. opilio) incidental to Bering Sea bottom trawl fisheries

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Alaska’s Bering Sea is home to some of the world’s most productive groundfish and crab stocks and the fisheries that depend on them. Their spatial overlap creates...

Deep Water Survey Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The deep water biodiversity surveys explore and describe the biodiversity of the bathy- and bentho-pelagic nekton using Midwater and bottom trawls centered in the...

78 FR 70015 - Proposed Information Collection; Comment Request; Large Pelagic Fishing Survey

Science.gov (United States)

2013-11-22

... Collection; Comment Request; Large Pelagic Fishing Survey AGENCY: National Oceanic and Atmospheric... effort to reduce paperwork and respondent burden, invites the general public and other Federal agencies... Pelagics Headboat Survey (LPHS) component. Increase the annual Large Pelagics Telephone Survey (LPTS...

Economic gains from introducing international ITQs - the case of the mackerel and herring fisheries in the Northeast Atlantic

DEFF Research Database (Denmark)

Thøgersen, Thomas Talund; Eigaard, Ole Ritzau; Fitzpatrick, M.

2015-01-01

Achieving a balance between fishing capacity and fishing opportunities is one of the major challenges in European fisheries. One way to achieve this is to introduce individual tradable quotas or similar management measures. In several mackerel and herring fisheries in the Northeast Atlantic...... that the gross cash flow can be improved by 21% by allowing the mackerel and herring quotas to be traded internationally in the Northeast Atlantic. This rent gain arises mainly from increased productivity by allowing tradability between areas and fleets. The analysis also shows that the Danish pelagic fleet...... will gain from increasing its share of mackerel and herring quotas, whereas the Irish fleets are incentivised to sell quota, if individual quotas are allowed to be traded among countries. This result is in line with the qualitative analyses that show that Irish fishermen targeting herring in the Celtic Sea...

Pelagic habitat: exploring the concept of good environmental status

DEFF Research Database (Denmark)

Dickey-Collas, Mark; McQuatters-Gollop, Abigail; Bresnan, Eileen

2017-01-01

Marine environmental legislation is increasingly expressing a need to consider the quality of pelagic habitats. This paper uses the European Union marine strategy framework to explore the concept of good environmental status (GES) of pelagic habitat with the aim to build a wider understanding of ...

Drivers of Labor-Related Indicators across Diverse Mediterranean Fisheries

Directory of Open Access Journals (Sweden)

Jennifer Gee

2017-11-01

Full Text Available This regional case study is focused on employment, remuneration and labor productivity, with a particular emphasis on the interplay between labor productivity and other labor-related indicators and macroeconomic conditions in Italy, Egypt, Lebanon and Greece. Its value lies in the high degree of consistency and comparability of the data, owing to a shared data collection methodology. This has allowed for the compilation of both national and regional comparisons. The data is treated in two groups—the first group consists of national data that considers all the active vessels in a country; the second group focuses on the trawl segments of Italy and Egypt. These two countries present an interesting case study because they are so different in terms of labor productivity and remuneration performance. For instance, in Italy labor shortages have caused a shift in fishing strategies towards less labor-intensive operations to maintain the socioeconomic sustainability of the fisheries, while in Egypt macroeconomic conditions have resulted in a larger labor pool and strong incentives to work in the fisheries sector. The regional study demonstrates that labor-related indicators are interconnected and there is an inversely proportional relationship between labor productivity and remuneration and employment levels. This relationship necessitates a combined analysis. The results across and between the countries were compared, with particular attention given to labor productivity and remuneration in the respective countries with a discussion centred around the potential drivers of labor productivity.

Solapamiento trófico entre el lobo marino de un pelo Otaria flavescens y la pesquería de arrastre demersal del golfo San Matías, Patagonia, Argentina Trophic overlap between the South American sea lion Otaria flavescens and the demersal trawl fishery in San Matías Gulf, Patagonia, Argentina

Directory of Open Access Journals (Sweden)

María Alejandra Romero

2011-07-01

Full Text Available A nivel internacional, paralelo a la declinación y al colapso de pesquerías de gran escala, surgió un interés creciente por el estudio de las interacciones entre mamíferos marinos y pesquerías. El golfo San Matías (Patagonia, Argentina es considerado un ecosistema pesquero independiente de las aguas de la Plataforma Continental Argentina, con condiciones oceanográficas y biológicas particulares. La condición de sistema semi-cerrado podría generar escenarios particulares para la interacción entre la flota pesquera de arrastre de fondo y la población de lobos marinos de un pelo Otaria flavescens. En el presente trabajo se caracterizó la dieta del predador y la composición de las capturas pesqueras a fin de evaluar el solapamiento trófico entre ambos componentes. A partir de este análisis y la comparación de las tallas de las presas consumidas, se encontró que la posibilidad de una interacción competitiva entre la flota pesquera y los lobos marinos, a partir de la utilización de recursos similares, sería baja en el ecosistema del golfo San Matías.As world fisheries began to decline and massive collapses were observed, the competition between marine mammals and fisheries became an issue of growing concern. San Matías Gulf (Patagonia, Argentina is considered to be a fishery ecosystem independent of the Argentine Continental Shelf waters, with particular oceanographic and biological properties. As a semi-enclosed ecosystem, this gulf may generate particular scenarios for interactions between the demersal trawl fishery fleet and the population of South American sea lions Otaria flavescens. In this paper, the diet of the top predator and the composition of fishery catches were characterized in order to assess the trophic overlap between these two components. This analysis and a comparison of the sizes of prey consumed revealed a low probability of competition for similar resources between the fishing fleet and the marine mammals

The footprint of bottom trawling in European waters: distribution, intensity, and seabed integrity

DEFF Research Database (Denmark)

Eigaard, Ole Ritzau; Bastardie, Francois; Hinzen, N.T.

2017-01-01

for 2010-2012 at a grid cell resolution of 1 x 1 min longitude and latitude. Trawling intensity profiles with seabed impact at the surface and subsurface level are presented for 14 management areas in the North-east Atlantic, Baltic Sea and Mediterranean Sea. The footprint of the management areas ranged...... between 53-99% and 6-94% for the depth zone from 0 to 200 m (Shallow) and from 201 to 1000 m (Deep), respectively. The footprint was estimated as the total area of all grid cells that were trawled fully or partially. Excluding the untrawled proportions reduced the footprint estimates to 28-85% and 2......-77%. Largest footprints per unit landings were observed off Portugal and in the Mediterranean Sea. Mean trawling intensity ranged between 0.5 and 8.5 times per year, but was less in the Deep zone with a maximum intensity of 6.4. Highest intensities were recorded in the Skagerrak-Kattegat, Iberian Portuguese...

Population biology and distribution of the portunid crab Callinectes ornatus (Decapoda: Brachyura) in an estuary-bay complex of southern Brazil

OpenAIRE

Timoteo T. Watanabe; Bruno S. Sant'Anna; Gustavo Y. Hattori; Fernando J. Zara

2014-01-01

Trawl fisheries are associated with catches of swimming crabs, which are an important economic resource for commercial as well for small-scale fisheries. This study evaluated the population biology and distribution of the swimming crab Callinectes ornatus (Ordway, 1863) in the Estuary-Bay of São Vicente, state of São Paulo, Brazil. Crabs were collected from a shrimp fishing boat equipped with a semi-balloon otter-trawl net, on eight transects (four in the estuary and four in the bay) from Mar...

77 FR 34331 - Western Pacific Pelagic Fisheries; Revised Swordfish Trip Limits in the Hawaii Deep-Set Longline...

Science.gov (United States)

2012-06-11

... long, a minimum of 15 branch lines between any two floats (except basket-style longline gear), no light... be amended as follows: PART 665--FISHERIES IN THE WESTERN PACIFIC 1. The authority citation for part... between any two floats (except basket-style longline gear which may have as few as 10 branch lines between...

Systems approach modelling of the interactive effects of fisheries, jellyfish and tourism in the Catalan coast

Science.gov (United States)

Tomlinson, Benjamin; Maynou, Francesc; Sabatés, Ana; Fuentes, Verónica; Canepa, Antonio; Sastre, Sergio

2018-02-01

Despite the large fluctuation in annual recordings of gelatinous plankton along the Catalan coast in the north western Mediterranean and the lack of long term data sets, there is a general perception that jellyfish abundances are increasing. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches - a valuable ecosystem service for the regional tourist industry. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of P. noctiluca upon the local fisheries, the tourist industry and the wider economy. The following sub-models were constructed and connected following the systems approach framework methodology: an age-class based fisheries model; a jellyfish population matrix model; a jellyfish stranding model; a study on the impact of jellyfish strandings on beach users; and an economic input-output matrix. Various future scenarios for different abundances of jellyfish blooms were run. The "Expected blooms" scenario is similar to the quantity and size of blooms for 2000-2010. For a hypothetical "No blooms" scenario (standard background level of jellyfish but without any blooms) landings would increase by around 294 tonnes (5.1%) per year (averaged over 10 years) or approximately 0.19 M€ in profits per year (4.5%), and strandings would decrease by 49%. In a "Frequent blooms" scenario, landings would decrease by around 147 tonnes per year (2.5%) and decrease profits by 0.10 M€ per year (2.3%), and strandings would increase by 32%. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these

High Post-Capture Survival for Sharks, Rays and Chimaeras Discarded in the Main Shark Fishery of Australia?

Science.gov (United States)

Braccini, Matias; Van Rijn, Jay; Frick, Lorenz

2012-01-01

Most sharks, rays and chimaeras (chondrichthyans) taken in commercial fisheries are discarded (i.e. returned to the ocean either dead or alive). Quantifying the post-capture survival (PCS) of discarded species is therefore essential for the improved management and conservation of this group. For all chondrichthyans taken in the main shark fishery of Australia, we quantified the immediate PCS of individuals reaching the deck of commercial shark gillnet fishing vessels and applied a risk-based method to semi-quantitatively determine delayed and total PCS. Estimates of immediate, delayed and total PCS were consistent, being very high for the most commonly discarded species (Port Jackson shark, Australian swellshark, and spikey dogfish) and low for the most important commercial species (gummy and school sharks). Increasing gillnet soak time or water temperature significantly decreased PCS. Chondrichthyans with bottom-dwelling habits had the highest PCS whereas those with pelagic habits had the lowest PCS. The risk-based approach can be easily implemented as a standard practice of on-board observing programs, providing a convenient first-step assessment of the PCS of all species taken in commercial fisheries. PMID:22384270

Fractal Hypothesis of the Pelagic Microbial Ecosystem—Can Simple Ecological Principles Lead to Self-Similar Complexity in the Pelagic Microbial Food Web?

Science.gov (United States)

Våge, Selina; Thingstad, T. Frede

2015-01-01

Trophic interactions are highly complex and modern sequencing techniques reveal enormous biodiversity across multiple scales in marine microbial communities. Within the chemically and physically relatively homogeneous pelagic environment, this calls for an explanation beyond spatial and temporal heterogeneity. Based on observations of simple parasite-host and predator-prey interactions occurring at different trophic levels and levels of phylogenetic resolution, we present a theoretical perspective on this enormous biodiversity, discussing in particular self-similar aspects of pelagic microbial food web organization. Fractal methods have been used to describe a variety of natural phenomena, with studies of habitat structures being an application in ecology. In contrast to mathematical fractals where pattern generating rules are readily known, however, identifying mechanisms that lead to natural fractals is not straight-forward. Here we put forward the hypothesis that trophic interactions between pelagic microbes may be organized in a fractal-like manner, with the emergent network resembling the structure of the Sierpinski triangle. We discuss a mechanism that could be underlying the formation of repeated patterns at different trophic levels and discuss how this may help understand characteristic biomass size-spectra that hint at scale-invariant properties of the pelagic environment. If the idea of simple underlying principles leading to a fractal-like organization of the pelagic food web could be formalized, this would extend an ecologists mindset on how biological complexity could be accounted for. It may furthermore benefit ecosystem modeling by facilitating adequate model resolution across multiple scales. PMID:26648929

Benthic life in the pelagic: Aggregate encounter and degradation rates by pelagic harpacticoid copepods

DEFF Research Database (Denmark)

Koski, Marja; Kiørboe, Thomas; Takahashi, K.

2005-01-01

We measured field abundances, feeding rates, swimming behavior, and particle colonization of two harpacticoids, the pelagic Microsetella norvegica and the semibenthic Amonardia normanni, to examine (1) if aggregates have a significant role in harpacticoid nutrition and (2) if harpacticoids...

Vertical distribution of pelagic photosynthesis

DEFF Research Database (Denmark)

Lyngsgaard, Maren Moltke

chlorophyll maxima (DCM) to be a general feature in the ocean. Today, it is generally accepted that DCMs occur in most of our oceans still, despite this empirical knowledge, subsurface primary production is still largely ignored in marine science. The work included in this PhD examines the vertical...... each of the three regions combined with 15 years of survey data for the Baltic Sea transition zone. Overall, the results of this PhD work show that the vertical distribution of phytoplankton and their activity is important for the understanding, dynamics and functioning of pelagic ecosystems. It, thus......, emphasizes that future research and modelling exercises aimed at improving understanding of pelagic ecosystems and their role in the global ocean should include a consideration of the vertical heterogeneity in phytoplankton distributions and activity....

Drone Use in Monioring Open Ocean Surface Debris, Including Paired Manta and Tucker Trawls for Relateing Sea State to Vertical Debris Distribution

Science.gov (United States)

Lattin, G.

2016-02-01

Monitoring debris at sea presents challenges not found in beach or riverine habitats, and is typically done with trawl nets of various apertures and mesh sizes, which limits the size of debris captured and the area surveyed. To partially overcome these limitations in monitoring floating debris, a Quadcopter drone with video transmitting and recording capabilities was deployed at the beginning and the end of manta trawl transects within the North Pacific Subtropical Gyre's eastern convergence zone. Subsurface tucker trawls at 10 meters were conducted at the same time as the manta trawls, in order to assess the effect of sea state on debris dispersal. Trawls were conducted on an 11 station grid used repeatedly since 1999. For drone observations, the operator and observer were stationed on the mother ship while two researchers collected observed debris using a rigid inflatable boat (RIB). The drone was flown to a distance of approximately 100 meters from the vessel in a zigzag or circular search pattern. Here we examine issues arising from drone deployment during the survey: 1) relation of area surveyed by drone to volume of water passing through trawl; 2) retrieval of drone-spotted and associated RIB spotted debris. 3) integrating post- flight image analysis into retrieved debris quantification; and 4) factors limiting drone effectiveness at sea. During the survey, debris too large for the manta trawl was spotted by the drone, and significant debris not observed using the drone was recovered by the RIB. The combination of drone sightings, RIB retrieval, and post flight image analysis leads to improved monitoring of debris at sea. We also examine the issue of the distribution of floating debris during sea states varying from 0-5 by comparing quantities from surface manta trawls to the tucker trawls at a nominal depth of 10 meters.

West Coast Regional Office Permits

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Fisheries implemented a license limitation program for the trawl and fixed gear sectors of Pacific Coast commercial groundfish fishery on January 1, 1993. The...

Pacific Coast Groundfish Individual Fishing Quota Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — On January 11, 2011, NOAA Fisheries implemented a new fishery management system for the West Coast Groundfish Trawl Catch Share Program as specified in the...

75 FR 10757 - Proposed Information Collection; Comment Request; Alaska Region Amendment 80 Permits and Reports

Science.gov (United States)

2010-03-09

... to the Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area... facilitates the formation of harvesting cooperatives in the head-and-gut trawl catcher/processor sector... non-AFA trawl catcher/processor sector or to be used in Amendment 80 cooperative formation) are...

Pelagic habitat visualization: the need for a third (and fourth) dimension: HabitatSpace

Science.gov (United States)

Beegle-Krause, C; Vance, Tiffany; Reusser, Debbie; Stuebe, David; Howlett, Eoin

2009-01-01

Habitat in open water is not simply a 2-D to 2.5-D surface such as the ocean bottom or the air-water interface. Rather, pelagic habitat is a 3-D volume of water that can change over time, leading us to the term habitat space. Visualization and analysis in 2-D is well supported with GIS tools, but a new tool was needed for visualization and analysis in four dimensions. Observational data (cruise profiles (xo, yo, z, to)), numerical circulation model fields (x,y,z,t), and trajectories (larval fish, 4-D line) need to be merged together in a meaningful way for visualization and analysis. As a first step toward this new framework, UNIDATA’s Integrated Data Viewer (IDV) has been used to create a set of tools for habitat analysis in 4-D. IDV was designed for 3-D+time geospatial data in the meteorological community. NetCDF JavaTM libraries allow the tool to read many file formats including remotely located data (e.g. data available via OPeNDAP ). With this project, IDV has been adapted for use in delineating habitat space for multiple fish species in the ocean. The ability to define and visualize boundaries of a water mass, which meets specific biologically relevant criteria (e.g., volume, connectedness, and inter-annual variability) based on model results and observational data, will allow managers to investigate the survival of individual year classes of commercially important fisheries. Better understanding of the survival of these year classes will lead to improved forecasting of fisheries recruitment.

Explosive diversification following a benthic to pelagic shift in freshwater fishes.

Science.gov (United States)

Hollingsworth, Phillip R; Simons, Andrew M; Fordyce, James A; Hulsey, C Darrin

2013-12-17

Interspecific divergence along a benthic to pelagic habitat axis is ubiquitous in freshwater fishes inhabiting lentic environments. In this study, we examined the influence of this habitat axis on the macroevolution of a diverse, lotic radiation using mtDNA and nDNA phylogenies for eastern North America's most species-rich freshwater fish clade, the open posterior myodome (OPM) cyprinids. We used ancestral state reconstruction to identify the earliest benthic to pelagic transition in this group and generated fossil-calibrated estimates of when this shift occurred. This transition could have represented evolution into a novel adaptive zone, and therefore, we tested for a period of accelerated lineage accumulation after this historical habitat shift. Ancestral state reconstructions inferred a similar and concordant region of our mtDNA and nDNA based gene trees as representing the shift from benthic to pelagic habitats in the OPM clade. Two independent tests conducted on each gene tree suggested an increased diversification rate after this inferred habitat transition. Furthermore, lineage through time analyses indicated rapid early cladogenesis in the clade arising after the benthic to pelagic shift. A burst of diversification followed the earliest benthic to pelagic transition during the radiation of OPM cyprinids in eastern North America. As such, the benthic/pelagic habitat axis has likely influenced the generation of biodiversity across disparate freshwater ecosystems.

Tourism as a driver of conflicts and changes in fisheries value chains in Marine Protected Areas.

Science.gov (United States)

Lopes, P F M; Mendes, L; Fonseca, V; Villasante, S

2017-09-15

Although critical tools for protecting ocean habitats, Marine Protected Areas (MPAs) are sometimes challenged for social impacts and conflicts they may generate. Some conflicts have an economic base, which, once understood, can be used to resolve associated socioenvironmental problems. We addressed how the fish trade in an MPA that combines no-take zones and tourist or resident zones creates incentives for increased fisheries. We performed a value chain analysis following the fish supply and trade through interviews that assessed consumer demand and preference. The results showed a simple and closed value chain driven by tourism (70% of the consumption). Both tourists and local consumers preferred high trophic level species (predators), but the former preferred large pelagics (tuna and dolphinfish) and the latter preferred reef species (barracuda and snapper). Pelagic predators are caught with fresh sardines, which are sometimes located only in the no-take zone. Pelagic species are mainly served as fillet, and the leftover fish parts end up as waste, an issue that, if properly addressed, can help reduce fishing pressure. Whereas some of the target species may be sustainable (e.g., dolphinfish), others are more vulnerable (e.g., wahoo) and should not be intensively fished. We advise setting stricter limits to the number of tourists visiting MPAs, according to their own capacity and peculiarities, in order to avoid conflicts with conservations goals through incentives for increased resource use. Copyright © 2017 Elsevier Ltd. All rights reserved.

AFSC/RACE/FBEP/Hurst: Contrasting coastal and shelf nursery habitats of Pacific cod in the southeastern Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a study examining the use of demersal and pelagic habitats in the southeast Bering Sea by age-0 Pacific cod, based on 4 years of demersal trawl...

Trawl survey data are applied in fish stock assessment mainly to ...

African Journals Online (AJOL)

denise

Merluccius capensis (shallow-water Cape hake) and. M. paradoxus (deep-water Cape hake) off Namibia provide an ... published data), meaning that the horizontal trawl opening will .... Acoustic data were post-processed twice daily. Hake.

A Pelagic Paleocene Seouence in the Biga Peninsula Northwest Turkey

Directory of Open Access Journals (Sweden)

M. Burak YIKILMAZ

2002-06-01

Full Text Available A sequence of pelagic limestone, calciturbidite, debris flow, greywacke, basalt and limestone blocks. up to several hundred metres across, occur west of the town of Biga in northwest Turkey. The pelagic limestones in this sequence, named as the Ballıkaya formation, comprise pelagic foraminifera of Palaeocene age. Neritic limestone of Mid-Eocene age lies unconformably over the Ballıkaya formation. The age and the sedimentary environment of the Ballıkaya formation indicate the presence of a tectonically active deep-sea environment in northwest Turkey during the Palaeocene, and constrain the main Alpide deformation in northwest Turkey to the Late Palaeocene - Early Eocene interval.

75 FR 5945 - Proposed Information Collection; Comment Request; Pacific Coast Groundfish, Rationalization...

Science.gov (United States)

2010-02-05

... Collection; Comment Request; Pacific Coast Groundfish, Rationalization Sociocultural Study AGENCY: National... requiring equivalent information. Fisheries rationalization programs have an impact on those individuals... rationalization program for the Pacific Coast Groundfish limited entry trawl fishery in January 2011. This...

OWEZ pelagic fish, progress report and progression after T1

NARCIS (Netherlands)

Ybema, M.S.; Gloe, D.; Lambers, R.H.L.

2009-01-01

This report presents the current status of pelagic fish research in the Offshore Windfarm Egmond aan Zee (OWEZ) after having finalized the T0 baseline survey in 2003 and the T1 survey after construction of the wind farm in 2007. The T0 study indicated a highly dynamic pelagic fish community along

Benthic and pelagic pathways of methylmercury bioaccumulation in estuarine food webs of the northeast United States.

Directory of Open Access Journals (Sweden)

Celia Y Chen

Full Text Available Methylmercury (MeHg is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine. MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides. Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column.

Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

DEFF Research Database (Denmark)

Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike

2016-01-01

such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

Pelagic shark bycatch in the tuna- and swordfish-directed longline ...

African Journals Online (AJOL)

The capture of pelagic sharks as bycatch of the South African pelagic longline fleet targeting tuna Thunnus spp. and swordfish Xiphias gladius was investigated during the period 1998–2005. In all, 26 species were caught, of which six are listed by the International Union for Conservation of Nature (IUCN) as Vulnerable and ...

Fish species, Fish biomass, Fishery survey, invertebrate species, and other variables collected from midwater net tows, and bottom trawl observations using net, trawl, and other instruments from the Arctic Ocean, and Beaufort Sea from August 6, 2008 to August 21, 2008 (NODC Accession 0112823)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska Fisheries Science Center's Status of Stocks and Multispecies Assessment (SSMA) Programs Fishery Interaction Team (FIT) conducted a fish survey in the...

AFSC/RACE/MACE: Results of 2012 Chukchi Sea Acoustic/Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — We conducted acoustic-trawl (AT) surveys of the Alaska northern Bering and Chukchi Seas during ice-free periods with a focus on Arctic cod (Boreogadus saida), a key...

Seamounts are hotspots of pelagic biodiversity in the open ocean.

Science.gov (United States)

Morato, Telmo; Hoyle, Simon D; Allain, Valerie; Nicol, Simon J

2010-05-25

The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30-40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators.

California Pelagic Longline Fishery

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch and effort, landings, and observer data from longline vessels fishing in the North Pacific outside the U.S. west coast EEZ. Logbooks and...

Deep-sea seamount fisheries: a review of global status and future prospects Pesquerías de aguas profundas realizadas en montes submarinos: revision global de su estado y perspectivas futuras

Directory of Open Access Journals (Sweden)

Malcolm R Clark

2009-01-01

Full Text Available Seamounts support a large number and wide diversity of fish species. A number of these spe-cies can form aggregations for spawning or feeding and are the target of large-scale trawl fisheries. Since the 1970s, seamounts throughout the worlds' oceans have been explored for commercial resources, starting with efforts by the Soviet Union and Japan, which deployed distant water fleets around the world. Since then, a large number of countries have pursued fisheries on seamounts, especially in the deep sea. The total cumula-tive catch from seamount trawl fisheries exceeds two million tonnes. Catch histories for many deep-sea species show rapidly declining landings, and careful management is required to increase the chances of sustain-able fisheries. The low productivity of many seamount species limits the prospects for the large-scale exploita-tion of fish and invertebrate resources on seamounts.Los montes submarinos constituyen el habitat de una vasta y amplia variedad de especies ícticas. Parte de estas especies pueden formar agregaciones reproductivas o alimenticias, siendo objeto de importantes pesquerías de arrastre. A partir de la década de los 70' los montes submarinos en los diversos océanos fueron explorados en busca de recursos comerciales, labores que se iniciaron con la expansion de flotas de aguas distantes de la Unión Soviética y Japón alrededor del mundo. Desde ese momento, un gran número de otros países ha desarrollado pesquerías en montes submarinos, especialmente en aguas profundas. La captura total acumulada que se ha extraído en los montes submarinos excede a dos millones de toneladas. La historia de las faenas pesqueras realizadas en numerosas especies de aguas profundas muestra una rápida disminución en los desembarques, razón por la cual requieren de un cuidadoso manejo para incrementar la oportunidad de lograr la condición de pesquerías sustentables. La baja productividad observada en diversas especies indica

Estimation of seafloor impact from demersal trawls, seines and dredges based on gear design and dimensions

DEFF Research Database (Denmark)

Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael

a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...

Comparative distribution of the fan mussel Atrina fragilis (Bivalvia, Pinnidae in protected and trawled areas of the north Aegean Sea (Thermaikos Gulf

Directory of Open Access Journals (Sweden)

K. FRYGANIOTIS

2013-02-01

Full Text Available The distribution of the fan mussel Atrina fragilis was studied at two contrasting areas of the north Aegean Sea (Thermaikos Gulf: one routinely trawled and one closed to trawlers for over 25 years. Significant differences were detected between the two areas with decreased values in density and size of A. fragilis individuals at the trawled area. As habitat differences, i.e. sediment composition and bathymetry, had non-significant effect, extensive trawling activities probably explain the observed results.

SWFSC FED Mid Water Trawl Juvenile Rockfish Survey, Surface Data, 1987-2015

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC FED Mid Water Trawl Juvenile Rockfish Survey: Station Information and Surface Data. Surveys have been conducted along the central California coast in May/June...

75 FR 41123 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea Subarea

Science.gov (United States)

2010-07-15

... nonpelagic trawl fishing industry. Modified Nonpelagic Trawl Gear Nonpelagic trawl gear uses a pair of long lines called sweeps to herd fish into the net. These lines drag across the bottom and may adversely... flatfish species. In 2008 and 2009, the AFSC and NOAA Office for Law Enforcement worked with the fishing...

Deep Sea Coral voucher sequence dataset - Identification of deep-sea corals collected during the 2009 - 2014 West Coast Groundfish Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Data for this project resides in the West Coast Groundfish Bottom Trawl Survey Database. Deep-sea corals are often components of trawling bycatch, though their...

Olfaction Contributes to Pelagic Navigation in a Coastal Shark.

Science.gov (United States)

Nosal, Andrew P; Chao, Yi; Farrara, John D; Chai, Fei; Hastings, Philip A

2016-01-01

How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities.

Global multi-decadal ocean climate and small-pelagic fish population

International Nuclear Information System (INIS)

Tourre, Yves M; Lluch-Cota, Salvador E; White, Warren B

2007-01-01

Ocean climate, environmental and biological conditions vary on several spatio-temporal scales. Besides climate change associated with anthropogenic activity, there is growing evidence of a natural global multi-decadal climate signal in the ocean-atmosphere-biosphere climate system. The spatio-temporal evolution of this signal is thus analyzed during the 20th century and compared to the variability of small-pelagic fish landings. It is argued that the low-frequency global ocean environment and plankton ecosystems must be modified such that small-pelagic populations vary accordingly. A small-pelagic global index or fishing 'regime indicator series' (RIS) (i.e. a small-pelagic abundance indicator) is used. RIS is derived from fish landings data in the four main fishing areas in the Pacific and Atlantic oceans. Global RIS changes phase (from positive to negative values) when SST multi-decadal anomalies are out-of-phase between the eastern Pacific and southern Atlantic. RIS also displays maxima during the mid-30s to early-40s and the late-70s to early-80s when the multi-decadal signal was approximately changing phases (Tourre and White 2006 Geophys. Res. Lett. 33 L06716). It is recognized that other factors may modulate fish stocks, including anthropogenic predation. Nevertheless it is proposed that variable climate and environment, and the low-frequency 'global synchrony' of small-pelagic landings (Schwartzlose et al 1999 S. Afr. J. Mar. Sci. 21 289-347), could be associated with the multi-decadal changes in global ocean climate conditions

77 FR 75101 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

Science.gov (United States)

2012-12-19

.... 120813333-2647-01] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National.... SUMMARY: NMFS proposes regulations to implement Amendment 17 to the Pacific Coast Salmon Fishery...

76 FR 81851 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

Science.gov (United States)

2011-12-29

.... 101206604-1758-02] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National...) to implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and...

76 FR 65673 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

Science.gov (United States)

2011-10-24

.... 101206604-1620-01] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

78 FR 10557 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

Science.gov (United States)

2013-02-14

.... 120813333-3107-02] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 17 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

SWFSC FED Mid Water Trawl Juvenile Rockfish Survey, CTD Data, 1987-2015

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC FED Mid Water Trawl Juvenile Rockfish Survey: CTD Data. Surveys have been conducted along the central California coast in May/June every year since 1983. In...

Adaptation of pelage color and pigment variations in Israeli subterranean blind mole rats, Spalax ehrenbergi [corrected].

Directory of Open Access Journals (Sweden)

Natarajan Singaravelan

Full Text Available Concealing coloration in rodents is well established. However, only a few studies examined how soil color, pelage color, hair-melanin content, and genetics (i.e., the causal chain synergize to configure it. This study investigates the causal chain of dorsal coloration in Israeli subterranean blind mole rats, Spalax ehrenbergi.We examined pelage coloration of 128 adult animals from 11 populations belonging to four species of Spalax ehrenbergi superspecies (Spalax galili, Spalax golani, Spalax carmeli, and Spalax judaei and the corresponding coloration of soil samples from the collection sites using a digital colorimeter. Additionally, we quantified hair-melanin contents of 67 animals using HPLC and sequenced the MC1R gene in 68 individuals from all four mole rat species.Due to high variability of soil colors, the correlation between soil and pelage color coordinates was weak and significant only between soil hue and pelage lightness. Multiple stepwise forward regression revealed that soil lightness was significantly associated with all pelage color variables. Pelage color lightness among the four species increased with the higher southward aridity in accordance to Gloger's rule (darker in humid habitats and lighter in arid habitats. Darker and lighter pelage colors are associated with darker basalt and terra rossa, and lighter rendzina soils, respectively. Despite soil lightness varying significantly, pelage lightness and eumelanin converged among populations living in similar soil types. Partial sequencing of the MC1R gene identified three allelic variants, two of which were predominant in northern species (S. galili and S. golani, and the third was exclusive to southern species (S. carmeli and S. judaei, which might have caused the differences found in pheomelanin/eumelanin ratio.Darker dorsal pelage in darker basalt and terra rossa soils in the north and lighter pelage in rendzina and loess soils in the south reflect the combined results of

Tejnefiskeri efter jomfruhummer. Et litteraturstudie

DEFF Research Database (Denmark)

Frandsen, Rikke; Krag, Ludvig Ahm; Andersen, Bo Sølgaard

The Danish quota for Norway lobster is fished by use of trawl. In the past 5 years, between 10 and 70 % of the quota has not been exploited. This is partly on account of restricted quotas on some of the other species that are targeted in this mixed species fishery. Furthermore, in order to protect...... cod, trawling is banned in some areas including areas known as Norway lobster grounds. Creels are highly selective gears both with regards to sizes and species and they lead to high quality landings. Compared to trawling, stationary gears such as creels also have much less impact on the benthic...... habitat and reduce fuel consumption. Commercial creeling for Norway lobster is for example found in Sweden, Norway, Scotland, and the Faroe Islands. However, all available literature report low catch rates and the viability of the fishery therefore depends upon fuel savings and the opportunity to achieve...

The Southern Oscillation, Hypoxia, and the Eastern Pacific Tuna Fishery

Science.gov (United States)

Webster, D.; Kiefer, D.; Lam, C. H.; Harrison, D. P.; Armstrong, E. M.; Hinton, M.; Luo, L.

2012-12-01

The Eastern Pacific tuna fishery, which is one of the world's major fisheries, covers thousands of square kilometers. The vessels of this fishery are registered in more than 30 nations and largely target bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (T. albacores) tuna. In both the Pelagic Habitat Analysis Module project, which is sponsored by NASA, and the Fishscape project, which is sponsored by NSF, we have attempted to define the habitat of the three species by matching a 50 year time series on fish catch and effort with oceanographic information obtained from satellite imagery and from a global circulation model. The fishery time series, which was provided by the Inter-American Tropical Tuna Commission, provided spatial maps of catch and effort at monthly time steps; the satellite imagery of the region consisted of sea surface temperature, chlorophyll, and height from GHRSST, SEAWiFS, and AVISO products, and the modeled flow field at selected depths was output from ECCO-92 simulations from 1992 to present. All information was integrated and analyzed within the EASy marine geographic information system. This GIS will also provides a home for the Fishscape spatial simulation model of the coupled dynamics of the ocean, fish, fleets, and markets. This model will then be applied to an assessment of the potential ecological and economic impacts of climate change, technological advances in fleet operations, and increases in fuel costs. We have determined by application of EOF analysis that the ECCO-2 simulation of sea surface height fits well with that of AVISO imagery; thus, if driven properly by predictions of future air-sea exchange, the model should provide good estimates of circulation patterns. We have also found that strong El Nino events lead to strong recruitment of all three species and strong La Nina events lead to weak recruitment. Finally, we have found that the general spatial distribution of the Eastern Pacific fishing grounds

In search of a better unit of effort in the coastal liftnet fishery with lights for small pelagics in Indonesia

NARCIS (Netherlands)

Oostenbrugge, van J.A.E.; Poos, J.J.; Densen, van W.L.T.; Machiels, M.A.M.

2002-01-01

Despite major criticism, catch per unit effort (CPUE) is still widely used as a measure for the size of the exploited stock, but its indicative value is affected by selection of a proper unit of effort. The unit of effort used in the Indonesian fisheries statistical system is poorly standardised

Pelagic Dealer Commercial Landings Monitoring (HMS Dealers)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains summarized pounds of select pelagic fish species bought by selected federally permitted seafood dealers in the SE Region of the US mainland....

75 FR 52308 - Submission for OMB Review; Comment Request

Science.gov (United States)

2010-08-25

... in the Exclusive Economic Zone under the Fishery Management Plan for Groundfish of the Bering Sea and.... 1801 et seq. (MSA). Amendment 80 to the FMP primarily allocated several Bering Sea and Aleutian Islands Management Area non-pollock trawl groundfish fisheries among fishing sectors, and facilitated the formation...

Bycatch in 36 and 40 mm PA Turkish twin rigged beam trawl codends

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... Thus, landings of the shrimp beam trawling fleet also include some commercially valuable fishes. ... Fishing has significant direct and indirect effects on the habitat, diversity ..... Statistics 2006. State Institute of Statistics Prime.

Management implications of the biodiversity and socio-economic impacts of shrimp trawler by-catch in Bahía de Kino, Sonora, México.

Science.gov (United States)

Meltzer, Lorayne; Blinick, Naomi S; Fleishman, Abram B

2012-01-01

The shrimp fishery is the most economically important fishery in Mexico. The trawler-based portion of this fishery results in high rates of by-catch. This study quantifies and describes the biodiversity of by-catch associated with trawling in the Bahía de Kino region of Sonora, Mexico. Data were collected from 55 trawls, on six boats, over 14 nights, during November of 2003, 2004, 2006-2009. By-catch rates within trawl samples averaged 85.9% measured by weight. A total of 183 by-catch species were identified during the course of this study, including 97 species of bony fish from 43 families, 19 species of elasmobranchs from 12 families, 66 species of invertebrates from eight phyla, and one species of marine turtle; seven of the documented by-catch species are listed on the IUCN Red List, CITES, or the Mexican NOM-059-ECOL-2010; 35 species documented in the by-catch are also targeted by local artisanal fishers. Some of the species frequently captured as juveniles in the by-catch are economically important to small-scale fishers in the region, and are particularly sensitive to overexploitation due to their life histories. This study highlights the need for further research quantifying the impacts of high levels of by-catch upon small-scale fishing economies in the region and presents strong ecological and economic rationale for by-catch management within the shrimp fishery of the Gulf of California. Site-specific by-catch management plans should be piloted in the Bahía de Kino region to address the growing momentum in national and international fisheries policy regimes toward the reduction of by-catch in shrimp fisheries.

Risks of ocean acidification in the California Current food web and fisheries: ecosystem model projections.

Science.gov (United States)

Marshall, Kristin N; Kaplan, Isaac C; Hodgson, Emma E; Hermann, Albert; Busch, D Shallin; McElhany, Paul; Essington, Timothy E; Harvey, Chris J; Fulton, Elizabeth A

2017-04-01

The benefits and ecosystem services that humans derive from the oceans are threatened by numerous global change stressors, one of which is ocean acidification. Here, we describe the effects of ocean acidification on an upwelling system that already experiences inherently low pH conditions, the California Current. We used an end-to-end ecosystem model (Atlantis), forced by downscaled global climate models and informed by a meta-analysis of the pH sensitivities of local taxa, to investigate the direct and indirect effects of future pH on biomass and fisheries revenues. Our model projects a 0.2-unit drop in pH during the summer upwelling season from 2013 to 2063, which results in wide-ranging magnitudes of effects across guilds and functional groups. The most dramatic direct effects of future pH may be expected on epibenthic invertebrates (crabs, shrimps, benthic grazers, benthic detritivores, bivalves), and strong indirect effects expected on some demersal fish, sharks, and epibenthic invertebrates (Dungeness crab) because they consume species known to be sensitive to changing pH. The model's pelagic community, including marine mammals and seabirds, was much less influenced by future pH. Some functional groups were less affected to changing pH in the model than might be expected from experimental studies in the empirical literature due to high population productivity (e.g., copepods, pteropods). Model results suggest strong effects of reduced pH on nearshore state-managed invertebrate fisheries, but modest effects on the groundfish fishery because individual groundfish species exhibited diverse responses to changing pH. Our results provide a set of projections that generally support and build upon previous findings and set the stage for hypotheses to guide future modeling and experimental analysis on the effects of OA on marine ecosystems and fisheries. © 2017 John Wiley & Sons Ltd.

KB WOT Fisheries 2018: maintaining excellence and innovation in fisheries research

NARCIS (Netherlands)

Damme, van C.J.G.; Verver, S.W.

2017-01-01

The KB WOT Fisheries programme is developed to maintain and develop expertise needed to carry out the Dutch statutory obligations in fisheries monitoring and advice. The KB WOT Fisheries programme developed for 2018 reflects the scientific and management needs of the WOT fisheries programme. The

AFSC/RACE/MACE: Results of 2015 acoustic trawl survey Shumagin/Sanak/PWS DY1502

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The surveys primary objective was to collect acoustic data and trawl information to estimate midwater abundance and distribution of walleye pollock (Gadus...

Straight line foraging in yellow-eyed penguins: new insights into cascading fisheries effects and orientation capabilities of marine predators.

Science.gov (United States)

Mattern, Thomas; Ellenberg, Ursula; Houston, David M; Lamare, Miles; Davis, Lloyd S; van Heezik, Yolanda; Seddon, Philip J

2013-01-01

Free-ranging marine predators rarely search for prey along straight lines because dynamic ocean processes usually require complex search strategies. If linear movement patterns occur they are usually associated with travelling events or migratory behaviour. However, recent fine scale tracking of flying seabirds has revealed straight-line movements while birds followed fishing vessels. Unlike flying seabirds, penguins are not known to target and follow fishing vessels. Yet yellow-eyed penguins from New Zealand often exhibit directed movement patterns while searching for prey at the seafloor, a behaviour that seems to contradict common movement ecology theories. While deploying GPS dive loggers on yellow-eyed penguins from the Otago Peninsula we found that the birds frequently followed straight lines for several kilometres with little horizontal deviation. In several cases individuals swam up and down the same line, while some of the lines were followed by more than one individual. Using a remote operated vehicle (ROV) we found a highly visible furrow on the seafloor most likely caused by an otter board of a demersal fish trawl, which ran in a straight line exactly matching the trajectory of a recent line identified from penguin tracks. We noted high abundances of benthic scavengers associated with fisheries-related bottom disturbance. While our data demonstrate the acute way-finding capabilities of benthic foraging yellow-eyed penguins, they also highlight how hidden cascading effects of coastal fisheries may alter behaviour and potentially even population dynamics of marine predators, an often overlooked fact in the examination of fisheries' impacts.

Straight line foraging in yellow-eyed penguins: new insights into cascading fisheries effects and orientation capabilities of marine predators.

Directory of Open Access Journals (Sweden)

Thomas Mattern

Full Text Available Free-ranging marine predators rarely search for prey along straight lines because dynamic ocean processes usually require complex search strategies. If linear movement patterns occur they are usually associated with travelling events or migratory behaviour. However, recent fine scale tracking of flying seabirds has revealed straight-line movements while birds followed fishing vessels. Unlike flying seabirds, penguins are not known to target and follow fishing vessels. Yet yellow-eyed penguins from New Zealand often exhibit directed movement patterns while searching for prey at the seafloor, a behaviour that seems to contradict common movement ecology theories. While deploying GPS dive loggers on yellow-eyed penguins from the Otago Peninsula we found that the birds frequently followed straight lines for several kilometres with little horizontal deviation. In several cases individuals swam up and down the same line, while some of the lines were followed by more than one individual. Using a remote operated vehicle (ROV we found a highly visible furrow on the seafloor most likely caused by an otter board of a demersal fish trawl, which ran in a straight line exactly matching the trajectory of a recent line identified from penguin tracks. We noted high abundances of benthic scavengers associated with fisheries-related bottom disturbance. While our data demonstrate the acute way-finding capabilities of benthic foraging yellow-eyed penguins, they also highlight how hidden cascading effects of coastal fisheries may alter behaviour and potentially even population dynamics of marine predators, an often overlooked fact in the examination of fisheries' impacts.

Diel effects on bottom-trawl survey catch rates of shallow- and deep ...

African Journals Online (AJOL)

Fishing in depths shallower than 400 m outside daylight hours should therefore be avoided in order to reduce bias and ensure consistency in abundance estimates from surveys. Keywords: Benguela Current system, consistency of survey indices, efficiency of bottom-trawl surveys, negative binomial GAM, transect survey ...

AFSC/RACE/MACE: Results of 2015 acoustic trawl survey Gulf of Alaska M1501

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Three trawl-resistant bottom- mounted moorings (TRBM) instrumented with newly developed autonomous battery powered 70 kHz split-beam echosounders were deployed in...

Integrating individual trip planning in energy efficiency – Building decision tree models for Danish fisheries

DEFF Research Database (Denmark)

Bastardie, Francois; Nielsen, J. Rasmus; Andersen, Bo Sølgaard

2013-01-01

efficiency for the value of catch per unit of fuel consumed is analysed by merging the questionnaire, logbook and VMS (vessel monitoring system) information. Logic decision trees and conditional behaviour probabilities are established from the responses of fishermen regarding a range of sequential......-intensive but efficient vessels conducting pelagic or industrial fishing are more inclined to base their decision on fish price only, while numerous smaller and less efficient vessels conducting demersal mixed or crustacean fishery usually consider other flexible factors, e.g., the potential for a large catch, weather...... the adaptations of individual fishermen to resource availability dynamics, increasing fuel prices, changes in regulations, and the consequences of socioeconomic external pressures on harvested stocks. A new methodology is described here to obtain quantitative information on the fishermen’s micro-scale decisions...

Explosive diversification following a benthic to pelagic shift in freshwater fishes

OpenAIRE

Hollingsworth, Phillip R; Simons, Andrew M; Fordyce, James A; Hulsey, C Darrin

2013-01-01

Background Interspecific divergence along a benthic to pelagic habitat axis is ubiquitous in freshwater fishes inhabiting lentic environments. In this study, we examined the influence of this habitat axis on the macroevolution of a diverse, lotic radiation using mtDNA and nDNA phylogenies for eastern North America’s most species-rich freshwater fish clade, the open posterior myodome (OPM) cyprinids. We used ancestral state reconstruction to identify the earliest benthic to pelagic transition ...

Female-biased sex ratios in marine pelagic copepods: Comment on Gusmao et al. (2013)

DEFF Research Database (Denmark)

Hirst, Andrew G.; Bonnet, D; Conway, DVP

2013-01-01

Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important error...... in their citation of our paper and briefly highlight where future work is needed in order to attribute the causes of strong sex ratio skew seen in some copepod families......Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important errors...

76 FR 10006 - Proposed Information Collection; Comment Request; Economic Surveys of American Samoa, Guam, and...

Science.gov (United States)

2011-02-23

... Mariana Islands (CNMI) Small Boat-Based Fisheries AGENCY: National Oceanic and Atmospheric Administration... paperwork and respondent burden, invites the general public and other Federal agencies to take this..., bottomfish, and pelagics fisheries with which to conduct economic analyses that will improve fishery...

Biodiversity, Community and Trophic Structure of the Suprabenthos of the Gulf of Cádiz-Guadalquivir Estuary Coupled System: Linking Pelagic-Benthic and Terrestrial-Marine Ecosystems.

Science.gov (United States)

Vilas, C.

2016-02-01

Suprabenthos biodiversity and species densities on both offshore and coastal systems are largely unknown. Main components like mysids, euphasiids or amphipods are omnivorous and constitute a major dietary component for many benthic and pelagic fishes, mammals, cephalopods and decapods. Despite their relevant ecological role linking pelagic-benthic food webs, suprabenthos have been chronically undersampled and their components underrepresented and underestimated in food web models. Many pelagic and demersal species of high commercial and ecological interest at the Gulf of Cádiz (GoC) feed at a bottom scattering layer identified from 0 to 200 m depth and up to 50 km from coast, related to the Guadalquivir Estuary (GE) influence coastal area, and present life history cycles based on a sequential use of habitats from GoC to GE nursery area, may be adapted to match the horizontal migrations of key suprabenthos prey species. In order to understand the ecological mechanisms through which the GE-GoC coupled ecosystem would influence the recruitment of these fishery resources, the suprabenthos was sampled by suprabenthic sldege (200 μm) from the shallow estuary to 75 m depth during June, August and November of 2013. We identified up to 300 species (H index 0.4-2-9 and Beta diversity 0.55), being copepods, molluscs, cumacea, cladocera, poliquets, decapods, mysids and amphipods the most important groups by biomass (mg/m3), finding densities up to 32.9 mg/m3 for copepods, 6 for mysids and up to 100 mg/m3 for decapods. Multivariate analysis determines depth as the most important variable explaining community structure, decreasing biodiversity with depth, while for sites at depths species show seasonal horizontal migrations between GoC and GE, connecting terrestrial and marine ecosystems.

Oceanographic data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

Biological data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

Inshore small-mesh trawling survey of the Cape south coast. Part 5 ...

African Journals Online (AJOL)

Inshore small-mesh trawling survey of the Cape south coast. Part 5. Crustacea, Stomatopoda, Isopoda and. Decapoda. B. Kensley and C.D. Buxton. Port Elizabeth Museum, Port Elizabeth. Forty-six species of Crustacea from the shallow marine waters of the southern Cape coast are listed. Five new records for the area.

Fish behaviour in responce to a midwater trawl footrope in temperate reservoirs

Czech Academy of Sciences Publication Activity Database

Sajdlová, Zuzana; Draštík, Vladislav; Jůza, Tomáš; Říha, Milan; Frouzová, Jaroslava; Čech, Martin; Vašek, Mojmír; Muška, Milan; Blabolil, Petr; Tušer, Michal; Kratochvíl, Michal; Peterka, Jiří; Mrkvička, Tomáš; Balk, Helge; Kubečka, Jan

2015-01-01

Roč. 172, December (2015), s. 105-113 ISSN 0165-7836 R&D Projects: GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : pair trawling * avoidance behaviour * SED echogram * open water * vertical track slope Subject RIV: EH - Ecology, Behaviour Impact factor: 2.230, year: 2015

Interspecies and spatial trends in polycyclic aromatic hydrocarbons (PAHs) in Atlantic and Mediterranean pelagic seabirds

International Nuclear Information System (INIS)

Roscales, Jose L.; Gonzalez-Solis, Jacob; Calabuig, Pascual; Jimenez, Begona

2011-01-01

PAHs were analyzed in the liver of 5 species of pelagic seabirds (Procellariiformes) from the northeast Atlantic and the Mediterranean. The main objective was to assess the trophic and geographic trends of PAHs in seabirds to evaluate their suitability as bioindicators of chronic marine pollution by these compounds. Although higher levels of PAHs have been described in the Mediterranean compared to other oceanic regions, we did not find significant spatial patterns and observed only minor effects of the geographic origin on seabird PAHs. However, we found significant higher PAH levels in petrel compared to shearwater species, which could be related to differences in their exploitation of mesopelagic and epipelagic resources, respectively, and the vertical dynamic of PAHs in the water column. Overall, although this study enhances the need of multi-species approaches to show a more comprehensive evaluation of marine pollution, seabirds emerged as poor indicators of pelagic chronic PAH levels. - Highlights: → PAHs in pelagic seabirds show specific inter-species patterns related to trophic ecology. → Geographic origin shows a minor effect over PAH levels in pelagic seabirds. → Pelagic seabirds seem to be poor indicators of chronic PAH levels. - PAH levels in Atlantic and Mediterranean pelagic seabirds show specific inter-species patterns related to trophic ecology but a minor influence of their geographic origin.

Seasonal changes of the pelagic fish assemblage in a temperate estuary

Science.gov (United States)

Hagan, S. M.; Able, K. W.

2003-01-01

The pelagic (i.e. fishes that spend most of their time swimming and feeding in the water column) fish assemblage was examined within a temperate estuary to determine the seasonal patterns of abundance, biomass, richness, and species composition. These measures were related to abiotic measures including temperature, salinity, water transparency, and depth. Pelagic fish (nGasterosteus aculeatus and age 1+ by M. menidia. Spring (April-early June) was overwhelmingly dominated by age 0+ C. harengus. Early summer (late June-early July) was relatively species rich and characterized by age 0+ of Brevoortia tyrannus, Pomatomus saltatrix, Alosa pseudoharengus, and age 1+ of A. mitchilli. Late summer (late July-August) remained relatively species rich and included mostly age 0+ of A. mitchilli, A. hepsetus, and M. menidia. Autumn (September-November) continued to have high catches of age 0+ of M. menidia and A. mitchilli. As expected for temperate estuaries, the best of the measured abiotic predictors of these groupings included temperature, salinity, and degree of change in temperature. However, timing of life history characteristics, such as location, and timing of reproduction and migration also influenced the seasonal occurrence of these pelagic species. The large abundance and biomass of a relatively few species, as observed in this study, are typical of estuaries, although this is one of the few studies that have focused solely on the pelagic component of estuarine fish assemblages.

Improving escape panel selectivity in Nephrops directed fisheries by actively stimulating fish behaviour

DEFF Research Database (Denmark)

Krag, Ludvig Ahm; Herrmann, Bent; Feekings, Jordan P.

2017-01-01

The efficiency of escape panels inserted in trawls relies on fish actively attempting to escape through them. However, several studies indicate that most fish drift towards the aft end of the trawl, passing the escape panel through which they easily could have escaped, without making contact with...

Assessing impacts of simulated oil spills on the Northeast Arctic cod fishery.

Science.gov (United States)

Carroll, JoLynn; Vikebø, Frode; Howell, Daniel; Broch, Ole Jacob; Nepstad, Raymond; Augustine, Starrlight; Skeie, Geir Morten; Bast, Radovan; Juselius, Jonas

2018-01-01

We simulate oil spills of 1500 and 4500m 3 /day lasting 14, 45, and 90days in the spawning grounds of the commercial fish species, Northeast Arctic cod. Modeling the life history of individual fish eggs and larvae, we predict deviations from the historical pattern of recruitment to the adult population due to toxic oil exposures. Reductions in survival for pelagic stages of cod were 0-10%, up to a maximum of 43%. These reductions resulted in a decrease in adult cod biomass of <3% for most scenarios, up to a maximum of 12%. In all simulations, the adult population remained at full reproductive potential with a sufficient number of juveniles surviving to replenish the population. The diverse age distribution helps protect the adult cod population from reductions in a single year's recruitment after a major oil spill. These results provide insights to assist in managing oil spill impacts on fisheries. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Submarine canyons as coral and sponge habitat on the eastern Bering Sea slope

Directory of Open Access Journals (Sweden)

Robert J. Miller

2015-07-01

Full Text Available Submarine canyons have been shown to positively influence pelagic and benthic biodiversity and ecosystem function. In the eastern Bering Sea, several immense canyons lie under the highly productive “green belt” along the continental slope. Two of these, Pribilof and Zhemchug canyons, are the focus of current conservation interest. We used a maximum entropy modeling approach to evaluate the importance of these two canyons, as well as canyons in general, as habitat for gorgonian (alcyonacean corals, pennatulacean corals, and sponges, in an area comprising most of the eastern Bering Sea slope and outer shelf. These invertebrates create physical structure that is a preferred habitat for many mobile species, including commercially important fish and invertebrates. We show that Pribilof canyon is a hotspot of structure-forming invertebrate habitat, containing over 50% of estimated high-quality gorgonian habitat and 45% of sponge habitat, despite making up only 1.7% of the total study area. The amount of quality habitat for gorgonians and sponges varied in other canyons, but canyons overall contained more high-quality habitat for structure-forming invertebrates compared to other slope areas. Bottom trawling effort was not well correlated with habitat quality for structure-forming invertebrates, and bottom-contact fishing effort in general, including longlining and trawling, was not particularly concentrated in the canyons examined. These results suggest that if conserving gorgonian coral habitat is a management goal, canyons, particularly Pribilof Canyon, may be a prime location to do this without excessive impact on fisheries.

Analysis of the contribution of the Netherlands commercial CPUE data to ICES stock assessments in the years 1995 - 2000

NARCIS (Netherlands)

Pastoors, M.A.; Bolle, L.J.

2003-01-01

The contribution of the Dutch commercial CPUE data to the stock assessments of North Sea plaice and sole in the years 1995-2000 has been analysed. The CPUE series are based on the total landings at age in the Dutch beam trawl fishery and the total effort (in HP days at sea) of this fishery. It is

75 FR 60867 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Amendments 20...

Science.gov (United States)

2010-10-01

... individual economic stability, provide full utilization of the trawl sector allocation, consider... rationalization program is intended to increase net economic benefits, create individual economic stability... of concern; improving economic performance; helping to maintain community stability; improving safety...

78 FR 56641 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Commercial...

Science.gov (United States)

2013-09-13

... rationalization program, including the shorebased IFQ program, was intended to increase net economic benefits, create individual economic stability, provide full utilization of the trawl sector allocation, consider..., Pacific cod and yellowtail rockfish and would likely have a favorable economic impact to groundfish...

Kennisbasis WOT Fisheries 2012 - Maintaining Excellence and Innovation in Fisheries Research

NARCIS (Netherlands)

Dickey-Collas, M.; Beek, van F.A.

2011-01-01

The KBWOT Fisheries programme is fundamental to the maintenance and development of the expertise that underpins the statutory obligations of fisheries monitoring and advice for the Netherlands. The structure of the KBWOT Fisheries programme for 2012 reflects the recent discussions on the research

AFSC/RACE/GAP/Palsson: Gulf of Alaska and Aleutian Islands Biennial Bottom Trawl Survey estimates of catch per unit effort, biomass, population at length, and associated tables

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The GOA/AI Bottom Trawl Estimate database contains abundance estimates for the Alaska Biennial Bottom Trawl Surveys conducted in the Gulf of Alaska and the Aleutian...

Abundance and tidal behaviour of pelagic fish in the gateway to the Wadden Sea

NARCIS (Netherlands)

Couperus, B.; Gastauer, S.; Fässler, S.M.M.; Tulp, I.; van der Veer, H.W.; Poos, J.J.

2016-01-01

The shallow coast of The Netherlands is an important habitat for small pelagic fish. They form one of the major links between plankton and the higher trophic levels. Predatory fish, sea mammals and birds rely on small pelagic fish as a major food source. Currently, monitoring of fish in the Dutch

Identification and chemical studies of pelagic masses of Sargassum ...

African Journals Online (AJOL)

The pelagic seaweed found offshore and negatively impacting fishing activity in ... the mixed Sargassum species were analyzed for the proximate composition, ... Keywords: Sargassum natans, Sargassum fluitans, brown algae, proximate ...

Stable pelagic vertebrate community structure through extreme Paleogene greenhouse conditions

Science.gov (United States)

Sibert, E. C.; Friedman, M.; Hull, P. M.; Hunt, G.; Norris, R. D.

2016-02-01

The species composition (structure) and energy transfer (function) of an ecosystem is reflected by the presence and type of consumers that it supports. Here we use ichthyoliths, microfossil fish teeth and shark denticles, to assess the ecological variability of the pelagic fish community structure and composition from the Late Cretaceous to the middle Eocene from a drill core in the South Pacific gyre (DSDP Site 596). We find that the overall vertebrate community structure, as measured by the relative abundance of sharks to ray-finned fishes, has a punctuated change at the Cretaceous/Paleogene mass extinction. The vertebrate community structure remained stable throughout the Paleogene despite a five-fold increase in overall abundance of ichthyoliths during the extreme greenhouse of the Early Eocene. Further, we use a novel system to quantify the morphological variation in fish teeth. We find that the morphospace occupied by the tooth assemblage is conserved throughout the interval, with a slight expansion following the Cretaceous-Paleogene mass extinction, and the evolution of a distinct morphotype-group around the Paleocene-Eocene boundary. While there are elevated rates of morphotype origination and extinction following the Cretaceous-Paleogene mass extinction, the extreme greenhouse warming of the Early Eocene and associated increase in fish production produce near-zero origination and extinction rates. The relative stability in composition of the pelagic vertebrate community during intervals of extreme climate change and across large ranges of total fish accumulation, suggests that pelagic ecosystem structure is robust to climate events, and that the overall structure of the pelagic fish community may be decoupled from both climate and ecosystem function.

75 FR 21749 - Spring 2010 Semiannual Agenda of Regulations

Science.gov (United States)

2010-04-26

... Specifications for the Northeast Multispecies Fishery 0648-AY29 Management Plan 86 FY 2010 Atlantic Deep-Sea Red... 18 to 0648-AW49 the Pelagics Fishery Management Plan; Shallow-Set Longline Swordfish Fishery 101... EFPs allowed the shore-based whiting fleet to temporarily deliver unsorted catch to processing plants...

KB WOT Fisheries 2015 - Maintaining Excellence and Innovation in Fisheries Research

NARCIS (Netherlands)

Damme, van C.J.G.; Verver, S.W.

2015-01-01

The KB WOT Fisheries programme is essential to the maintenance and development of the expertise which are needed for the Dutch statutory obligations in fisheries monitoring and advice. The contents of the KB WOT Fisheries programme for 2015 reflects the needs of the research developments the WOT

Abundance and tidal behaviour of pelagic fish in the gateway to the Wadden Sea

NARCIS (Netherlands)

Couperus, Bram; Gastauer, Sven; Fässler, Sascha M.M.; Tulp, Ingrid; Veer, van der Henk W.; Poos, Jan Jaap

2016-01-01

The shallow coast of The Netherlands is an important habitat for small pelagic fish. They form one of the major links between plankton and the higher trophic levels. Predatory fish, sea mammals and birds rely on small pelagic fish as a major food source. Currently, monitoring of fish in the Dutch

Supply regimes in fisheries

DEFF Research Database (Denmark)

Nielsen, Max

2006-01-01

Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extremes......, the traditional understanding of supply regimes in fisheries needs modification. This paper identifies through a case study of the East Baltic cod fishery supply regimes in fisheries, taking alternative fisheries management schemes and mesh size limitations into account. An age-structured Beverton-Holt based bio......-economic supply model with mesh sizes is developed. It is found that in the presence of realistic management schemes, the supply curves are close to vertical in the relevant range. Also, the supply curve under open access with mesh size limitations is almost vertical in the relevant range, owing to constant...

KB WOT Fisheries 2014 - Maintaining Excellence and Innovation in Fisheries Research

NARCIS (Netherlands)

Damme, van C.J.G.; Verver, S.W.

2013-01-01

The KB WOT Fisheries programme is fundamental to the maintenance and development of expertise needed to carry out the statutory obligations of the Dutch WOT Fisheries monitoring and advice. The structure of the KB WOT Fisheries programme 2014 is a result of discussions on the research direction and

Atlantic Herring Acoustic Surveys

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and underwater...

AFSC/RACE/SAP/Armistead: 1975 - 2016 eastern Bering Sea Crab Distribution For Web

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Resource Assessment and Conservation Engineering Division (RACE) of the Alaska Fisheries Science Center (AFSC) conducts bottom trawl surveys to monitor the...

Fisheries regulation

DEFF Research Database (Denmark)

Jensen, Frank; Frost, Hans Staby; Abildtrup, Jens

2017-01-01

Economists normally claim that a stock externality arises within fisheries because each individual fisherman does not take the effect on stock size into account when making harvest decisions. Due to the stock externality, it is commonly argued that fisheries regulation is necessary, but regulatory...... decisions are complicated by a tremendous amount of uncertainty and asymmetric information. This paper provides an overview of selected parts of the literature on the regulation of fisheries under uncertainty and asymmetric information, and possible areas for future research are identified. Specifically...

Fish and fishery historical data since the 19th century in the Adriatic Sea, Mediterranean

Science.gov (United States)

Fortibuoni, Tomaso; Libralato, Simone; Arneri, Enrico; Giovanardi, Otello; Solidoro, Cosimo; Raicevich, Saša

2017-09-01

Historic data on biodiversity provide the context for present observations and allow studying long-term changes in marine populations. Here we present multiple datasets on fish and fisheries of the Adriatic Sea covering the last two centuries encompassing from qualitative observations to standardised scientific monitoring. The datasets consist of three groups: (1) early naturalists' descriptions of fish fauna, including information (e.g., presence, perceived abundance, size) on 255 fish species for the period 1818-1936 (2) historical landings from major Northern Adriatic fish markets (Venice, Trieste, Rijeka) for the period 1902-1968, Italian official landings for the Northern and Central Adriatic (1953-2012) and landings from the Lagoon of Venice (1945-2001) (3) trawl-survey data from seven surveys spanning the period 1948-1991 and including Catch per Unit of Effort data (kgh-1 and/or nh-1) for 956 hauls performed at 301 stations. The integration of these datasets has already demonstrated to be useful to analyse historical marine community changes over time, and its availability through open-source data portal will facilitate analyses in the framework of marine historical ecology.

Trawling for Subsidies

DEFF Research Database (Denmark)

Svendsen, Gert Tinggaard; Brandt, Urs Steiner

2009-01-01

groups traditionally perceived as opponents may have mutual interests. Solving the current deadlocks in the EU fishery negotiations highlights the need to reveal the true incentives that motivate stakeholders such as the symbiosis and alignment of interests identified here....... their budgets both for altruistic reasons (to restore fish stocks) and for private reasons (by increasing demand for their services). We analyze the outcome of a game where the biologists and the fishermen are informed about the true stock size while the decision-maker is not. Our model shows that interest...

Distribution of pelagic harpacticoid copepods from the Indian ocean

Digital Repository Service at National Institute of Oceanography (India)

Haridas, P.; Rao, T.S.S.

Pelagic harpacticoid copepods have been studied from the International Indian Ocean Expedition collections. Macrosetella gracilis and Miracia efferata were the most common species of harpacticoids with high densities near land masses. Other three...

75 FR 26702 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Amendments 20...

Science.gov (United States)

2010-05-12

... increase net economic benefits, create individual economic stability, provide full utilization of the trawl... (Amendments 20 and 21) is intended to increase net economic benefits, create individual economic stability... licenses, quota share accounts, vessel accounts, further tracking and monitoring components, and economic...

75 FR 44938 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

Science.gov (United States)

2010-07-30

... Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery AGENCY: National... moratorium on fishing for Atlantic coastal sharks in the State waters of New Jersey. NMFS canceled the... Fisheries Commission's (Commission) Interstate Fishery Management Plan for Atlantic Coastal Sharks (Coastal...

Fishery Employment Support Systems and Status of Fishery Job Training in Japan

OpenAIRE

Kawasaki, Junji

2016-01-01

Attracting fishermen has become one of the critical challenges to maintain a basic fisheries production system. Therefore, institutions in Japan have been introducing courses, such as fisheries techniques, to attract students to this industry. The aim of the present study is to identify effective methods of developing job training systems to attract more fishery workers to the industry. The current job training courses for becoming a fishery worker are analyzed, and the results indicate that ...

Biological aspects of the Sailfin dory Zenopsis conchifer (Lowe, 1852 caught by deep-sea trawling fishery off southern Brazil

Directory of Open Access Journals (Sweden)

Rodrigo Silvestre Martins

2012-06-01

Full Text Available Biological aspects of sailfin dory, Zenopsis conchifer, were studied from 839 individuals obtained from deep-sea commercial bottom trawling off southern Brazil at depths up to 526 m in 2002 and 2003. Samples included fish from 101 mm Lt and 15 g up to 640 mm Lt and 2,9 g. The sex-ratio was 50% at 150 mm Lt and between 300-350 mm Lt, with females outnumbering males in the remaining size classes. Reproductive activity seems to peak between July and August (austral winter. Size at attainment of 50% maturity (Lt50 was 311 mm Lt in females. The mean length and maturity of the specimens increased with depth, suggesting that larger fish concentrate in deeper waters.Aspectos biológicos do peixe-galo-de-profundidade, Zenopsis conchifer, foram estudados a partir de 839 peixes amostrados na pesca comercial de arrasto de profundidade (até 526 m no sul do Brasil entre 2002 e 2003. As amostras incluíram peixes entre 101 mm TL e 15 g até 640 mm TL e 2.952 g. A proporção sexual foi próxima à paridade na classe de tamanho de 150 mm TL e entre 300-350 mm TL, sendo que as fêmeas predominaram nas demais classes. A atividade reprodutiva apresentou um pico durante o inverno. O tamanho de primeira maturação (TL50 nas fêmeas foi de 311 mm TL. Os comprimentos corporais e a maturidade sexual aumentaram com a profundidade, sugerindo que os maiores exemplares se concentram águas profundas.

Spatial structure and distribution of small pelagic fish in the northwestern Mediterranean Sea.

Science.gov (United States)

Saraux, Claire; Fromentin, Jean-Marc; Bigot, Jean-Louis; Bourdeix, Jean-Hervé; Morfin, Marie; Roos, David; Van Beveren, Elisabeth; Bez, Nicolas

2014-01-01

Understanding the ecological and anthropogenic drivers of population dynamics requires detailed studies on habitat selection and spatial distribution. Although small pelagic fish aggregate in large shoals and usually exhibit important spatial structure, their dynamics in time and space remain unpredictable and challenging. In the Gulf of Lions (north-western Mediterranean), sardine and anchovy biomasses have declined over the past 5 years causing an important fishery crisis while sprat abundance rose. Applying geostatistical tools on scientific acoustic surveys conducted in the Gulf of Lions, we investigated anchovy, sardine and sprat spatial distributions and structures over 10 years. Our results show that sardines and sprats were more coastal than anchovies. The spatial structure of the three species was fairly stable over time according to variogram outputs, while year-to-year variations in kriged maps highlighted substantial changes in their location. Support for the McCall's basin hypothesis (covariation of both population density and presence area with biomass) was found only in sprats, the most variable of the three species. An innovative method to investigate species collocation at different scales revealed that globally the three species strongly overlap. Although species often co-occurred in terms of presence/absence, their biomass density differed at local scale, suggesting potential interspecific avoidance or different sensitivity to local environmental characteristics. Persistent favourable areas were finally detected, but their environmental characteristics remain to be determined.

Selective haddock (Melanogrammus aeglefinus) trawling: Avoiding cod (Gadus morhua) bycatch

DEFF Research Database (Denmark)

Krag, Ludvig Ahm; Holst, René; Madsen, Niels

2010-01-01

The critical condition of the North Sea cod stocks has resulted in restrictions on not only cod, but also haddock and other species that are caught together with cod. Thus full exploitation of the haddock stock is unachievable unless cod can be excluded from the haddock catch. We designed a selec...... dependent: smaller cod escaped the trawl in greater numbers than did larger individuals. Whiting, saithe. lemon sole, and plaice were included in the analysis. (C) 2009 Elsevier B.V. All rights reserved....

Ecosystems Surveys Branch Gear Efficiency Study

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — An experiment aimed at quantifying the herding efficiency of flatfish for the Northeast Fisheries Science Center (NEFSC) survey trawl bridles was conducted during...

Introduction to fisheries oceanography

Digital Repository Service at National Institute of Oceanography (India)

Sumitra-Vijayaraghavan

Fisheries oceanography can be applied to fisheries ecology, fisheries management and practical fishing. Physico-chemical parameters of the environment (temperature, currents, waves, light, oxygen and salinity) have profound effect on fish...

Mixed fisheries forecasts—lessons learned from their initial application to North Sea fisheries

DEFF Research Database (Denmark)

Holmes, S.J.; Ulrich, Clara; Reeves, S.A.

2012-01-01

the work with the existing single‐stock assessments. The explicit representation of the complexity of the fisheries also raises questions about the extent to which mixed fisheries science can be used to give ”advice” in the traditional sense. This paper addresses the challenges and issues that have arisen......Mixed fisheries and technical interactions in European fisheries have been a subject of research for many years. The establishment in 2010 of an ICES Working Group tasked with producing annual mixed fisheries forecasts and advice for North Sea demersal fisheries represents a commitment to use...... these approaches in routine scientific advice for the first time. The demersal fisheries of the North Sea provide a particularly interesting context for this work because of their high complexity in terms of the numbers of fleets, gears, métiers, and species involved, and also because mixedfishery effects have...

Regional metier definition: a comparative investigation of statistical methods using a workflow applied to international otter trawl fisheries in the North Sea

OpenAIRE

Deporte, Nicolas; Ulrich, Clara; Mahevas, Stephanie; Demaneche, Sebastien; Bastardie, Francois

2012-01-01

The European Common Fisheries Policy recognizes the importance of accounting for heterogeneity in fishing practices, and metier-based sampling is now at the core of the EU Data Collection Framework. The implementation of such an approach would require Member States to agree on the standard regional metier definitions and on practical rules to categorize logbook records into metiers. Several alternative approaches have been used in the past to categorize landings profiles, but no consensus has...

Population regulation and role of mesozooplankton in shaping marine pelagic food webs

DEFF Research Database (Denmark)

Kiørboe, Thomas

1998-01-01

Copepods constitute the majority of the mesozooplankton in the oceans. By eating and being eaten copepods have implications for the flow of matter and energy in the pelagic environment. I first consider population regulation mechanisms in copepods by briefly reviewing estimates of growth and mort...... activity for plankton food webs, particularly their role in retarding vertical fluxes and, thus, the loss of material from the euphotic zone......Copepods constitute the majority of the mesozooplankton in the oceans. By eating and being eaten copepods have implications for the flow of matter and energy in the pelagic environment. I first consider population regulation mechanisms in copepods by briefly reviewing estimates of growth...... to variations in fecundity. This is consistent with the observed tremendous variation in copepod fecundity rates, relatively low and constant mortality rates and with morphological and behavioral characteristics of pelagic copepods (e.g., predator perception and escape capability, vertical migration), which can...

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

Directory of Open Access Journals (Sweden)

C. Deceliere-Vergès

2008-01-01

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

AFSC/ABL: 2008 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2008 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

AFSC/ABL: 2007 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2007 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

AFSC/ABL: 2012 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch from the 2012 Bering Sea walleye pollock (Gadus chalcogrammus) trawl fishery was...

AFSC/ABL: 2009 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2009 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

AFSC/ABL: 2011 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch from the 2011 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

AFSC/ABL: 2006 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2006 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

AFSC/ABL: 2005 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2005 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was...

Dynamic catch trends in the history of recreational spearfishing in Australia.

Science.gov (United States)

Young, Matthew A L; Foale, Simon; Bellwood, David R

2015-06-01

The sustained decline in marine fisheries worldwide underscores the need to understand and monitor fisheries trends and fisher behavior. Recreational fisheries are unique in that they are not subject to the typical drivers that influence commercial and artisanal fisheries (e.g., markets or food security). Nevertheless, although exposed to a different set of drivers (i.e., interest or relaxation), recreational fisheries can contribute to fishery declines. Recreational fisheries are also difficult to assess due to an absence of past monitoring and traditional fisheries data. Therefore, we utilized a nontraditional data source (a chronology of spearfishing publications) to document historical trends in recreational spearfishing in Australia between 1952 and 2009. We extracted data on reported fish captures, advertising, and spearfisher commentary and used regression models and ordination analyses to assess historical change. The proportion of coastal fish captures reported declined approximately 80%, whereas the proportion of coral reef and pelagic fish reports increased 1750% and 560%, respectively. Catch composition shifted markedly from coastal temperate or subtropical fishes during the 1950s to 1970s to coral reef and pelagic species in the 1990s to 2000s. Advertising data and commentary by spearfishers indicated that pelagic fish species became desired targets. The mean weight of trophy coral reef fishes also declined significantly over the study period (from approximately 30-8 kg). Recreational fishing presents a highly dynamic social-ecological interface and a challenge for management. Our results emphasize the need for regulatory agencies to work closely with recreational fishing bodies to observe fisher behavior, detect shifts in target species or fishing intensity, and adapt regulatory measures. © 2015 Society for Conservation Biology.

Impact of Fishery Policy on Fishery Manufacture Output, Economy and Welfare in Indonesia

Science.gov (United States)

Firmansyah; Oktavilia, Shanty; Sugiyanto, F. X.; Hamzah, Ibnu N.

2018-02-01

The fisheries sector and fish manufacturing industry are the bright prospect sectors of Indonesia, due to its huge potency, which has not been worked out optimally. In facts, these sectors can generate a large amount of foreign exchange. The Government has paid significant attention to the development of these sectors. This study simulates the impact of fishery policies on the production of fish manufacturing industry, national economic and welfare in Indonesia. By employing the Input-Output Analysis approach, impacts of various government policy scenarios are developed, covering fisheries technical policy, as well as infrastructure development policies in the fisheries sector. This study indicates that the policies in the fisheries sector increase the output of fishery, the production of fish manufacturing industry, the sectoral and national outputs, as well as the level of national income.

78 FR 30780 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

Science.gov (United States)

2013-05-23

... Commercial Salmon Fisheries; Inseason Action 3 AGENCY: National Marine Fisheries Service (NMFS), National... in the ocean salmon fisheries. This inseason action modified the commercial fisheries in the area... ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS announced the commercial and recreational...

Reproduction and community structure of fish from winter catch sites from industrial shrimp bycatch from the northeast and southeast Mexican Pacific

Directory of Open Access Journals (Sweden)

Jorge de Jesus Tirado-Ibarra

2018-03-01

Full Text Available The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI levels were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru and Diapterus peruvianus. The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls.

AFSC/ABL: Chum salmon bycatch genetic stock identification 1994-1995 Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In some years, the Bering Sea trawl fishery incidentally harvests (bycatch) large numbers of chum salmon. Because chum salmon were declining in some western Alaska...

AFSC/ABL: 2010 Chum Salmon Bycatch Sample Analysis Bering Sea

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2010 Bering Sea groundfish trawl fishery was undertaken to determine the...

75 FR 59154 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Trip Limit...

Science.gov (United States)

2010-09-27

... (453.6 kg) per trip, Georges Bank (GB) yellowtail flounder to 100 lb (45.4 kg) per trip, and white hake... the U.S./Canada Management Area to include the entire Western U.S./Canada Area; and authorizes the use of the rope separator trawl in the Western U.S./Canada Area for NE multispecies vessels fishing in...

78 FR 35153 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

Science.gov (United States)

2013-06-12

... Commercial Salmon Fisheries; Inseason Actions 4 and 5 AGENCY: National Marine Fisheries Service (NMFS... inseason actions in the ocean salmon fisheries. These inseason actions modified the commercial fisheries in...: Background In the 2013 annual management measures for ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS...

Feeding ecology of some fish species occurring in artisanal fishery of Socotra Island (Yemen).

Science.gov (United States)

Hassan Ali', Mohammed Kaed; Belluscio, Andrea; Ventura, Daniele; Ardizzone, Giandomenico

2016-04-30

The demersal species Lethrinus borbonicus, Lethrinus mahsena, Lethrinus microdon, Lethrinus nebulosus, Lutjanus bohar, Lutjanus gibbus, Lutjanus kasmira, Epinephelus fasciatus, Epinephelus stoliczkae, Carangoides gymnostethus and Euthynnus affinis are important coastal fishes species of the northern coast of Socotra (Yemen), exploited by local fishery. The biology and feeding ecology of these species are poorly known in the area. A total of 1239 specimens were sampled from the main fishing landing site of the island (Hadibo). Total length and weight were measured, stomach contents were analyzed, diet overlap, Fulton's Condition index, and trophic levels were estimated. C. gymnostethus, L. microdon and L. kasmira occupied the highest position (T=4.50), L. nebulosus occupied the lower one (TL=3.41). The role of the increasing abundance of small pelagic fish in the diet of many species after the upwelling event is evident, but also different feeding strategies are reported, according to fish ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of the dolphinfish Coryphaena hippurus(Perciformes: Coryphaenidae fishery in Pacific Panama

Directory of Open Access Journals (Sweden)

Héctor M Guzman

2015-09-01

Full Text Available The dolphinfish (Coryphaena hippurusis a highly migratory pelagic species commercially exploited by industrial, artisanal and recreational fisheries in tropical and subtropical areas of the world's oceans. Herein, we evaluated the dolphinfish industrial fishery in Pacific Panama for the first time generating a growth model and examining fluctuations in annual total catch and in catch per unit effort (CPUE over a four-year period (2006-2009. Annual and monthly catch values and biological parameters of 14 913 individuals were obtained onboard industrial vessels, landing sites and records from processing plants. Size frequency for industrial vessels showed a normal distribution between 353 and 1 715 mm (average, 1 010.85 mm; n = 10 459. Fish weight averaged 4.94 kg (SD. Sex ratio was slightly biased toward females. More than 90% of the analyzed fish were sexually mature. The length-weight relationship was positive and significant, reflecting allometric growth. Growth parameters using the von Bertalanffy equation revealed a growth efficiency of 0 = 4.61, which is within the reported range for Coryphaena hippurus(3.95-4.70. The largest fish were between age classes 2 and 3 (7001 400 mm. Total catch per year and catch per unit effort (CPUE per year fluctuated, with the highest values recorded between 2008 and 2009. Catch values reported herein are preliminary and appear to be below those recorded elsewhere in the region and cautiously may represent an indicator of sustainable use of this marine resource even considering the absence of management actions in Panama.

77 FR 8776 - Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish...

Science.gov (United States)

2012-02-15

.... 120201086-2085-01] RIN 0648-XA904 Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish Specifications AGENCY: National Marine Fisheries Service (NMFS), National... comments. SUMMARY: NMFS proposes specifications for the 2012 Atlantic bluefish fishery, including an annual...

78 FR 50347 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

Science.gov (United States)

2013-08-19

... Commercial Salmon Fisheries; Inseason Actions 6 Through 11 AGENCY: National Marine Fisheries Service (NMFS... salmon fisheries. These inseason actions modified the commercial fisheries in the area from the U.S...: Background In the 2013 annual management measures for ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS...