Spatial Changes in Trawl Fishing Effort in Response to Footrope Diameter Restrictions in the U.S. West Coast Bottom Trawl Fishery

2003 ◽  
Vol 23 (3) ◽  
pp. 693-702 ◽  
Author(s):  
Robert W. Hannah
Keyword(s):  
West Coast ◽  
Fishing Effort ◽  
Bottom Trawl ◽  
Trawl Fishery ◽  
Spatial Changes ◽  
Trawl Fishing ◽  
The U.S

scholarly journals Biology and population dynamics of by-catch fish species of the bottom trawl fishery in the western Mediterranean

2014 ◽  
Vol 15 (3) ◽  
pp. 613 ◽  
Author(s):  
F. ORDINES ◽  
M.T. FARRIOLS ◽  
J. LLEONART ◽  
B. GUIJARRO ◽  
A. QUETGLAS ◽  
...  
Keyword(s):  
Population Analysis ◽  
Conservation Status ◽  
Fishing Effort ◽  
Western Mediterranean ◽  
Distribution Range ◽  
Bottom Trawl ◽  
Trawl Fishery ◽  
Virtual Population ◽  
Trawl Fishing ◽  
By Catch

The teleosts Chelidonichthys cuculus, Trigloporus lastoviza, Serranus cabrilla and Trachinus draco, are important by-catch species, in terms of landed biomass and commercial value, from the continental shelf bottom trawl fishery off the Balearic Islands (western Mediterranean). The main biological parameters of these species were calculated from monthly biological samplings, and were used along with three years pseudo-cohorts (2008-2010) obtained from monitoring on-board of the bottom trawl fleet, to assess their exploitation level through Virtual Population Analysis (VPA) and Yield per Recruit (Y/R) analysis. Time series of fishery independent indicators based on MEDITS surveys data such as the evolution of the abundance and biomass, the distribution range, and the Conservation Status of Fish b (CSFb), were also analyzed. All four species analyzed showed growth overfishing. The reductions of the fishing effort required to reach the Y/RF0,1 reference point were lower, 66-73% depending on the species, to those reported for the target species M. merluccius (87%), but higher than that reported for M. surmuletus (53%), in the study area in the period 2000-2010. The abundance and biomass, and the distribution range did not show any trend for the period 2001-2011, whereas the CSFb showed signs of recovery that may be due to the displacement of the trawl fishing effort from the shelf to the slope during the last decade. Our results underline the necessary incorporation of monitoring and assessment of by-catch species to the management of fisheries as their populations can show a more pronounced overexploitation than target ones.

scholarly journals Improving Catch Utilization in the U.S. West Coast Groundfish Bottom Trawl Fishery: an Evaluation of T90-Mesh and Diamond-Mesh Cod Ends

2017 ◽  
Vol 9 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Mark J. M. Lomeli ◽  
Owen S. Hamel ◽  
W. Waldo Wakefield ◽  
Daniel L. Erickson
Keyword(s):  
West Coast ◽  
Bottom Trawl ◽  
Trawl Fishery ◽  
The U.S

scholarly journals Utilization of pop-up satellite archival transmitting tags to evaluate thorny skate (Amblyraja radiata) discard mortality in the Gulf of Maine groundfish bottom trawl fishery

2019 ◽  
Author(s):  
Ryan Knotek ◽  
Jeff Kneebone ◽  
James Sulikowski ◽  
Tobey Curtis ◽  
Joseph Jurek ◽  
...  
Keyword(s):  
New England ◽  
Fishery Management ◽  
Gulf Of Maine ◽  
Bottom Trawl ◽  
Incidental Capture ◽  
Trawl Fishery ◽  
Discard Mortality ◽  
Stock Biomass ◽  
Trawl Fishing ◽  
Fishing Practices

Abstract Thorny skate (Amblyraja radiata) remain one of the most overfished species in the Gulf of Maine (GOM) despite being designated as a prohibited (zero-possession, mandatory release) species by the New England Fishery Management Council in 2003. To better understand the extent to which discard mortality (DM) occurring after incidental capture in the GOM groundfish bottom trawl fishery may be impeding recovery, 75 individuals (55–94 cm total length, TL) were tagged with pop-up satellite archival transmitting (PSAT) tags and monitored for up to 28 days following capture under representative commercial trawl fishing practices. Data recovered from 61 PSAT-tagged skate were analysed with a longitudinal survival analysis to estimate DM and identify influential capture-related variables. DM rate was a function of TL, with larger skates (>70 cm; DM = 16.5%) experiencing lower mortality than smaller conspecifics (55–70 cm; DM = 24.5%). From our results, we estimate annual thorny skate DM in the GOM groundfish bottom trawl fishery to be 79.2 ± 0.2 mt, which accounts for <1% of the existing stock biomass in the GOM (8400 mt). This study confirms that thorny skate are relatively resilient to bottom trawl fishing practices in the GOM, and suggests that other sources of mortality may be impeding population recovery.

scholarly journals MAXIMUM SUSTAINABLE YIELD OF TRAWL FISHERY ALONG THE SOUTH-WEST COAST OF INDIA: BAYESIAN ESTIMATION APPROACH

2020 ◽  
Vol 67 (1) ◽  
Author(s):  
T. V. Sathianandan ◽  
Somy Kuriakose ◽  
K. G. Mini ◽  
P. K. Safeena
Keyword(s):  
Bayesian Estimation ◽  
Marine Fish ◽  
West Coast ◽  
Fishing Effort ◽  
Maximum Sustainable Yield ◽  
Sustainable Yield ◽  
The South ◽  
Trawl Fishery ◽  
South West ◽  
South West Coast

The south-west region of the Indian coast is shared by three maritime states and it contributes nearly 32% to the total marine fish production of the country. Mechanised trawl fishery accounts for 44% of the marine fish harvest in the south-west coast and a number of resources are harvested by trawl nets from this region. An assessment of the trawl fishery to determine sustainable harvest levels for mechanised trawlers in the region was carried out using time series data on annual landings and fishing effort of mechanised trawlers during the period 1990-2015. A Bayesian estimation method for Schaefer model was used for the analysis. Posterior probability densities of parameters of the model, maximum sustainable yield (MSY) and corresponding biomass were obtained through Bayesian estimation for the trawl fishery in south-west coast and the harvest levels were found to be above MSY from 2012 onwards. Forecasts of biomass and fish landings by mechanised trawlers upto 2025 under different levels of fishing effort were also simulated using the model to study the dynamic changes over time. It was found that the numbers of multiday trawlers and single day trawlers operating in this region have to be reduced by 207 and 36 respectively to retain the harvest at sustainable level.

scholarly journals Standardized catch rate of cockfish, Callorhinchus callorynchus, in a bottom trawl fishery of Patagonia: Is it possible its use as a predictor of abundance trend?

2015 ◽  
Vol 63 (2) ◽  
pp. 147-160 ◽  
Author(s):  
Juan F. Bernasconi ◽  
María Raquel Perier ◽  
Edgardo E. Di Giácomo
Keyword(s):  
Linear Models ◽  
Fishing Effort ◽  
Catch Rate ◽  
Bottom Trawl ◽  
General Linear ◽  
Homogeneous Distribution ◽  
Annual Trend ◽  
Trawl Fishery ◽  
Total Variability ◽  
Best Fit

Abstract The catch per unit of effort (CPUE) data of cockfish, Callorhinchus callorynchus, during 1986-2011 was evaluated for the bottom trawl fishery of the San Matías gulf (Patagonia, Argentina). The objective of this work was to detect what are the factors related to fishery dynamic that affect catch rate of cockfish and to assess standardized CPUE by General linear models (GLMs) and General linear mixed models (GLMMs) as a relative abundance index. The annual trend of the catch rate indicated an increase during the evaluated period. The nominal CPUE and the indices standardized by the Delta-GLM and Delta-GLMM showed the same annual trend, with increases of 57%, 61.1% and 60.7%, respectively. The LogNormal models have the best-fit model and explained 23.5% of the total variability. The factors year, month, depth and hake CPUE explained the highest variability. The analysis of the models indicated that the catch rate of cockfish is subject to the lack of an homogeneous distribution of the fishing effort during different years, months and vessels. This was related to the fleet dynamic searching the targets species. The increasing trend of CPUE and landings would be indicating an increase in effort directionality to the cockfish in the last decade.

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