The brown shrimp, Farfantepenaeus californiensis, is the most important shrimp species in the Mexican Pacific coastal fisheries, with annual yields averaging 20,000 metric tons. The Mexican state of Sinaloa has the la...The brown shrimp, Farfantepenaeus californiensis, is the most important shrimp species in the Mexican Pacific coastal fisheries, with annual yields averaging 20,000 metric tons. The Mexican state of Sinaloa has the largest Mexican fleet of shrimp trawlers (736 boats) with annual landings of 7000 tons of brown shrimp on average. The status of the brown shrimp fishery was assessed using commercial catch and effort data of the Sinaloa shrimp trawl fleet over 16 years, from 1995 to 2011. We developed a biomass dynamic Schaefer model and used resampling techniques to analyze the catch-per-unit effort (CPUE) of the trawl brown shrimp fishery in the southeastern Gulf of California,Mexico. To ascertain robustness of our conclusions, two hypotheses were tested: observation and process error. Explicitly accounting for observation errors produced the best model fit to available data than including process errors. We identified several sources of observation error, for example discriminating fishing effort by species, changes in catch ability and misreported catch. The brown shrimp fishery showed symptoms of overfishing, although catch reported in the last fishing season considered in the analyses seems to indicate a rapid recovery of the stock. Finally, we predicted for the 2011-12 fishing season a catch of 9630 tonsof brown shrimp.展开更多
A population analysis was made using data of the grunt Pomadasys panamensis. The information is from the catch from 260 hauls in estuarine waters, open-ocean waters, and off the coast of Sinaloa and northern Nayarit, ...A population analysis was made using data of the grunt Pomadasys panamensis. The information is from the catch from 260 hauls in estuarine waters, open-ocean waters, and off the coast of Sinaloa and northern Nayarit, Mexico, in the southeastern Gulf of California. The area of influence is about 120,000 km2 and includes about a third of the drag area of the largest shrimp fleet of the American Pacific. The average length in the population was 210 mm. The maximum length was 430 mm and the minimum was 50 mm. The analysis for the frequency distributions of the lengths and the multinomial solution produced representative modal groups for 160 mm, 190 mm, and 230 mm. The simulation of the biomass density gave an estimate close to 90 t, with 650,000 organisms before starting the fishing season in the region. The density was 0.19 kg ha–1. The colonization was 0.42% or 42 %. The model was validated using the Aikaikae criterion (AIC). The results provide an overview of the initial biomass densities and population structure of the species caught as bycatch, demonstrating the importance of this species abundance in the shrimp fishery, and generating a source of monetary income to the crew of the fishing fleet. The persistence of the species to fishing provides an example to study the mechanisms of survival.展开更多
Samples taken during the closed fishing seasons from 1992 to 2010 were analyzed at sea. These data along with the landing records for the fishing periods from 1992-1993 to 2009-2010 were used to allow the situation of...Samples taken during the closed fishing seasons from 1992 to 2010 were analyzed at sea. These data along with the landing records for the fishing periods from 1992-1993 to 2009-2010 were used to allow the situation of Litopenaeus van-namei from the coasts of Sinaloa and Nayarit to be analyzed by means of stochastic models and by a graphic approach for the surplus biomass. Using the catch from 1993-1994 as a reference point and comparing this to the 2008-2009 catch revealed a stock decrease of about 65%. By taking into account the percentage contribution to total shrimp land-ings, these changes showed a decrease from 76% to 12%. There were changes between 2000 and 2001 when the fleet grew by 50%. Considering a 3600 t maximum sustained yield (MSY) in the series 1992-2010, 50% of the reports are lower. It is necessary to recover the stock.展开更多
文摘The brown shrimp, Farfantepenaeus californiensis, is the most important shrimp species in the Mexican Pacific coastal fisheries, with annual yields averaging 20,000 metric tons. The Mexican state of Sinaloa has the largest Mexican fleet of shrimp trawlers (736 boats) with annual landings of 7000 tons of brown shrimp on average. The status of the brown shrimp fishery was assessed using commercial catch and effort data of the Sinaloa shrimp trawl fleet over 16 years, from 1995 to 2011. We developed a biomass dynamic Schaefer model and used resampling techniques to analyze the catch-per-unit effort (CPUE) of the trawl brown shrimp fishery in the southeastern Gulf of California,Mexico. To ascertain robustness of our conclusions, two hypotheses were tested: observation and process error. Explicitly accounting for observation errors produced the best model fit to available data than including process errors. We identified several sources of observation error, for example discriminating fishing effort by species, changes in catch ability and misreported catch. The brown shrimp fishery showed symptoms of overfishing, although catch reported in the last fishing season considered in the analyses seems to indicate a rapid recovery of the stock. Finally, we predicted for the 2011-12 fishing season a catch of 9630 tonsof brown shrimp.
文摘A population analysis was made using data of the grunt Pomadasys panamensis. The information is from the catch from 260 hauls in estuarine waters, open-ocean waters, and off the coast of Sinaloa and northern Nayarit, Mexico, in the southeastern Gulf of California. The area of influence is about 120,000 km2 and includes about a third of the drag area of the largest shrimp fleet of the American Pacific. The average length in the population was 210 mm. The maximum length was 430 mm and the minimum was 50 mm. The analysis for the frequency distributions of the lengths and the multinomial solution produced representative modal groups for 160 mm, 190 mm, and 230 mm. The simulation of the biomass density gave an estimate close to 90 t, with 650,000 organisms before starting the fishing season in the region. The density was 0.19 kg ha–1. The colonization was 0.42% or 42 %. The model was validated using the Aikaikae criterion (AIC). The results provide an overview of the initial biomass densities and population structure of the species caught as bycatch, demonstrating the importance of this species abundance in the shrimp fishery, and generating a source of monetary income to the crew of the fishing fleet. The persistence of the species to fishing provides an example to study the mechanisms of survival.
文摘Samples taken during the closed fishing seasons from 1992 to 2010 were analyzed at sea. These data along with the landing records for the fishing periods from 1992-1993 to 2009-2010 were used to allow the situation of Litopenaeus van-namei from the coasts of Sinaloa and Nayarit to be analyzed by means of stochastic models and by a graphic approach for the surplus biomass. Using the catch from 1993-1994 as a reference point and comparing this to the 2008-2009 catch revealed a stock decrease of about 65%. By taking into account the percentage contribution to total shrimp land-ings, these changes showed a decrease from 76% to 12%. There were changes between 2000 and 2001 when the fleet grew by 50%. Considering a 3600 t maximum sustained yield (MSY) in the series 1992-2010, 50% of the reports are lower. It is necessary to recover the stock.
