There are records of the presence of Jack mackerel Trachurus murphyiin the artisanal fishery landings in Peru since 1907. Since 2000 Jack mackerel T. murphyicatches are ranked third after anchovy Engraulis ringensand jumbo squid Dosidicus gigas. Artisanal, industrial purse seine and offshore (factory trawlers) fleets take part in the Peruvian catches of T. murphyi. In 2011 the industrial purse-seine fleet with license to fish for T. murphyialong the Peruvian coast comprised of 62 industrial steel vessels (30177 m 3) and 42 industrial wood vessels (3082 m 3 ). Catches of T. murphyihad a significant increase after 1972, with maximum catches in 1977, 1996-97 and 2001, after which several years of low availability followed, with the lowest catches in 2010. However, this low availability trend was reversed in 2011, and catches reached almost 260 thousand tons that year. A general inverse rela...

Five evaluation cruises for pelagic resources were performed between April1997 and September 1998 on Peruvian coast, these allowed to observe changes in composition by species, distribution, size structure, reproduction, and population levels. These changes are similar to those observed in both El Niño 1972-73 and 1982-83, especially with respect to anchovy biomass decrease and increase of other pelagic species. Considerable changes in anchovy size structure in post-Niño period were observed, while sardine, samasa and Pacific mackerel showed good recruitment. Also the reproductive activity was increased, even in juveniles, with outstanding proliferation of sexual mature sardine with 18-20 cm length, this situation has not been recorded before.

Monitoring the anchovy fishery is of great importance for assuring the sustainability of the Humboldt ecosystem. The on-board observers program constitutes a rich platform for data collection for monitoring, as it consists of the collection of data from vessels during their fishing trips, regarding catches, size distribution, discards, catch per unit of effort, among others. To get robust indicators from these data, it is necessary to use a solid statistical procedure for computing the number of fishing trips to sample. This work presents a method with those characteristics, for computing each indicator independently and at different time scales. We show that the optimum size varies depending on the objective (indicator) and the time scale. Based on these results, practical recommendations for fixing the sample size are given. We finally discuss the aplicability of this methodology for o...

There are records of the presence of Jack mackerel Trachurus murphyiin the artisanal fishery landings in Peru since 1907. Since 2000 Jack mackerel T. murphyicatches are ranked third after anchovy Engraulis ringensand jumbo squid Dosidicus gigas. Artisanal, industrial purse seine and offshore (factory trawlers) fleets take part in the Peruvian catches of T. murphyi. In 2011 the industrial purse-seine fleet with license to fish for T. murphyialong the Peruvian coast comprised of 62 industrial steel vessels (30177 m 3) and 42 industrial wood vessels (3082 m 3 ). Catches of T. murphyihad a significant increase after 1972, with maximum catches in 1977, 1996-97 and 2001, after which several years of low availability followed, with the lowest catches in 2010. However, this low availability trend was reversed in 2011, and catches reached almost 260 thousand tons that year. A general inverse rela...

En el período abril 1997 setiembre 1998 fueron realizados 5 cruceros de evaluación de los recursos pelágicos en la costa peruana, éstos permitieron observar cambios en la composición por especies, distribución, estructura por tamaño, reproducción y niveles poblacionales de los principales recursos pelágicos. Estos cambios guardan similitud con los observados en los eventos El Niño 1972-73 y 1982-83, especialmente en cuanto a la disminución de la biomasa de anchoveta y el incremento de otras especies pelágicas. En el período post-Niño se observó cambios notables en la estructura por tallas de anchoveta, mientras que la sardina, samas a y caballa coincidieron en mostrar buenos reclutamientos. La actividad reproductiva también se incrementó, inclusive en tallas juveniles, destacando la incidencia de sardinas sexualmente maduras con longitudes de 18-20 cm, situación que no ...

El monitoreo de la pesquería de anchoveta en el Perú es de suma importancia para la sostenibilidad del ecosistema de Humboldt. El Programa de observadores a bordo Bitácoras de Pesca constituye una rica plataforma de recolección de datos de las embarcaciones durante sus viajes de pesca, y donde se recopila información acerca de las capturas en cada lance, distribuciones de tallas, descartes, captura incidental, captura por unidad de esfuerzo, entre otros. Para que los indicadores obtenidos a partir de esta información tengan robustez es preciso contar con un método de solidez estadística para el cálculo del número necesario de viajes a muestrear. Este trabajo presenta un método con estas características, para calcular el número óptimo de viajes de manera independiente para cada una de las variables y a diferentes escalas de tiempo. Se muestra que, dependiendo del objetivo y ...