Interannual variability in growth of walleye pollock, Theragra chalcogramma, in the central Bering Sea

Abstract

Interannual variability in growth of walleye pollock, Theragra chalcogramma, was examined. Adult walleye pollock were collected from the central Bering Sea (Aleutian Basin) from 1978 to 1999. Average fork lengths were found to be approximately 47 cm during the 1970–80s, this increased to 56 cm in the late 1990s. Age was determined for 4805 individuals using the otolith break and burn method. Ages ranged from 5–23 years and the year classes of 1978 and 1989 were dominant in the 1980s and the 1990s, respectively. Fish had significantly larger length‐at‐age in the 1990s compared to the 1970–80s, and interannual variability in age–length relationship was clearly observed. Taking into consideration a recent decrease of the walleye pollock biomass in the central Bering Sea, density‐dependent growth was supported as one possibility of the growth variability. At the same time, we could not rule out the possibility that oceanographic variability affected the growth of walleye pollock in the area.

Trophodynamic modeling of walleye pollock (Theragra chalcogramma) in the Doto area, northern Japan: model description and baseline simulations

“…, 2002). As for walleye pollock, there has been no direct evidence of density‐dependent growth, although interannual variation of growth has been found in the central Bering Sea (Akira et al. , 2001) and Doto area (T. Hamatsu, Hokkaido National Fisheries Research Institute, personal communication).…”

An Empty Donut Hole: the Great Collapse of a North American Fishery

“…An obvious cause for a rise and decline would be an environmental effect. However, there is no obvious relationship of pollock dynamics in the area with temperature changes (Akira et al 2001: Fig. 7).…”

Inter-cohort growth variability and its implication for fishery management of the common sardine (Strangomera bentincki) stock off the coast of south-central Chile

“…The variability in somatic fish growth rates has been studied for an increasing number of populations as a function of gender, temporal and spatial scales (Francis, 1997;Akira et al, 2001;Martins, 2007). Changes in length-at-age have been reported for both demersal, (i.e.…”

“…Atlantic mackerel (Scomber scombrus), Spanish mackerel (Scomber japonicus) and Pacific herring (Clupea palasii)). The causes of the changes have been associated to food availability, water temperature, density-dependence, size-selective mortality (natural or fishing), and predation stress (Stokesbury et al, 1999;Akira et al, 2001;Sinclair et al, 2002;Moyle and Cech, 2002;Ali et al, 2003).…”