Ryer, Clifford H. Olla, Bori L.
Published in
Environmental Biology of Fishes
It is widely held that when predator avoidance conflicts with other activities, such as feeding, avoidance of predators often takes precedence. In this study, we examine how predation risk and food distribution interact to influence the schooling behavior and swimming speed of foraging juvenile walleye pollock, Theragra chalcogramma. Fish were accl...
Gritsai, E. V.
Published in
Russian Journal of Marine Biology
Geographic and interannual variability of the number of annuli and the radius of the first scale annulus, as well as the retrospective length of year-old walleye pollock from the western, northern, and eastern parts of the Bering Sea, was examined using data for the years 1995, 1996, 1998, and 1999. The characteristics of the first scale annulus we...
Jurado-Molina, Jesús Livingston, Patricia Galluci, Vincent F.
A sensitivity analysis of a multispecies virtual population analysis (MSVPA) model parameterized for the Bering Sea was carried out using two methods for the analysis. In the first method, four variables related to the predation mortality M2 and population size of age-1 walleye pollock (Theragra chalcogramma) and Pacific cod (Gadus macrocephalus) w...
Hunt, George L Megrey, Bernard A
The eastern Bering Sea and the Barents Sea share a number of common biophysical characteristics. For example, both are seasonally ice-covered, high-latitude, shelf seas, dependent on advection for heat and for replenishment of nutrients on their shelves, and with ecosystems dominated by a single species of gadoid fish. At the same time, they differ...
Nash, R.D.M. Dickey-Collas, M.
The inter-annual variability in year class strength (1976-2000) of North Sea herring (Clupea harengus) was investigated using Paulik diagrams based on survey data and Virtual Population Analysis. The herring life cycle was split into five stages: spawning stock biomass (SSB), egg production, larvae, fish with 0 winter rings on the otolith (0-wr), 1...
Fujimori, Yasuzumi Chiba, Kenji Oshima, Tatsuki Miyashita, Kazushi Honda, Satoshi
Published in
Fisheries Science
Variations in trawl dimension, bottom contact, and catch with differing warp lengths during walleye pollock surveys conducted by the Fisheries Research Agency were examined. The ratio of warp length to fishing depth (scope ratio) was set at 2.5, 3.0 and 3.5 at depths of 110 m. At tact the bottom. Footgear contact was complete when the scope ratio w...
Ciannelli, Lorenzo Bailey, Kevin M Chan, Kung-Sik Belgrano, Andrea Stenseth, Nils Chr
Published in
Proceedings of the Royal Society B: Biological Sciences
In 1976 the North Pacific climate shifted, resulting in an average increase of the water temperature. In the Gulf of Alaska the climate shift was followed (i.e. early 1980s) by a gradual but dramatic increase in the abundance of groundfish species that typically prey on pre-recruitment stages of walleye pollock. In the present study we used a previ...
Ohkubo, Nobuyuki Sawaguchi, Sayumi Hamatsu, Tomonori Matsubara, Takahiro
Published in
Fisheries Science
To elucidate the utilization of the major yolk nutrient stocks in eggs and larvae of walleye pollock Theragra chalcogramma, the contents of free amino acids (FAA), the major yolk protein (180 kDa lipovitellin originated from vitellogenin B in ovulated eggs: oLv B), and lipids were measured. Most eggs hatched 18 days after fertilization at 5°C, and ...
Hamatsu, Tomonori Yabuki, Keizou
Published in
Fisheries Science
To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of age-3-5 fish decrea...
Shimizu, Takashi Takagi, Tsutomu Korte, Holger Hiraishi, Tomonori Yamamoto, Katsutaro
Published in
Fisheries Science
The net-shape and loading analysis system (NaLA) was developed to determine fishing net configuration and load in a previous study. The system has since been applied to general gill nets and aquaculture nets, and its validity has been proven through model experiments in tanks. In this study, the system was applied to estimate the dynamic behavior o...
