Satellite data and assimilation products are used to investigate fluctuations in the catch of Japanese eel (Anguilla japonica) in eastern Asian countries. It has been reported that the salinity front has extended farther south, which has shifted the eel's spawning grounds to a lower latitude, resulting in smaller eel catches in 1983, 1992, and 1998. This study demonstrates that interannual vari...

Data on the abundance of spawning pink salmon (Oncorhynchus gorbuscha) are presented for rivers of southern Sakhalin Island and Iturup Island. Fluctuations in abundance are more dependent on marine survival than on the abundance of fry migrating downstream. This is explained by the favorable spawning conditions in small rivers with dense aggregations on the spawning grounds. We found stable lon...

The energetic and physiological challenges of spawning migrations in semelparous Pacific salmon (Oncorhynchus spp.) have been well characterized. However, the accompanying costs associated with oxidative stress during this nonfeeding migration and the potential connection to senescence have not been explored. Oxidative stress is caused by an imbalance between free radical production and absorpt...

Walleye pollock (Theragra chalcogramma) form persistent midwater and near-bottom schools in the daytime during the winter spawning season in the eastern Bering Sea (EBS). Two spawning areas in the EBS, north of Unimak Island and near the Pribilof Islands, are also the main fishing grounds. To study the schooling pattern of pollock and its impact on fishing behavior on these two fishing grounds,...

Life-history traits such as spawning migrations and timing of reproduction are adaptations to specific environmental constraints and seasonal cycles in many organisms' annual routines. In this study we analyse how offspring fitness constrains spawning phenology in a large migratory apex predator, the Atlantic bluefin tuna. The reproductive schedule of Atlantic bluefin tuna varies between spawni...

Life-history theory suggests that animals may skip reproductive events after initial maturation to maximize lifetime fitness. In iteroparous teleosts, verifying past spawning history is particularly difficult; the degree of skipped spawning at the population level therefore remains unknown. We unequivocally show frequent skipped spawning in Northeast Arctic cod (NEAC) in a massive field and lab...

Putative spawning waves of Atlantic herring Clupea harengus were collected from 4 locations and genetically compared using 9 microsatellite loci. Shelf-scale (100s km) spatial differences were measured (max FST = 0.01, p < 0.001) and 1 sub-annual temporal difference (FST = 0.0058, p = 0.001) was revealed between spawning fish (predominantly comprising the same year-class) collected, 6 d apart, ...

Larval Atlantic croaker Micropogonias undulatus (1 to 7 mm in standard length) were collected on the east coast of the United States from North Carolina to Delaware during 2000. We defined 3 water-mass boundaries for potential groups of spawning Atlantic croaker using temperature and salinity measured at each sampling station. We tested the hypothesis that distinct otolith chemistries existed a...

Data from pelagic trawl surveys by TINRO-center from 1987 to 1996 in the Okhotsk Sea indicate that coho abundance is underestimated by coastal observations. The approximate Asian coho spawning biomass is 7,300-16,000 tons for the 1990s. Ways of improving Asian coho salmon resource management are discussed. Collection of precise fishery and escapement statistics must be expanded in areas previou...

Philopatry to spawning grounds combined with well-known migratory patterns in the flatfish Pleuronectes platessa (plaice) has led to the hypothesis that regional populations may reflect relatively discrete, genetic stocks. Using six microsatellite loci we genotyped 240 adult individuals collected from locations in Norway, the Faeroe plateau, the Irish Sea, the Femer Baelt, Denmark, and the sout...