The Oyashio shelf region and the seasonally ice-covered areas north of Hokkaido are highly productive, supporting a wide range of species including marine mammals, seabirds and commercially important species in the western subarctic Pacific. The fishes include gadids, such as walleye pollock and Pacific cod, and subarctic migratory pelagic fishes such as chum salmon and pink salmon. It is also ...

In the Aleutian Islands ecosystem, food habits of many noncommercial species such as skates have not been studied. This study provides the basic information on food habits and diet overlap of 7 skate species found in the Aleutian Islands area. These species include the Aleutian skate (Bathyraja aleutica), big skate (Raja binoculata), Bering skate (B. interrupta), Alaska skate (B. parmifera), bl...

Abstract The ratio of female to male Walleye Sander vitreus across the spatial scale large reservoirs and during nonspawning times receives little attention, even though standardized sampling occurs this time. This study evaluated whether proportion collected from seasonal at different areas within a reservoir fell 0.450–0.550 range, which would closely reflect 1:1 female-to-male sex ratio. We ...

Walleye dermal sarcoma virus (WDSV) has been identified as the causative agent of a benign neoplasia of walleye Stizostedion vitreum, walleye dermal sarcoma (WDS). We conducted an experimental transmission regimen to determine if WDSV is capable of inducing dermal sarcoma in the closely related sauger S. canadense. Nearly all of young-of-the-year saugers (96%) inoculated with filtrates of sprin...

Nucleotide polymorphism at the pantophysin (Pan I) locus in walleye pollock, Theragra chalcogramma, was examined using DNA sequence data. Two distinct allelic lineages were detected in pollock, resulting from three amino acid replacement mutations in the first intravesicular domain of the protein. The common Pan I allelic group, comprising 94% of the samples, was less polymorphic (pi = 0.005) t...

Migrating fish traversing velocity barriers are often forced to swim at speeds greater than their maximum sustained speed (U(ms)). Failure to select an appropriate swim speed under these conditions can prevent fish from successfully negotiating otherwise passable barriers. I propose a new model of a distance-maximizing strategy for fishes traversing velocity barriers, derived from the relations...

High-resolution, two-dimensional measurements of aquatic-organism density are collected routinely during echo integration trawl surveys. School-detection algorithms are commonly used to describe and analyse spatial distributions of pelagic and semi-pelagic organisms observed in echograms. This approach is appropriate for species that form well-defined schools, but is limited when used for speci...

In 2011, Lake Erie experienced a record-setting harmful algal bloom (HAB), posing significant risks to ecosystem services, including its $1.5 billion sport fishing industry. Using a mail survey of 3,000 Ohio recreational anglers and a choice experiment, this article provides the first empirical evidence in the US to link HABs to damages to Great Lakes recreational anglers. We account for the he...