Spring distribution of capelin Mallotus villosus catervarius in the eastern part of the Sea of Okhotsk in 2000–2019

Data on the local distribution of capelin in the eastern part of the Sea of Okhotsk in 2000–2019 are very limited. Maps of the distribution were made based on results of complex pelagic surveys in 2000–2019. It is demonstrated, that spring distribution of capelin in the Eastern Sea of Okhotsk varied depending temperature conditions in each particular year. Major aggregations of capelin were observed within Shelikhov Gulf in spring. In the “cold” years these aggregations were in the south-western part of the West Kamchatkan shelf, and in the “warm” years – in the north-western part. In sense of bathymetric distribution the main body of the capelin aggregations was observed in the upper part of the shelf at the depth <125 m at the temperatures bit lower zero.

Stable isotope analysis reveals that humpback whales (Megaptera novaeangliae) primarily consume capelin (Mallotus villosus) in coastal Newfoundland, Canada

On the Newfoundland, Canada foraging ground, humpback whales (Megaptera novaeangliae (Borowski, 1781)) are found associated with a dominant forage fish species, capelin (Mallotus villosus (Müller, 1776), that experienced a population collapse in the early 1990s and has not recovered. Our primary goal was to reconstruct dietary proportions of humpback whales on their summer foraging grounds off the northeastern Newfoundland coast during July-August, 2016 and 2017 using a Bayesian stable isotope mixing model (MixSiar). Modelled dietary proportions were similar in both years, with capelin comprising ~90% of the diet. However, both δ13C and δ15N in humpback whale skin differed significantly between years, resulting in minimal dietary niche overlap (9%). Lipid-extracted and nonlipid-extracted skin samples were used to develop a lipid normalization equation: ∆13C = – 3.184 + 1.011(C:N). Overall, findings suggest that capelin is the primary prey type of humpback whales in coastal Newfoundland, despite the continued collapsed state of the capelin population. Findings also reiterate that dietary reconstruction from stable isotope analysis of cetacean skin can be misinterpreted without concurrently sampled isotopic ratios of potential prey types.

CAPELIN (MALLOTUS VILLOSUS CATERVARIUS) OF THE TAU BAY OF THE SEA OF OKHOTSK: ECOLOGY, CURRENT STATE OF THE STOCK AND PROSPECTS OF FISHING

On the basis of the materials collected in 2011-2019, the ecology, the current state of the stock and some features of the biology of the capelin living in the Tauyskaya Bay (Northern part of the sea of Okhotsk) are considered. A brief biological characteristic of its age and size-weight indicators, as well as the sex ratio is given. The prospects of industrial development are shown.