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Based on the analysis of long-term data from bottom trawl surveys (1977–2021), changes in the spatial distribution, position of the boundaries of the ranges and the catch rates of the nine most common deep-sea skates of the genus Bathyraja in the Russian waters of the Northwestern Pacific (B. violacea, B. aleutica, B. matsubarai, B. maculata, B. bergi, B. taranetzi, B. minispinosa, B. interrupta, and B. isotrachys) are considered. During the surveyed period, significant changes in the spatial distribution were observed, which are probably due to both subjective reasons (changes in the number of trawling stations, surveyed depths, etc.) and climatic changes. No monotonous displacement of the northern or southern boundaries of the range or its center in one direction was observed in any area of any species during the entire observation period. At the same time, shifts in the boundaries of the ranges of different species in different areas occurred for different decades, i.e., the boundaries of the ranges slowly fluctuated or “pulsed” near some average annual position. In general, from the 1970s to the 1980s, the number of skates grew; from the 1980s to the 1990s, it decreased; from the 1990s to the 2000s, it fluctuated at the achieved level; from the 2000s to the 2010s, it grew again; and from the 2010s to the 2020s, it decreased again. These trends coincide with previously identified ecosystem rearrangements under the influence of climatic and oceanological changes. The identification of links between changes in spatial distribution, range boundaries and catch rates with climatic and oceanological factors require separate additional studies.

Physiculus cynodon is a member of the Moridae family and possesses a ventral bioluminescent organ. Although it has been captured by commercial vessels for decades, our understanding of its biology and ecology remains fragmented. This paper provides data on the species’ spatial and vertical distributions; age and growth; size, age, sex compositions; and sex ratio in the waters around the Emperor Seamounts and the northwestern Hawaiian Ridge. This information is based on the analysis of multi-year Russian data obtained from scientific surveys and observations on commercial fishing vessels. The northernmost capture of this species has been recorded at Nintoku Seamount. Additionally, this species was regularly encountered at depths ranging from 53 to 900 m on seamounts such as Lira (Annei), Koko, Milwaukee (Yuryaku and Kammu), Colahan, and C-H of the Emperor Seamounts and Hancock, Zapadnaya, and Academician Berg of the northwestern Hawaiian Ridge. Catch rates of P. cynodon gradually decreased in a southeastern direction. Notably, the relative abundance of this species in bottom trawl catches significantly surpasses that in pelagic catches. The age of the fish in the catch varied from 9 to 37 years, and its growth is described by the VBGF equation with the following coefficients: L∞ = 858.6, k = 0.030, t0 = 3.5. While the growth patterns for males and females were similar, it is worth mentioning that males rarely survive beyond the age of 25 years.

This study analysed long-term trawl survey data to investigate changes in the spatial distribution, range boundaries, and catch rates of the five most common shark species in the Russian waters of the northwestern Pacific. Significant alterations in the spatial distributions of these shark species were observed during the study period. The 1980s witnessed the most widespread distribution and maximum catches of salmon and blue sharks. In the 2000s, the North Pacific spiny dogfish exhibited its broadest distribution, with maximum catches recorded in the 1980s and 2010s. The Pacific sleeper shark exhibited its widest distribution in the 1980s, with maximum catches occurring in the 2000s. Shortfin mako were recorded within the study area only in the 1980s and 2010s, with maximum catches occurring in the latter period. Shifts in the range of boundaries during the study period exhibited different patterns among the species. Statistically significant shifts in boundaries were found for Pacific spiny dogfish, salmon sharks, and Pacific sleeper sharks. During the review period, salmon shark catches significantly decreased in Pacific waters and in the study area as a whole, but the reasons for this difference have not yet been determined. For the other shark species, statistically significant changes in catch size were not revealed. The observed significant changes in the spatial distribution and position of the boundaries of the ranges are likely due to both subjective reasons and climatic changes.

Motivation I describe the GIS that is based on a new database of zooplankton collected by Juday net with a 0.1 m2 opening (0.168 mm mesh). Main types of variables contained The average density (in milligrams per cubic metre) of plankton and their different constituents in 1° trapeziums. Location Chukchi, Bering, Okhotsk, Japan/East seas and Pacific Ocean. Time period 1984–2013. Taxa studied All mesofauna; > 214 species of holo‐ and meroplankton. Methods GIS creation, data analysis and literature review. Software format Any that is capable of working with shapefiles. Results Maps of the spatio‐temporal distribution of plankton with various taxonomic groups and dimensions were compiled and analysed. Based on these maps and on the literature, a hypothesis was made regarding the negative correlation of the zooplankton size with temperature. It was also revealed that some fluctuations in the abundance of plankton in the Bering Sea and the ocean are in phase, whereas in the Sea of Okhotsk and the Sea of Japan the fluctuations are fully out of phase. In particular, during the transition from the light to the dark time of the day in the Sea of Okhotsk and the Sea of Japan, the density of plankton almost everywhere throughout the epipelagic zone increases; however, in the Bering Sea and the ocean, over large parts of the water area, it decreases. This means that the common practice by trophologists of attempting to replace the day‐time catch in plankton nets with the night‐time catches to assess the food reserves for fish will yield significantly different results in these waters. Main conclusion This unique GIS could be useful to planktonologists, ichthyologists, hydrobiologists, trophologists, ecologists, biogeographers and modellers for understanding patterns and drivers of plankton diversity and biomass variations at large scales. Unfortunately, owing to lack of funding, it has not been brought to the levels of species, size classes and developmental stages that could be available in the final release.

A checklist is presented of animal species obtained in 68,903 trawl tows during 459 research surveys performed by the Pacific Research Fisheries Center (TINRO-Center) over an area measuring nearly 25 million km 2 in the Chukchi and Bering seas, Sea of Okhotsk, Sea of Japan and North Pacific Ocean in 1977–2014 at depths of 5 to 2,200 m. The checklist comprises 949 fish species, 588 invertebrate species, and four cyclostome species (some specimens were identified only to genus or family level). For each species details are given on the type of trawl (benthic and/or pelagic) and basins where the species was found. Comprehensiveness of data, taxonomic composition of catches, dependence of species richness on the survey area, sample size, and habitat, are considered. Ratios of various taxonomic groups of trawl macrofauna in pelagic and benthic zones and in different basins are analysed. Basins are compared based on species composition.

A checklist of 1541 animal species from the Chukchi, Bering, Okhotsk, and Japan seas and the North Pacific Ocean was generated based on 459 research vessel surveys (68 903 trawl tows at depths from 5 to 2200 m) in the period 1977–2014. The study area spanned over 25 million km2. For each species, the scientific name is given, as well as English and Russian common names, along with the following details: areas where species were collected, trawl type (benthic and (or) midwater), real or potential commercial importance, and possible product yield and minimum wholesale prices. Almost 20% of species in trawl catches had no commercial value, and >50% were cheap or very cheap (US$0.5–$2·kg−1). Only 3.3% of species were expensive and very expensive (US$10–$30·kg−1), and their numbers increased from north to south. About 33% of species can be considered as unexploited reserves for fisheries. These are mainly small fishes and invertebrates, with total biomass many times exceeding that of currently exploited biological resources. Product output for most species exceeded 90% of the raw mass. Occurrence of such species was much higher in the pelagic zone than on the seafloor. The most abundant local commercial species are characterized by significant natural fluctuations in abundance. Therefore, a sustainable fishery in the region can be secured (among other factors) by expansion of the assortment of commercial bioresources. A regional supply of bioresources provides such an opportunity. The checklist can be used for development of bioresource management, aquaculture and conservation, assessment of environmental damage caused by climate change, and (or) anthropogenic impact (including pollution, man-made hydro-technical constructions, oil–gas extractions, nuclear reactor accidents, etc.).

A checklist of 1541 animal species from the Chukchi, Bering, Okhotsk, and Japan seas and the North Pacific Ocean was generated based on 459 research vessel surveys (68 903 trawl tows at depths from 5 to 2200 m) in the period 1977–2014. The study area spanned over 25 million km2. For each species, the scientific name is given, as well as English and Russian common names, along with the following details: areas where species were collected, trawl type (benthic and (or) midwater), real or potential commercial importance, and possible product yield and minimum wholesale prices. Almost 20% of species in trawl catches had no commercial value, and >50% were cheap or very cheap (US$0.5–$2·kg−1). Only 3.3% of species were expensive and very expensive (US$10–$30·kg−1), and their numbers increased from north to south. About 33% of species can be considered as unexploited reserves for fisheries. These are mainly small fishes and invertebrates, with total biomass many times exceeding that of currently exploited biological resources. Product output for most species exceeded 90% of the raw mass. Occurrence of such species was much higher in the pelagic zone than on the seafloor. The most abundant local commercial species are characterized by significant natural fluctuations in abundance. Therefore, a sustainable fishery in the region can be secured (among other factors) by expansion of the assortment of commercial bioresources. A regional supply of bioresources provides such an opportunity. The checklist can be used for development of bioresource management, aquaculture and conservation, assessment of environmental damage caused by climate change, and (or) anthropogenic impact (including pollution, man-made hydro-technical constructions, oil–gas extractions, nuclear reactor accidents, etc.).

Aim The aim of the present study is the analysis of the latitudinal distribution of taxonomic richness (number of genera and families) of ichthyofauna at the western and eastern coasts of the Japan Sea for the purpose of identification of natural boundaries, and subsequent comparison with results obtained using the distribution analysis of species richness. Location Japan Sea (Korean - East Sea). Methods All statistical procedures were based on well-tried and widely accepted numerical methodology and the STATISTICA program package. For identifying the statistically meaningful (non-random) maxima and minima in taxonomic richness (n), arithmetic differences in the number of taxa at ith and i - 1th geographical latitudes and the measurements of$D=(\\sqrt{n_{i}}-\\sqrt{n_{i-1}})^{2}$, as well as residuals in polynomial trends and clustering (Ward's method) of genera and family lists, were analysed. The relationship between the number and the scope of taxa was approximated by Zipf-Pareto-Mandelbrot frequency distribution: p(N)=k/N1+k, where p(N) is a relative number of taxa, each of them includes N taxa of the next lower rank; k is a constant. The determination of the constant was made by a nonlinear estimation procedure using quasi-Newton algorithms approximating the second-order derivatives of the loss function to guide the search for estimation of the minimum/best parameter estimates. Results The comparison between all the types of analysis gives similar results and the boundaries of faunistic units identified from taxonomic lists of species, genera and families are practically coincident at herein accepted regional biogeographical scaling. The relation between the number and the scope of taxa is approximated satisfactorily by Zipf-Pareto-Mandelbrot model. Main conclusions The differences obtained by other authors in the results of zoning by species, genera and family lists are largely pre-determined by commonly used quantitative analytical methods: theoretical-and-graph methods and clustering procedures. The distribution analysis of species and superspecific taxa gives closely approaching results for relatively high latitudes and sharply diverging results for relatively low latitudes. The Zipf-Pareto-Mandelbrot distribution describing the relation between the number and the scope of taxa uniquely pre-supposes definite quantitative relationships between various rank taxa. So, the predicted species number S may be calculated on observed genera number G. If the values of species/genus ratios (S/G) are tabulated for various G, it turns out that the relationship S/G shows an almost linear variation (between 1.78 and 2.50) in the interval between twenty and 1000 species, abruptly rising with further increase in the length of species list. Therefore, the S/G ratios widely used and considered important by various ecological and biogeographical concepts are a statistical artefact. Variation analysis of taxonomic richness is a basic operational procedure in faunistic biogeography.

Aim The aim of the present study is the distribution analysis of species richness of ichthyofauna at the east and west coasts of the Japan Sea for the purpose of identification of natural biogeographic boundaries, subsequent faunistic zoning and comparison between faunistic and bioclimatic (bio-oceanographic) zoning patterns. Location Japan Sea (Korean-East Sea). Methods All statistical procedures are based on well-tried and widely accepted numerical methodology and the STATISTICA program package. For identifying the statistically meaningful (non-random) maxima and minima in species richness, arithmetical differences in the number of species at ith and i + 1st latitudes are calculated, also trend residuals obtained by smoothing the moving average by three points and residuals in polynomial trends are analysed. Subsequent clustering of species lists for separate biogeographical units marked by local maxima and minima in species richness permits to identify the extent of mutual correspondence between the units and to make an outline for faunistic zoning. Similarity degree of faunistic lists was estimated in terms of Czekanowski-Sörensen coefficient. Results Quantitative analysis of latitudinal distribution of species richness (1130 species) of the Japan Sea ichthyofauna is indicative of the position of the following 10 local maxima and minima: at 35, 40, 43, 47, 49 and 51⚬N on the west coast and at 36, 39, 43 and 46⚬N on the east coast. In most cases local minima of the polynomial trend residuals are coincident with southern boundaries of faunistic units while local maxima with northern boundaries. Separated analysis of qualitative composition of ichthyofauna of the west and east coasts of the Japan Sea discloses 11 areas of the greatest faunistic similarity. Main conclusions The latitudinal variations in the species richness near both sea coasts represent an alternation between relatively flattened smooth portions (cach 1 unit long) and sufficiently steep jumps between them. Regular interchange between local minima and maxima of species richness is accountable to spatial non-uniformity of hydrological structure resulting from alternation of variously directed and differently heated (warm and cold) circulations of waters and frontal zones. It is notable that faunistic zoning does not initially require any exact knowledge of biotic taxonomic composition and may be produced only from the variation pattern of the species richness under study. The suggested faunistic zoning scheme distinguishes the following provinces: South Korea, East Korea, South Primorie, North Primorie, Northern Japan Sea, Middle Honshu, Uetsu, Tsugaru, Soya and West Sakhalin. The comparison between faunistic units and distribution of temperature parameters and currents permits identification of subarctic, cold-temperate, mild-temperate and warm-temperate bioclimatic zones existing in the Japan Sea.