Fishing for oil and meat drives irreversible defaunation of deepwater sharks and rays.

The deep ocean is the last natural biodiversity refuge from the reach of human activities. Deepwater sharks and rays are among the most sensitive marine vertebrates to overexploitation. One-third of threatened deepwater sharks are targeted, and half the species targeted for the international liver-oil trade are threatened with extinction. Steep population declines cannot be easily reversed owing to long generation lengths, low recovery potentials, and the near absence of management. Depth and spatial limits to fishing activity could improve conservation when implemented alongside catch regulations, bycatch mitigation, and international trade regulation. Deepwater sharks and rays require immediate trade and fishing regulations to prevent irreversible defaunation and promote recovery of this threatened megafauna group.

A dataset of zooplankton occurrence, abundance, and biomass in the Far East seas and adjacent Pacific Ocean waters.

Planktonic animals drifting or floating in the sea have small body sizes and weights from hundreds to thousands of milligrams, and are primarily the food for other zooplankton and macrofauna: fish, cephalopods, seabirds and marine mammals, and also the larval pool of many benthic invertebrates. This paper describes a unique dataset of zooplankton collected from 1984 to 2013 in the North Pacific (the Bering Sea, Sea of Okhotsk, Sea of Japan and adjacent Pacific Ocean waters), one of the most productive and economically important regions of the world's oceans using a Juday net made of kapron sieve No. 49 (0.168 mm mesh) with a 0.1 m2 opening. The information in this dataset has already been used to quantify the inventory of marine biological resources and assess the waters of the Russian Far Eastern seas and adjacent Pacific Ocean. In 2016, five tabular reference books were printed in Russian in limited numbers containing the species composition, occurrence (number and percentage of samples), abundance and biomass (in individuals per cubic meter, milligrams per cubic meter) of zooplankton in the surveyed area. The data are grouped by species, developmental stages, size fractions (animal length of 0.6-1.2 mm "fine/small," 1.2-3.2 mm "medium" and >3.2 mm "large"), standard regions (their total area is more than 6 million km2 ), vertical layers of water, light and dark time of the day, four seasons of the year and multiyear periods, in which there were considerable changes in the biota of the region caused by global climate and oceanographic factors. This information has recently been verified, corrected, translated into English, transformed from text to digital format, and supplemented by GIS with maps of the standard regions by which data were aggregated using morphometric parameters (volume of water in cubic kilometers in the region, in its epipelagic 0-200 m, and upper epipelagic 0-50 m water layers, occupied area in square kilometers, longitude and latitude of their centroids in decimal degrees) to increase their availability to the scientific community worldwide. The data enable the evaluation of the total plankton stock of the Russian Far Eastern seas in the North Pacific (in trillions of specimens and thousands of tons), recalculate the volumetric characteristics of density into areal characteristics (in billions of specimens per square kilometer or tons per square kilometer), and, using previously published tables on calorific value and chemical composition of zooplankton, obtain their energy characteristics. Such data are crucial for the proper management of marine resources, aquaculture development, nature conservation, and the assessment of the anthropogenic impact on nature. The presented metadata provide a detailed description of how this unique dataset was created, sources and volume of gathered information, its benefits and drawbacks, some results on the quantitative inventory of marine biological resources and assessment of waters in the North Pacific, and future prospects for the use of this type of dataset in applied and fundamental research. There are no copyright restrictions on the data; please cite this data paper when the data are used in publications.

Long-Term Changes in the Distribution and Abundance of Nine Deep-Water Skates (Arhynchobatidae: Rajiformes: Chondrichthyes) in the Northwestern Pacific.

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.

Geographical zonation in the distribution of the integral characteristics of net zooplankton in Far Eastern seas and in the North Pacific.

Earlier, it was shown that the integral characteristics of pelagic and bottom trawl macrofauna in one of the most productive and economically important regions of the world's oceans exhibiting a varying degree of circum-continental zonation, but no evidence of latitudinal zonation was found. New data on net zooplankton, which were sampled in the same marine expeditions as macrofauna, makes it possible to crosscheck the above spatial regularities and hypotheses regarding the reasons for their origin. The spatial distribution patterns of 6 integral characteristics of zooplankton are studied at different levels of the spatial scale using GIS and statistical analysis - abundance N, biomass M, diversity H', species richness S, evenness J, and the mean individual body weight of animals W. It is shown that these characteristics are subject to circum-continental zonation, which manifested as an increase in W and a decrease in N, M and J corresponding with the distance from land to the open sea. In the same direction, the variability of all the integral characteristics decrease. Classical manifestations of the latitudinal zonation of zooplankton are observed to an even higher degree: Humboldt-Wallace's law, Bergman's rule, and the increase of biomass from the equator to the poles with decreasing temperature and increasing mineral nutrient concentrations. Between the previously and newly obtained results, a clear systemic contradiction arose. A hypothesis is put forward regarding why the law of geographical provinciality in this case is observed only with respect to macrofauna, without affecting zooplankton. Several particular additions to Zenkevich-Bogorov's concept of the biological structure of the Ocean were formulated.

Species richness and taxonomic composition of trawl macrofauna of the North Pacific and its adjacent seas.

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 km2 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.