Adjacent Pacific Waters Research Articles

The Characteristics of Feeding Migrations of Hatchery-Reared Pacific Salmon Juveniles in the Sea of Okhotsk Basin and Adjacent Pacific Waters in the Autumn–Winter Period (Regional Identification, Abundance, Distribution of Catches, Biological Characteristics, and Mortality Rate Estimates)

The Characteristics of Feeding Migrations of Hatchery-Reared Pacific Salmon Juveniles in the Sea of Okhotsk Basin and Adjacent Pacific Waters in the Autumn–Winter Period (Regional Identification, Abundance, Distribution of Catches, Biological Characteristics, and Mortality Rate Estimates)

Characteristics of feeding migrations of hatchery juveniles of pacific salmon in the basin of Okhotsk Sea and adjacent Pacific waters in the autumn-winter period (regional identification, abundance and distribution of catches, bio-logical indices, estimates of mortality)

Long-term data on feeding migrations of hatchery pacific salmon (pink and chum salmon) in the Okhotsk Sea and adjacent Pacific waters in the autumn-winter of 2011–2021 are generalized. The study is based on materials (otolith samples, biological indices) collected in the trawl surveys conducted by TINRO, as well as on international statistics on releases and tagging of pacific salmon at the Russian and Japanese hatcheries. The main patterns of intraspecific structure, migration routes, spatial distribution, and volumes of catch are determined for these species, as well as the size-weight parameters of fish originated from different regions. Natural mortality of salmon juveniles at the stage of migration from the coastal zone to the open sea is estimated at systemic level for the first time.

Role of Marginal Seas in Deep Ocean Regeneration of Dissolved Silica: A Case Study in the Marginal Seas of the Western Pacific

Deep ocean regeneration of dissolved silica (DSi) is an essential part of the ocean silica cycle and is driven by a complex series of biogeochemical processes. Here we compare the distributions of DSi and other environmental parameters in several western Pacific marginal seas to explore the role of marginal seas in deep ocean DSi regeneration. Results show that in oligotrophic marginal seas (such as the South China Sea), the DSi content in deep waters is similar to that of the adjacent Pacific waters. However, in productive marginal seas (such as the Bering Sea), the DSi content in deep waters is markedly higher than that in adjacent Pacific waters at the same depths. This is mainly due to deep ocean DSi regeneration in the marginal sea basin, which is fueled by the high biogenic particle flux from the productive surface waters. On a global scale, deep ocean DSi regeneration is accelerated in productive marginal seas, causing marginal seas such as the Bering Sea to have the highest DSi concentrations of all global waters.

ELECTRONIC ATLAS OF TYPICAL ACOUSTIC IMAGES FOR COMMERCIAL FISH SPECIES IN THE FAR-EASTERN SEAS OF RUSSIA

The first version of the software is developed for presentation of metaarchive and library of typical acoustic images of marine organisms for their size and species identification on echograms. It displays certain typical acoustic images of commercial fishes in the Far- Eastern Seas and their descriptions as electronic atlas and allows to choose a typical acoustic image by area (using its coordinates and/or name of fishery district), time of day, season, and object (species and size). For this atlas, the echograms of different fish species from the Bering, Chukchi, Okhotsk Seas and adjacent Pacific waters accompanied with the data on location, time, and results of trawling were accumulated since 1996. The options «Filter», «Echogram parameters», «Trawling parameters», «List of echograms», «Catch», «Size composition», «Maturity», and «Echogram image» are presented on the window of this atlas. The «Filter» limits the area of echograms search by coordinates, borders of fishery district, time of day, season, species and size of fish. The «Echogram parameters» allows to select the echogram palette suitable for the type of echosounder and gives information on time and distance of the record. The atlas could be applied in trawl-acoustic surveys and for maintenance of fisheries in the Far-Eastern Seas, as well as a guide for work with scientific and fishery sonar devices.

A Comparative Study of the Far Eastern Seas and the Northern Pacific Ocean Based on Integral Parameters of Net Zooplankton in the Epipelagic Layer

Integral parameters of zooplankton community, including species diversity and its components were compared between the Chukchi Sea, Bering Sea, Sea of Okhotsk, Sea of Japan, and adjacent Pacific waters based on the data obtained by standard Juday net with a mouth area of 0.1 m2 during the large-scale surveys conducted by the Pacific Fisheries Research Center (TINRO Center) in 1984–2013. These parameters were calculated for the total surveyed area of approximately 7.0 million km2 and separately for each of the considered water bodies. In Pacific waters, species richness is higher than that in all the seas, while the concentration of individuals (expressed in terms of abundance, ind./m3) and evenness of their distribution over species were lower. The only sea with a larger mean size of organisms compared to the ocean is the Bering Sea. A lower species diversity than in the ocean has been recorded only from the Chukchi Sea; a lower density (in terms of biomass, g/m3) was determined only from the Sea of Japan. Among the four seas, the Chukchi Sea ranks first in terms of biomass and abundance of zooplankton, second in species evenness, third in the mean size of individuals, and last in species richness and diversity. The Bering Sea ranks first in terms of mean size of plankton organisms, second in species richness, diversity, and biomass, third in abundance, and last in species evenness. The Sea of Okhotsk ranks second in terms of mean size of individuals, last in their abundance, and third in the other parameters. The Sea of Japan ranks first in terms of species richness, evenness, and diversity, second in abundance, and last in mean size of zooplankton organisms, and, therefore, their biomass. The biomass of zooplankton, in accordance with the concentration of nutrients, increases in the southto-north direction (while its absolute abundance depends largely on the size of the body of water). The mean size of organisms increases in the same direction; the evenness of their distribution over species increases in the reverse direction (with the exception of both parameters for the Chukchi Sea). The rank of a water body for its biodiversity coincides with the species richness rank. The latter increases from north to south (except for the Okhotsk Sea), but greatly depends on the surveyed area and, even more, on the surveyed volume of water. A study of the literature data found some unexpected statistically significant relationships of the integral parameters of zooplankton with those of pelagic and bottom macrofauna, as well as with the parameters of zooplankton production, on the size of the considered bodies of water. The causes and the biological meanings of most of these relationships still do not have any rational interpretation. Their testing at other spatial scales will be continued in future works.

Comparative study of the Far-Eastern Seas and the North Pacific by integral parameters of net zooplankton in the epipelagic layer

Species diversity and other integral parameters of zooplankton community in the Japan, Okhotsk, Bering, Chukchi seas and adjacent Pacific waters (total area close to 7.0 . 10 6 km 2 ) are compared on the data obtained in the large-scale surveys conducted by Pacific Fish. Res. Center (TINRO) in 1984-2013. Standard Juday net with mesh size 0.186 mm and mouth area 0.1 m 2 was used for sampling. Among four seas, the Chukchi Sea takes the 1 st place by abundance (ind./m 3 ) and biomass (mg/m 3 ) of zooplankton, 2 nd by species evenness, 3 rd by mean size of organisms, and the last by species richness and diversity. The Bering Sea is the 1 st by mean size of animals, 2 nd by species richness, diversity and biomass, 3 rd by abundance, and the last by species evenness. The Okhotsk Sea takes the 2 nd place by mean size of zooplankton, the last by its abundance, and the 3 rd by other parameters. The Japan Sea is the 1 st by species richness, evenness and diversity, 2 nd by abundance, and the last by mean size of zooplankton and therefore by its biomass. Zooplankton in the Pacific waters has the lowest abundance, but its biomass is higher there in comparison with the Japan Sea. Species richness is the highest in the Pacific, but species diversity is higher there than in the Chukchi Sea and species evenness is the lowest. Mean size of zooplankton organisms in the Pacific is rather large but smaller than in the Bering Sea. In general, zooplankton abundance increases northward in accordance with nutrients supply, as well as the mean size of animals (with exclusion of the Chukchi Sea), but uniformity of the species abundance has opposite tendency (except the Chukchi Sea again). The rank in biodiversity coincides with the rank in species richness. The latter decreases from south to north (with exclusion of the Okhotsk Sea), but depends strongly on size of the surveyed area and surveyed volume of water. Some unexpected statistically significant relationships are found between the integral parameters of zooplankton and these parameters for pelagic and bottom macrofauna which have not yet any rational interpretation.

First experience of using a new database on net zooplankton in the Far-Eastern Seas and adjacent Pacific waters

Unique database on zooplankton collected by 0.1 m 2 Juday planktonic net (mesh size 0.168 mm) in the Chukchi, Bering, Okhotsk, and Japan Seas and the North Pacific in 1984-2013 is presented. History of its creation, sources and volume of the data are described and the first operating experience and prospects of its using for applied and fundamental researches of marine biological resources are explained. Some new results based on this database are discussed. In particular, 5 tabular reference-books of species composition, occurrence and abundance of zooplankton for the main fishing grounds in the Russian part of this region were prepared and published in 2014-2015, where the information is summarized by species, stages of development, size fractions, biostatistical areas, water layers, light and dark time of day, four seasons, and quasi-decadal periods. Charts of spatio-temporal distribution of certain taxonomic and dimensional groups are drawn. Assumption is offered on negative dependence of zooplankton body size on water temperature, that needs additional verification. Vertical zooplankton migrations are considered and there is concluded that its biomass in the upper layer increases usually in the nighttime in the Okhotsk and Japan Seas but in the daytime in the Bering Sea and North Pacific, therefore attempts to recalculate the daytime biomass to the nighttime one using constant coefficients give opposite results for these pairs of regions. Prospects for developing of GIS and atlases of zooplankton for the North Pacific are discussed with examples of charts for the data generalized by abovementioned criteria, but this application is postponed until the best times because of funding reduction.

Supplements to the generalized quantitative assessments of benthic macrofauna in the Far Eastern Seas and adjacent waters of the Pacific Ocean. Report 1. Regional features of distribution for biomass of fish

Long-term information on mean annual biomass of the main taxa of bottom and demersal fishes on the shelf and upper continental slope (down to 2025 m) in the Far Eastern Seas and adjacent Pacific waters is summarized. Mean annual biomass of fish in the benthic layer (without pelagic species) is estimated as 9.8 . 10 6 t (60.2 % in the Okhotsk Sea, 20.4 % in the Bering Sea, 11.2 % in the Pacific waters at Kuril Islands, 4.1 % in the Japan Sea, and 4.1 % in the Pacific waters at Kamchatka). Schemes of these species distribution in the pelagic layers are presented, too. Even truly bottom fishes rise to the pelagic layers sometimes (mostly in the nighttime). Eggs, larvae and juveniles of many demersal and benthic species dwell mainly in the pelagic layers, transported by currents everywhere including the open waters beyond the continental shelf and slope; elder fish, from the stage of fingerlings, are able for migrations, even against stream. Biomass of the species majority is proportional to square of shelf and slope, with exception of the species associated with complicated bottom topography (rocks, canyons, guyots, etc.), in particular at steep slopes.

Some aspects of biogeography with reference to zoning of the Far- Eastern Seas of Russia and adjacent waters of the Pacific Ocean

Formation of biogeography, its methodological features, and its status as interdisciplinary science combining biological and geographical aspects are discussed. There is noted that the descriptive period of biogeography has passed, and now any «manifestation of life on the globe» requires its explanation. These explanations are reduced to three non-adversarial restrictions: environmental (ecology), temporal (history of origin, evolution), and spatial (geography). General regularities of life distribution over the Earth surface are analyzed, in particular the features of pelagic organisms habitat, and the concept of «dynamic biogeography» is discussed. Latitudinal zoning of epi- and mesopelagic layers in the Far-Eastern Seas of Russia and adjacent Pacific waters is proposed on the basis of data about areas and distribution of 493 species of nekton (fishes and squids) for the 30-year period (1980-2009) obtained from 27 thousand trawl samples caught in 272 expeditions. This zoning uses a new approach related to the chorological direction in marine biogeography realized with the index of latitudinal zoning (ILZ). For this index calculation, all types of species areas (formerly expressed in verbal forms) were identified with numerical codes, which were averaged for all species in each sample, then the regions with certain ILZ values and borders between them were determined on the maps of ILZ distribution, and latitudinal zones and subzones were defined. There is found that the epipelagic layer of the Okhotsk and Bering Seas corresponds to the high-boreal latitudinal subzone and the epipelagic layer of the northwestern Japan Sea and the major part of Russian EEZ in the Pacific corresponds to the low-boreal latitudinal subzone. Fauna of nekton in the mesopelagic layer of all studied regions corresponds by its chorological structure to the low-boreal latitudinal subzone. So, zoning of epipelagic and mezopelagic layers is significantly different, with the fragmentation reducing with depth, possibly due to weakening of climatic factors influence. The biogeographical zoning is not literally zonal but corresponds to structure of the environments (water masses, fronts, currents, gyres, eddies, etc.).

Seasonal behavior of dissolved cadmium and Cd/PO4 ratio in Todos Santos Bay: A retention site of upwelled waters in the Baja California peninsula, Mexico

This work analyzes the spatial and seasonal variability of dissolved cadmium (Cdd) and the cadmium to phosphate ratio (Cd/PO4) in surface waters of Todos Santos Bay (TSB), a semi-enclosed bay within the upwelling zone of the Baja California peninsula (Mexico). The waters inside the bay (17.74±0.42°C) were on average warmer than the adjacent Pacific waters (14.67±0.52°C) indicating the retentive nature of circulation within TSB. Cdd and PO4 concentrations and Cd/PO4 ratios for this region are comparable to those reported for the California Current System. Cdd (0.30±0.036nM) and PO4 (0.97±0.061μM) concentrations outside of the bay presented a seasonal signal which was positively correlated with the local coastal upwelling index (CUI), suggesting that the magnitude of temporal variability of Cdd is partially controlled by the intensity of upwelling. In contrast, average Cdd (0.15±0.018nM) and PO4 (0.51±0.034μM) concentrations within the bay were approximately 50% less than those of the oceanic region, indicating that both elements are removed inside TSB. The dissolved Cd/PO4 ratio was not constant on a seasonal scale between the inside and outside of the bay, with higher values in the spring associated with upwelling conditions and greater phytoplankton biomass. Our findings show that there is a decoupling of Cd and PO4 cycles within TSB during the upwelling season, which is caused by an intensification of biological activity associated with the retention of water inside the bay. To explain the decoupling between Cd and PO4, we speculate that during the upwelling season this coastal system is temporarily relieved from micronutrient Zn limitation, causing an increase in the dissolved Cd/PO4 ratio due to preferential uptake of PO4 by phytoplankton. The seasonal variability of the dissolved Cd/PO4 ratios suggests that the Cd/Ca proxy must be used with caution to reconstruct past PO4 concentrations in surface waters of upwelling regions.

Jellyfish of the Far Eastern Seas of Russia. 3. Biomass and abundance

The biomass and abundance of large jellyfish (Cnidaria: Scyphozoa, Hydrozoa) was estimated and their seasonal and interannual dynamics was studied based on the data of trawl surveys conducted by the Pacific Research Fisheries Center (TINRO Center) in the Sea of Okhotsk, Bering Sea, Sea of Japan, and the Northwestern Pacific Ocean (NWPO) in 1991–2009. Most of the jellyfish biomass (over 95%) in the Sea of Okhotsk, Bering Sea, and NWPO was formed by Chrysaora spp., Cyanea capillata, Aequorea spp., Phacellophora camtschatica, and Aurelia limbata. The same species along with Calycopsis nematophora predominated in abundance in the Bering Sea and NWPO, while Ptychogena lactea, C. capillata, and Chrysaora spp. were most abundant in the Sea of Okhotsk. In the northwestern Sea of Japan, Aurelia aurita, C. capillata, and Aequorea spp. predominated both in abundance and biomass. Generally, the jellyfish abundance reached the highest values in the summer and fall and decreased abruptly in the winter. Meanwhile, the seasonal dynamics proved to be specific for each species and were manifested in some of them by reaching maximum values at various periods of the warm season, whereas the other (Tima sachalinensis and P. lactea) showed the reverse pattern of seasonal variations, with the highest abundance in cold months. Jellyfish biomass and abundance varied greatly from year to year, which was related to the short lifecycle and alternation between sexual and asexual generations, in which reproductive success was predetermined by various environmental factors. In the fall, year-to-year fluctuations of the relative biomass could increase by ten times. In 1991–2009, it varied from 200 to 2000 kg/km2 in the northern Sea of Okhotsk, from 500 to 4200 kg/km2 in the northwestern Bering Sea, and from 300 to 3700 kg/km2 in the southwestern Bering Sea. Taking the jellyfish abundance estimates into account, along with the vertical distribution and the seasonal dynamics, the overall biomass of large species that occurred in trawl catches in Far Eastern seas and adjacent Pacific waters during the warm season could reach 13.0–15.0 million tons, of which up to about 6.0 million tons would be concentrated in the western Bering Sea and 5.5–6.0 million tons in the Sea of Okhotsk.

Low nekton abundance in the western Bering Sea according to trawl survey data and model estimates

Complex trawl surveys were conducted in the upper epipelagic zone of the western Bering Sea and adjacent Pacific waters in the summer and fall seasons of 2002–2006. The abundance of small nekton (micronekton) was estimated using two independent methods: traditional trawling and a mathematical model of selective feeding by fish. According to the trawl data, total micronekton density varied from 1 to 158 (average 40) mg/m3 on the northwestern Bering Sea shelf and from 6 to 151 (37) mg/m3 in deep-water areas of the southwestern Bering Sea and adjacent Pacific waters. According to model calculations, micronekton density was higher—72–193 (141) mg/m3 on the shelf and 78–507 (228) mg/m3 in the deep-water part of the studied area. Both trawl and model data showed that small nekton on the northwestern shelf mostly consisted of larval and juvenile walleye pollock, as well as small fish species, such as capelin and Pacific sand lance. In the deepwater areas, mesopelagic fish and squid (northern lampfish, northern smoothtongue, and boreopacific gonate squid), which migrate to the surface at night, juvenile Atka mackerel, and shortarm gonate squid dominated among micronekton. The advantages and disadvantages of both the trawl and model methods for calculating the abundance of small fish and squid were considered. Comparison of abundance estimates for mass fish species, obtained through trawl and model methods, enabled us to analyze trawl catchability coefficients and propose a more differentiated division of micronekton into size classes than had been done earlier. A function that characterizes the dependence of the catchability coefficient (CC) on body length was offered for juvenile Atka mackerel. This equation can be also used for evaluation of CC for other fishes that have similar size and behavior.

Notes on the Winter Distribution of Birds in the Western Antarctic and Adjacent Pacific Waters

Notes on the Winter Distribution of Birds in the Western Antarctic and Adjacent Pacific Waters