Southern Kuril Islands Research Articles

A southernmost record of the Pacific black scabbardfish Aphanopus arigato (Scombriformes, Trichiuridae) from the South China Sea

Abstract In this study, a single specimen of Pacific black scabbardfish Aphanopus arigato Parin, 1994 was collected at a depth of ~500 m near Dongsha Island in southwestern Taiwan (18°49′ to 20°45′N and 112°46′ to 116°15′E), on 14 March 2023. This is the southernmost record of A. arigato, with a significantly wide range extension from northern Japan, and southern Kuril Islands to the South China Sea. We also provide comparisons of the morphological measurements, first description of sagittae otoliths, and a partial sequence of the cytochrome oxidase subunit I gene for the specimen studied in this study.

ПРОСТРАНСТВЕННО-ВРЕМЕННАЯ ИЗМЕНЧИВОСТЬ ПОТОКА ЯВНОГО ТЕПЛА НА ПОВЕРХНОСТИ СЕВЕРО-ЗАПАДНОЙ ЧАСТИ ТИХОГО ОКЕАНА И ДАЛЬНЕВОСТОЧНЫХ МОРЕЙ ПО ДАННЫМ РЕАНАЛИЗА ERA5

An array of ERA5 reanalysis data on the sensible heat flux on the surface of the Northwestern Pacific Ocean and the Far Eastern seas for 1998–2022 is analyzed. It is shown that the positive values of this flux (directed from the atmosphere to the ocean) were observed in spring and summer, the maximum values in May were about 2 MJ/m2 in the southwestern part of the Sea of Okhotsk, and on the ocean shelf of the southern Kuril Islands and Hokkaido Island. Negative values (backflow) are observed in autumn and winter, they reach –14 MJ/m2 in December. The imbalance between these fluxes is covered by the advection of warm waters by the Tsushima and Kuroshio Currents. The variations of the parameter are dominated by the annual course, interannual variations are expressed in its modulation with periods of about 3 and 11 years, unidirectional trends are weak.

Metals in Soils of the Southern Kuril Islands

Metals in Soils of the Southern Kuril Islands

Взаимодействия СССР/РФ и Японии по принятию соглашений о безвизовых поездках между Южными Курильскими островами и Японией (1964–1999 гг.)

The article examines the process of drafting agreements between the USSR/the Russian Federation and Japan on visa-free trips of Japanese to the Southern Kuril Islands, and residents of the latter to Japan. It is shown that two forms of visa-free contacts were put into effect: one – for the purpose of visiting the graves of relatives, the second – for establishing humanitarian ties. The parties declared that such contacts carry the mission of humanity and mutual understanding between neighboring peoples. However, Tokyo's main motive was to defend its claims to the possession of the Southern Kuril Islands.

Transformation of vegetation cover of the Southern Kuril Islands under the influence of natural and anthropogenic factors

Transformation of vegetation cover of the Southern Kuril Islands under the influence of natural and anthropogenic factors

The state of spawning grounds, a study of the biology and population dynamics of pacific salmon on Kunashir Island (Southern Kuril Islands) in 2023

The purpose: formation of scientific foundations for improving the efficiency of salmon management on Kunashir Island (South Kuril zone) to ensure the sustainable exploitation of the commercial stock of Pacific salmon, maintain the necessary level of their reproduction, preserve the habitat, as well as improve scientific approaches to forecasting commercial catches.Methods used: the work was carried out in accordance with the methods generally accepted in fisheries research.Result: information was obtained on the dynamics of Pacific salmon entry, the filling of spawning grounds and the state of reservoirs on Kunashir Island. The collection of materials characterizing the biological indicators of chum salmon producers was carried out. Statistical information was obtained on catches of chum salmon and artificial reproduction of salmon fish on Kunashir Island.Practical significance: information on the filling of the spawning grounds of Pacific salmon on Kunashir Island and the quality indicators of their producers will be used to substantiate fishing regulation measures. Data on the state of artificial and natural reproduction of Pacific salmon are intended to develop a strategy for the development of artificial reproduction on Kunashir Island.

Transformations of the Vegetation Cover on the Southern Kuril Islands under the Impact of Natural and Anthropogenic Factors

Transformations of the Vegetation Cover on the Southern Kuril Islands under the Impact of Natural and Anthropogenic Factors

The dynamics of arabesque greenling fishery off south Kuril Islands

The purpose of this work was to characterize the biological and commercial indicators of arabesque greenling in the Kunashir Strait during 1998–2022.The basic material for the article was the data collected during the net fishery of arabesque greenling by the fleet of small-tonnage vessels of the Japanese fishing cooperative in the city of Rausu in the eastern (Russian) zone of the Kunashir Strait.Results: It is shown that the stock resources of arabesque greenling in the waters of the southern Kuril Islands have been declining during for a long period of time. Despite a short-term growth of catch per effort in 2018–2021, in 2022 there was again a decrease of fishery indicators. The negative trend of catch per effort is directly associated with the features of dynamics of arabesque greenling resources distributed in Kunashir Strait and in the Sea of Okhotsk waters of Hokkaido.Practical significance: The new information makes it possible to determine the current trends in total biomass changing for commercial fish and to clarify the fishery capabilities of the area in the nearest future.

Ice age land bridges to continental islands: Repeated migration of the forest‐dwelling sable in northeastern Asia

AbstractAimThe continental island system comprising Sakhalin, Hokkaido and the southern Kuril Islands (SHSK) in northeastern Asia serves as one of the southernmost habitats for many boreal and arctic organisms, with colonization via land bridges formed during glacial periods. To understand the impacts of past land‐bridge formation under Quaternary climate changes across SHSK, we investigated the demographic history of forest‐dwelling marten species.LocationSakhalin, Hokkaido and the southern Kuril Islands in northeastern Asia.TaxonSable, Martes zibellina (Carnivora, Mustelidae).MethodsWe employed multiplexed inter‐simple sequence repeat genotyping by sequencing (MIG‐seq) to obtain genome‐wide single nucleotide polymorphisms (SNPs). We tested possible scenarios of colonization and diversification for SHSK sables using several population genetics approaches including clustering analysis, population tree estimation and approximate Bayesian computation modelling. We also examined haplotype diversity for the mitochondrial ND2 gene.ResultsThe genetic diversity of the island populations and their affinity for continental populations were found to be higher in the order Sakhalin > Hokkaido > Iturup in both nuclear SNP and mitochondrial DNA analyses. Demographic analyses indicated that the sable migrated repeatedly from the continent, particularly to the neighbouring Sakhalin Island. However, only an earlier colonized lineage has persisted on marginal Iturup Island since the Middle Pleistocene. The stronger effects of repeated migrations and/or isolation influenced by the distance to the continent have shaped the contemporary genetic diversity and differentiation of sable populations in SHSK.Main ConclusionsGenome‐wide and comprehensive sampling approaches demonstrated that the forest‐dwelling sable had long‐term persistence with partial admixture of multiple lineages in SHSK, suggesting the existence of forest corridors and refugia on the islands during the last several glacial periods. The SHSK system of continental islands is valuable for understanding the impacts of Quaternary climate changes on the genetic diversity and evolutionary histories of boreal organisms.

Winter-autumn fishery of walleye pollock <i>Gadus chalcogrammus</i> (Gadidae) by bottom gill nets in the Kunashir Strait in 1999–2022

Japanese gill net fishery of walleye pollock in the Kunashir Strait, also well-known as local spawning grounds of this species, has been carried out in the eastern (Russian) part for more than 20 years. The results of the fishery allow us to consider general trends in the long-term changes of the local stock in mentioned dynamic and still underexamined area on the border of the Sea of Okhotsk and the Pacific Ocean. The use of a large series of standardized catch per effort as an index of stock biomass indicates specific dynamics of walleye pollock stock biomass in the Kunashir Strait, different from the behavior in the adjacent ocean waters of the southern Kuril Islands. On the background of a long-term trend of decreasing catch per effort in the Kunashir Strait, the CPUE in the ocean waters of the islands, as well as in the southern part of the Sea of Okhotsk, demonstrates opposite trend of increase of this parameter.

The search for hybrids between Myriophyllum sibiricum and M. spicatum (Haloragaceae) in North Eurasia allowed to clarify their morphological differences and distribution

Myriophyllum sibiricum and M. spicatum are sympatric in large part of their vast ranges in Eurasia and North America and have different habitat preferences only in East Europe and Siberia. Such absence of both geographic and ecological isolation should trigger extensive hybridization between these species that is indeed observed in North America. The hybrid could be reliably documented only with genetic markers, and in Eurasia this was done only in China. Using genetic markers (ITS2 region of nuclear ribosomal DNA and trnL-trnF intergenic spacer of cpDNA) we documented hybrids between M. sibiricum and M. spicatum on the North Asian Pacific islands with dynamic geological history and climate (Commander and the southern Kuril islands). The hybrid also originated in East Europe (Ivanovo Region) as a result of ecological isolation break due to rapid artificial habitat change. Using genetically verified material throughout temperate Eurasia we clarified morphological characters discriminating M. sibiricum and M. spicatum and, basing on them, refined the species distribution. For the first time we provide a full morphological characteristic of the hybrid between M. sibiricum and M. spicatum and suggest a name for it, M. × hybridum.

Modeling of tsunami wave height distribution functions along the east coast of Sakhalin Island

The functions of the distribution of tsunami wave heights along the eastern coast of Sakhalin Island from sources located along the Kuril Islands are being studied. Known information about the tsunami on Sakhalin is given. Many of them were modeled numerically, which made it possible to assess the hazard of tsunami waves. The present work focuses on the functions of distributing the heights of tsunami waves, which were not previously calculated for this region at all. To this case, calculations were made of the propagation of tsunami waves from hypothetical strong earthquakes with M = 8.2 located in the regions of the Northern, Middle and Southern Kuril Islands. These calculations were carried out using the NAMI-DANCE computational code, which solves non-linear shallow water equations using nested grids with a minimum grid is about 9 m. Having no reliable coastal topography, the modeling was carried out to a depth of about 3 m. The results of the calculations confirmed that the calculated functions of the distribution of tsunami wave heights along the eastern coast of Sakhalin are well approximated by the lognormal function. The parameters of these distributions depend on the location of the source even with the same earthquake parameters, which once again emphasizes the significant role of seabed bathymetry on the characteristics of a tsunami on the shore.

Phylogeography and chromosome number variation in Micranthes nelsoniana and related species (Saxifragaceae) in Northeast Asia

Abstract Micranthes nelsoniana possesses multiple different variants and numerous chromosomes. Based on the internal transcribed spacer (ITS) and chloroplast (cp)DNA sequences, the phylogeography of M. nelsoniana and its relatives in Northeast Asia was investigated, with extensive sampling around the Kuril Islands. The Arctic–Asian continent and a clade of marginal islands were the two main groupings that comprised the ITS phylogenetic tree. The island clade was separated into five well-supported clades: Kamchatka and Hokkaido highlands, Kuril–Aleutian Islands, southern Kuril Islands, Japanese archipelago, and Primorye region. Micranthes fusca was found in Japan and in the southern Kuril Islands. It is a separate species that created several types of hybrids between M. nelsoniana in the centre of the Kuril Islands based on a comparison of the ITS and cpDNA networks. Micranthes nelsoniana and M. ohwii appear to have hybridized in the northern Kuril Islands. Cytological investigation on the local species of M. nelsoniana showed that the chromosomal numbers are: 2n = 24, 26, 28, 30, 50, and 80. Among them, two usual numbers to this area, 2n = 24 and 50, appear to encourage interspecific gene exchange. The genomes of Hokkaido plants with high chromosome counts were cloned, revealing that they contained genes of both continental and marginal origins. This study revealed the crucial role of marginal islands along Northeast Asia in the genetic diversity of M. nelsoniana and related species.

Наливные рыболовные суда - новый тренд на промысле минтая у южных Курильских островов

The intensive development of fish processing factories built on the southern Kuril Islands stimulated the use of fishing vessels with RSW (Refrigerated Sea Water) storage tanks to deliver catches to coastal factories. At the moment, 8 fishing RSW-trawlers are operating in the southern Kuriles area. The capacity of RSW tanks on them varies from 500 to 2200 tons with a total one-time storage volume of 8 thousand tons. The main object of the fishery is walleye pollock. The walleye pollock catch by RSW-trawlers in 2022 reached 112 thousand tons. The main pollock harvesting area is the waters of the southern Kuril Islands, where about 70% of the total allowable catch (TAC) of this species is caught by RSW-trawlers. Compared to traditional trawlers-processor, RSW-trawlers fishering is more rational and “transparent” in relation to resources, because it exclude the possibility of discarding juveniles and substandard fish. It is assumed that the trend towards the use of RSW-trawlers in the Far East fishery basin will increase.

Fish Species Composition of Bottom Gillnet Catches by Japanese Fishing Vessels Operated in Russian Zone of Kunashir Strait in 1998–2014

Overall, 85 fish species assigned to 56 genera, 27 families, and 13 orders were observed in the bottom net catches from the Kunashir Strait in 1998–2014. The highest number of species (18) represented the family Pleuronectidae, while the family Cottidae involved the lower number of species (14). Thus, 35 species were found in the Nemuro Strait (including the Kunashir Strait) for the first time. Considering the information in the literature, the total number of fish species in the strait separating the Southern Kuril Islands from the Hokkaido Island increased to 173.

Morphology and Specific Features of Formation of Thermal Lake Utinaya Banya (Iturup Island, Southern Kuril Islands)

Abstract —This paper describes a set of studies performed at a thermal manifestation (Lake Utinaya Banya) on the Iturup Island (Kuril Islands). These studies include bathymetric survey of the lake basin, geometric leveling across the lake, pitting, sampling of thermal waters from the lake and springs, hydrochemical research, and isotopic analysis of oxygen and hydrogen in the lake water. It is suggested by the shape of the lake basin (close to lenticular with a significant concentric depression), the underwater gas-hydrothermal vents, the bank along the perimeter of the lake basin, and the presence of several layers of clastic deposits at the top of the rampart that the lake was formed by a hydrothermal eruption. The lake temperature has remained constant over the years and ranges on average from 25 to 15 °C, depending on the season. The water of Lake Utinaya Banya is represented by acidic, sulfate calcium, and low-mineralized waters.

ADDITION TO THE MOSS FLORA OF THE SOUTHERN KURILE ISLANDS (RUSSIAN FAR EAST)

As a result of identification the moss collections from Shikotan, Kunashir, Iturup and Urup islands (Southern Kuril Islands, Russian Far East) collected by T.I. Koroteeva, V.E. Fedosov, A.V. Shkurko, N.S. Liksakova, and A.K. Ezhkin in 2015–2021, new species for the islands were revealed: 6 ones for Urup, 8 for Iturup, 10 for Kunashir, and 19 for Shikotan. For the first time, 4 species new for the Kuril Islands were discovered, including three new for the Sakhalin Region (Forsstroemia cryphaeoides, Haplocladium intermedium, Rhizogemma staphylina, Meteorium buchananii). Another 3 species found in the islands are new for the Southern Kuriles (Dicranum fragilfolium, Gollania turgens, Hygroamblystegium varium). Most of the discovered species are rare in both the Sakhalin Region and the Russian Far East. To date, the moss flora of the Southern Kurils numbers 468 species and is the richest bryoflora in Russia.

The phylogenetic position of Maritrema afanassjewi Belopol'skaya, 1952 (Digenea, Plagiorchiida: Microphallidae), a parasite of the Ussuri brown bear, Ursus arctos lasiotus Gray, 1867 (Carnivora, Ursidae)

Adult digeneans of Maritrema afanassjewi Belopol'skaya, 1952 parasitize birds and mammals along the North Pacific coasts and were previously studied in terms of morphology. However, morphological features not supported by molecular characterization are considered an insufficient tool for the identification of evolutionary lineages of microphallid digeneans. Here we provide the first data on the phylogenetic position of this species inferred from sequences of the 28S rRNA gene and the ITS2 locus of the nuclear DNA, as well as additional morphometric data. The trematodes were isolated from the intestine of the Ussuri brown bear ( Ursus arctos lasiotus Gray, 1867) on Iturup Island (the southern Kuril Islands). This is the second record of M. afanassjewi in the brown bear. The phylogeny based on the 28S rRNA gene was poorly resolved for this parasite species. The analyses based on the ITS2 locus dataset showed that M. afanassjewi was a low-supported sister to Maritrema subdolum Jägerskiöld, 1909.

Pink salmon fishery in the Far-Eastern fishing basin in 2022: preliminary studies, forecast, interpretation of the fishing season results

Results of marine trawl surveys for accounting of pink salmon in 2021 and 2022 and the main results of the salmon fishery in 2022 are presented. The main stages of forecasting of the pink salmon fishery in the Far Eastern basin are described. Differentiation of mixed aggregations of pink salmon is discussed. In 2022, specialists of Kamchatka Branch used for the first time a new method based on variability of SNP loci, along with the traditional methods (morphological express-method and genetic method based on mtDNA analysis). This method provided additional dividing the mixed aggregations of autumn pink salmon in the Sakhalin-Kuril area to the herds from southern Kuril Islands and from eastern Sakhalin. The fishery forecasts for pink salmon were adjusted several times during the fishing season. These adjustments had no a significant effect for the catch increasing in the Okhotsk Sea basin, but allowed to land 10,500 t additionally in the Bering Sea.

On coho salmon <i>Oncorhynchus kisutch</i> from Iturup Island

Results of biological analysis are presented for 162 specimens of coho salmon caught at the coast and in the rivers of Iturup Island (southern Kuril Islands) during their spawning migration in August-October, 2021. Almost all females and males close to puberty in the current year spent one year in the sea and were aged 1.1+ (66.7 %) and 2.1+ (30.0 %). The fish that spent two years in the sea were single – 1 specimen aged 1.2+ and 3 specimens aged 2.2+ (2.5 %). Taking into account the age of puberty and the body weight (2.63 kg for females and 2.44 kg for males, on average) the spawners reproduction in short streams is assumed. The high value of the gonad-somatic index (up to 20–22 % for some females) is other evidence that all these fish cannot run to other spawning areas but at least a part of them should spawn in the water bodies of Iturup Island. Indeed, some coho salmon were captured directly in the rivers. Beside the spawning fish, two actively feeding coho females aged 0.0+ (0.55 kg) and 1.0+ (1.11 kg) were caught with fixed nets.