Northern Kuril Islands Research Articles

Panmixia and local endemism: a revision of the Eubranchus rupium species complex with a description of new species.

Species of the genus Eubranchus Forbes, 1838 (Mollusca: Gastropoda: Nudibranchia) are common faunistic elements of boreal benthic ecosystems, associated with hydroid communities. Recent studies have suggested that the widely distributed trans-Arctic E. rupium (Møller, 1842) constitutes a complex of at least three candidate species, but the detailed taxonomy of the complex remains unresolved. The purpose of the present paper is to conduct an integrative taxonomic study including molecular genetic methods (a phylogenetic analysis using COI , 16S rRNA and histone H3 with application of species delimitation methods) and morphological study (light and scanning electron microscopy) of E. rupium and closely related species. The specific aims of this study were to establish the species boundaries, morphological variability, and the phylogeographic structure within this group. The phylogeographic analysis included a TCS -based network analysis, an analysis of molecular variance (AMOVA), divergence time estimations, and ancestral area reconstructions. We demonstrate that specimens initially identified as E. rupium included three distinctive species: the nominal E. rupium with an amphiboreal range, the new species Eubranchus novik sp. nov. from the Sea of Japan, for which a taxonomic description is provided in this paper, and Eubranchus sp. from the northern Kuril Islands, which requires the collection and study of additional material for formal description. Our results confirm the amphiboreal distribution of E. rupium , as no geographic structure was found across Pacific, Arctic and Atlantic populations, and the results of the AMOVA analysis showed no differences between groups of samples from different geographic regions. The divergence of the 'Eubrancus rupium species complex' is estimated from the late Miocene or the Miocene-Pliocene boundary to the late Pliocene. It is hypothesised that the most probable ancestral region for the Eubranchus rupium species complex is the north-western Pacific, and the subsequent speciation likely occurred due to dispersal followed by allopatric speciation. ZooBank: urn:lsid:zoobank.org:pub:228E0C46-0BF7-4DDD-9C00-67B50E298D65.

New species of snailfish of the genus Crystallichthys (Cottiformes: Liparidae) from the Pacific waters off Kamchatka

A new species of snailfish, Crystallichthys longirostris sp. nov., is described from Kronotskiy Bay, southeastern Kamchatka, from depths of 192 to 200 m. The new species differs from the three other species of the genus, C. mirabilis Jordan et Gilbert, 1898, C. cyclospilus Gilbert et Burke, 1912, and C. cameliae (Nalbant, 1965), in the unusually elongated shape of the narrow snout, the dot-like round pupil, simple (not three-lobed) teeth, and the short distance from the anus to the beginning of the anal fin (9% vs. 17–19% of standard length). The colour is pink, with clearly defined red-brown rings in an elongated oval shape. The new species is also recorded near the Northern Kuril Islands at a depth of 309 m. The diagnosis of the genus Crystallichthys Jordan et Gilbert, 1898 is emended considering the characters of the new species.

Hydrological and ecological survey of the Matrosskaya River (Paramushir Island, northern Kuril Islands, Sakhalin Region)

Hydrological and ecological survey of the Matrosskaya River (Paramushir Island, northern Kuril Islands, Sakhalin Region)

Dynamics of fishery and distribution of aggregations for saffron cod Eleginus gracilis (Tilesius) at northern Kuril Islands

The fishery on winter-spring accumulations of saffron cod in the area of northern Kuril Islands has a long history with varying intensity, though this species is not abundant both in the Pacific and Okhotsk Sea waters of this area. The annual catch ranged from 1.8 to 167.4 t in 2003–2022, on average 40.8 t/yr. The fish with length of 24–56 cm were presented in commercial catches of Danish seine, with prevalence of the 36–48 cm size group. The average length of saffron cod in the catches was changed from 35.4 cm in summer to 43.2 cm in winter that coincided with the fishing depth increasing in winter. The main commercial concentrations of the species had formed between the islands of Paramushir and Shumshu and in the area of the First Kuril Strait.

The Features of Demersal Fish Seasonal Distribution on the Pacific Shelf off the Northern Kuril Islands

The Features of Demersal Fish Seasonal Distribution on the Pacific Shelf off the Northern Kuril Islands

Variability of stock status walleye pollock fishery

The analysis of the variability of walleye pollock stocks assessment and fisheries showed that in most areas the degree of exploitation is at a low level (4,7–13,5%), with the exception of the Navarinsky region of the Bering Sea, the coast of eastern Kamchatka, the northern Kuril Islands and western Sakhalin (16,7–18,9%). Climate change has a significant impact on the of walleye pollock stocks assessment. Positive anomalies of the PDO climate index (Pacific Decadal Oscillation) create favorable conditions for northern populations, whereas for southern populations living on the southern border of the area, on the contrary, those periods when negative anomalies are noted are more comfortable. Subject to the implementation of the cooling scenario in the North Pacific Ocean, walleye pollock biomass centers may shift to the southern regions (the economic zone of the DPRK), which will lead to a significant reduction in catches in the economic zones of the Russian Federation and the United States, which are currently the main players in the walleye pollock market.

БЕЛОПЛЕЧИЕ ОРЛАНЫ (HALIAEETUS PELAGICUS) ЗИМОЙ В АНТРОПОГЕННЫХ УСЛОВИЯХ КАМЧАТКИ И СЕВЕРНЫХ КУРИЛЬСКИХ ОСТРОВОВ

In winter, in Kamchatka and Northern Kuril Islands (Paramushir Island) Steller's Sea eagles regularly patrol fishing vessels near marine harbors and control their unloading process to be able to eat the discarded and injured fish, other seafood and food household wastes from the ships. They also willingly use landfills and industrial water discharges as habitats in case food wastes are present there. Besides, in Kamchatka Steller's Sea eagles use artificial structures (in particular, power transmission towers) as roost sites, can pick up animals hit by cars on the roads as prey and land on the snow-free concrete surface of the runway at the airport (Yelizovo city). This is similar to the well-known situation for the wintering conditions of Sea eagles from Japan, and the difference is that the larger portion of the local winter population of Sea eagles winters in Hokkaido under the anthropogenic conditions, and a smaller portion winters in Kamchatka.

An Eхplosive–Effusive Eruption of Alaid Volcano in 2022 (Atlasova Island, Northern Kuril Islands)

An Eхplosive–Effusive Eruption of Alaid Volcano in 2022 (Atlasova Island, Northern Kuril Islands)

Intra-Seasonal Variability of Sea Level on the Southwestern Bering Sea Shelf and Its Impact on the East Kamchatka and East Sakhalin Currents

The East Kamchatka and East Sakhalin Currents (EKC and ESC) are the western boundary currents of the subarctic North Pacific and Okhotsk Sea. Variability in the EKC and ESC velocities could exert a substantial effect on ecosystems and fish stocks in the southwestern Bering Sea and Okhotsk Sea. Using satellite-derived data (sea surface heights, geostrophic current velocities, and sea surface temperatures, 2002–2020), we demonstrate that changes in zonal wind generate sea level variations on the shelf in the southwestern Bering Sea over a period of 18–29 days and with an amplitude of 5–20 cm. The ebb/flood events on the shelf lead to changes in the velocity, direction, and position of the EKC. The sea level anomalies propagate along the western Kamchatka, northern Kuril Islands and the northern and western Okhotsk Sea and result in the variability of geostrophic current velocities in the ESC zone. The strengthening (weakening) of ESC leads to an increase (a decrease) in SST in the southern part of the Okhotsk Sea by 1–3 °C. In the northwestern Okhotsk Sea, in addition to wind-induced variability, there are temporary changes in the geostrophic currents with a period of 14 days caused by fortnightly tides.

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.

Route assessment of state of the spawning stock in the lower ritral of the Utesny creek (Paramushir Island, northern Kuril Islands, Sakhalin Region)

The route survey in the lower part of the Utesny creek (Paramushir Island) was conducted to explore the state of spawning grounds for pink salmon Oncorhynchus gorbuscha and to examine their filling by spawners. The spawners were subjected to biological analysis with measuring their morphometric and physiological parameters. Besides, the data on granulometric composition of soils on the spawning grounds were updated.

Brief results of research on scallops off the northern Kuril Islands in autumn 2022

The purpose of the work: to collect materials for assessing the state and dynamics of scallop stocks in the North Kuril zone, to study the spatial structure of settlements, to monitor the dynamics, distribution and composition of commercial catches in 2022.Materials and Methods: The work was carried out on a specialized rowing vessel “Vladimir Nikora” performed 210 dredging in the area limited by coordinates 49°20'N 49°30'N. and 154°57'E154°53'E at depths of 79-170 meters. The data collection tool is an industrial scallop dredge with a working width of 3.7 m (scallop dredge 1.04 / 3.74 m). The material type of the scallop dredge bag is kapron. The length of the dredging was 0.4-0.5 miles. The research covered the water area of 23 square meters. miles. Biological analysis was carried out for 5 thousand specimens of chlamy scallops. The biological state of hydrobionts was studied according to the methods generally accepted in fisheries research. For comparability of data on the distribution of hydrobionts, the catchability coefficient of the scallop dredge was used equal to 1. The linear dimensions of the scallops were measured with an accuracy of 1 mm.The practical significance of the research: to provide commercial and biological information materials on the total allowable catches of scallops in the North Kuril.

Biological Characteristics of the Great Sculpin Myoxocephalus polyacanthocephalus (Cottidae) from Pacific Waters off the Kuril Islands and Southeastern Kamchatka in Autumn Period

The spatial distribution, size-sex composition, feeding of Myoxocephalus polyacanthocephalus and accompanying species in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka in the autumn period are considered. In August–November 1997, this species was represented in catches by individuals with a length of 30-89 (on average 47.8 ± 0.5) cm and a body weight of 300–11000 (2321 ± 90) g. Females dominated over males; the sex ratio was 1.2 : 1.0. The relationship between the body weight and length of great sculpin is described by the exponential equation: W = 0.0031FL3.446 (R2 = 0.935). The food spectrum of great sculpin includes fish (56.2% of the diet), mainly the walleye pollock Gadus chalcogrammus and Atka mackerel Pleurogrammus monopterygius (19.9 and 11.9%, respectively); fish processing wastes (19.6%), mainly heads of Atka mackerel (12.2%); as well as decapods (18.6%), mainly the snow crab Chionoecetes opilio (14.1%). As great sculpin grow, decapods are replaced by fish in the diet and walleye pollock is replaced by Atka mackerel and Liparidae. The size and sex composition and feeding patterns of great sculpin as well as the species composition of the accompanying species differed in some parts of the surveyed area. The co-occurrence of great sculpin with walleye pollock and the northern rock sole Lepidopsetta polyxystra was 100%.

Эксплозивная активность вулкана Чикурачки в январе–феврале 2023 г. (о. Парамушир, Северные Курильские острова)

The first information about the eruption of Chikurachki volcano in 2023 (Paramushir Island, Northern Kuril Islands) obtained on the basis of satellite and visual data is presented. In the period from January 28 to February 8, 2023, another explosive eruption of Chikurachki volcano, which in its nature was similar to the previous five episodes of explosive activity of the volcano that occurred throughout 2022. The volcano activity was characterized by the manifestation of moderate volcanic activity: both separate explosions and phases of a relatively calm and prolonged (several hours) emission of an ash-gas mixture were observed. In total, in the period from January 28 to February 8 of 2023, eight ejections were recorded at a height of 2.5 to 4.5 km a.s.l. Ash plumes were directed mainly to the east and northeast, their length was 100–155 km. Given the high activity and explosive nature of the activities of Chikurachki volcano in recent years, during which extended ash plumes form, the volcano is potentially dangerous for international and local airlines.

НАСЕЛЕНИЕ МОРСКИХ ПТИЦ НА ТРАЛОВОМ ПРОМЫСЛЕ МИНТАЯ В ТИХООКЕАНСКИХ ВОДАХ КАМЧАТКИИ СЕВЕРНЫХ КУРИЛЬСКИХ ОСТРОВОВ В ПОЗДНЕОСЕННИЙ ПЕРИОД

The research was carried out in October – December 2022 in the Pacific waters of Kamchatka and the Northern Kuril Islands on aboard medium-tonnage trawler fishing for pollock. We counted seabirds on line transects and in near-vessel aggregations. A total of 28 species were recorded, mainly larids and alcids. The density of bird distribution in the surveyed seawater area was 25.8 birds/km2 on average. Among them alcids (58.6%) and procellariids (27.4%) predominated. Most of the tubenoses and larids (15 species) wandering in the fishing areas were concentrated near the trawler, where they fed on catch processing waste. The most abundant were the northern fulmar and short-tailed shearwater, whose numbers reached 20 and 5 thousand individuals, respectively. The size of the near-vessel aggregations varied significantly during the fishing period. The population of seabirds had a transitional character, as it consisted of resident species that still continued to stay in the nesting areas, as well as transiting and arriving here for the winter from other regions.

Эффузивно-эксплозивное извержение вулкана Алаид в 2022 г. (о. Атласова, Северные Курильские острова)

Data are presented on a moderate effusive-explosive eruption of the summit crater of Alaid volcano (Atlasov Island, Northern Kuril Islands) observed from September 10 to December 1, 2022. Based on satellite and visual data, it was found that as a result of Strombolian-Volcan activity two lava flows, 2.6 and 1 km long, were poured out on the southern slope of the volcano, and at least 16 emissions occurred to a height of 2.5 to 6 km a.s.l. The ash plumes spread out mainly in the southeast and east-southeast directions, their maximum length reaching 300–500 km. The eruption posed a danger to local airlines. The lava outpouring provoked the formation of lahars that descended the southern slope of the volcano and reached the island coast. The alluvial fan formed from mudflow masses partially deposited beyound the coastline, causing an increase in the island land.

Парамуширское землетрясение 25 марта 2020 г. Mw = 7.4

The strong Mw = 7.4 earthquake occurred on March 25, 2020 in the region of Northern Kuril Islands, with its epicenter on the ocean side of the Kuril-Kamchatka deep-water trench, to the east from its axis. The earthquake was felt on all the Kuril Islands, South and East Kamchatka, the maximum shaking was recorded in Severo-Kurilsk with intensity I = VI–VII. Distinct tsunami wave was also registered. In the article, this earthquake and its tectonic position are discussed in the context of the seismicity of the Kuril-Kamchatka arc. The actions of duty shifts in earthquake processing are described, and a detailed description of macroseismic effects is given. The results of the analysis of peak ground motion amplitudes, focal mechanisms and models of the source, tsunami propagation features are also shown. Coseismic displacements revealed by GNSS observation data are presented and compared with model data. Peculiarities and stages of the aftershock process are discussed and the size of the source area is estimated.

The spring ichthyoplankton of pacific water off northern Kuril Islands

The aim of the work is assesment of the species composition and spatial distribution of spring ichthyoplankton in area off northern Kuril Islands.Material and methods. It is based on the data of ichthyoplankton sampling in 2011, 2015 and 2016 yrs, trawl surveys in 2011 and 2015, and hydrological surveys in 2015 and 2016 yrs. Maps of the fish distribution at various stages of ontogenesis were made. Cluster analysis was used to identify the structure of ichthyoplankton in the 2015 collections.Novelty. For the first time, data on ichthyoplankton collected by the SakhNIRO in the 2010s near the northern Kuril Islands are presented. The ichthyoplankton complexes of the spring 2015 are identified and their spatial location is shown.Results. Eggs and larvae of 26 fish species were identified in ichthyoplankton collection, 86 species of teleosts were noted in trawl catches. The dominant components of ichthyoplankton were the walleye pollock eggs Gadus chalcogrammus, the larvae of the Pacific sand lance Ammodytes hexapterus and the larvae of sculpins gen. Gymnocanthus. Most species abundant in ichthyoplankton were among the most significant in trawl catches. The maximum abundance of ichthyoplankton, more than 600 ind./m2, in the area of the Northern Kuril occurred at the beginning of May. The structure of ichthyoplankton in April-May of 2015–2016 was quite similar, at the level of 60–70%.Practical significance. Knowledge of the main spawning areas of commercial fish and the places of development of their early stages is an important component for making decisions on the rational use of biological resources.

Some issues of walleye pollock reproduction in the pacific waters adjacent to the Kamchatka peninsula and the northern Kuril Islands in 2013–2022.

Purpose: To characterize some issues of East Kamchatka pollock reproduction in the last 10 years.Methods: complex (ichthyoplankton and hydrological) surveys in the Pacific waters adjacent to the Kamchatka Peninsula and the northern Kuril Islands, surveys in the spawning center — the “North” canyon, located in Avacha Bay, layer-by-layer surveys in the canyons and on the shelf.Novelty: the currently available data on the main spawning areas of the Eastern Kamchatka pollock were supplemented, new data on the state of the spawning stock, vertical distribution of eggs at different stages of development were presented.Results: During the period under consideration, the main pollock spawning in Avacha and Kronotsky bays occurred above deep-water canyons, and on the shelf near southeastern Kamchatka and northern Kuril Islands — in the whole surveyed water area, in some years — to the south of the island Paramushir. According to the results of ichthyoplankton surveys, model calculations, the spawning stock of the Eastern Kamchatka pollock peaked in 2010, and then it gradually decreased. Currently, resources are at an average level. Horizons of the main pollock spawning in deep-water canyons change in an inter-a nnual aspect. In addition, as egg development, as a result of internal processes occurring in the canyons (internal waves), it, then rises, then falls in the underlying layers of water.Practical significance: The results of the work can be used to improve the method of assessment of the current and prospective state of stocks, justification of the TAC of the Eastern Kamchatka pollock.

The Finding of the Dark Dusky Rockfish Sebastes ciliatus (Tilesius, 1813) (Sebastidae) in the Commander Archipelago with Notes on its “Captures” in Near-Surface Waters of the Northern Kuril Islands

The Finding of the Dark Dusky Rockfish Sebastes ciliatus (Tilesius, 1813) (Sebastidae) in the Commander Archipelago with Notes on its “Captures” in Near-Surface Waters of the Northern Kuril Islands