scholarly journals Vertical distribution of bivalves fauna in the northwestern Tatar Strait (Japan Sea)

2020 ◽  
Vol 200 (3) ◽  
pp. 635-655
Author(s):  
Р. A. Dulenina ◽  
A. A. Dulenin
Keyword(s):  
Species Richness ◽  
Vertical Distribution ◽  
Cold Water ◽  
Japan Sea ◽  
Warm Water Species ◽  
Tatar Strait ◽  
Sublittoral Zone ◽  
Depth Ranges ◽  
Northwestern Tatar Strait ◽  
Water Species

General patterns of bivalves distribution by depth in the northwestern Tatar Strait (within Khabarovsk region) are analyzed on the data of 384 trawl, 573 drag, and 1177 diving stations during research surveys in 2003–2016 where the samples were collected with commonly accepted methods. Depths from 0 to 600 m were surveyed. Besides, scientific publications and archival materials related to this area were taken into account. The species richness (y) decreases with depth (x) exponentially from 51 species at 1–20 m to 3 species at 400–600 m that could be approximated satisfactory by the equation y = 31.799. e–0.0502x (r2 = 0.89). Sublittoral and bathial faunas can be separated by cluster analysis of special composition in the depth range 0–150 m and 150–600 m, respectively, with similarity of 0.11 between them. Within these boundaries, 5 local faunas are distinguished: I (< 2 m, the surf zone at the upper boundary of the sublittoral zone), II (2–30 m, the upper sublittoral zone), III (30–150 m, the lower sublittoral zone), IV (150–400 m, the transitional zone) and V (400–600 m, the upper bathyal zone), with similarity between them from 0.14 to 0.36. The upper sublittoral zone has the maximum species richness — 64 species and is the habitat for a «core» of Bivalve fauna with almost ⅔ of its species, preserving the ratio of the main biogeographic groups typical for the researched area. Commercial fishery of scallop Mizuhopecten yessoensis exploited this zone mainly and now is banned to prevent reduction of its stock. Other commercial bivalves, as Callista brevisiphonata, Serripes laperousii, Keenocardium californiense, and Mercenaria stimpsoni, which commercial stocks are estimated in order of 105 t, are also concentrated in this zone but are not landed currently. Portion of moderately cold-water species (wide-boreal and low-boreal) increases and portion of warm-water species (subtropical-boreal and subtropical-low-boreal) decreases with depth, with the slope coefficients of the regressions α = 9.2 ± 4.1 (p = 0.11) and α = –9.6 ± 2.3 (p = 0.03), respectively. The coldwater species are absent in the surf and upper bathyal zones but their portion in other zones is 20–26 %. Rather high portion of boreal-arctic species on shallow depths reflects relative severity of the northwestern Tatar Strait that is the most cold-water area of the Japan Sea. The warm-water species are completely absent in the upper bathyal zone, i.e. at the depths > 400 m. On the other hand, portion of banal species increases and portion of specific species decreases with depth, also portion of rare species increases and portion of mass species decreases with depth, with the slope coefficients α = 9.10 ± 0.49 (p = 0.0003) and α = –4.5 ± 2.5 (p = 0.01), respectively. Vertical distribution of frequent species is rather uniform: 33–57 %. These patterns of the species distribution by zones almost do not change spatially: distribution of different biogeographic groups of species in three coastal areas (47–49о N, 49–51о N, and > 51о N) has no statistically significant differences. Distribution of species richness and composition by depth ranges relates to ecotopic variation (74 % of diversity), to the degree of exploration (22 %), and to the influence of such complex factor as a depth (4 %). Further faunistic studies are recommended in the most diverse areas, as bays, harbours, and capes vicinities with variable grounds and submarine vegetation, in all available depth ranges. Such surveys can provide faunistically representative information on the species wealth. The list of Bivalve mollusk species for the northwestern Tatar Strait can be enlarged possibly in 1/5 if detailed studies of their fauna will be conducted. The fauna on great depths is the most underexplored. The total expected number of bivalve species in this area is at least 120.

scholarly journals Optimal methods for identification of dominants for submerged aquatic vegetation on a case of the northwestern Tatar Strait

2020 ◽  
Vol 200 (3) ◽  
pp. 767-788
Author(s):  
A. A. Dulenin
Keyword(s):  
Aquatic Vegetation ◽  
Japan Sea ◽  
Projective Cover ◽  
Visual Methods ◽  
Qualitative And Quantitative ◽  
Tatar Strait ◽  
Sublittoral Zone ◽  
Macrophyte Species ◽  
Northwestern Tatar Strait ◽  
Indices Of Similarity

Dominant species are identified at infracenotic level for aquatic vegetation in the sublittoral zone of the northwestern Tatar Strait (Japan Sea) on the data collected in 2010–2019. Seven different methods of the identifying are considered based both on visual qualitative and quantitative assessments and on instrumental estimations of abundance for 44 macrophyte species. Depending on applied method, 19–25 species (7–22 % of total number of species) are identified as the dominants, including 10 species identified by all methods. List of these 10 species is defined as the core of vegetation that determines its general properties and the species are determined as unconditional dominants, in opposite to other ones identified by at least one method — conditional dominants. All macrophyte species in areas of low abundance do not meet the dominance criteria. All lists of dominants, including those based on visual estimates of projective cover and its physiognomy, are statistically indistinguishable (p = 0.55–0.92, by pairs of lists) and highly similar (Bray-Curtis index 0.80–0.95, Jacquard index 0.65–0.87), with one exception for the list identified by the method of ranking for the average projective cover (indices of similarity with other lists: 0.68–0.71 by Bray-Curtis, 0.46–0.56 by Jacquard). This visual method of projective cover assessment is combined with the procedure of species dividing to dominant and non-dominant groups. Quantitative criteria of projective cover and biomass, by species (thresholds 0.2 and 1.0 kg/m3, respectively) are used for dividing on cenotic and landscape levels and ranking with Brotskaya-Zenkevich index and its modification for projective cover is used for dividing on regional level. Visual methods are available for verification, but the lists of dominants based on visual and instrumental assessments should be mutually verified.

Seasonal cycles of activity and inactivity in some hydroids from Virginia and South Carolina, U.S.A.

1990 ◽  
Vol 68 (3) ◽  
pp. 442-450 ◽  
Author(s):  
Dale R. Calder
Keyword(s):  
South Carolina ◽  
Water Temperature ◽  
Cold Water ◽  
Warm Water ◽  
Late Winter ◽  
Tissue Water ◽  
Warm Water Species ◽  
Temperature Regimes ◽  
Water Species ◽  
Cold Water Species

Hydroids investigated in estuaries of Virginia and South Carolina, USA, were characteristically seasonal in occurrence. Of 20 species studied in Virginia, 14 were active only during warmer months and 6 only during colder months of the year. Seven of the 18 species examined in South Carolina were active all year, whereas 9 were active only in warmer months and 2 only during colder months. Reflecting the differing temperature regimes of the two study areas, warm-water species were active for a longer period of time in South Carolina than in Virginia; cold-water species were active longer in Virginia than in South Carolina. Warm-water species commenced activity in late winter or spring at higher temperatures than those coinciding with hydranth regression in autumn or early winter. Activity in cold-water species began at lower temperatures than those observed at regression in spring. Correlations were apparent in the seasonality, water temperature tolerances, and latitudinal distribution of most species. Field observations and laboratory experiments demonstrated that a number of species survived unfavourable periods as dormant coenosarc in stems and stolons. With the return of favourable conditions, new growth began and hydranths were regenerated from dormant tissue. Water temperature is considered the prime factor influencing the seasonal activity–inactivity cycles of hydroids in the two study areas.

Euphausiid invasion/dispersal in gulf stream cold-core rings

1983 ◽  
Vol 34 (4) ◽  
pp. 625 ◽  
Author(s):  
PH Wiebe ◽  
GR Flierl
Keyword(s):  
Gulf Stream ◽  
Cold Water ◽  
Warm Water ◽  
Dispersal Patterns ◽  
Near Surface ◽  
Warm Water Species ◽  
Living Species ◽  
Varied Response ◽  
Cold Core ◽  
Water Species

Invasion/dispersal patterns in the distribution and abundance of euphausiid species in four 2-8-month- old cold-core rings from the Gulf Stream suggest that several different physical exchange mechanisms are operating. The most important of these appear to be horizontal mixing in the mixed layer and exchange due to movement into or out of the trapped region at depth. A zone of minimum exchange is evident between 150 and 400 m. Changes in vertical distribution and abundance of warm-water species invading the ring environs suggest that only a few species, such as Stylocheiron carinatum, are able to penetrate and take advantage of the changing ring conditions in young- to middle-aged rings (2-8 months). Other near-surface warm-water species penetrate at slower rates regardless of whether they are vertical migrators (Euphausia brevis, E. hemigibba, E. tenera, Thysanopoda aequalis) or non-migrators (S. suhmii, S. abbreviatum). Deeper-living species such as S. afine, S. elongatum, Nematoscelis microps, and N. tenella, show minimal penetration of core waters in these four rings. Cold-water species expatriated in cold-core rings also show a varied response to ring decay, with some species disappearing rapidly-3-4 months (Thysanopoda longicaudata)-and others persisting for substantial periods-0.5-1 year (N. megalops, E. krohnii). Distribution of the latter two species indicates dispersal out beyond the ring core at the surface in the case of E. krohnii and at depths of 400-1 000 m in the case of N. megalops.

scholarly journals Current state of resources for japanese flying squid Todarodes pacificus in the northwestern Tatar Strait (Japan Sea)

2020 ◽  
Vol 200 (3) ◽  
pp. 586-604
Author(s):  
P. A. Dulenina ◽  
E. I. Ustinova ◽  
A. A. Dulenin
Keyword(s):  
Body Weight ◽  
Relative Number ◽  
Japan Sea ◽  
Zooplankton Biomass ◽  
The Body ◽  
Spawning Period ◽  
Tatar Strait ◽  
Todarodes Pacificus ◽  
Squid Abundance ◽  
Northwestern Tatar Strait

Data on commercial catches of japanese flying squid Todarodes pacificus in the northwestern Tatar Strait in 2003–2019 are analyzed. To assess the resours status in the study area, the relative number (individuals per jigger winch per hour) and biomass (kilograms per vessel per day) marks recognized to be the most applicable winch per hour or the catch in kg per vessel per day. The average CPUE value was 35.6 ± 3.6 ind./winch/hour; increasing trend of CPUE is observed (α = 1.5 ± 0.6, r2 = 0.3, p < 0.03). The squid abundance decreased slightly in the last 2 years, with CPUE decreasing to 28 ind./winch/hour in 2019, though the squid biomass was relatively stable (average CPUE 582.0 ± 45.8 kg/vessel/day) — decreased number of caught individuals was compensated by individual body weight increasing. Long-term tendency to the body weight increasing was noted: the average body weight was 205.0 ± 4.0 g in 2004, 256.0 ± 3.5 g in 2012, and 297.0 ± 6.3 g in 2019. Possible climate change influence on the squid population was discussed. Because of warming in the reproductive area of T. pacificus in the southern Japan Sea, SST in the spawning period reached 20–25 оC and exceeded the value optimal for reproduction and larvae development (15–23 оC), so the squid abundance decreased. On the contrary, in the northern Japan Sea (in the Tatar Strait) the warming caused better conditions for the squid feeding: the higher zooplankton biomass in this area was observed under SST 13–18 оC that is reached every year recently. On the other hand, the Tsushima Current intensifying promoted active migrations of T. pacificus to the northwestern Tatar Strait. These factors of climate warming ensure favorable environments for northward migrations of T. pacificus and forming of dense feeding aggregations in the northwestern Tatar Strait that allows to expect good conditions for the squid fishery in this area in the nearest future.

scholarly journals Salinity effects on cultured Neogloboquadrina pachyderma (sinistral) from high latitudes: new paleoenvironmental insights

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Jacqueline Bertlich ◽  
Nikolaus Gussone ◽  
Jasper Berndt ◽  
Heinrich F. Arlinghaus ◽  
Gerhard S. Dieckmann
Keyword(s):  
Sea Ice ◽  
Cold Water ◽  
Weddell Sea ◽  
Wall Thickening ◽  
High Latitudes ◽  
Neogloboquadrina Pachyderma ◽  
Antarctic Sea Ice ◽  
The Antarctic ◽  
Water Species ◽  
Cold Water Species

AbstractThis study presents culture experiments of the cold water species Neogloboquadrina pachyderma (sinistral) and provides new insights into the incorporation of elements in foraminiferal calcite of common and newly established proxies for paleoenvironmental applications (shell Mg/Ca, Sr/Ca and Na/Ca). Specimens were collected from sea ice during the austral winter in the Antarctic Weddell Sea and subsequently cultured at different salinities and a constant temperature. Incorporation of the fluorescent dye calcein showed new chamber formation in the culture at salinities of 30, 31, and 69. Cultured foraminifers at salinities of 46 to 83 only revealed chamber wall thickening, indicated by the fluorescence of the whole shell. Signs of reproduction and the associated gametogenic calcite were not observed in any of the culture experiments. Trace element analyses were performed using an electron microprobe, which revealed increased shell Mg/Ca, Sr/Ca, and Na/Ca values at higher salinities, with Mg/Ca showing the lowest sensitivity to salinity changes. This study enhances the knowledge about unusually high element concentrations in foraminifera shells from high latitudes. Neogloboquadrina pachyderma appears to be able to calcify in the Antarctic sea ice within brine channels, which have low temperatures and exceptionally high salinities due to ongoing sea ice formation.

Estimating optimal salinity and temperature of chaetognaths

2012 ◽  
Vol 92 (6) ◽  
pp. 1399-1407 ◽  
Author(s):  
Dong Zhang ◽  
Zhao-Li Xu
Keyword(s):  
Survey Data ◽  
East China Sea ◽  
Marine Organisms ◽  
Warm Water ◽  
East China ◽  
Optimal Temperature ◽  
The East China Sea ◽  
Warm Water Species ◽  
China Sea ◽  
Water Species

Determining optimal temperature and salinity for marine organisms is a challenge for marine ecologists because not every species can be easily maintained in the laboratory for testing the influence of environmental parameters. To find a simple method to estimate the optimal temperature and salinity for marine organisms based on survey data, a reciprocal quadratic yield-density model was used for determining the optimal temperature or salinity from abundance data for six pelagic Chaetognatha species. The data for the modelling were collected in four surveys in the East China Sea (23°30′–33°N 118°30′–128°E) from 1997 to 2000. According to both survey data and results from the models, we analysed qualitatively and quantitatively the ecological characteristics of those species. Estimated optimal temperatures and salinities are 17.3°C and 14.1‰ for Sagitta nagae, 20.3°C and 13.8‰ for S. bedoti, 24.9°C and 32.9‰ for S. enflata, 22.5°C and 16.5‰ for S. ferox, 24.5°C and 34.1‰ for S. pacifica and 17.3°C and 14.1‰ for S. pulchra, respectively. Three ecological groups were evident in the East China Sea: the neritic, warm temperate water species (S. nagae); the neritic, warm water species (S. pulchra, S. ferox and S. bedoti); and the oceanic, warm water species (S. enflata and S. pacifica). Our results validate that the model is applicable for describing the relationship between chaetognaths abundance and temperature or salinity.

scholarly journals Seasonal changes of biological condition and reproductive cycle of hampback shrimp Pandalus hypsinotus (Caridea, Pandalidae) in the Tatar Strait

2021 ◽  
Vol 201 (3) ◽  
pp. 547-560
Author(s):  
D. N. Yuriev ◽  
G. V. Zhukovskaya
Keyword(s):  
Reproductive Cycle ◽  
Japan Sea ◽  
Biological Condition ◽  
Tatar Strait ◽  
Stage Of Development ◽  
Long Time ◽  
Pass Through ◽  
The Individual ◽  
Almost All ◽  
Trawl Catches

Research and commercial trawl catches of humpback shrimp Pandalus hypsinotus from the Tatar Strait (Japan Sea) in 2004–2020 were investigated, with bioanalysis of about 45 thousand specimens. Average timing of group molting, spawning, and eggs laying are determined, terms of gonads and eggs development are estimated. Prespawning and molting of the females occur between January-April, with the peaks in early February and middle February, respectively. All oviparous females have 30–40 days to lay eggs, and molt during 50–55 days; the peak of the eggs laying occurs in late June. The males molt in July-August, afterwards the largest individuals change gender and new intersexes are formed. The males have the second molting in October-December, with the peak in late November. In January, after finish of the males molting, a new annual reproduction cycle starts from the prespawning molting of females. Both vitellogenesis and embryogenesis are observed through the year, though females with developing gonads prevail from August to January (because of a long time span between winter and summer moltings while the egg carrying continued 15 months) but oviparous females — from February to July. The individual reproductive cycle of Pandalus hypsinotus in the Tatar Strait lasts 24 months, with 9 months of vitellogenesis (quick growth of gonads) and 15 months of embryogenesis. During the 2-year reproductive cycle, most of females pass through the following stages: i) gonads development (just after eggs laying) when almost all oviparous females (up to 95 % in May) have green gonads under carapace that corresponds to the stage of development «eggs laid — gonads weakly developed»; ii) summer molting from August when females lose hairs on pleopods and the gonads growth accelerates; iii) respawning in January-March (together with the firstly spawning intersexes, with slight delay of the latter); iv) initial developing of eggs during summer; v) stage of «eyed eggs» from December to March; and vi) eggs laying and molting from late March to late May; then the 2-year reproductive cycle repeats.

scholarly journals Dynamics of stock for yesso scallop Mizuhopecten yessoensis (Jay, 1856) in the northwestern Tatar Strait from the beginning of its fishery to nowadays

2021 ◽  
Vol 201 (3) ◽  
pp. 533-546
Author(s):  
P. A. Dulenina ◽  
A. A. Dulenin
Keyword(s):  
Shell Height ◽  
Mizuhopecten Yessoensis ◽  
Tatar Strait ◽  
Yesso Scallop ◽  
The Mean ◽  
Commercial Value ◽  
Northwestern Tatar Strait ◽  
Commercial Stock

Settlements of yesso scallop Mizuhopecten yessoensis in the northwestern Tatar Strait (within the waters of Khabarovsk Region) are considered on the data of scuba (< 20 m depth) and dredge (> 20 m depth) surveys conducted in 2001–2018. To 2018, only two settlements remain in this area from 9–12 ones in 2010–2014; both remained settlements have no commercial value. Trend to decreasing of the settlements density is shown: the mean density was 3.0 ind./m2 in 2001, 0.20 ind./m2 in 2010, and 0.0005 ind./m2 in 2018. Commercially valuable scallops with the shell height > 120 mm prevailed in the settlements (86–100 %), whereas juveniles were rare or absent (1.6 %, on average) in all years of surveys. CPUE decreased from 200 kg/diver/hour in 2001–2003 to 10 kg/diver/hour in 2018. These changes are obviously reasoned by overexploitation of the population using dredging and scuba gathering. Total commercial stock of yesso scallop dropped to the minimal value in 2018: 200 t, that was in 4.5 times lower than the established limit. Thus, 5 years ban is established for M. yessoensis landing in the area.

scholarly journals Oxythermal habitat as a primary driver of ecological niche and genetic diversity in cisco (Coregonus artedi)

2021 ◽  
Author(s):  
Ryan C Grow ◽  
Kyle D Zimmer ◽  
Jennifer L Cruise ◽  
Simon K Emms ◽  
Loren M Miller ◽  
...  
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Dissolved Oxygen ◽  
Cold Water ◽  
Global Scale ◽  
Isotopic Niche ◽  
Coregonus Artedi ◽  
Primary Driver ◽  
Water Species ◽  
Cold Water Species

Cisco (Coregonus artedi) are threatened by climate change and lake eutrophication, and their oxythermal habitat can be assessed with TDO3, the water temperature at which dissolved oxygen equals 3 mg L-1. We assessed the influence of TDO3 on cisco habitat use, genetic diversity, diets, and isotopic niche in 32 lakes ranging from oligotrophic to eutrophic. Results showed that as TDO3 increased cisco were captured higher in the water column, in a narrower band, with higher minimum temperatures and lower minimum dissolved oxygen. TDO3 was also negatively related to cisco allelic richness and expected heterozygosity, likely driven by summer kill events. Moreover, TDO3 influenced the isotopic niche of cisco, as fish captured deeper were more depleted in δ13C and more enriched in δ15N compared to epilimnetic baselines. Lastly, cisco in high TDO3 lakes consumed more Daphnia, had fewer empty stomachs, and achieved larger body size. Our work identifies specific characteristics of cisco populations that respond to climate change and eutrophication effects, and provides a framework for understanding responses of other cold-water species at the global scale.

Sign in / Sign up

Export Citation Format

Share Document