scholarly journals Macrozoobentos on the shelf of the Kronotsky Gulf

2022 ◽  
pp. 59-66
Author(s):  
E. A. Arkhipova ◽  
A. I. Buyanovsky ◽  
D. D. Danilin ◽  
S. G. Korostelev
Keyword(s):  
Spatial Distribution ◽  
Taxonomic Composition ◽  
Average Density ◽  
Total Biomass ◽  
Main Role ◽  
Depth Range ◽  
Bottom Communities ◽  
Average Biomass ◽  
Bottom Grab

Data about the taxonomic composition and spatial distribution of bottom invertebrates of Kronotsky Gulf were obtained on results of bottom grab survey carried in September 2002. Analysis of the samples revealed 72 species of Polychaeta, 21 species of molluscs (Bivalvia), 17 species of crustaceans (mostly Amphipoda), 2 species of echinodermata (Echinoidea and Ophiuroidea). The average biomass in the depth range 25–200 m was 242±116 g/m2 where average density was 306±51 organisms/m2. The most high values of biomass were observed in the outlet parts of the rivers Zhupanova, Semyachik, Kronotskaya, where contribution of sea dollar Echinarachnius parma communities was principal. Despite fluctuations of the biomass of particular taxons during 50 years, the total biomass keeps stable (206–242 g/m2). Like in 1949 E. parma plays the main role in most bottom communities.

scholarly journals CURRENT DATA ON COMPOSITION AND DISTRIBUTION OF TRAWL MACROZOOBENTHOS IN THE RUSSIAN WATERS OF THE JAPAN SEA

2018 ◽  
Vol 193 ◽  
pp. 33-49 ◽  
Author(s):  
N. V. Kolpakov ◽  
I. A. Korneichuk ◽  
V. A. Nadtochy
Keyword(s):  
Peter The Great Bay ◽  
Japan Sea ◽  
Snow Crab ◽  
Total Biomass ◽  
Trawl Survey ◽  
Depth Range ◽  
Sea Stars ◽  
Southern Primorye ◽  
The Japan Sea ◽  
Average Biomass

The bottom trawl survey (430 stations) was conducted over the shelf and continental slope in the Russian sector of the Japan Sea (total depth range 10–750 m) on April 1 — July 8, 2015. In total, 211 taxa of invertebrates were recorded in the trawl catches. Most of them belonged to sea stars (36), shrimps (32), gastropods (27), bivalves (23), crabs and craboids (11), polychaetes (11), coral polyps (10), and sponges (10). The total biomass of macrozoobenthos in the surveyed area was assessed as 1572.5 . 103 t (136.6 . 103 t in Peter the Great Bay, 341.5 . 103 t at southern Primorye, 686.0 . 103 t at northern Primorye, and 408.4 . 103 t at western Sakhalin) that was higher than the mean long-term level. The total stock of commercial invertebrates was assessed as 630.0 . 103 t. Its highest portion (265.2 . 103 t or 42.1 %) was concentrated in the western Tatar Strait. The average biomass of macrozoobenthos was 13.5 ± 1.1 g/m2 , including 6.3 ± 0.5 g/m2 of commercial species. The most abundant groups were basket stars (372.2 . 103 t), crabs (231.6 . 103 t), shrimp (226.9 . 103 t), sponges (182.9 . 103 t), sea lilies (167.5 . 103 t), sea stars (77.2 . 103 t), sea urchins (59.0 . 103 t), craboids (48.7 . 103 t), and bivalves (49.5 . 103 t). Vertical distribution of both total and commercial benthos was distinguished by peaks on the upper shelf (10–50 m) and upper slope (300–400 m). Over the surveyed northern Japan Sea waters, 18 biocoenotic complexes of trawl macrozoobenthos were identified. The largest area was occupied by the complex of immobile sestonophagous sea lily Heliometra glacialis (131 stations in the depth range of 104–692 m with average biomass 5.5 g/m2 ), other wide-spread complexes were those of polyphagous snow crab Chionoecetes opilio (71 stations, 27–552 m, 4.4 g/m2 ), mobile sestonophagous basket star Gorgonocephalus eucnemis (40 stations, 58–372 m, 6.6 g/m2 ), and polyphagous fawn sea urchin Strongylocentrotus pallidus (40 stations, 17–351 m, 4.7 g/m2 ).

scholarly journals HUBUNGAN ANTARA KOMPOSISI IKAN TARGET DAN PRESENTASE TUTUPAN KARANG HIDUP DI KEPULAUAN KEI KECIL, MALUKU

2020 ◽  
Vol 26 (3) ◽  
pp. 147
Author(s):  
Ana Faricha ◽  
Isa Nagib Edrus ◽  
Rizkie Satriya Utama ◽  
Ahmad R. Dzumalex ◽  
Abdullah Salatalohi ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fishes ◽  
Average Density ◽  
Species Variation ◽  
Live Coral ◽  
Visual Census ◽  
Underwater Visual Census ◽  
Ecological Values ◽  
Average Biomass ◽  
The Relationship

Ikan terumbu karang memiliki peranan penting baik secara ekonomi maupun ekologi, namun kondisi terumbu karang termasuk di perairan Indonesia yang menjadi habitat utama ikan karang mengalami degradasi. Penelitian ikan karang sudah banyak dilakukan, namun di Indonesia kondisi habitat ikan karang memiliki karakter yang berbeda-beda. Tujuan penelitian ini adalah untuk mengetahui hubungan antara komposisi ikan karang target dan tutupan karang hidup. Penelitian ini dilakukan pada bulan Oktober 2019 di Kepulauan Kei Kecil, Maluku. Metode yang digunakan adalah UVC (Underwater Visual Census) untuk data ikan karang dan UPT (Underwater Photo Transect) untuk mengkaji tutupan karang hidup. Hasil pengamatan menunjukkan bahwa terdapat 130 spesies ikan karang target yang mewakili 19 famili, dengan variasi jenis ikan target antar lokasi pengamatan berkisar antara 25-66 spesies. Kepadatan rata-rata ikan karang target sebesar 8.811 ± 4.107 Ind/ha, dan biomassa rata-rata 1.335 ± 899 Kg/ha. Komposisi ikan karang target yang memiliki kedekatan dengan tutupan karang hidup yaitu famili Siganidae, Serranidae, Lutjanidae, Holocentridae, dan Pomacentridae. Akan tetapi hubungan tersebut rendah, dan kemungkinan besar ada faktor lain yang mempengaruhi. Reef fishes have an important economic and ecological values. However, the coral reef of the globe including in the most of the Indonesian waters which is the vital habitat for reef fishes is degraded. Study on the reef fishes is an abundance, while the habitat characteristic of reef fishes in Indonesian waters has a differences. The aim of this study is to determine the relationship between the target reef fishes compositions and the percentage live coral covers. This study was carried out in October 2019 at the Kei Kecil islands, Maluku. The method used in this study is UVC (Underwater Visual Census) for collecting the reef fishes data, and the UPT (Underwater Photo Transect) for assessing the live coral coverage. The result shows that there are about 130 fishes, which representing 19 families, with species variation ranges from 25 to 66 species among the observation sites. The average density of target fishes was about 8.811 ± 4.107 Ind/ha, whereas the average biomass of target fishes was 1,335 ± 899 Kg/ha. The target reef fishes compositions that has relation with live coral covers is family Siganidae, Serranidae, Lutjanidae, Holocentridae, and Pomacentridae. However, this relationship is weak, and may influenced by other factors.

scholarly journals Bayesian spatial multispecies modelling to assess pelagic fish stocks from acoustic- and trawl-survey data

2012 ◽  
Vol 69 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Teppo Juntunen ◽  
Jarno Vanhatalo ◽  
Heikki Peltonen ◽  
Samu Mäntyniemi
Keyword(s):  
Spatial Distribution ◽  
Survey Data ◽  
Spatial Model ◽  
Pelagic Fish ◽  
Clupea Harengus ◽  
Environmental Data ◽  
Total Biomass ◽  
Trawl Survey ◽  
Linear Predictor ◽  
Fish Stocks

Abstract Juntunen, T., Vanhatalo, J., Peltonen, H., and Mäntyniemi, S. 2012. Bayesian spatial multispecies modelling to assess pelagic fish stocks from acoustic- and trawl-survey data. – ICES Journal of Marine Science, 69: 95–104. A Bayesian spatial model was constructed to estimate the abundance of multiple fish species in a pelagic environment. Acoustic- and trawl-survey data were combined with environmental data to predict the spatial distribution of (i) the acoustic backscattering of fish, (ii) the relative proportion of each species, and (iii) their mean length in the Gulf of Finland in the northeastern Baltic Sea. By combining the three spatial model layers, the spatial distribution of the biomass of each species was estimated. The model consists of a linear predictor on environmental variables and a spatial random effect given by a Gaussian process. A Bayesian approach is a natural choice for the task because it provides a theoretically justified means of summarizing the uncertainties from various model layers. In the study area, three species dominate pelagic waters: sprat (Sprattus sprattus), herring (Clupea harengus), and three-spined stickleback (Gasterosteus aculeatus). Results are presented for each model layer and for estimated total biomass for each species in 2 × 2 km lattices. The posterior mean and central 95% credible intervals of total biomass were sprat 45.7 kt (27.7–71.6), herring 24.6 kt (9.7–41.3), and three-spined stickleback 1.9 kt (0.9–3.2).

scholarly journals Spatial distribution of picoseston in the Saratov reservoir in summer

2021 ◽  
pp. 176-190
Author(s):  
E. S. Krasnova ◽  
M. V. Umanskaya
Keyword(s):  
Spatial Distribution ◽  
Food Webs ◽  
Significant Contribution ◽  
Heterotrophic Bacteria ◽  
Total Biomass ◽  
Total Abundance ◽  
Saratov Reservoir ◽  
Autotrophic Picoplankton ◽  
Upper Volga ◽  
Planktonic Food

The structure and spatial distribution of picoseston in the Saratov reservoir in July 2011 and August 2014 are described. On average, the total abundance of cells and particles forming picoseston was 1.87±0.73×106 cells (part.)/mL; and the total biomass of picoseston was 43.8±19.4 µg C/L. During the study period, solitary heterotrophic bacteria and phototrophic picocyanobacteria prevailed in the picoseston of the Saratov reservoir, amounting to 77–100% of its total abundance and biomass. The proportion of picodetrital particles was extremely small (on average, 4.1% of the total biomass of picoseston). The high heterogeneity of picoceston distribution (Cv is 130% and 110% for abundance and biomass, respectively) was found in the Saratov reservoir during the study period. On average, the abundance and biomass of heterotrophic bacterioplaknton and picodetritus at stations of the tributary estuaries were slightly higher than in the riverbed. At the same time, the abundance of picocyanobacteria was higher, and the biomass was lower at the estuarine stations compared to the riverbed ones. The total number of bacterioplankton and autotrophic picoplankton in the Saratov reservoir in 2011 and 2014 corresponded to the mesotrophic level of productivity. Picodetrital particles, in contrast to the Upper Volga and Kama reservoirs, make no significant contribution to the planktonic food webs of the Saratov reservoir, at least during the study period.

scholarly journals The influence of depth on the Mediterranean reef fish assemblage revealed by the new video on underwater scooter method

2020 ◽  
Vol 61 (2) ◽  
pp. 145-162
Author(s):  
Igor Glavičić ◽  
Marcelo Kovačić ◽  
Dejan Paliska ◽  
Dani Laslo
Keyword(s):  
Reef Fish ◽  
Fish Assemblage ◽  
Environmental Variables ◽  
Fish Assemblages ◽  
Average Density ◽  
Depth Range ◽  
Fish Assemblage Structure ◽  
Visual Census ◽  
Reef Fish Assemblage ◽  
Significant Difference

The new video on underwater scooter method in combination with rebreather diving techniques was introduced and applied for visual census of fish assemblages. The presently applied method facilitates deeper visual census studies below 40 m, where they have rarely been done before due to the increasing research challenges with depth. The video on underwater scooter method is also expected to be less disturbing and faster compared to swimming divers. The method was applied in visual census study of fish assemblages from 8 to 50 m depth conducted at two locations in the east Adriatic using 102 video transects. The environmental variables contributing to the variation of the reef fish community in the depth range of the infralittoral and upper circalittoral bottoms were also recorded. Thirty-one fish species were recorded on transects and 10.3% of all individuals were not identified to the species level. The average density on transects was 0.8 individuals/m², with C. chromis, C. julis and G. auratus being both the most abundant and the most frequent species. Three environmental variables, depth, bottom with zoocover and eastern orientation of the coast, were identified as highly significant for species occurrence. Abundance and species richness of fish assemblages showed no significant variation with depths, inclinations, orientations and sites. A significant difference in the fish assemblage structure was found among orientations, depths and inclinations with the gradient change of species composition with increasing depth and with increasing inclination.

scholarly journals Spatial distribution and abundance of Hemigrapsus crenulatus (H. Milne Edwards, 1837) (Decapoda, Varunidae) in the Puerto Cisnes estuary (44°S, Aysen region, Chile)

Crustaceana ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1465-1482 ◽  
Author(s):  
Rolando Vega-Aguayo ◽  
Guillermo Figueroa-Muñoz ◽  
Marco A. Retamal ◽  
Patricio De los Ríos
Keyword(s):  
Spatial Distribution ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Average Density ◽  
Chilean Patagonia ◽  
Wide Range ◽  
The Status ◽  
Estuarine Beaches ◽  
Intertidal Level

Abstract Our knowledge on the status of Hemigrapsus crenulatus (H. Milne Edwards, 1837) populations along the Chilean coast is scarce. The aim of the present study was to quantitatively estimate the spatial distribution and abundance of Hemigrapsus crenulatus in the Puerto Cisnes estuary (44°S, Aysen region, Chilean Patagonia). The spatial distribution appeared to be aggregated, with 3.64 ± 7.99 ind/m2 as gross density, and 10.50 ± 10.62 ind/m2 as a potential ecological density, i.e., if the quadrants with zero individuals are not taken into consideration. The equation of the negative binomial distribution was: where: . The average density of Hemigrapsus crenulatus under stones is lower if all beach surfaces are considered. Its abundance or dominance on estuarine beaches probably would be due to the fact that this species is one of the crustaceans of the lower intertidal level that can survive under a wide range of salinity values.

Qualitative and quantitative composition of phytoplankton in the Golden Horn Bay, Japan Sea

2018 ◽  
Vol 194 ◽  
pp. 167-174
Author(s):  
I. V. Stonik
Keyword(s):  
Phytoplankton Biomass ◽  
Japan Sea ◽  
Organic Pollution ◽  
Average Density ◽  
Quantitative Composition ◽  
Iodine Solution ◽  
Qualitative And Quantitative ◽  
Golden Horn ◽  
Average Biomass ◽  
Phytoplankton Cells

Qualitative and quantitative composition of phytoplankton in the Golden Horn Bay (Japan Sea) was investigated in the period from October 2009 to October 2010. The water samples of 1 L volume were taken with Molchanov bottle at the 36th Berth where ship-repairing yards were located and naval and commercial ships were moored. The samples were fixed in Utermӧhl iodine solution and phytoplankton cells were concentrated by precipitation or by reverse fil­tration, then the concentrated samples were processed under microscope. In total, 135 species and intraspecific taxa of microalgae were detected, which belonged to 7 divisions. Average density of phytoplankton cells varied from 1.9 . 103 to 610.3 . 103 cells/L, its average biomass varied from 0.02 to 11.70 g/m3. Four peaks of the phytoplankton cells density were registered: in summer, spring, winter and fall (in descending order), with the highest density in June, but only one peak of the phytoplankton biomass was observed in February. The highest density (up to 1 . 106 cells/L) was formed by euglenophytes that was similar to the neighboring Amur Bay and obviously indicated organic pollution of the Golden Horn Bay waters. Comparing with results of previous observations in the 1990s and 2000s, the species diversity of dominant diatoms and euglenophytes has increased recently. These species are known as indicators of eutrophic waters and/or organic pollution.  

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