scholarly journals ЛЕТНЕЕ ПИТАНИЕ СИВУЧА В ВОДАХ ДАЛЬНЕГО ВОСТОКА РОССИИ В 2004–2008 ГОДАХ

2021 ◽  
Vol 13 (4) ◽  
pp. 1
Author(s):  
И.А. Усатов ◽  
В.Н. Бурканов
Keyword(s):  
Sea Of Okhotsk ◽  
Pacific Salmon ◽  
Summer Season ◽  
Sea Lion ◽  
Commander Islands ◽  
Sand Lance ◽  
Food Items ◽  
Undigested Food ◽  
The Kuril Islands ◽  
Atka Mackerel

The diet of Steller sea lion Eumetopias jubatus was studied based on undigested food parts found in feces collected in the summer season on 20 rookeries in the Russian Far East. A total of 915 samples were analyzed between 2004 and 2008, in which 65 food items were identified. The frequency of occurrence of 11 diet items was greater than 5%, including Atka mackerel Pleurogrammus monopterygius (64.8%), Pollock Theragra chalcogramma (44.3%), Pacific salmon Salmonidae (20.5%), Irish lord Hemilepidotus sp. (20.4%), Pacific sand lance Ammodytes hexapterus (15.8%), Pacific herring Clupea pallasi (9.5%), Squid and Octopus Cephalopoda (8.4%), Pacific cod Gadus macrocephalus (5, 9%), Pacific sandfish Trichodon trichodon (5.9%), Flatfishes Pleuronectidae (5.8%), Threespine stickleback Gasterosteus aculaeatus (4.9%). Three regions with different diets were identified – the Sea of Okhotsk, the Kuril Islands, and Kamchatka with the Commander Islands. In the Sea of Okhotsk, Pollock and Herring (83.6% by frequency of occurrence) dominated among undigested food remains in feces. The diet at the Kuril Islands rookeries was variable within the region. The general pattern was a low diversity of diet at each Kuril Island sites and predominance of 1-3 food items, probably the most accessible near the sites (Pollock, Squid and Octopus, Atka mackerel, Pacific salmon). The diet pattern in Kamchatka and the Commander Islands in the summer season was characterized by a high diet diversity. In contrast to other regions, the diet includes in high proportion small non-commercial species – Sand lance, Irish lord, Pacific sandfish, Flatfishes, Threespine stickleback and others. The regional patterns of sea lion diets show the spatial distribution and areas of abundant biomass of the main food items. The diet patterns of sea lions from rookeries differed from haulouts in having a higher content of abundant food items. Long-term changes in diet structure were not statistically significant.

scholarly journals MODERN VIEWS ON THE CIRCULATION OF HERPES VIRUSES IN THE OKHOTSK SEA STELLER SEA LION (EUMETOPIAS JUBATUS, SCHREBER, 1776)

2019 ◽  
Vol 14 (2) ◽  
pp. 35-47
Author(s):  
A. A. Derko ◽  
A. Yu. Alekseev ◽  
K. A. Sharshov ◽  
V. N. Burkanov ◽  
J. M. Jamalutdinov ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Kuril Islands ◽  
Steller Sea Lion ◽  
Okhotsk Sea ◽  
Herpes Viruses ◽  
Literature Study ◽  
Sea Lion ◽  
The Sea Of Okhotsk ◽  
The Kuril Islands ◽  
Sera Samples

Aim. To evaluate the possibility of herpes viruses circulation and possible routes of transmission in population of Steller sea lions of the Sea of Okhotsk by combining a thorough literature study with screening of blood sera samples of Steller sea lion puppies of the Sea of Okhotsk obtained in 2008‐2012.Methods. We investigated 370 blood sera of puppies of the Steller sea lion (2008‐2012) from Tyulenij island, Chkalova island and from the Kurile Islands for the presence of antibodies to two members of the subfamily Alphaherpesvirinae and Gam‐ maherpesvirinae using enzyme‐linked immunosorbent assay (ELISA).Results. The data showed that out of 370 sera samples, 50 contained antibodies to the varicella‐zoster virus (subfamily Alphaherpesvirinae) and 46 – to the Epstein‐Barr virus (subfamily Gammaherpesvirinae).Main conclusions. The literature study revealed that the ecology peculiarities of species contribute to the realization of the main ways of transmission of herpes viruses between individuals. We were also able to identify possible risk factors for the transmission of non‐specific herpes viruses between Steller sea lion and the animals with which they are forced to coexist. The results obtained are in a good agreement with the literature data and indirectly confirm the circulation of herpes viruses in the Steller sea lion of the Kuril Islands, as well as the island Tyulenij. We observe a significant difference in the number of Steller sea lion puppies with the presence of antibodies to gamma‐herpes viruses on the Kuril Islands and the Okhotsk Sea is‐ lands (Р > 99,7). Differences in the number of Steller sea lion puppies with the presence of anti‐ bodies to alpha herpes viruses were not reliably detected. 

Mitochondrial cytochromebgene sequence diversity among Steller’s sea lion rookeries in the Kuril Islands and the Sea of Okhotsk

Mammal Study ◽  
2008 ◽  
Vol 33 (3) ◽  
pp. 125-129
Author(s):  
Tatsuya Kariya ◽  
Makoto Igarashi ◽  
Kazuo Wada ◽  
Vladimir N. Burkanov ◽  
Satoshi Koyama ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Sequence Diversity ◽  
Kuril Islands ◽  
Sea Lion ◽  
The Sea Of Okhotsk ◽  
The Kuril Islands

Bioaccumulation of HCHs and DDTs in organs of Pacific salmon (genus Oncorhynchus) from the Sea of Okhotsk and the Bering Sea

Chemosphere ◽  
2016 ◽  
Vol 157 ◽  
pp. 174-180 ◽  
Author(s):  
Olga N. Lukyanova ◽  
Vasiliy Yu. Tsygankov ◽  
Margarita D. Boyarova ◽  
Nadezhda K. Khristoforova
Keyword(s):  
Bering Sea ◽  
Sea Of Okhotsk ◽  
Pacific Salmon ◽  
The Sea Of Okhotsk ◽  
The Bering Sea

scholarly journals STATE OF STOCKS AND MODERN FISHERY OF ATKA MACKEREL PLEUROGRAMMUS MONOPTERYGIUS (PALLAS, 1810) IN THE OLYUTORSKY-NAVARINSKY AREA OF THE BERING SEA

2020 ◽  
Vol 200 ◽  
pp. 38-57
Author(s):  
A. O. Zolotov ◽  
O. G. Zolotov ◽  
Yu. K. Kurbanov
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
Aleutian Islands ◽  
Commander Islands ◽  
Spawning Grounds ◽  
Spawning Stock ◽  
Atka Mackerel ◽  
Pleurogrammus Monopterygius ◽  
Commercial Stock ◽  
The Bering Sea

Atka mackerel Pleurogrammus monopterygius is one of the mass species of fam. Hexagrammidae that inhabits the boreal and subarctic waters of the North Pacific and forms two large populations in its western and eastern parts. Reproductive range of the eastern, Aleutian population extends from the Gulf of Alaska, along Aleutian Islands to Commander Islands, with the main spawning grounds at the Aleutians and in the southeastern Bering Sea. From these areas, the fish at early stages of ontogenesis spread widely in system of the Bering Sea currents to the western-southwestern Bering Sea, where the atka mackerel aggregations are formed on the external shelf at prominent capes, as Cape Olyutorsky. Dynamics of the atka mackerel stock in the Olyutorsky-Navarinsky area in 1994–2019 is presented on the base of bottom trawl surveys, fishery statistics, and open NOAA data. After the period of low stock in the middle 1990s, the atka mackerel abundance increased sharply to the maximum in 2006–2008, when the spawning stock in this area was about 9.5 . 103 t and the commercial stock about 14.0 . 103 t. Since that time, trend to decreasing is observed, with the spawning stock 3.6 . 103 t and the commercial stock 5.6 . 103 t in 2013, and recent stabilization at the low level with slight decline continuing. A possible reason of the sharp increase in 2000s could be the intensive transport of the atka mackerel juveniles from the main spawning grounds at Aleutian Islands to the area at Cape Olyutorsky. The catches of atka mackerel in the Olyutorsky-Navarinsky area in 1994–2018 corresponded well with its stock dynamics.

scholarly journals Feeding and food supply of juvenile fishes in the eastern Bering Sea in 2003-2012

2015 ◽  
Vol 181 (2) ◽  
pp. 129-140
Author(s):  
Natalia A. Kuznetsova
Keyword(s):  
Bering Sea ◽  
Cold Water ◽  
Walleye Pollock ◽  
Feeding Intensity ◽  
Sand Lance ◽  
Food Ration ◽  
Eastern Bering Sea ◽  
Fish Juveniles ◽  
Calanus Marshallae ◽  
Atka Mackerel

Feeding of fish juveniles in the eastern Bering Sea is investigated for the periods of 2003-2006 considered as relatively «warm» and 2007-2012 considered as relatively «cold». Small- and medium-sized zooplankton was the dominant prey in the 2003-2006, in particular copepods prevailed in the food of walleye pollock (41.5 %), pacific herring (48.3 %), and sand lance (71.7 %) juveniles, which in turn were the prey for pollock, herring and cod yearlings and other predators. On the contrary, large-sized zooplankton was more abundant in the 2007-2012, so arrowwarms ( Sagitta sp.), large-sized copepods (in particular Calanus marshallae ), euphausiids (mainly Thysanoessa raschii ), hyperiids, and pteropods were the prey for young fish: C. marshallae - for juveniles of pollock (40-45 % by weight) and capelin (32-34 %), Th. raschii - for yearlings of pollock (51 %) and herring (36-46 %), cold-water hyperiid T. libellula - for adult pollock (24 %), juvenile cod (9-18 %) and juvenile herring (9-11 %), whereas portion of fish in the diets was insignificant. In the warm period (2003-2006), juvenile pollock, herring, sand lance and capelin were zooplankton-eaters with the diets similarity 67 %, while yearlings of pollock and juveniles of cod, herring, sandfish, and atka mackerel were fish-eaters preying upon pollock juveniles. In the cold period (2007-2012), the diets of juvenile pollock, juvenile and adult capelin, and juvenile sand lance were also similar at 85-70 % but they preferred large-sized copepods and euphausiids ( C. marshallae and Th. raschii ), while yearlings of pollock, yearlings and adults of herring, and juveniles of sand fish and cod had the diets of 70 % similarity with Th. raschii prevalence. Feeding intensity was high for all species: the mean stomach fullness was 150-200 ‱ for pollock juveniles and yearlings, 200-250 ‱ for cod juveniles, 200-258 ‱ for sand lance juveniles, 302 ‱ for herring juveniles, and 178-250 ‱ for juvenile atka mackerel. The fullness had diurnal rhythm with three peaks: at noon - up to 179 ‱, in evening - up to 213 ‱, and at night - up to 204 ‱ (the data for walleye pollock juveniles in «cold» years only). Daily food ration of juvenile pollock is estimated as 6.7 % of its body weight in the «warm» years and 7.0 % in the «cold» years.

scholarly journals Food and feeding behaviour of Mozambique tilapia (Oreochromis mossambicus Peters) from Borna Reservoir of Maharashtra, India

2016 ◽  
Vol 4 (3) ◽  
pp. 431 ◽  
Author(s):  
Vishwas Balasaheb Sakhare ◽  
Shivaji Gyanba Jetithor
Keyword(s):  
Food Analysis ◽  
Aquatic Insects ◽  
Feeding Behaviour ◽  
Oreochromis Mossambicus ◽  
Summer Season ◽  
Mozambique Tilapia ◽  
Food Items ◽  
Food And Feeding

The food analysis of 80 specimens of Oreochromis mossambicus collected from Borna Reservoir of Maharashtra, India revealed that the food  of juveniles mainly consisted of rotifers (35%), followed by copepods (30%), Chlorophyceae (20%), Bacillariophyceae (10%)  and aquatic insects (5%). While the food items recorded in the gut of adults were Chlorophyceae (40%), followed by Bacillariophyceae (30%), rotifers (15%), copepods (10%) and aquatic insects (5%). During present study it was found that the juveniles of O. mossamobicus mainly feed on zooplankton, and adults on phytoplankton. Intense feeding was noticed during summer season and juveniles were the active feeders.

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