PICES XV FIS_Paper-2849 Poster
Dynamics of the flounders spawning during the spring seasons 1984-2005 depending on hydrological conditions of the Okhotsk Sea
Elena N. Andreeva, Svetlana V. Davidova and Anatoly V. Smirnov
Pacific Research Fisheries Centre (TINRO-Centre), 4 Shevchenko Alley, Vladivostok, 690950, Russia. E-mail:
During 1984-2005, catches of fish eggs in the Okhotsk Sea were dominated (97%) by flounders (Pleuronectes quadrituberculatus, Hippoglossoides (robustus and dubius), excepting the eggs of walleye pollock (Theragra chalcogramma). The eggs of flounders were widely distributed in the waters of the Okhotsk Sea above depths of 16-1000 m. However, highest egg densities were found in three areas. Average density of eggs near the western coast of the Kamchatka Peninsula changed year to year from 10 to 80 eggs per m². At the northern part of the Okhotsk Sea – the Pritauiskiy shelf and Schelikhov Bay - average density changed from 2 to 66 eggs per m². According to long-time observations, these areas were the main spawning grounds of flounders in March-July above depths of 40-170 m. Maximal catches of flounders were collected in “hydrological warm” spring seasons characterized by small area of ice cover (1984-1996). Since 1998 (1998-2005 - “hydrological cold” spring seasons) decreased of catches of flounders eggs was observed. On the decadal scale, a negative correlation exits between the number of flounder eggs and the degree of development ice cover (-0.67). During 1984-1996, eggs of flounders were widely distributed in the Okhotsk Sea, from the Schelikhov Bay to the southern coastal area of the Sakhalin Island, in general above depths of 50-100 m. During 1998-2005, the area of the egg distribution significantly decreased and eggs were caught in deeper areas, 100-200 m.
PICES XV FIS_Paper-2839 Poster
Observations on the morphology and distribution of gonatid paralarvae in the northeast Pacific
John R. Bower, Saya Shimura and Shuichi Abe
Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido, 041-8611, Japan
E-mail:
Gonatid squid paralarvae in the North Pacific are difficult to identify because most species are undescribed. In this study, we used genetic techniques to identify and describe the paralarvae of several gonatid species, and then examined their distribution patterns. Paralarvae were collected during seven summer cruises (1999-2006) in the North Pacific aboard the Hokkaido University ship Oshoro Maru, and specimens were divided into morphotypes based on their physical characteristics. The PCR was then used to amplify and sequence the COI gene. Using this method, we positively identified the paralarvae of two important gonatid species in the North Pacific: Gonatopsis borealis and Berryteuthis anonychus. B. anonychus paralarvae occurred north of the Subarctic Boundary from the Subarctic Current to the Alaska Stream, and previously published size data from juveniles and adults in this region suggest that this species migrates northward during spring. These and other observations will be presented.
PICES XV FIS_Paper-2805 Poster
The Okhotsk Sea pollock stock assessment using GIS “Fishery”
Oleg Bulatov, Olga Moiseeva and Georgiy Moiseenko
Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), 17 Verkhnyaya Krasnoselskaya, Moscow, 107140, Russia
E-mail:
Data were obtained from large Russian fishering vessels in January-April 1998-2006. Pollock biomass was calculated for Kamchatka-Kuril, Western Kamchatka and Northern Okhotsk Sea areas. Software products of ESRI, ArcView GIS, and a server of database Oracle, Oracle9i, were used. Daily data (type of trawls and catch per one hour) from Russian fishering vessels provided the basis for the calculations. In each quadrangle (around 55x55km) biomass was estimated monthly. We found that pollock biomass fluctuated widely in each area both seasonally and interannually. Stock assessment dynamics of walleye pollock is discussed.
PICES XV FIS_Paper-3110 Poster
Environmental effects on landings of penaeid shrimp in the Yellow Sea
Jung Hwa Choi, Dae Soo Chang, Kang-seok Hwang, Young-yull Chun and Jong Bin Kim
Fisheries Resources Research Team, National Fisheries Research and Development Institute, Gijang gun, Busan, 619-902, Republic of Korea. E-mail:
Korean fishermen catch penaeid shrimp in the Yellow Sea (middle of western coast of Korea) by using beam trawl and stow nets. During the past 40 years, the shrimp landings fluctuated with a cycle of about 10 years. Recently, landing decreased rapidly, possibly due to habitat loss and environmental degradation. Land reclamation projects have reduced spawning and nursery grounds in the coastal area, while climatic and hydrological changes could affect growth and survival of shrimps. To evaluate effects of environmental changes, time series of shrimp catch and environmental factors (seawater temperature, salinity, nutrient and precipitation of rainfall season) from 1993 to 2001 are being analyzed. Preliminary results indicated that shrimp catch is related to concurrent seawater temperature and salinity and to nutrient levels and annual precipitation with one-year time lag. We will eventually develop models to predict potential yield and landing of penaeid shrimp based on habitat loss and environmental conditions.
PICES XV FIS_Paper-3157 Poster
Dynamics of oceanographic conditions near the Japanese Archipelago: Fluctuations, processes in ecosystems and mass pelagic species
Vladimir A. Belyaev1, Vladimir B. Darnitskiy2, Elena I. Ustinova2 and Svetlana P. Bomko2
1 Interdepartmental Ichthyologic Commission, Tverskaya Street 27/1, Moscow, Russia. E-mail:
2 Pacific Research Fisheries Centre (TINRO-Centre), 4 Shevchenko Alley, Vladivostok, 690950, Russia
An understanding of the fluctuations in abundance of Far East sardine and others pelagic fishes require specification of their internal population dynamics and a detailed elaboration of oceanographic processes near Japan and Ocean regions. In recent years, catches of sardines by the Russian fleet in the southern portion of the Okhotsk Sea have been many times larger that earlier levels. Scientists from different countries process large amounts of data on near surface atmosphere and the upper and baroclinic layers of the ocean to identify step changes in the environment. This yields an objective picture of interannual variability of the oceanographic conditions. A published spectral analysis of EOF data from the last 50 years of 20th Century in the Japanese Sea identified 11-, 7-8- and 3-4-yr periodicity for the first component; 11- and 2-3yr for the second and 19- and 2-3-yr periodicity for the third component. Another analysis of thermal conditions in the Japanese Sea in 1932-1941 and 1950-1958 revealed periodicity of warming and cooling for 7 years and 3-4 years, respectively. Yet, other authors have shown that water temperature anomalies in any decade or month are practically unrelated to the subsequent anomalies. We report on some features of the internal dynamics of sardine populations relevant to the 20th Century wave of high abundance.
PICES XV FIS_Paper-2780 Poster
Geographic variations of seasonal spawning structure of Pleuronectiformes in the northern Pacific Ocean
Yurii P. Diakov
Kamchatka Research Institute of Fisheries and Oceanography (KamchatNIRO), 18 Naberezhnaya Street, Petropavlovsk-Kamchatsky, 683602, Russia. E-mail:
Variability of spawning timing and several early ontogenetic characteristics were studied for 56 species of Pleuronectiformes in the Bering Sea, Okhotsk Sea and Sea of Japan. Two types of adaptive strategies were uncovered. The first type includes mechanisms to reduce the strength of potential competition for food during early ontogenesis. Given broad geographic diversity of flounder species from higher to lower latitudes and a decline in abundance of particular species from north to south, intraspecies competition is most likely in the north and interspecies competition is most likely in the south. This adaptive strategy implies the following north to south patterns: decline in average duration of spawning; increase in the number of the seasonal-spawning groups; increase in the hierarchical structuring of fauna in this number; increase in the seasonal differentiation of spawning of different species; increase in the number of batch-spawning species; and a decrease of age of metamorphosis causing a reduction of exogenous feeding periods of larvae. The other type of adaptation is the adaptation to seasonal changes of environment, influencing food supply of fish in early ontogenesis. The period favorable for egg and larval development is shorter in the north than in the south. Mechanisms of adaptation include later displacement of spawning timing of some species with increasing latitude. This shortens the time lag between larval emergence and plankton blooms. Most northern species prefer the warm period of the year for spawning, whereas the spawning timing of southern flounder species is distributed more evenly throughout the year.
PICES XV FIS_Paper-2797 Poster
Feeding of mass nekton species in the epipelagic waters of the northwestern Japan Sea
Natalia Dolganova and Artyom Lazhentsev
Pacific Research Fisheries Centre (TINRO-Centre), 4 Shevchenko Alley, Vladivostok, 690950, Russia. E-mail:
Feeding of five basic species of nekton (2500 stomachs) in the upper 50-meter layer of the Japan Sea in the Russia EEZ was investigated in autumn. Squids − Todarodes pacificus and Watasenia scintillans – make up more than 54% of the trawl catch. Prey of adult T. pacificus predominantly consists of nektonic species
(63.5 %), and the prey of young squids largely consists of planktonic species (91%). The daily diet of T. pacificus is 3% and 9% of body weight, respectively. Watasenia scintillans eats amphipods, copepods and euphausiids, accounting for 4.3% of it’s body weight on a daily basis. Three species of fish – juvenile Oncorhynchus gorbuscha and Pleurogrammus azonus, and also Engraulis japonicus – in aggregate account for 41.5% of the trawl catch. Planktonic prey accounts for 70%, and up to 96% of their diet, from 6.5 - 9.3% of body weight daily. There are some regional distinctions in the food spectrums and daily diets. Copepods, comprising one third of total zooplankton biomass, do not play an important role in the feeding of nektonic animals (except for an anchovy), but hyperiids, accounting for only one tenth of zooplankton biomass, are actively consumed by all species of fishes and squids.
PICES XV FIS_Paper-2779 Poster
Feeding of red king crab (Paralithodes camtschaticus) juveniles in the North Pacific and Barents Sea
Maria V. Eletskaya, Vadim A. Shtrik and Minna I. Tarverdieva
Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), 17 Verkhnyaya Krasnoselskaya, Moscow, 107140, Russia
E-mail:
The population abundance of the red king crab, one of the most commercially important crustacean species, has drastically declined in the North Pacific. Larval culture under controlled conditions is currently considered as one way to restock its populations. Our data on feeding habits and rations of 0-4 year old juveniles both in the native area (Russian Far East) and the Barents Sea should become an important component of the final phase of culture cycle: release of the juveniles to the sea. Our studies demonstrated that in both areas the range of prey species expands as the juveniles grow and migrate to deeper waters. Juvenile diet varies in relation to season (summer/autumn). The range of prey species of the juveniles in the Barents Sea differs from that in the North Pacific. For example, in western Kamtchatka main prey species were hydroids, crustaceans, mollusks, echinoids, polychaetes, bryozoans, and sponges, while in the Barents Sea juveniles mainly consumed benthic algae, detritus and silt, echinoids, crustaceans, mollusks, and bryozoans. Interestingly, in Kamtchatka the percentage of juveniles with algae in the stomachs was 13.1%, and the amount of algae constituted less than 1% of all food consumed; at the same time, in the Barents Sea algae were found in 77.7/100% of specimens in autumn/summer, respectively, and constituted up to 100% of stomach contents. Therefore, selection of suitable sites and timing of release of juveniles of a certain age class should consider the depths and the availability of primary food objects.
PICES XV FIS_Paper-2765 Oral
Status of fishes in the outer shelf and upper slope of the Northern and Western Bering Sea
Alexander I. Glubokov
Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), 17 Verkhnyaya Krasnoselskaya, Moscow, 107140, Russia
E-mail:
Up to 4.5 million tons of seafood was harvested in the second half of the 1980s in the Bering Sea, an area of only 0.6% of the global ocean. This makes its productivity commensurable with that of the Peruvian and West African upwelling areas. Fish occupy upper trophic levels and can be regarded as an integrated indicator of the overall ecosystem condition. On the one hand, the status of fish stocks reflect seasonal and interannual climatic and oceanographic changes. On the other hand, it shows the effect of fishing. A gradual transfer to multispecies fisheries requires knowledge of succession regularities of biota in general and fishes in particular. Twenty eight research cruises were conducted in the northern and western parts of the Bering Sea during 1995-2004. The study examined species composition of fish communities, frequency of occurrence and distribution density of 67 fish species in the North and 62 in the Northwest Bering Sea. A qualitative and quantitative seasonal analysis of fish community structure allowed us to make the following conclusions. Density of other bottom fish and the role of dominant species increases when pollock biomass declines. At the present time the bottom fishes of the North and Northwest Bering Sea are dominated by cod and great sculpin, as well as Pollock. In terms of importance they are followed by region-specific community structures: northern rock sole and Alaska plaice in Navarin region; skates and Pacific halibut in Koryak region; and yellow Irishlord and darkfin sculpin in Karagin-Olutor region.
PICES XV FIS_Paper-3094 Oral
Ecosystem-based fishery management; A pragmatic approach
Churchill Grimes1, D. Goodman2, P. Lawson3, R. Marasco4, A. Punt5 and T. Quinn6
1 Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Santa Cruz, CA, U.S.A.
E-mail:
2 Department of Ecology, Montana State University, Bozeman, MT, U.S.A.
3 Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 2032 Southeast OSU Drive, Newport, OR, 97365, U.S.A.
4 Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, WA, U.S.A.
5 University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA, U.S.A.
6 University of Alaska, Fisheries Division, Juneau, AK, U.S.A.
Ecosystem-based fishery management (EBFM) is ever more frequently the focus of fisheries management discussions. While EBFM means different thing to different people, the underlying concern is the overexploitation of fish stocks. Historically, ecology, fisheries biology, oceanography, and fisheries economics have not been well integrated in fisheries management. However, it is generally acknowledged that far more attention needs to be focused on a coupled understanding of many factors for more successful fisheries management. Information on physical, chemical and biological oceanography, population biology, community structure and dynamics, and the likely social and economic ramifications of management changes must be considered explicitly. Recognizing that the process of incorporating ecosystem consideration into fishery management is an evolutionary one, three issues related to EBFM are identified and discussed to facilitate the transition to EBMF. The issues are: (1) how to define EBFM for use by management bodies, (2) what characteristics are specific to an EBFM approach, and (3) what are the next steps that management bodies should take to move forward from the existing management approach that consider ecosystem interactions in an implicit and often peripheral way to one that considers these interactions explicitly.