PATTERNS OF MATURATION, GONAD MATURITY GRADATION AND CYCLE OF MATURATION OF PACIFIC COD (GADUS MACROCEPHALUS)
Nadezhda P. Sergeeva, Alexander I. Varkentin
Leading Scientist; Head of Department, PhD in Biology; Kamchatka Research Institute of Fisheries and Oceanography
PACIFIC COD, GONADS, OOCyTES, DEVELOPMENT STAGES, CyCLE OF MATURATION, GRADUATION
Gonad size and weight dynamics and gonad-somatic index have been analyzed step-by-step during maturation, oocyte size structure and condition of Pacific cod oocytes in ovaries at different stages of maturation has been figured out. Cycle of maturation and graduation of gonad maturity is demonstrated.
THE SIZE STRUCTURE OF NORTHERN SHRIMP PANDALUS EOUS(MAKAROV, 1935), IN THE EASTERN OKHOTSK SEA WATERS ADJACENT WEST KAMCHATKA
Oksana G. Mikhaylova
Researcher, Kamchatka Research Institute of Fisheries and Oceanography
NORTHERN SHRIMP, WEST KAMCHATKA, BODY LENGTH, MORPHOMERIC ANALYSIS, T-CRITERION, F-CRITERION
The composition of the body length of northern shrimp from the Eastern Okhotsk Sea waters on West Kamchatka was analyzed from the data pool for 2001–2014. The body length varied in the range 24–148 mm. Large-sized individuals with the body length 110–120 mm dominated almost all period analyzed. The average length in the catches varied from 85.5 to 111.5 mm. In some years the average length was less. Some correlations, including between the body length and the carapace length (Lb–Lc) and the body length and the body weight (Lb–W), were analyzed. Comparative analysis of the body length diagrams in 2 seasons of same one year has demonstrated visible (5–10 mm) displacement of the body length toward a higher size from early (or mid) summer as a result of postmolting growth. Aside of the analysis of the size composition of the northern shrimp on West Kamchatka, the first ever general morphometric analysis of individuals provided in mentioned area was carried out, which has indicated that males were minimum similar in body length or weight to females, free of eggs or with eggs on pleopods: the groups demonstrated authentic differences on four characteristics.
ANALYSIS OF THE USE OF JUVENILE CHUM SALMON ONCORHYNCHUS KETA AUTUMN TRAWL SURVEY DATA IN THE ASSESSMENT OF ADULT RETURNS IN THE NORTH-EAST OF KAMCHATKA
Еkaterina S. Voronova, Viktor G. Yerokhin, Eugeny А. Shevlyakov, Mark G. Feldman
Research Assistant; Head of Lab., PhD in Biology; Head of Lab., PhD in Biology; Leading Scientist, PhD in Biology; Kamchatka Research Institute of Fisheries and Oceanography
CHUM SALMON, PINK SALMON, UNDERYEARLING, JUVENILE TRAWL SURVEY, FORECASTING SALMON RECRUITMENT, REGRESSION ANALYSIS
The number of underyearlings in 16 generations of chum salmon (Oncorhynchus keta) was calculated from results of juvenile salmon trawl surveys in the Southwestern Bering Sea. Correlation between the number of the underyearlings and the mature stocks was evaluated from regression analysis. The model used for description of the correlation between observed juvenile chum salmon escapements and adult returns demonstrated satisfactory results about generation abundance in eight of 13 returns observed.
THE DYNAMICS OF THE CHINOOK SALMON STOCK IN KAMCHATKA RIVER WITH REGARD TO THE FISHERY DYNAMICS
Olga V. Zikunova
Researcher, Kamchatka Research institute of Fisheries and Oceanography
CHINOOK SALMON, SPAWNERS, KAMCHATSKY GULF, KAMCHATKA RIVER, FISHERY
Current specifics of the condition of the stock of chinook salmon in Kamchatka River can be characterized by increased spawning runs which demonstrate significant structural transformations; the age composition has changed toward younger groups, and the percent of females has decreased. In the river basins where the fishery management is well organized, including the basin of Kamchatka River, the main factor, limiting the stock abundance and forming biological indexes of salmons is the fishery. An important instrument in interpreting the mechanisms of the influence of the fishery onto the condition of the chinook salmon stock is the analysis of archive and current extensive data pools. The basis data pool consisted of Russian official commercial fishery statistics of chinook salmon catches on drift-net fishing at sea from 1952, drift-net fishing near shore in Kamchatsky Gulf and in the basin of Kamchatka River from 1934. For today 80% of chinook salmon stock in Kamchatka River are harvested by fixed nets set within Kamchatsky Gulf southward from the river mouth. The most impressive effects on the character and scale of the commercial use of chinook salmon are strongly depend on existing multispecies fishery of Pacific salmon in the basin, where the main target species is sockeye salmon. Aside of the nearshore fishery, not the last role in revealed transformation of the structure of the chinook salmon parental stocks and in the size-age composition and sex range, is played by the drift-net fishing at sea.
THE MID-SUMMER PHYTOPLANKTON OF THE NORTHERN PART OF WEST KAMCHATKAN SHELF IN 2008
Ekaterina V. Lepskaya
Leading Scientist, PhD in Biology; Kamchatka Research Institute of Fisheries and Oceanography
OKHOTSK SEA, WEST KAMCHATKAN SHELF, PHYTOPLANKTON, ABUNDANCE, BIOMASS, DISTRIBUTION
Distribution of phytoplankton was examined at two local test sites in the waters of the north part of West Kamchatkan shelf in early August in 2008. 65 species and subspecies taxons of microalgae from 3 classes (Bacillariophyceae, Dinophyceae, Chrysophyceae) were identified. The average abundance and biomass of phytoplankton was respectively 24 and 34 thousand cells/m 3and 305 and 357 mg/m 3. It was demonstrated, that on the local, almost «dot» plots in scale of the general square of the West Kamchatkan shelf, the distribution of the biomass of the phytoplankton was nonhomogeneous, although average biomass on tested sites was similar. Comparison to literature data most likely indicated of seasonal variations of phytoplankton, which are stable during 90 recent years.
THE ANNOTATED LIST OF LAMPREYS ANDFISH OF THE EAST-SIBERIAN SEA BASIN
Аlexander F. Kirillov, Оlga D. Apsolikhova, Filipp N. Zhirkov, Lena N. Karpova, Yury А. Sveshnikov, Evgeniy V. Burmistrov
Assistant Professor, PhD in Biology, Leading Scientist; PhD in Biology, Leading Scientist; Head of Laboratory; Director; Head of Lab.; Head of division; Yakutsk branch of FSBSI “Gosrybcenter”
LAMPREYS, FISH, MARINE FISH, FRESHWATER FISH, SEMI-ANADROMOUS FISH, ANADROMOUS FISH, EASTSIBERIAN SEA, FRESHWATER, CATALOG OF FISH, TYPES OF HABITATS, FISH ECOTYPES, FISHERY
The paper considers the modern taxonomic composition and distribution of lampreys and fish in the East-Siberian Sea basin. Following list includes 3 classes, 14 orders, 25 families, 47 genera and 69 species of lampreys and fish, which inhabit the East-Siberian Sea and rivers and lakes of its basin. Freshwater fish (with anadromous and semianadromous) include 36 taxa from 24 genera, 14 families and 10 orders. The fauna of marine fish is represented by 33 species (including subspecies) from 23 genera, 13 families and 8 orders and has eelpout-sculpin-snailfish shape. The largest orders are Scorpaeniformes — 3 families, 8 genera and 12 species and Perciformes — 4, 5 and 11 respectively. The main fishing effort in freshwater of the East-Siberian Sea basin is focused on catch of whitefishes, which make up about 90% of the total fish catch. Marine fishery is not carried out.