Preview

Izvestiya TINRO

Advanced search
Vol 199 (2019)

BIOLOGICAL RESOURCES

3-18 596
Abstract

Dredgе survey (177 stations) was conducted in the northwestern Tatar Strait (northward from 48° N) at the depths 14–82 m in summer 2018 (from July 21 to August 7). In the dredge catches, 76 species and taxa of benthic invertebrates are recorded, including 42 epibenthic species, mainly Ophiura sarsi, Evasterias echinosoma, Strongylocentrotus pallidus, Paralithodes brevipes, Cucumaria japonica, P. camtschaticus, Mizuhopecten yessoensis, and S. intermedius. The areas of their aggregations are determined. The largest area was occupied by the settlements of polyphagous S. pallidus (5100 km22 at the depths 30–60 m). Specific biomass of epibenthos is calculated, its average value within the surveyed area was 21.5 ± 2.0 g/m2. Depth ranges of the species domination are defined. The dominant species changed with latitude: in the southern part of the survey, Paralithodes camtschaticus dominated with the biomass of 5.1 ± 4.4 g/m2 in the upper 20 m layer (48–49° N), replaced at the depth of 20–30 m by P. brevipes (22.2 ± 14.2 g/m2 between 48–49° N) or C. japonica (28.2 ± 3.0 g/m2 between 49–50° N), both species changed deeper to S. pallidus (4.3 ± 1.1 g/m2); in the northern part of the survey (50–51° N), S. intermedius dominated in the upper 30 m layer with the biomass of 14.7 ± 9.5 g/m2, Mizuhopecten yessoensis (9.7 ± 6.2 g/m2 ) and Evasterias echinosoma (5.1 ± 1,0 g/m2 ) prevailed in the depth range of 30–40 m and were replaced by S. pallidus (18.0 ± 9.5 g/m2) below 50 m; in the northernmost shallow tip of the Strait, Ophiura sarsi dominated absolutely with the biomass of 13.0 ± 1.1 g/m2) in the whole depth range down to 30 m. The greatest species richness and abundance of epibenthos were observed at the depths not exceeding 40 m. Statistically significant decreasing of quantitative parameters of the epibenthos with the depth is observed because of the bottom temperature and topical diversity declination with depth. However, environmental conditions have no significant impact on latitudinal distribution of abundance, wealth and species diversity of the epifauna in the surveyed area. The grouping of epibenthos with specific species structure that could be classified as the circumlittoral one is defined in the upper shelf zone in the northernmost area with the depth < 30 m (somewhere < 40 m).

19-34 1091
Abstract
The monitoring of chum and pink salmon escapement to spawning grounds in the Amur River basin was stopped in 2009. To start it again, a proved choice of the rivers is necessary for adequate controlling of these species number, by the spawning habitats of their population groups within the basin. For this purpose, results of the monitoring in 1949–2000 and the data on human settlements in the medieval times are analyzed. The lower reaches of the Amur were anciently inhabited by the paleoasiatic Nivkh people and the upper reaches where the fall chum spawned in spring waters were inhabited by the people of Pokrovskaya archeological culture — their burial grounds coincided with the spawning area of fall chum salmon. To reach these spawning grounds, fall chum salmon migrated up to the distance of 3427 km from the Amur mouth, but since the 20th century they occur rarely in the upper reaches of the Amur, in particular within Chinese territory where they are not observed in more than 50 years; recently they spawn in spring waters at the distance 500–1200 km from the Amur mouth, mainly in its right tributaries. The reproduction centers of other two populations of chum salmon, as the summer chum and fall chum breeding in hyporheic waters, are located in the Amgun River basin (the lower left tributary of the Amur). The fourth population is the lake chum salmon breeding in spring waters of Lake Chlya located on the left bank in the lower reaches of the Amur River. Centers of reproduction for both pink salmon populations, differentiated by even and odd years of spawning, are located in the Amgun River. Several test rivers are selected within all mentioned centers of reproduction, they are: Kerbi, Duki, Im, Somnya, Aksha, Khilka, Beshenaya, Gur, Anui, Khor, Kur, and Bira. This list is similar to the list of the rivers where chum and pink salmons were monitored in the 20th century
35-48 536
Abstract
Current size structure of mussel Crenomytilus grayanus in the coastal waters at Primorye (Japan Sea) is considered on results of diving surveys conducted in 2003–2018. In total, 3635 mussel specimens were weighed and measured. Size structure of the mussel settlements is determined for each surveyed area using the data on shell length. The following parameters are evaluated: i) index of settling — ratio of mollusks number with shell < 30 mm (spat, yearlings) and > 50 mm (adults); ii) index of maturation — ratio of mollusks number with shell 35–50 mm (pre-reproductive) and > 50 mm (adult); iii) index of commercial recruitment — ratio of mollusks number with shell 90–100 mm (recruits) and >100 mm (commercial stock). The portion of mussels with non-commercial size exceeds 50 % in most settlements that indicates their active natural reproduction. The index of settling varied from 0.03 to 1.80, by areas; the index of maturation — from 0.04 to 0.58; the index of commercial recruitment — from 0.03 to 0.53.The indices variations are not proportional and depend on presence of the pelagic larvae in plankton and on survival of the juveniles. Low settling of spat in some years could be leveled by its good survival in favorable environments. Potential annual recruitment to commercial stock of C. grayanus in the coastal waters of Primorye is estimated as 5 . 103 t. State of the C. grayanus settlements beyond the areas of anthropogenic impact and active fishing is evaluated as stable.
49-63 421
Abstract
The water temperature difference between relatively cold and warm years is not significant for somatic growth and number of sclerites in the external zone of scale out of the annual ring («plus zone») for yearlings of coho salmon in the lower stream of the Bolshaya River (West Kamchatka). The temperature effect is ambiguous and depends on month. In 20 days since May 15, number of the sclerites formed in this zone is definitely higher in warm years (0.77 sclerites, on average) than in cold years (0.51 sclerites), but in 120 days the difference almost disappears: 10.39 sclerites in warm years and 10.13 sclerites in cold years. So, each scleritis forms in approximately 10.4 days during June-August, no matter either warm or cold year it is. In September, the number of sclerites in the «plus zone» could be even smaller in some warm years than in some cold years. The temperature effect absence can be explained by low temperature in the river during the whole period from May to October (6.44 о C in May, 8.80 о C in June, 11.83 о C in July, 12.25 о C in August, 10.10 о C in September, and 6.33 о C in October, on average), that is close to the lowest limit of the optimal temperature range for coho juveniles (11.5–16.8 о C). Difference of the yearlings body length is also insignificant: in the period of 20–90 days from May 15 of 2007–2018, their mean body length increased in 2–5 mm more in the years with temperature above the norm in July than in the years with temperature below the norm, but within the period from middle May to late August the increments values coincide frequently for both types of years. All differences in the body length and number of sclerites between the coho yearlings in warm and cold years do not exceed the level of statistical errors. That’s why merging of all materials on juvenile coho salmon in the Bolshaya River is recommended, without their separation to cohorts of warm and cold years.
64-82 484
Abstract
Structure of scales is investigated for coho salmon juveniles from several sites of their feeding in the Kamchatka River basin, from Pushchino (685 km from the river mouth) to Lake Nerpichye (at the mouth). The underyearlings begin their migrations over the river basin to individual plots soon after their emerging from nests, only part of them feed and winter at the spawning grounds (between Pushchino — Milkovo). A number of coho juveniles stay for feeding and wintering in the tributaries of the Kamchatka River, some of them migrate during spring–summer floods (mid May–June) to the old water bodies in its upper and middle reaches (near Milkovo, Dolinovka, Taezhny, Dedova Yurta, Lake Kulpik) and to the floodplain and lagoon–estuary lakes (Lake Kurazhechnoye, Lake Kursin, and others), having or yet having no scales. Aboriginal coho salmon never spawn in these floodplain water bodies, but the juveniles are observed there all the year round. After wintering, seasonal growth and forming a zone of closely-spaced sclerites of scale (ZCS) — annual ring start in early May or middle May (till early June for some individuals), both for coho yearlings and older juveniles. An additional ZCS (1st type) can be formed earlier on the coho scale in some lakes because of the feeding change. Besides, another additional ZSC (2nd type) can be formed on the scale of coho yearlings (1+) in the old water bodies at Dolinovka, Taezhny, Dedova Yurta, in the lakes Kulpik, Kurazhechnoye, Kursin, and Azabachye and in the Azabachya Channel (at the Dyakonovsky Brook) in late July — August because of seasonal changes in the feeding.
83-97 717
Abstract

Data on biology, ecology and fishery of asiatic smelt in the Uda River during its spawning migration are analyzed. The spawning begins in May-June in 2–11 km from the river mouth and lasts 3–10 days. Timing of its start varies from May 22 (2014 and 2018) to June 14 (2001), with 24 days difference. The spawning migration begins under the water temperature 6.0 оС, during the spawning the temperature varies from 6.2 to 11.9 оС. The river flow velocity on the spawning grounds is 1.2–2.6 m/s, the river depth varies from 0.3 to 2.5 m. Age of the spawners is 2–8 years, their length is 11.5–32.0 cm and weight 10.8–275.0 g, males usually prevail in number (63–81 %). Depending on the year-class strength, the fish in age of 3 or 4 years prevail among the spawners. After spawning, females leave the spawning grounds immediately — in that time their occurrence in the catches below the spawning grounds can reach 85 %. Size of the spawners decreases during the migration, for males the decreasing was from 19.0 to 15.0 cm in 2007, from 20.2 to 18.8 cm in 2014, from 19.3 to 16.6 cm in 2015, and from 19.4 to 16.0 cm in 2016, for females — from 21.0 to 18.0 cm in 2007, from 22.1 to 19.6 cm in 2014, from 21.3 to 19.0 cm in 2015, and from 24.5 to 16.1 cm in 2016. Annual increments of the smelt body length are 0.7–7.8 cm, on average 3.9 cm, for the body weight 17.1–39.9 g, on average 32.1 g. The minimum registered size of mature male and female was 11.5 and 13.0 cm, respectively. Percentage of the smelt with non-commercial size during spawning migration was 19.2 % in 2007, 0.4 % in 2014, 15.4 % in 2015, and 28.4 % in 2016. The group linear growth of asiatic smelt could be approximated by Bertalanffy equation: L = 30.5 [1 – e–0.317 (t – 0.533)]. Its body length dependence on weight is described by the equation of simple allometry: W = 0.002 L3.380 (determination r 2 = 0.92–0.99). The body weight depends on age as the function: Wt = 2.974t 2.136. Individual absolute fecundity of the smelt in the Uda varies from 11300 to 141300 eggs, on average 52500 eggs in 2016 and 50400 eggs in 2007; these values are close to the smelt fecundity in the Ulbeya and Inya rivers. The fecundity variation generally increases with the age: the registered ranges of absolute fecundity (thousand eggs) were, by age groups: 19.1 for 3 years, 53.5 for 4 years, 37.8 for 5 years, 57.5 for 6 years, and 60.3 for 7 years old fish, the ranges of relative fecundity (eggs/g of body weight) were: 864, 537, 565, 501, and 449 eggs/g for the same age groups. The total population fecundity was 32.7. 109 eggs in 2016. The individual absolute fecundity has the following dependencies on body length, weight, and age: AF(L) = 0.001 L3.437, AF(W) = 0.650 W0.986, and AF(t) = 1.661 t 2.250, respectively. The stock of asiatic smelt in the Uda is represented by migrating fish only. Its fishery was conducted by 8 companies, their total annual landing increased from 10 t in 2012 to 373 t in 2017 and slightly decreased recently: the mean landing for 2013–2019 was 276 t. The spawning biomass of smelt was estimated from 637 to 1734 t, by years, that was about 70 % of the biomass of mature smelt in the Shantar Sea.

98-116 643
Abstract
The data on northern shrimp Pandalus eous from the northwestern Japan Sea are presented, as the bioanalysis results for 204,502 ind. in trawl catches of research and fishing vessels collected in 2004–2018. The data were combined in the common database that allowed to consider annual time-series of biological parameters with 10-day resolution and to reveal long-term cycles of these parameters and determine their periods and phases. Dynamics of the mass molting was clarified for certain years. Duration of reproductive cycle for the northern shrimp females in the Japan Sea is determined as 2 years. In the first year of this cycle, the gonads develop in intersexes and females (group I) that is finished with their pre-spawning molting and spawning. In the second year of the cycle, the females (group II) hatch the eggs on pleopods, release the larvae, and then molt, too. Appearance of the hairs for egg attaching to pleopods in the process of molting is considered usually as a sign of the females transverse from the group I to the group II. In the studied population, the females of both groups were presented in the catches in approximately equal proportion throughout the year. Molting of both groups occurred simultaneously, with the peaks in early-middle May and finish by the end of June. New reproductive cycle for one of the two groups started in July. The gonads of group I and the eggs of group II developed intensively from November to March-April. Hatching of the larvae proceeded actively in March-April, with the peak in early April, spawning — in April-May, with the peak in early May. Hence, in the scale of population, the time from the gonads appearance to completion of their development and spawning for 50 % of the group I individuals is 7 months and the time of gestation for the group II is 11 months. Sex change in males began in August-October, the transitional stage between the peaks of molting lasted about 8 months: from the summer-autumn molting of males to the pre-spawning molting of intersexes — during this time they change their secondary sexual characteristics. In total, five mass molts of northern shrimp in the northwestern Japan Sea are observed annually: i) winter molting of males, with the peak in middle February; ii) pre-spawning molting, with the peak in early May; iii) molting of females after hatching of larvae, with the peak in middle May; iv) summer-autumn molting of males with partial sex change, with the peak in early September; and v) autumn molting of females, with the peak in early November. All molts have similar dynamics: each of them lasts about 3 months with the intensive molting during 1.0–1.5 months, at the peak of molt the portion of molting shrimp in catches increases to 55–71 % of the respective group. Generalized scheme of reproduction-molting cycle of northern shrimp in the northwestern Japan Sea is proposed.
117-121 687
Abstract
Morphological description is given for whitebrow skate Bathyraja minispinosa caught in the northwestern Pacific in 1978–1989, both juveniles and adults. Counts for vertebras, pectoral fin, teeth rows, and intestinal valves are presented. The species biology is discussed.
122-128 467
Abstract
Ability for hematopoiesis of spleen, intestinal mucosa, and liver is investigated for early ontogenesis of common bream Abramis brama L., a species of bony fish widespread in the Russian waters, including Astrakhan region. The samples (24 ind.) were collected in the fish farm in Kamyzyaksky district of the region in middle May 2018, after hatching. Histological analysis was made by conventional methods. Both spleen, liver, and intestinal mucosa were formed in the first days after hatching. In the spleen, such signs of hematopoiesis as dispersed new developing blood particles were found just in the first day. In the intestinal mucosa, the first foci of hematopoiesis appeared in the nineteenth day. These organs were formed completely by the end of larval development, and the most intense level of hematopoiesis was observed in that time, with forming of blood cells of all rows of hematopoiesis. On the contrary, no signs of hematopoiesis were found in the liver throughout the larval and juvenile periods.
129-140 600
Abstract
Eelpout Lycodes brashnikovi is a common species of bottom ichthyofauna in the waters at West Kamchatka. It distributes through the whole surveyed area, with sporadic dense aggregations at the depths of 50–150 and 200–300 m. It is an eurythermic species. Adult fish with the length 36–45 cm prevail in its trawl catches (on average 59.3 %); its maximum length is 52 cm. Catches of other species from the family Zoarcidae are insignificant on the shelf of West Kamchatka in summer, so Lycodes brashnikovi is considered as the most numerous representative of this family in this season.
141-151 618
Abstract

In vitro morphological development of whitespotted greenling Hexagrammos stelleri from the northern Okhotsk Sea is described in detail and illustrated from the eggs fertilization to the larvae transition to exogenous feeding. Mean diameter of the fertilized eggs is determined as 2.03 mm (1.80–2.30 mm). The embryos hatch in 30 days and 6 hours after fertilization of eggs under the water temperature of 7.1–12.4 оC (on average 11.5 оC). The hatched prelarvae have the size TL 7.73–9.20 mm (on average 8.49 ± 0.09 mm) and SL 7.48–8.80 (8.15 ± 0.08 mm).

152-162 1055
Abstract
An instrumental aerial survey was conducted in the Russian part of the Chukchi Sea and the eastern East-Siberian Sea in the spring of 2016 to investigate new technical capabilities for estimating abundance and distribution of ringed and bearded seals on the spring ice. Density of both species decreased with distance to the mainland; the largest concentrations of ringed seals were detected in coastal waters, including the Koluchinskaya and Chaunskaya Bays. Taking into account the portion of seals in the water (on average 32 %) and the portion of seals that were disturbed by the aircraft engine noise and dove (on average 30.2 % of ringed seals and 5.9 % of bearded seals), the number of ringed seals in the surveyed area was estimated as 50,839 (СI 95 %: 25,400–73,859; CV = 23.8 %), and the number of bearded seals as 14,590 (CI 95 %: 6,404–24,560; CV = 31.1 %). These estimates are considered to be biased low, primarily due to asynchronic collapse of the ringed seal snow lairs in different parts of the surveyed area, which caused a highly variable detection probability of this species that was difficult to account for.

ENVIRONMENTS OF FISHERIES RESOURCES

163-178 576
Abstract
The study is continuing, which first results were published in 2019 [Khen et al., 2019]. The main patterns of long-term variability are considered for selected climate indices in the North Pacific and links between them are identified on the common methodological basis. The following indices are analyzed: AO (Arctic Oscillation), PDO (Pacific Decadal Oscillation), Nino 3.4 (index of El-Nino — South Oscillation), ALPI (Aleutian Low Pressure index), NPI (North Pacific index), PNA (Pacific/North American index), SHI (Siberian High index), and WP (West Pacific index). Their time-series are provided on websites of the world climate centers, with exception of the Siberian High index that was calculated from the reanalysis data on the sea level pressure provided by the USA National Center for Environmental Prediction (NCEP) — National Center for Atmospheric Research (NCAR) for 1950–2018. Data were analysed using standard statistical methods. Regime shifts are detected using Rodionov’s method of sequential regime shift detection including the regime shift index (RSI) and tools of automatic detection of the regime shifts with improved performance at the ends of time series. Variations of all indices since the middle 20th century correspond to warming that is not monotonous but combines phases of quick transition from one climatic regime to another — climate shifts and periods of relatively stable state between them. The most important climate shifts happened in 1977 and 1989 and they were noted for majority of the considered indices. Values of the indices heightened in the former shift and slightly lowered in the latter one, except of NPI that had opposite changes. PDO, WP and NPI had another positive shift in the recent years (2015–2017) that allows to assume transition to a new climate regime which will be warmer than the previous one in the last two decades. Long-term periodicity coincided with the 19-year cycle of lunar declination is revealed for PDO, ALPI, NPI and PNA; its spectral power amplifies considerably after removing of high-frequency variability by running 5-year averaging of the time series. Nino 3.4 showed a prominent 11-year cycle, possibly associated with the solar activity. SHI, AO and WP changed with periods about two decades: the main frequency is 26 years for SHI, 20 years for AO, and 17 years for WP, but the peaks of spectral power for the two latter indices is low, i.e. non-periodic oscillations dominate for them. Secondary peaks of spectral power are much lower than the main ones, they correspond to cycles of 7–8 years for AO and PDO, 11 years for WP, and 15 years for SHI. The indices of the North Pacific quartette (PDO, ALPI, NPI and PNA) are closely related between each other with high correlation coefficients (0.67–0.96). The Nino 3.4 index is also linked with them, but with lower correlation (0.45–0.56). SHI has statistically significant relationship with AO only, and WP correlates with Nino 3.4. Contribution of the large-scale climate processes to environmental variability in the Far-Eastern Seas of Russia and the Northwestern Pacific will be considered in the next issue.
179-192 841
Abstract
Published data on direct and indirect impacts of suspended matter on freshwater fish are overviewed, both for short-term (hours) experiments and long-term (weeks and months) monitoring in natural conditions. Lethal or paralethal concentrations of the suspended matter are determined for 18 species from 8 families. Accumulation effect of the permanent concentration is observed for charr Salvelinus malma in the laboratory experiment. The most common fish families of the freshwater ichthyofauna in Russia are ranked by threshold of their sensitivity to suspended matter in the order: sturgeon and catfish (1000 mg/L) — carp (250 mg/L) — perch (100 mg/L) — salmon (10 mg/L, with paralethal concentration 25–35 mg/L). Fish mortality is estimated in dependence on the suspended matter concentration and time of exposure, by species. Environmental consequences of the suspended sediments impact are assessed for fish communities of the rivers of Kamchatka, the Lena River, and the Selenga River.
193-213 897
Abstract
Pacific saury Cololabis saira is widely distributed in the North Pacific, with commercial harvesting in the area between 140–172о E. Relationship of its commercial catches distribution with environmental factors is investigated using the daily SST data, the daily data set of multivariate ocean variational estimation system (MOVE) produced by Meteorological Research Institute (Japan) for the area between 140–159о E (about 95 % of all catches and 100 % of the Russian catches of saury were landed in this area in 1994–2017), and the daily set of saury catches position with 1 km resolution collected by the Russian vessel monitoring system. Spatial resolution for all data sets is upscaled to the resolution of MOVE system (0.1 x 0.1 degree). Contribution and permutation importance for the catch distribution are estimated for 184 possible combinations of SST and MOVE products with the lags of 0–7 days and moving average window from 0 to 7 days using the method of maximum entropy (MaxEnt). For synchronic relationships, the best results are found for SST, water temperature at 50 m depth and its spatial gradient, moreover, SST provides high contribution with the lag up to 2 days and the temperature at 50 m and its gradient — with the lag 3–7 days. The same sets of environmental parameters are used for the catches distribution modeling with GAMs and Random Forest techniques; the latter method shows better accuracy and other indices of the confusion matrix. Year-to-year changes of the total area with predicted conditions favorable for the saury fishery within the EEZ of Russia and Japan correlate strongly (r = 0.96, p < 0.05) with the total annual catch of saury, in particular for the extreme years (high catches in 2008, 2014, and 2018, low catch in 2017).
214-230 630
Abstract
All available deep-water oceanographic data obtained in the Bering Sea in 1929–2019 are analyzed (101,425 oceanographic stations). Lower boundary of the upper mixed layer is determined from the vertical temperature profiles using the criterion of temperature deflection from SST (10 % for June-October and 0.2, 0.3, and 0.5 o С for November-May). The mixed layer is rather thin in June-September, its thickness is 10–20 m over the major part of the sea, and 30–40 m at the straits between central Aleutian Islands. In DecemberMarch, the mixed layer depth increases to 120–160 m in the northern deep-water sea and up to 180–200 m at the straits between central and eastern Aleutian Islands, though it is thinner in plumes of warm waters entering from the Pacific. At the continental shelf, the mixed layer can be traced to the depth of 20–40 m in the eastern Bering Sea and 60–80 m at Kamchatka in December-January and to 60–80 m in the eastern Bering Sea and 80–100 m at Kamchatka in February-March. The mixed layer temperature distribution is distinguished by two completely different seasonal patterns. The winter distribution pattern with the highest temperature in the areas adjacent to the Aleutian Straits is typical for November-June. The summer pattern with high temperature in the Karaginsky Bay, Bristol Bay, and Norton Sound and lower temperature near the Aleutian Straits is typical for July-October. On the contrary, the salinity distribution pattern is stable, with the highest salinity at the central and eastern Aleutian Straits and lower salinity in the coastal zone as the Anadyr Bay and Norton Sound influenced by the river runoff.

AQUACULTURE

231-240 492
Abstract
Pacific oyster Crassostrea gigas (Thunberg, 1793) is a prospective species for aquaculture in Primorye. Marine farms demand the oyster spat for commercial growing. Abilities of the natural spat collecting are evaluated for 8 areas of Peter the Great Bay with the oyster settlements using the data of plankton surveys conducted in the period from 2001 to 2017. Dense concentrations of the oyster larvae suitable for the spat collecting were found in the following areas: i) the northern Amur Bay (depth < 10 m), ii) Novgorodskaya Bay, iii) Perevoznaya Bay, and iv) the area at southwestern coast of Peschany/Sand Peninsula. In these areas, the larvae were observed rather early (early-middle July), with high abundance (103 –104 ind./m3 ), and at all stages of ontogenesis including the last one ready for settling in high concentration (101 –103 ind./m3 ). The spat settling occurred there in middle-late July. Sometimes dense but unstable concentrations of the oyster larvae were found in the Troitsa Bay and in the southern Amur Bay (total abundance < 200 ind./m3 , ready for settling < 20 ind./m3 in the years of poor spawning), timing of the settling was also too variable there (from late June to late August), so commercial collecting of the spat is impossible in these areas.

TECHNOLOGY FOR PROCESSING OF AQUATIC ORGANISMS,

241-248 559
Abstract
Data on fractional composition of proteins and peptides in the dry fermentolizate and starter feed developed in TINRO are presented and compared with that composition in natural prey consumed by salmon juveniles and in compound feed for them used in fish farms. The dry fermentolizate is produced on base of raw pollock with successive processes of grinding, fermentation (45 min. under temperature 45–50 о C with complex enzyme preparation Protosubtilin G3x), bone separation, and pasteurization (15–20 min. under temperature 85–90 оC). The starter feed includes fish flour (pollock), wheat flour, dry fermentolizate, bran, hydrolysis yeast, milk powder, premix, and vegetable oil in a certain proportion. Methods of fractional composition investigation for the water-soluble part of protein component in feeding products are described in detail. The fractional composition is determined using the medium pressure gel permeation chromatography. General chemical composition of the high-protein dry fermentolizate and starter feed is presented. Contents of polypeptides and low molecular weight proteins with MM of 1.0–10.0 kDa, proteins with MM of 0.1–10.0 kDa and > 10.0 kDa for the new-developed starter feed with addition of dry fermentolizate coincide with those for natural prey of salmon larvae and juveniles (chironomids, oligochaetes, gammarus), so it corresponds to real nutritional needs of juvenile salmon.

METHODS OF INVESTIGATIONS

249-255 436
Abstract
New mathematical methods for determining of multicomponent invariants are developed by detection of their constancy using the measures of percentage similarity. Typification of the descriptive sets is proposed. An important type for verification of invariants is considered — generally normalized descriptive sets, with exception of 0 and 1 components. In this type of descriptive sets, the invariants and relative spectra match, the arithmetic mean of multicomponent invariants and the mediant also match. Taxonomic invariants for the macrophyte floras in the Avachinskaya Guba Bay are determined for 1970 and 1991, and their rapid changes under anthropogenic impacts are demonstrated.


Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


ISSN 1606-9919 (Print)
ISSN 2658-5510 (Online)