Small-sized Fish Research Articles

Bioaccumulation and distribution of 137 Cesium in the Humpback Grouper Fish (Cromileptes altivelis)

Melinda K, Suseno H, Prihatini W. 2015.Bioaccumulation and distribution of137Cesium in the Humpback Grouper Fish(Cromileptes altivelis). Nusantara Bioscience 7:180-184.Humpback grouper fish (Cromileptes altivelis) is a highly valuable exportcommodity of food products. The high demand of this species needs to be supported by the intensive coastal aquaculture. However, thecoastal aquaculture has been jeopardized by several threats, for an exampleradionuclide pollutant 137Cesium (Cs) generated fromnuclear reactor wastes. The pollutant accumulation in fish occurs because of continuing exposure to the pollutant-containing medium. This research was conducted from May to June 2015 at the Laboratory of Oceanic Radioecology,Center for Technology of RadiationSafety and Meteorology, National Nuclear Energy Agency, South Jakarta. This research observed the level of bioaccumulation anddistribution of 137Cs inC. altivelis bodies. Radionucleid 137Cs of 2 Bq/mL concentration was inducted to two groups of fish, i.e. mediumsize (average body mass of 65.8g) and small size (average body mass of 34.7g). The calculation of concentration factor valuesatsteady state (CFss) was done to determine the level of bioaccumulation 137Cs in fish body. The distribution of Cs in fish body wasanalyzed by calculating the percentage of accumulation 137Cs in a certain organ to the total accumulation in fish body. The resultsshowed that the value of CFss of medium size fish was 1.23 and CFss for small fish was 2.01. It means that small size fish accumulated 137Cs almost twice as much as larger fish. The accumulation of 137Cs in C. Altivelis was foundmost in its muscle (meat), which was63.34%. This research findings provide reason for us to be more careful in consuming humpback grouper fish coming from Cspolluted water due to the impact ofbiomagnifications of 137Cs in fish.

沿岸における小型刺網漁業とその資源-VII

In the present paper, the author analysed ecologicaly the fish population taken by the stopping-net in the coastal waters of Tomioka, Amakusa Islands during the three years from 1958 to 1960. The results obtained from this study are as follows: 1) Both the inner and outer bay serve as the nursery ground and the fish populations there consist mainly of the small-size (young) fishes (Table 1). 2) The catches per fishing and the coefficients of their variation of Mugil cephalus, Gerres oyena and Lateolabrax japonicus are about 19, 11 and 4 in kg., and 1.3, 2.0 and 1.5, respec-tively. This fact seems to demonstrate the characteristics of this net (Fig. 1 and Table 2). 3) The net is used mostly for the feeders, specially the Mugild fishes, Mugil cephalus in winter (Fig. 2). Further, based on the information given in the previous and present papers, the stopping-net fishery was analysed from the standpoints of the amount of catch, fishery ground and fish population.

A Taxonomic Study of the Genus Ammodytes from the East Coast of North America (Teleostei: Ammodytes)

Two species, Ammodytes hexapterus Pallas, 1831 and Ammodytes dubius Reinhardt, 1838, are recognized from collections from Hudson Baywestern Greenland to Virginia along the east coast of North America. A. hexapterus, which ranges inshore from 41-600N, is a deep-bodied fish with meristic-character counts of V = 61-73; D = 51-62; A = 23-33. It may be partially divided into a group of fish of small size with low meristic counts from semienclosed bays and a group of fish of larger size with a wide range of meristic counts from along exposed coastal areas. A. dubius, a northern and offshore form, ranges from 37-69?N, usually in waters of salinities higher than 30%c. It is a slender sand lance with meristic-character counts of V = 64-75(78); D = 55-67; A = 26-35, which show a marked latitudinal dine.

Geomorphology of the Davis Sea bottom : Beresnov A.F., 1962. Mezhd. Geofiz. Komitet, Prezidiume Akad. Nauk SSSR, Rezult. Issled. Programme Mezhd. Geofiz. Goda Okeanol. Issled., 5: 43–59

The environment of the East China Sea has been greatly impacted by both fishing and land-based pollution over the past decades, with a concomitant decline of fishery resources. Imposition of a seasonal fishing moratorium and a trawling prohibition zone has failed to engender recovery of fish communities. To help understand the respective impacts of environmental factors and fishing activities in the East China Sea ecosystem, fish samples and environmental parameters were collected in prohibited and open fishing areas, during the seasonal fishing moratorium. The inshore area of the East China Sea, corresponding to the prohibited zone for trawling, had extremely high nutrient concentrations and relatively low dissolved oxygen. The diversity index of demersal fish showed significantly negative correlations with nutrient concentrations and positive correlations with bottom-water dissolved oxygen. The inshore area of the East China Sea was heavily dominated by small-sized fishes, such as Gobiids—Amblychaeturichthys hexanema and Apogonids—Apogon lineatus, reflecting low survival of most fish species. In contrast, the offshore areas, with lower nutrient concentrations and higher dissolved oxygen, had higher biodiversity. These findings suggest that eutrophication and subsequent hypoxia is responsible for the limited recovery of fishery resources in the trawling prohibition area of the East China Sea. Therefore, a multi-pronged fishery management that involves both fishing restriction and environmental improvement is urgently needed in the East China Sea.

ミッドウェー・ハワイ諸島周辺とマーシャル・ファンニング諸島周辺に於けるメバチの漁況と体長の周期変化,両周期変化間及び両漁場間の関係

1) Fishing condition (rate-of-catch) in sub-areas, A, B and C (Fig. 1) changes periodically; in sub-areas A and B good fishing season is from December to February while in sub-area C nice fishing period lasts from December up to June of next year. 2) Fork-length composition (fork-length frequency) in sub-areas A, B, C and D changes periodically (Fig. 3). In sub-areas A and B, young stage fish occupy most of the frequency from December to March in odd years, small-sized fish do so from December to March in even year, and large-sized fish do so from April to November. In sub-areas C and D, medium-sized fish are dominant from July to December and so are large-sized fish from January to June in the body-length formation. 3) Most part of the frequency is occupied by young stage or small-sized fish in period of nice fishing and by large-sized fish in period of poor fishing in sub-areas A and B. Majority of the frequency is occupied by large-sized fish in period of good fishing in subarea C and by medium-sized fish in period of poor fishing. 4) It is presumed that fish group that has been spawned and has grown in sub-areas C and D is recruited to young stage or small-sized fish groups in sub-areas A and B, young stage or small-sized fish groups in sub-areas A and B are recruited to medium-sized fish group in subareas C and D, and large-sized fish groups in sub-areas A and B and in those C and D interchange with each other.

太平洋北西部に於けるメカジキの漁況と体長の周年変化及び分布と回游について

Changes noticeable in a whole year in the fishing condition (rate-of-catch) and the bodylength formation (body-length frequency) of swordfish, Xiphias gladius, inhabiting in the northwestern part of the Pacific Ocean. The author has made a study by means of summarizing by month the rate-of-catch (the fishing condition) and the body-length frequency (the bodylength formation) have been determined by Kanagawa Prefectural Fisheries Experimental Station for each month for series of years with no regard to any particular year so as to minimize errors happening due to comparative scarcity of data. In so doing, also, he has avoided inclusion of data obtained from other sources than longline in order to eliminate any error arising from use of any differect type of fishing gear. From the study with such precautions the following presumptions have been obtained: 1) The area where swordfish live chiefly in the northwestern part of the Pacific Ocean is defined by Lat. 20°-45°N, Long. 140°-180°E. 2) Fishing condition of this species in a whole year in each of the sub-area within the zone above-mentioned changes in such a manner as is shown in Figs. 4 and 5. 3) The mean body-length of the species in each of the sub-area exhibits such a change as is shown in Figs. 4 and 5 while the body-length formation displays such a change as is shown in Figs. 7 and 8. 4) Swordfish in the area are generally distributed and migrate in such a manner as is shown in Fig. 6. 5) Swordfish in the area may be divided into 4 body-length groups and fish of each group are distributed and migrate in such a manner as is shown in Fig. 9, A-D. 6) High rate-of-catch of this species in sub-areas A-E and G is brought by migration of medium-, and large-sized, fish groups. High fishing rate of this species occurring in January of every year in sub-areas H and I of a young fish group together with a small-sized one and that occurring in May and June in the same sub-areas of medium- and large-sized, one. 7) Recruitment of the small-sized fish group into the medium-sized one is made chiefly in the sub-area F but it also takes place in sub-areas E, H and I.

水産物の腐敗に関する研究-XV

In the previous paper, we have reported that the round fish was slower in putrefaction than the minced muscle. It was also confirmed in the present experiments on the round fish and fillet. But in fish of small size, there has been scarcely found of differences in the process of putrefaction between them. Of course, the rate of putrefaction in these bodies will be attributed to the tenderness of muscle in accompany with their small size. The difference of the putrefaction between the minced muscle and the same muscle cooked at comparatively low temperature (denatured) was scarcely found. It seems, therefore, that the tenderness in the minced muscle has no relation to the rate of putrefaction.

Research Items

Management of Small Artificial Lakes GEORGE W. BENNETT gives a "Summary of Fisheries Investigations, 1938–1942" on this subject (Bull Illinois Nat. Hist. Surv., 22; 1943). The primary objective of fish management is to produce and maintain good fishing. The author defines 'good fishing' as including the element of numbers of fish caught for unit of time or effort, as well as that of size of individual fish. There is much to be done in maintaining these small artificial lakes, and this report gives a valuable summary of researches. The best fishes for these Illinois artificial lakes are large-mouth bass Huro salmoides, white and black crappies Pomoxis nigro-maculatus, bluegills Lepomis macrochirus and black and yellow bullheads Ameiurus natalis natalis. Other fish are apparently of little value in hook-and-line fishing. The chief causes for poor fishing are past improper stocking, large population of rough fish or other fishes of little use for angling, and stunting as a result of over-population. Lakes should be cropped in order to produce and maintain good yields. A cropping plan should include measures to control the numbers of fish of small size as well as the total poundage of large fish taken by anglers. Simple combinations of fishes tested to determine their value for angling shows the bass-bluegill combination to be one of the most satisfactory.

Californian Fisheries

THE report on the commercial fish catches of California for the year 1940 (State of California Department of Natural Resources. Division of Fish and Game. Bureau of Marine Fisheries. Fish Bulletin No. 58 ; 1942) makes available the summaries of commercial fish landings in each region of the State and also includes tables of numbers and nationality of the commercial fishermen and the number of boats of each type engaged in the fishery. A rapid development of the shark fishery is outstanding and is caused by the high price offered for liver oils of high vitamin A potency. This increase in the shark fishery, with intensive mackerel fishing and the large amount of sport fishing, has resulted in an increase of 350 boats fn 1940-41 registrations over the previous year and is most noticeable in the group between 25 ft. and 39 ft. Jong. There has been a steady development of sport fishing in the ocean waters of Southern California, and the amount of small fish required as bait nuist be considered together with its effect on the several species used as bait. The statistical records include not only the sport catch itself but also the harvesting of the small-sized fishes used by the anglers for bait. Sardines and anchovies are the most important in the bait catch,, comprising 98 per cent of the total, the fishes being 2½-6 in. long. A useful list of the common and scientific names of fishes, crustaceans and molluscs involved in the fisheries is given at the end of the report.