Showing papers by "Indonesian Institute of Sciences published in 1987"

Mercury content in the water and marine organisms in Angke Estuary, Jakarta Bay.

Abstract: The methyl-mercury pollution in the marine as well as in estuarine or brackish water environment usually due to industrial waste. In some locations of the Jakarta Bay, the mercury content in sea water was in the range 2.8 to 35.2 ppb and tends to be increase with the rapidly industrial growth in the Jakarta. These values were higher than the normal level of mercury in sea water which usually was not more than 0.15 ppb. The Angke Estuary is one of the fishing area especially for the Jakarta Brackish water culture. This estuary received industrial wastes from the Jakarta city and neighboring areas. In the present paper, the author reports, the result of observation of mercury content in the river water, sea water and marine organisms in Angke Estuary, Jakarta Bay.

Heavy metal content in some seafoods collected from muara angke fish auction place, jakarta.

Abstract: Determination of heavy metal content (Hg, Pb, Cd, Cu, Cr, Zn) in some seafoods collected from Muara Angke Fish Auction Place were carried out during February to July 1979. The results showed that Zn content in seafoods a nalyzed was always much higher than the other heavy metals. The concentration levels of the six heavy metals observed were low. It is almost of the same level as the metal concentration of other seafoods observed in various parts of the world oceans, but still lower than the maximum standard set for human consumption as established by Tasmania, Australia and World Health Organization. The mean per capita consumption of fish in Jakarta is only about 165 g per week, while the Provisional Tolerated Weekly Intake for Hg, set by WHO/FAO at 300 ug level, would be attained by consuming 1500 g Rastrelliger sp., or 698 gPenaeus setiferus, or 545 g Sepia sp., and or 1250 g Pecten sp. Therefore, at present the level of metal content in fishes sold at TPI Muara Angke can be considered as not dangerous to human health as long as these quantities are not surpassed.

Larval development of the indonesian blue swimming crab, portunus pelagicus (l) (crustacea : decapoda : portunidae) reared in the laboratory

Abstract: A number of 137,870 freshly hatched larvae of Portunus pelagicus (L) were reared in one thousand litre container. The combination of Brachionus plicatilis and newly hatched nauplii of Artemia salina were fed to the larvae. The number of megalopa obtained was only 277. Ecological factor such as temperature, salinity, pH and dissolved oxygen were recorded. The effect of different food sources of the previous authors are compared. The detail description of the four zoeal stages and one megalopal stage are made and figured with emphasis on the number and type of setae on each appendages. A pattern of zoeal chromatophores is also sketched and described.

Beberapa Jenis Kerang Kijing (Suku: Unionidae) Dan Keong Di Tepi Perairan Sungai Rengas Dan Sungkai, Propinsi Jambi

Abstract: RISTIYANTI M.MARWOTO. 1987.Some fresh water mussels family L'nionidae and gastropods from Rengas and Sungkai Rivers in Jambi province. Berita Biologi 3(7): 306 -309.Four species of unionids were found in Rengas river; of these Pseudodon vondenbuschianus,Contradens ascia dimotus,Ctenodesma sp.and Rectidens gracilis,while Physunio superbus and C. ascia dimotus were found in Sungkai river.The density of p.superbus was higher than the other species (7 ind/0.09 m ),it seems was affected by the organic detritus and the differences of the substratum sediment.Some of P.superbus were mature with many eggs and glochidia larvae inside the outer gills.The length of this mature mussels is 28 - 56 mm, while the average is 52 mm.The difficulties in finding young Union idae may be due to their size is relatively small it was or caused by the specific biology of these animals.The occurance of some gastropods in Rengas and Sungkai river were also discussed.

Keong Gondang Pila Ampullacea : Makanan Dan Reproduksinya (Gastropoda : Ampullaritoae)

Abstract: M. DJAJASASMITA. 1987. The apple-snail Pilaampulacea: its food and reproduction (Gastropoda: ampullariidaej. Berita Biologi 3(7) : 342 - 346. The food and reproduction of the apple-snail Pila ampullacea have been studied in the laboratory, reared in aquarium, fed with dead papaya leaves (Carica papaya) and water hyacinths (Eichhomia. crassipes); shrimp crips and fish pellets which are fed by way of trial, were readily eaten.The eggs, 5-10 mm in diameter, are laid in clusters of 15-50 or more, on the aquarium walls about 10 cm off water level. In its natural habitat, in Lake Maja; West Java, the eggs clusters are found stickedon the stems of the kirai palms (Metroxylon rumphii) (which grow densely in the lake) about 75 cm above water level.In the ponds of the Bogor Botanical Garden, the egg cluster were attached on the stems of the aquatic plants (Cyperus papyrus, Hanguana malayana, Sagittaria lancifolia and Thali geniculata) 20-70 cm off the water edge.The egg cluster is covered by a calcareous layer, it is presumed, that this calcareous covering may absorbed dew/rain water, to prevent the eggs desiccating, Some egg clusters laid in the laboratory which are not provided by calcareous layer (it seems due to the physiological disturbance) were desiccating and failed to hatch. The females may deposit 1-2 egg clusters monthly in the rainy season, or may not at,all in the dry season. The peak of the spawning is coincided with the rainy season.

Currents and mixing on the sill of ambon bay measured with drogues

Abstract: Currents and mixing properties on the sill of Ambon Bay were measured with drogues. Current speed of 0.62 m/sec was observed. A mixing model suggests material released on the sill would decrease by a factor of 2 x 104 in one hour. Drogue construction and data reduction methods are described.