The Indonesian Sea Large Marine Ecosystem (LME) is a tropical LME of about 400,000 square kilometers (km2) situated at the confluence of the Pacific and Indian Oceans. It has a composite structure of environmental conditions, with local areas of upwelling, strong wind-driven and tidal currents, and nutrient inputs from rivers or human activities. The LME is influenced by a monsoonal system, with a pattern of surface currents varying during the southeast and northwest monsoon. It experiences annual and interannual variations in surface temperature. The warm ocean and its links to the atmosphere create the El Niño Southern Oscillation (ENSO) phenomenon. LME book chapters and articles include Morgan, 1989, Zijlstra and Baars, 1990, and Kadri et al, 1999.The Indonesian Sea LME extends in an east/west direction across a distance of 5,000 km. Geologically, it lies at the confluence of three tectonic plates: the Eurasian Plate, the Indo-Australian Plate and the Pacific Plate. There are numerous islands, active volcanoes and earthquake occurrences. For a map of the eastern Banda Sea and the northern Arafura Sea, indicating geomorphology and isobaths, see Zijlstra and Baars, 1990, page 55. The LME has complex ocean-atmospheric dynamics. For a map of surface current patterns during the southeast and northwest monsoon and for the locations of areas of upwelling and downwelling during both periods, see Wyrtki (1958), and Zijlstra and Baars, 1990, p. 56. The influence of El Niño, La Niña and the Australian and Asian monsoons contribute to the unique climate conditions in this region, an object of global climatology research. For more information on Borneo’s Marine Ecosystem and the Greenhouse Risk Factor, see Kadri et al, 1999. The Indonesian Sea LME is considered a Class II, moderately high (150-300 grams of carbon per square meter per year) productivity ecosystem based on SeaWiFS global primary productivity estimates. The Banda Sea, and the Aru Basin in particular, are areas of extensive upwelling. For locations of upwelling during both monsoons, see Zijlstra and Baars, 1990. Nutrient concentrations are influenced by ocean mixing and sea surface temperatures. The sea water exchange between the Pacific and Indian Oceans impacts seasonal cycles of primary and secondary marine productivity. For more information on the plankton system, see Zijlstra and Baars, 1990. Pelagic fish resources appear to be significantly higher during periods of seasonal upwelling. Fish species harvested in this LME are giant gouramy, common carp, milk fish, tilapia, tuna, skipjack tuna, barramundi, anchovy, travelly, mackerel, garfish, shrimp, thumb nail (parrotfish), octopus, squid, crab, and lobster. Black marlin is a highly mobile species, fished recreation ally. The coral reef environment harbors all kinds of reef fish. Ornamental fish species are harvested and exported to the United States, Japan and Germany. These include the clownfish (Amphiprion), damselfish (Dascyllus), and wrasse (Coris gaimardi). Pearl oysters, tortoises and turtles, as well as exotic species of crabs and mollusks living both in salt and fresh water, are found in this LME. There are marked changes in the abundance, activity and composition of almost all components of the pelagic system of the Banda Sea, related to the monsoon-induced alternation between periods of upwelling and downwelling (see Zijlstra and Baars, 1990). However, the Food and Agriculture Organization (FAO) 10-year trend shows a steady increase of the total catch (see FAO, 2003), from 1.1 million tons in 1990, to 1.6 million tons in 1999. There is a high catch percentage for clupeoids (herrings, sardines and anchovies) (23%), coastal fishes, crustaceans, molluscs and demersal fishes. For more information on micronekton and fish, see Zijlstra and Baars, 1990. The Central Research Institute for Fisheries (CRIFI) is under the Indonesian Ministry of Agriculture. The University of British Columbia Fisheries Center has detailed fish catch statistics for this LME. For a portrayal of the data, see the graph above.The fishing practices for commercial shrimp harvesting are harmful to endangered sea turtles that are vulnerable to retention in shrimp trawls as bycatch. Artisanal fishing and aquaculture appear to have less harmful effects. Not much is known about the status of the ecosystem in regards to pollution or coastal habitat alteration. Apart from fisheries, a major ecosystem issue is urban expansion and industrialization along the thousands of miles of coastline of the Philippines archipelago. This has resulted in water pollution from industrial wastes, sewage problems, and air pollution. Oil spills, slowly degrading toxic wastes from chemical and non-chemical industries, agricultural runoff and the dumping of materials such as metals threaten inland and coastal waters. Toxic materials settle into sea-floor sediments where they accumulate as hazards to living organisms that feed on bottom mud. Long-lasting chemicals may enter the food web and contaminate fish and shellfish. There are threats to the reefs and mangroves. For information on ozone depletion and the greenhouse risk, see Kadri et al, 1999.
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