Biological resources in the Sea of Okhotsk Large Marine Ecosystem: Their status and commercial use

Abstract

The ecosystem studies of biological resources in the Sea of Okhotsk Large Marine Ecosystem (LME), launched by the Pacific Research Fisheries Center (TINRO-Center) in the 1980s, are considered in this brief review. Quantitative data on biomass, distribution density and diet of plankton, benthos, nekton, and nektobenthos were collected annually on three to five integrated expeditions annually covering all seasons. These studies show that the biological capacity and the stock size of commercial aquatic species have always been underestimated. According to the latest estimates, the total organic matter produced annually ranges within 17.85–23.9 billion tons of wet weight, of which the primary production accounts for 63–78%. Production of other components is: microzooplankton, up to 2100.0 million t; bacterioplankton, to 5200.0 million t; euryphagous zooplankton (mainly euphausiids and copepods), to 2520.0 million t; predatory zooplankton, to 480.0 million t; zoobenthos, to 340.0 million t; nekton, to 22.7 million t; nektobenthos, to 2.2 million t; marine mammals and birds, 0.1 million t. The stock status of most species of fish and invertebrates are considered to be in good or satisfactory shape. Fishing is regulated based on the precautionary approach. The current annual commercial catch is 1.5–1.7 million tons. In the absence of harvesting of marine mammals, the populations of cetaceans, pinnipeds and sea otter have recovered.