. Biology of the seas of the Marine biology -- Soviet Union; Hydrology -- Soviet Union. 738 BIOLOGY OF THE SEAS OF THE stenobathic forms. Horizontal movements are more difficult to explain. It may only be suggested that their propagation is restricted by some chemical characteristics of the medium. Moreover, it may be assumed that deep-water animals have a much increased sensitivity to changes in the factors of en- vironment, since they are not subject to daily, seasonal or secular Fig. 362. Bipolar distribution of deep-water animals of the Ocean (Vinogradova). 1
. Biology of the seas of the Marine biology -- Soviet Union; Hydrology -- Soviet Union. 738 BIOLOGY OF THE SEAS OF THE stenobathic forms. Horizontal movements are more difficult to explain. It may only be suggested that their propagation is restricted by some chemical characteristics of the medium. Moreover, it may be assumed that deep-water animals have a much increased sensitivity to changes in the factors of en- vironment, since they are not subject to daily, seasonal or secular Fig. 362. Bipolar distribution of deep-water animals of the Ocean (Vinogradova). 1 Phascolion eutense (Sipunculoidea); 2 Tatianellia grandis (Echiuroidea); 3 Scina wcgleri var. abyssalis (Amphipoda); 4 Munidopsis antonii (Decapoda); 5 Glypho- crangon rimapes (Decapoda); 6 Nymphon procerum (Pantopoda); 7 Hymen- aster anomalus (Asteroidea); 8 Kolga nana (Holothurioidea); 9 Culeolus shumi; 10 C. murrai (Ascidia). (2,000-7,300 m.) V. COMMERCIAL IMPORTANCE OF THE FAR EASTERN SEAS The Far Eastern Seas are commercially very rich. They contain about 800 species offish and approximately 200 of these are commercial or may become so (P. Moiseev, 1953). It is to be noted that 60 years ago fishing in Russian waters was confined to river estuaries and the coastal zones. 'More than 96 per cent of the catch was composed of salmon, Oncorhynchus keta, Oncorhynchus gorbusha and others, which entered the river from the sea for spawning, and about 2-6 per cent was herring, caught in the coastal, low-salinity areas; the remaining yield was composed mostly of Osmerus spenlanus dentex, navaga {Eleginus navaga gracilis) and the Acipenseridae, also caught in the rivers' (T. Rass, 1955). Now the Acipenseridae constitute no more than a third of the yield, and the fisheries have mostly moved into the open sea. The Salmonidae trade, in particular, has mostly moved into the northwestern part of the Pacific Ocean (Fig. 363a).. Please note that these images are extracted from scanned page i
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