. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering Ecosystem dynamics 615 Biomass ( x 10 tons) 2 4 6 8 10 I I I I I I n I I I I I I I Capelin, sand lance Herring Squid Atka mackerel 1 Salmon ? Pollock Rockfishes Cods Sablefish Cottids and others Yellowfin sole, rock sole Alaska plaice Other flatfishes Flathead sole Arrowtooth flounder Halibut, turbot Shrimps Crabs Figure 37-4. Equilibrium biomasses of three different regimes in tiie eastern Bering Sea. Very little information has been availabl
. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering Ecosystem dynamics 615 Biomass ( x 10 tons) 2 4 6 8 10 I I I I I I n I I I I I I I Capelin, sand lance Herring Squid Atka mackerel 1 Salmon ? Pollock Rockfishes Cods Sablefish Cottids and others Yellowfin sole, rock sole Alaska plaice Other flatfishes Flathead sole Arrowtooth flounder Halibut, turbot Shrimps Crabs Figure 37-4. Equilibrium biomasses of three different regimes in tiie eastern Bering Sea. Very little information has been available about the benthos. However, recent work, much of which is reported in Section XII of this book, improves this situation considerably. The total equilibrium bio- masses require about 50 g/m^ standing stock of benthos. The existence of this standing stock is entirely possible if we compare the eastern Bering Sea with the well-investigated Barents Sea. Quantitative zooplankton data from the eastern Bering Sea have been sparse; recent information is given in Section X of this book. Soviet studies in the early 1960's were quantitatively deficient, giving only the minimum standing stocks of copepods and no quantitative data on abundant euphausiids (Laevastu et al. 1976). Since the total equilibrium biomasses consume about 50 g/m^ of zooplankton, the annual production of zooplankton must be at least this amount. The annual turnover rate (last column in Table 37-1) (turnover rate - annual consumption/mean standing stock) provides information on the preda- tion and other mortalities of the species or groups of species. In the marine ecosystem, the younger, smaller organisms are most vulnerable to predation. The growth rate of the biomass is highest at the younger ages. Thus the growth rates determine the length of the period during which a given species is most vulnerable to predation. The distribution of biomass with age and the predation-vulnerability (Fig. 37-5) are shown for two s
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