In this paper, we consider how marine birds and fish interact. Although some of what we present is only speculative, we identify certain areas that have received little or no scientific study, areas in which further research is needed for a better understanding of the role of commercial fish in the ecology and dynamics of marine birds in the eastern Bering Sea.
Commercial Fish Resources of the Eastern Bering Sea
Most of the fishing in the eastern Bering Sea is done by Japan and the Soviet Union. Japan resumed fishing in the Bering Sea in 1953 (7 years after World War II), the Soviet Union started fishing in the region in 1959, and since the early 1960's both nations have accelerated their exploitation of Bering Sea fish stocks (Chitwood 1969).
Species of major concern to Japan and the Soviet Union include fish—walleye pollock (Theragra chalcogramma), yellowfin sole (Limanda aspera), Pacific cod (Gadus macrocephalus), Pacific ocean perch (Sebastes alutus), Pacific herring (Clupea harengus pallasi), and sablefish (Anoplopoma fimbria)—and snow crabs (Chionoecetes spp.). The distribution of the principal species being harvested in Bristol Bay and the eastern Bering Sea are shown in Figs. 1, 2, and 3. The weight of each of the major species in the total catches made by foreign and domestic fishermen in 1973 is shown in Table 1. In 1972, the catch of commercial finfish in the eastern Bering Sea alone amounted to 5% of the total world catch of marine fishes (H. Larkins, personal communication).
Most species of commercial fish in the Bering Sea are in a state of decline or in a depressed condition from overexploitation (Table 1). This is indicated by a reduction in the catch per unit of effort and in the mean size of fish in the commercial catch (H. Larkins, personal communication). The notable exception is the king crab (Paralithodes sp.), which has increased in abundance in recent years as a result of reduced foreign fishing.
| Species | Catch (metric tons) |
|---|---|
| Fish | |
| Pollock | 1,500,000 |
| Flatfish | 125,000 |
| Pacific cod | 45,000 |
| Herring | 35,033 |
| Salmon | 11,785 |
| Sablefish | 7,000 |
| Pacific halibut | 222 |
| Other | 40,000 |
| Shellfish | |
| King crabs | 26,798 |
| Snow crabs | 17,694 |
| Shrimp | Minor |
Fig. 1. Areas of major concentrations of ground fish (Pacific pollock, halibut, yellowfin sole, rock sole, flathead sole, Pacific ocean perch, and Pacific cod) in Bristol Bay and the Bering Sea.
