A new study by NOAA Alaska Fisheries Science Center biologists illuminates predator-prey dynamics between Pacific cod and commercially important snow and Tanner crabs. Scientists examined diet data collected during surveys of the eastern Bering Sea together with spatial models. They discovered the single most important factor related to total crab consumption by Pacific cod is the overall abundance of the Pacific cod population.
However, the study also revealed a critical size-based difference: The total quantity of crab eaten by small cod is related to their physical overlap with crab populations. For large cod, year-to-year variation in overlap had a smaller relative influence on the total quantity of crab eaten. These findings can help improve projections of cod predation on crab and contribute to more accurate crab population models.
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