Why are annual catch limits important?
Monitoring catch levels annually—as is done with annual catch limits—helps reduce the chance of overfishing and ensures the long-term biological and economic sustainability of U.S. fisheries. Setting an annual catch limit is a multistep process.
What definitions should I know?
Overfishing: The annual rate of catch is too high.
Maximum sustainable yield: The largest, long-term average catch that can be taken under existing conditions.
Scientific uncertainty: Uncertainty in the information about a stock and its maximum sustainable yield reference points. Sources of scientific uncertainty could include stock assessment results, time lags in assessment updates, projections, potential ecosystem and environmental effects, or other factors.
Management uncertainty: Uncertainty in the ability of managers to constrain catch so that the annual catch limit is not exceeded, as well as uncertainty in quantifying the true catch amounts (i.e., estimation errors). Sources could include late catch reporting, misreporting, underreporting, or other factors.
Step 1: Calculate the overfishing limit
The regional fishery management councils calculate the stock’s overfishing limit, which is a catch level that corresponds to the stock’s maximum sustainable yield. Fishing above the overfishing limit would likely result in overfishing and jeopardize the stock’s capacity to produce maximum sustainable yield. If scientists are unable to estimate the maximum sustainable yield of a fish stock, the councils sometimes choose not to specify an overfishing limit.
Step 2: Recommend the acceptable biological catch
Each council has a Scientific and Statistical Committee that recommends the stock’s acceptable biological catch. This catch limit is adjusted downward from the overfishing limit to account for scientific uncertainty. If an overfishing limit has not been identified, the committee may recommend an acceptable biological catch based on historical catch levels that are considered sustainable.
Step 3: Specify the annual catch limit
Next, the councils specify the stock’s annual catch limit, which cannot exceed the recommended acceptable biological catch. The annual catch limit is often set equal to the acceptable biological catch.
Step 4: Set annual catch targets
Councils can opt to set annual catch targets, which are set below the annual catch limit to account for management uncertainty. Once the council specifies annual catch limits or targets, it develops fishing regulations (e.g., gear restrictions, fish length limits, bag limits, seasons) to achieve those catch levels. Councils also decide on accountability measures to use if annual catch limit or targets are exceeded.