Getting real time, accurate fish population data is a weak spot in fisheries management science. Fisheries data coming from fishermen has problems with quality control and bias; fisheries data from the government’s trawl surveys is expensive, episodic, and selectively samples small swaths of the ecosystem. The data issue is nonetheless hyper-critical since the fisheries stock assessment models on which all fishery management decisions are based, even the best ones, are only as good as the data inputs.  Given data limitations, the current ability to cost-effectively and accurately understand what is happening to fish populations in response to management changes and environmental or other factors is characteristically uncertain.

Many fishermen say that the scientists don’t see as many fish as the fishermen do. There are legitimate and sound reasons why scientists and fishermen see different abundances of fish; it doesn’t mean the science is “bad.” In fact, it is quite good in New England. The trend lines for stock biomass are accurate in projecting relative upward or downward changes in overall stock abundances. But these differing perspectives as to what fishermen and scientists “see” out on  the water does produce a confidence gap that is a major problem and science uncertainties force managers to set lower catch limits than might otherwise be possible.

Read the complete article from Talking Fish.