The ‘Illusion of Plenty’ in Fisheries Management

“The problem is when fish are aggregating in these huge masses, fishermen can still catch a lot each trip, so everything looks fine-but in reality the true population is declining,” said Erisman, a member of the Scripps Center for Marine Biodiversity and Conservation. “So as the true abundance is declining, the fisheries data used to assess the health of the fisheries are not showing that and give no indication of a collapse-this is referred to as ‘the illusion of plenty.'”

That is from one of the authors of a new study that found that two important California recreational fisheries collapsed even as the catches remained stable.  More here.

This ‘illusion of plenty’ fits well with a point made before by Daniel Pauly that fish finding technology has distorted our perception of abundance. (I’ve written on that ‘sampling bias’ here.)