Kelp bass photo: Wikipedia
According to a new study coming from the Scripps Institution of Oceanography, two of the most important recreational fisheries in Southern California have collapsed--barred sand bass and kelp bass. In terms of total biomass, each species has decreased 90% since 1980.
That's the dramatic part. The perhaps more interesting part, in terms of fisheries management, is this: The amount of each of these fish caught has remained stable for years, despite the overall decline. Here's why:
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. 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. (Scripps Oceanography News)
h/t Yale e360
Though both these species have collapsed in Southern California, more widely, the situation is different. IUCN lists kelp bass as being a species of least concern, the lowest ranking a species can get in the spectrum of how threatened a species is.