Status of Red Snapper (1988-2005): How has the health of the red snapper population changed over time?
Fishery managers are required by law to prevent overfishing and rebuild depleted fish populations. Overfishing refers to the rate at which fish are removed from a population. Scientists conduct stock assessments to determine the status of fish populations and how many fish can safely be removed from populations without causing them to decline over the long term. If overfishing occurs eventually too many fish will be removed from a population and it will become depleted or overfished (population abundance is too low), resulting in smaller catches.
Fishery scientists and managers define rates of fishing mortality (rate that fish are removed from a population by fishing) to allow a fish population to produce the maximum amount of harvest over time or to rebuild a fish population if it has become depleted. Fishery scientists and managers also define various targets and thresholds for population abundance. For example, they define the minimum abundance level necessary to prevent the population from declining over the long term and the abundance level that would allow the population to produce the maximum harvest over the long term. The latter is used as the “rebuilding target” when populations become depleted or overfished.
In the case of Gulf of Mexico red snapper, the rebuilding target is based on spawning potential. Spawning potential refers to the number of eggs a fish produces over its lifetime in a fished population compared to the number of eggs produced by a fish in an unfished population. The target spawning potential for Gulf red snapper is 26%, which means fishery regulations are designed to increase the population to a level where it is producing about one quarter of the eggs that would be produced by an unfished population.
NOAA’s National Marine Fisheries Service has conducted ten assessments of Gulf red snapper since the late 1980s(2). The most recent assessment was completed in May 2013 (http://www.sefsc.noaa.gov/sedar/). The first assessment was conducted in 1988 and concluded red snapper was overfished (population abundance was too low) and undergoing overfishing (rate at which fish are removed from the water by fishing was too high)(14). Six additional assessments were conducted in the 1990s and another in 2005; all reached the same conclusions - too many fish were being killed by directed fisheries and shrimp trawlers(2).
The red snapper population was rapidly depleted from 1950 through the late 1980s as commercial and recreational landings and shrimp effort increased(13)(16). The population reached its lowest level in 1990, when spawning potential declined to just 2.6%—well below the level necessary to sustain the red snapper population(16). Today spawning potential is about 13%, far higher than just five years ago, and a little over half way to the target level(24).
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