Visual Censusing of Two Coral Fishes Important to the Marine Aquarium Trade.

Abstract

Although overfishing of edible species has been a substantial factor in the degradation of coral reefs (Hughes 1994), little attention has been paid to the effects of removing selected species of coral fishes for the marine aquarium trade. The global catch of fishes destined for distribution to aquarium hobbyists is substantial, and many of the species selected are important contributors to coral-reef ecosystems. In the U.S. alone, coral fishes are kept in approximately 1% of the estimated 86 million households (Andrews 1990). With few exceptions these specimens are caught wild, often from regions where collecting activities are difficult to monitor (Hingco & Rivera 1991) and population data are lacking. Sensible resource management requires that collections be monitored to minimize habitat destruction and overfishing and that catch limits be based on recruitment dynamics of the target species. Here we assess the populations of adult and juvenile dusky damselfish (Stegastes dorsopunicans) and beaugregories (S. leucostictus) at an unexploited location in the northern part of the Caicos Bank in the Turks and Caicos Islands, British West Indies. Juvenile damselfishes meet the saltwater hobbyist's predilection for species of bright coloration, small size, and extended captive survivorship (Spotte 1993). Our objective was to determine if visual censuses conducted quarterly are sufficiently sensitive to detect natural fluctuations in numbers of target species.