Abstract

A number of reef fish, particularly large-bodied, slow-growing and late-maturing species, form aggregations for the purpose of courtship and spawning. Many of these same species have life history traits that render them susceptible to extinction. Factors that contribute to this susceptibility are either intrinsic and extrinsic. Intrinsic factors characteristics such as large body size, long life, slow growth and late sexual maturity, mating systems and behavior patterns that are susceptible to exploitation, Allee effects, specialized habitat or microhabitat requirements, limited dispersal potential, limited recruitment potential, limited geographical distributions or endemism, broad geographic distributions but low abundances locally, or disjunct distributions. Extrinsic factors include characteristics such as over-exploitation, or natural and anthropogenic effects that result in habitat degradation or loss. Data on resident and transient reef fish spawning aggregation species were analysed with the IUCN/SSC’s Susceptibility Matrix to detect species that possess one or more of life history characteristics that render them susceptible to localized extinctions as a consequence of extrinsic factors. The analysis indicated that many transient aggregating fishes, such as groupers and snappers, and resident aggregating species, such as wrasses, parrotfishes, and surgeonfishes, all taken in reef fisheries, are especially susceptible because of over-exploitation. While this outcome is known generally for representatives of each of these taxa, the method used here provides a more rapid and quantitative means of assessing extinction susceptibility for a wide range of species

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