Snappers on the Great Barrier Reef

By Jake Kritzer

Fishes of the family Lutjanidae, commonly known as snappers, are a diverse and abundant group of predators on tropical reefs worldwide. Species within the family on the Great Barrier Reef vary in body size and ecology, with the large deepwater 'reds' such as the red emperor being prized targets of both commercial and recreational fishers. However, several smaller, shallow-dwelling species also play a role in the line fishery on the Great Barrier Reef.

Despite the presently low commercial catch levels of smaller snappers such as stripey bass, hussar, and black spot snapper, future increases in the harvest is likely. Increased interest in Asian cuisine in Australia has already seen demand for small tropical snappers increase, and this could increase further if more valuable species become severely depleted, both overseas and in Australia, or unavailable to domestic markets.

Research to date indicates that lutjanids tend to prefer inshore and mid shelf reefs and do not tend to move from reef to reef as adults, except for moses perch that move to coral reefs from estuaries. Snappers also tend to be long-lived fish, for example the five-line snapper can live up to 32 years. Maximum size, however, is reached quite early in life, by which time most are reproductively mature. These fish tend to spawn from late spring to early summer, but it is unclear if they aggregate to spawn.

Because small snappers are long-lived fish, these fish may be vulnerable to overfishing. This highlights the need for more information about the reproductive characteristics of these small snappers if management regimes are to be appropriate. This information may be needed sooner rather than latter, if fishing pressure increases.