Prior to mid 1990s, the spawning aggregation at Whyalla, in northern Spencer Gulf, was fished at sustainable levels for snapper bait. However, in the mid 1990’s, fishers actively targeted cuttlefish, and large numbers of the breeding aggregation were removed from the system. Since the lifecycle of Sepia apama is very short (1-2 yrs), if a cohort of breeders is fished out, the following generation is likely to be severely impacted. To avoid long-term population decline, even local extinction, a renewable moratorium preventing fishing was introduced in 1999. In subsequent years, the cuttlefish numbers increased again, and ecotourism in the area began to thrive, as it does at this writing (2007). The most recent survey, done in 2005, showed a slight decline in abundance since the estimates made in 1998 and 2001. This survey indicates that declines may be the result of multiple factors - not solely over-exploitation from targeted human fishing. More precise molecular data on population genetics will help determine the composition of the hundreds of thousands of cuttlefish that constitute this extremely unique mass spawning aggregation. This is a clear case of ecotourism aiding conservation.

References

The University of Adelaide Cuttlefish Project

Steer, M. A. and K. C. Hall. 2005. Estimated abundance and biomass of the unique spawning aggregation of the giant Australian cuttlefish (Sepia apama) in northern Spencer Gulf, South Australia. Report to Coastal Protection Branch, Department for Environment and Heritage, South Australia. South Australian Research and Development Institute (Aquatic Sciences), Adelaide, RD 05/0012-1.