Fish spawning aggregations and the future of fishing

[1]A spawning aggregation of fish is a grouping of a single species in higher-than-usual numbers for the purpose of reproduction. I bet you're glad we’ve got that off our chest!

Fish spawning aggregations or FSA's are amazing natural gatherings of one and sometime many species.  Typically they occur at special places on a reef where the fish somehow "know" to gather. Then in amazing "secret ceremonies" they collectively launch their eggs and sperm to the currents. These aggregations occur not only at a fixed place but also at a predicatble phase of moon and tide.

As fish spawning aggregations concentrate the mature adult fish in a partiicular place this makes them an easy target. People naturally prefer to catch fish when they are easy to catch. Who can blame them! It may seem strange that a fishery would be based on fishing the critical link in the life-cycle that renews it from year to year - but worldwide many fisheries are.

In the modern age of high tech vessels, refrigeration and GPS navigation this makes aggregating fish species very vulnerable to over-fishing at the time when the species is securing the next generation. Oddly, the importance of spawning aggregations to fisheries management has only really become formally recognised over the last decade. Today the seasonal closure of spawning aggregations to fishing is an important tool for fishery managers worldwide.

[2] Before then this knowledge was solely in the hands of the fishers themselves. Thirty years ago one of those fishers was Lyle Squire Snr. Lyle Snr. is the patriarch of our company. In his youth as an avid spear fisher and diver Lyle gained a profound knowledge of the underwater behaviour of many reef fishes.

Lyle’s knowledge and enthusiasm for this subject lead him to work with researcher Dr Melita Samoilys on a project investigating reproduction in coral trout for the Queensland Department of Primary Industries.  When Lyle Snr. started this work, science and management were sceptical about the very existence of spawning aggregations. 

[3]However, Lyle not only knew they existed but also how and when to find them. His knowledge soon became in-demand and he became the go-to man for finding FSA's.  Later, Lyle exported this knowledge around the western Pacific through involvement in programs to identify and protect spawning aggregations. This included a three year survey of the reefs of Palau for the Nature Conservancy and involvement in numerous projects in Komodo national Park in Indonesia, Manus Island in Papua New Guinea and various parts of the Solomon Islands. 

 

[4]Today the coral trout spawning study sites identified by Lyle in 1992 at Scott and Elford reefs continue to be monitored through a collaborative research project between Cairns Marine, the Qld. Department of Primary Industries and the Great Barrier Reef Marine Park Authority. This study, which constitutes the longest time series of spawning aggregation observations on the Great Barrier Reef, is supported by Cairns Marine through provision of vessel and logistical support. 

 

 

 

 

 

[5]Worldwide millions of people depend on reefs for their livelihoods. Fishers in particular have an enormous reservoir of knowledge about the species and places with which they live and work.  At Cairns Marine we use the fact that our professional divers spend more time in the waters of the Great Barrier Reef than anyone else to pool observations and provide real-time on-the-ground information from the reef. We put this information back into the community by contributing to management committees and through our participation in research programs.

 

 

 

 

[6] At Cairns Marine we believe that sustainability must be the cornerstone of industry and we are proud of our connection with the seasonal spawning closures introduced by Queensland government in September 2003. The first year of closures was 2004 (Oct, Nov, Dec) and there have been three nine day closures each year since.

 

 

 

 

 

Resources:

http://www2.dpi.qld.gov.au/extra/pdf/fishweb/StatusReport_CoralReefFinfi... [7]


http://www.reef.crc.org.au/research/fishing_fisheries/statusfisheries/statusline.htm 

Society for the Conservaion of Reef Fish Aggregations

http://www.scrfa.org/index.htm 

Spawning aggregations of reef fishes on the Great BarrierReef : implications for management.

Russell, Martin, 2001
Great Barrier Reef Marine Park Authority Report
ISBN 1 876945 00 1.