Cuttlefish conservation in Whyalla has been somewhat of a long, but ultimately (for now at least…) successful journey. Talk to the local divers who have been around for a while and they will tell you that early on they did not think there was anything that special about the annual aggregation of Giant Australian Cuttlefish around Black Point and Point Lowly.
They assumed that similar events must be occurring elsewhere, but as word spread and marine biologists and scientists from around the world came to see for themselves, the exceptional nature of the aggregation became clear – it just does not happen anywhere else in the world!
A great story, no doubt… but if it were not for the tremendous efforts of some of those local Whyalla divers and nature’s amazing capability to restore itself when we get out of the way, the chances are that it would now be significantly different story!
Cuttlefish Conservation in Whyalla – Why Whyalla?
In all probability the annual aggregation has been happening for hundreds, if not thousands, of years. The Giant Australian Cuttlefish is a short-lived animal with a life-cycle of one to two years. It is also semelparous, which means it has a single reproductive episode and then dies, whereas us humans (and most animals) are iteroparous and are capable of multiple reproductive cycles over the course of our lives.
The main aggregation area around Point Lowly and Black Point is perfectly suited for the purpose the cuttlefish have adopted it for – it is relatively sheltered and unlike much of the upper Spencer Gulf which is mainly sand, sea grass flats and mud banks, there are numerous shallow rocky reefs which are perfect places for the females to hide their eggs.
So, here is a species that has evolved and thrived in a very specific manner because it has the almost perfect location to ensure its propagation – then along comes man…
Cuttlefish Conservation in Whyalla – Rampant Greed
Things changed significantly for the Giant Australian Cuttlefish population of the upper Spencer Gulf back in 1997 when about 250,000 of them – roughly 250 tonnes – were taken during the annual aggregation by commercial fishermen for export to Southeast Asia.
Up until 1997 there had been very limited recreational and commercial fishing of the cuttlefish, but so lucrative was the 1997 catch that the word spread and in 1998 a much larger contingent of boats arrived in Whyalla even before the cuttlefish did!
Within 4 weeks an estimated 150 tonnes of cuttlefish had been harvested and the stock was so devastated there was basically not much left to catch!
After much local lobbying the South Australian Primary Industries Minister stepped in and, in a widely applauded decision, closed the area to fishing until September 1998 and ordered a three-year assessment of the overall situation.
In 1999 SARDI (South Australian Research and Development Institute) assessed the upper Spencer Gulf population at 182,585 and their subsequent surveys in 2000 and 2001 showed similar, but slightly less numbers.
The next proper survey was in 2005 and then again in 2008 – which showed respective numbers of 127,785 and 75,295.
SARDI commenced their surveys again in 2013 and recorded a total population of 13,492… meaning a 97% decline against the 1999 high of 182,585 – which in itself was recorded after the loss of about 400,000 cuttlefish because of the devastating harvesting in 1997 and 1998.
Those terrible numbers in 2013 prompted a total ban on catching cuttlefish in the upper Spencer Gulf and most interestingly the SARDI surveys of 2014 recorded a population of 57,317 in 2014 and 130,771 in 2015 – which would indicate that the total ban is working, but the total population is still well below where it was after the terrible events of 1997 and 1998.
So for now at least, it looks it looks like the immediate danger may have passed, and we can thank the tremendous lobbying efforts of the local Whyalla diving community for that!