Busselton Jetty marine scientists have reported increased fish stocks around the 1.8km heritage listed structure, with fish species data collected since 2007 showing a rise in both individual species sightings and their abundance.
There has been a 30% increase in the annual numbers of species sighted from the Underwater Observatory during the last 12 years and a similar increase in the average number of species sighted each month, with the current species list showing over 150 different species of fish being observed.
Increased diversity and a filling out of the Jetty’s ecosystem has been observed with multiple species taking up similar roles in the ecosystem, for example both Pink Snapper and West Australian Dhufish are now regularly sighted species. These increases in demersal fish observations are also likely influenced by the west coast demersal ban during the spawning season and a promising sign for these stocks.
The repairs to the decking at the end of the Jetty which was damaged by fire in 1999 and the implementation of a fishing exclusion zone at the northern end of the Jetty has helped to ensure plenty of habitat is available to be enjoyed by marine species, with limited human impact.
Marine life observation data has been collected by Jetty staff through daily surveys and includes observations on both the types of fish present and the numbers of individual fish sighted.
BJI Marine Scientist Sophie Teede said the warming of the waters has resulted in sightings of a Queensland Grouper, Reef Bannerfish, Scissortail Sergeant and Lionfish which were observed during the 2011/12 marine heatwave and highlighted the impact that warming oceans will have on species distributions as these species typically show a tropical distribution.
However, a recent phenomenon of very cold water off the West Australian coast had seen the return of species such as Australian Herring and large numbers of Old Wives again being sighted beneath the Jetty.
Local fishermen Graeme Gelmi said he has noticed an increase in Silver Trevally (Skippy), due to the cold water off the West Australian coast. This was supported by Tony Vudrag who regularly fishes on the Jetty and has also been catching King George Whiting and Herring.
The best times to fish at the Jetty appear to be early in the morning or the mid-afternoon and the places that have seen good results are near the end of the Jetty and at the first gazebo.
Blue swimming crabs have also been caught off the Jetty in recent weeks as it is coming into crab season according to Mr Gelmi, however it seems to be squid that is the most popular species caught off the Jetty.