Are mysterious sunfish strandings in WA becoming more frequent?
Redmap WA, 30 Sep 2014.
Throughout the months of May and June each year, the otherwise rarely sighted slender sunfish (Ranzania laevis) have a tendency to strand themselves along Western Australia’s south coast but is this phenomena becoming more frequent?
Over the years, slender sunfish (Ranzania laevis) strandings have been recorded periodically as far back as 1928, when 50 sunfish were reported to have washed up in the Albany area. Fisheries and Marine Officer Diaries from the 1960’s, discovered in the archives at Albany’s Old Whaling Station, also note mass sunfish stranding events.
While strandings of sunfish are considered a natural phenomenon along the south coast of WA, they do appear to be occurring more frequently and involving greater numbers of fish. Reports now occur mostly every year instead of only every few years.
Dr Kim Smith, Finfish Scientist from the Department of Fisheries, has investigated sunfish strandings and says that this increase could just be a result of having more people around to see them. However, significant ocean warming and more frequent strong Leeuwin current events could be resulting in a genuine increase in sunfish strandings.
“To understand the influence of changing ocean conditions, we need to have reliable and long-term records of the strandings”, says Dr Smith.
“Redmap is ideal to record the photographic evidence and other information surrounding sunfish strandings. It will enable researchers to capture valuable data, and create a baseline for further studies”, says Dr Smith.
Beachcombers, beach walkers and budding ‘citizen scientists’ are all urged to log all sightings of slender sunfish to Redmap, and to record as much information as possible when they do so including the size and number of fish.
Interestingly, all slender sunfish seen on beaches in Australia so far have been adults. If any juvenile sunfish (30 cm or less) are found please keep (freeze, if required) and donate to the Department of Fisheries so that more can be learnt about the biology of this mysterious fish.