Hotter ocean threatens fish stocks
Rising water temperatures caused by climate change will threaten a rollcall of WA's most valuable fisheries including rock lobster, snapper and herring, research reveals.
Four years after a marine heatwave destroyed fisheries along the Gascoyne and Mid West coasts, the Department of Fisheries has flagged such events are likely to become increasingly common.
The department has released a report into the effects of climate change on the State's fisheries.
It noted there had been a general "southward shift" of some tropical species in recent years, with one known as rabbitfish even establishing a viable breeding population in Cockburn Sound.
However, the department warned there were downsides to the changes because many of the State's most important fisheries would be most at risk from the effects.
Chief among them was the western rock lobster fishery, which is worth about $200 million to $300 million a year and is by far WA's most valuable.
The department said that as sea temperatures rose and the frequency of winter storms across the State's southern half fell, the "recruitment" of baby rock lobsters could suffer.
Many other fisheries were also under threat, including popular recreational target species such as snapper, baldchin groper, dhufish, herring and tailor.
Key commercial species such as prawns, scallops and blue swimmer crabs would also be affected.
According to the department, some key changes to the climate were likely to be an increase in water temperatures, more frequent La Nina events and a gradual weakening of the Leeuwin current.
"With an increased likelihood of changes in the trends of abundance occurring as a result of climate change, there is an increased likelihood of the need for management intervention," the report said.
The research comes amid heightened concerns about the implications of climate change for WA fisheries after a marine heatwave wiped out stocks off the west coast in the summer of 2010-11.
'There is an increased likelihood of the need for management intervention.'" *Department of Fisheries * report
