New research reveals fish are diving deeper to escape the heat, and the findings could help predict the effects of future ocean warming.
To make their findings, a team of researchers tagged 60 redthroat emperor fish at Heron Island in the southern Great Barrier Reef, James Cook University reported. The fish were monitored for up to a year, and during this time the researchers observed the fish were less likely to be seen on the reef slope on hotter days.
The researchers looked at temperature, air pressure rainfall, wind and moon phases as potential reasons behind this phenomenon, but could only find a correlation associated with temperature.
"This is a commercially important fish and we are looking at a significant depth shift," said lead researcher Leanne Currey. "If it's not around in the shallows in the future then fishers will have to redirect their efforts and it may be significantly harder to catch them."
The researcher also warned that instead of diving deeper, the fish could instead move south in search of cooler waters at similar depths to what they are used to. This may already be happening, some redthroat emperor had recently been caught off Perth, which is surprisingly far from their typical West Australian coast habitat.
In the future the researchers hope to determine if these commercially important fish will be able to physiologically adapt to warmer ocean temperatures as some other species can.
The findings were reported in a recent edition of the journal Coral Reefs.