As sea surface temperatures rise, fish are being driven deeper into the water to escape the heat, says a new study.
The researchers from James Cook University in Queensland, Australia tagged 60 redthroat emperor fish at Heron Island in the southern Great Barrier Reef to evaluate the impact of climate change on sea life. The fish were equipped with transmitters that identified them individually and signaled their depth to an array of receivers around the island.
The experiment monitored fish for up to a year and found the fish were less likely to be found on the reef slope on warmer days.
The research team considered temperature, air pressure rainfall, wind and moon phases as reasons for the shift, but discovered the only significant correlation was with temperature — the redthroat emperor were consistently monitored when water was less than 24 degrees Celsius.
Most studies looked at the effect ocean warming would have on fish biology, not on how they would distribute themselves to compensate for higher temperatures, said lead researcher Leanne Currey. “This is a commercially important fish and we are looking at a significant depth shift,” she said. The findings appeared in the journal Coral Reefs.