THE rapid pace of climate change could lead to a swift decline in the number of fish living near the equator, an Australian-led study has found.

Researchers say rising sea temperatures may cause fish in these areas to head to cooler waters, significantly affecting the communities that rely on them.

Lead researcher Dr Jodie Rummer of James Cook University says the study found at least one species couldn't survive in waters that were 3C warmer.

Many fish living near the equator are unlikely to adapt to changes in their environment, because they generally experience only slight changes in temperature.

"There are dire consequences ahead if these fish cannot adapt to the pace at which oceans are warming," Dr Rummer said.

As temperatures rise, fish may lose their ability to evade predators, find food and breed, the study by an international team of researchers found.

Dr Rummer says many equatorial fish populations are already living close to their thermal limits.

She says one outcome may be a decline in fish populations as species move away from the equator in search of cooler waters.

"This will have a substantial impact on the human societies that depend on these fish," Dr Rummer said.

Millions of people who rely on fish for their survival, including those in Papua New Guinea and Indonesia, could be affected, she says.

Dr Rummer says more research needs to be carried out to better understand the link between an organism and its environment to ensure strategies are in place to better protect marine life.

"This is particularly urgent when considering food security for human communities," she said.

The study appeared in the Global Change Biology journal.

The Intergovernmental Panel on Climate Change released a report in 2013 that predicted temperatures and sea levels would continue to rise.