Researcher Pleads To Save Fish From Global Warming

December 9, 2005

Release from: ABC News Online

Some fish species could come under threat if temperatures continue to rise, according to a far north Queensland marine expert.

Dr Marcus Sheaves from James Cook University's ecology department says small lagoons where fish lay their eggs are drying up, meaning major waterways are not being replenished.

He says landholders need to make an effort to keep small lagoons and dams topped up to ensure the survival of fish species.

"In some years even the very big pools will dry right out. So if the big pools aren't connected for a few years and we don't get substantial rainfall and flooding, they get more shallow and become more hostile environments," he said.

"The water becomes warmer, pelicans come in to eat the fish and eventually it just dries out."

The estuarine ecologist says small waterways act as nurseries for juvenile fish before they make their way into major waterways.

But he says that could change with global warming.

"Quite a number of the pools won't be able to replenish their juveniles back into the main river. Little juveniles and marine species like barramundi move into the wetland at very small sizes when they are connected," he said.

"In the wet tropics it happens quite regularly, but in the dry tropics it doesn't happen every year. You haven't got successful entry of juveniles every year.

"What we are doing is that habitats that are recognised as being important as nursery grounds for a lot of species, as more of these pools are converted into farm land and into dams, unless we make sure the connections are maintained then we are going to have less viable habitats such as [for] barramundi."