Warming oceans heat up marine life

Warm sea temperatures might be handy for humans who love the beach, but it’s apparently less fun for some creatures that call the ocean home.

New research involving scientists at Southern Cross University’s National Marine Science Center, as well as the Universities of Sydney and Wollongong, has revealed baby abalone and sea urchins, animals which play an important role in the ocean ecosystem, struggle to grow in warming ocean conditions.

Researchers reared abalone and sea urchin embryos in ocean temperatures projected for the years 2100 and beyond by the Intergovernmental Panel on Climate Change.

Abalone (right) were particularly sensitive to the changes. While sea urchins fared better, they also suffered when temperatures were set to four degrees above current ocean levels.

Dr Symon Dworjanyn, from the university’s National Marine Science Center, said the research results were important given abalone and sea urchins played a very important role in marine ecosystem function.

“They are herbivorous grazers, spending most of their time eating seaweed – which are the equivalent of the trees, shrubs and grass of the ocean. This thins out seaweed providing habitat for a diversity of species,” he said.

Dr Dworjanyn said the research could lead to various possible conclusions on the impact that warming oceans could have on the wider sea ecosystem.

“When these grazers are removed we might expect that important habitats they create by removing large seaweeds will disappear and so will the fish and other seaweeds living in these habitats,” he said. (Other marine life at risk: on right: stingrays)

“However, at the same time the critters tested here will be disappearing. We might predict a suit of more temperature, tolerant tropical species will arrive.

“As we change the world’s climate we are effectively conducting one large, uncontrolled experiment, the result of which is difficult to know.” (Left: box jellyfish)

Dr Dworjanyn also said there could be economic implications if the experiment results were replicated in real life.

“Abalone are Australia’s fourth-largest seafood export, worth close to $200 million a year,” he said.

“But perhaps more importantly, these invertebrates play a pivotal role in maintaining habitats for a whole range of fish and invertebrates species that are the lifeblood of our fishing industry.” (Left: Sea turtle)

The results of Dr Dworjanyn and his colleagues have been published in the scientific journal, Proceedings of the Royal Society B.

Source:
Northern Star,"Warming oceans heat up marine life", accessed February 10, 2011