Marine food webs facing collapse amid rising sea temperatures: Australian study

CANBERRA, Aug. 14 (Xinhua) -- Australian scientists have warned that marine ecosystems are on the brink of collapse as a result of rising sea temperatures.

In a study published on Friday, a team of researchers from the University of Adelaide found growing evidence that ecosystems will not cope well with rising sea temperatures caused by global warming.

The team, led by author Ivan Nagelkerken, from the university's Environment Institute, recreated a coastal ecosystem at the South Australian Research and Development Institute (SARDI) and subjected it to simulated ocean acidification and warming.

They found that further warming of oceans in the near future would have a profound impact on species at the top of the marine food web such as fish.

"An ecological tipping point may be passed beyond which the top of the food web can no longer be supported, with an ensuing collapse into shorter, bottom-heavy trophic pyramids," Nagelkerken said.

"This will weaken the health and sustainability of ocean ecosystems unless species are capable of genetic adaptation to climate stressors in the near future.

"Healthy food webs are critical for ecosystems so that the world's oceans can continue to provide an important source of food for humans."

The research found that marine food webs will be imbalanced as a result of rising sea temperatures with an abundance of weedy plant species but a shortage of invertebrates.

"Where food web architecture lacks adjustability, ecosystems lack the capacity to adapt to global change and ecosystem degradation is likely," co-author Sean Connell said.

"Marine food webs that are not able to adapt to global change show all the signs of being transformed into a food web dominated by weedy algae.

"Even though there were more plants at the bottom of the food web, this increased energy does not flow upwards towards the top of the food web." Enditem