Warming oceans are impacting the breeding patterns and habitat of marine life, effectively rearranging the broader marine landscape as species adjust to a changing climate, according to a new research statement from Australian national research body, CSIRO, on Monday.
The international team led by CSIRO's Climate Adaptation Flagship and University of Queensland marine ecologists Elvira Poloczanska and Anthony Richardson, included 19 researchers from Australia, USA, Canada, UK, Europe and South Africa. They identified more than 1,700 changes, including 222 in Australia.
According to this three-year study published Monday in Nature Climate Change, marine species are shifting their geographic distribution towards cooler regions and doing so much faster than their land-based counterparts.
Despite the ocean having absorbed 80 percent of the heat added to the global climate system, the ocean's thermal capacity has led to surface waters warming three times slower than air temperatures over land, Dr Poloczanska explained.
"The leading edge or 'front line' of a marine species' distribution is moving towards the poles at the average rate of 72 km per decade, which is considerably faster than terrestrial species moving poleward at an average of 6 km per decade," she said."This is despite sea surface temperatures warming three times slower than land temperatures."
She said winter and spring temperatures, over both the ocean and land, are warming fastest, which might advance phenological events such as the start of growing seasons and the timing of reproduction. In addition, anthropogenic carbon dioxide uptake by the oceans is altering seawater carbonate chemistry, which can impact some marine organisms.
The research team also considered changes in species' life cycle, such as breeding times, to find these are also changing as seas warm.
In addition, although the study reported global impacts, there is strong evidence of change in the Australian marine environment.
Poloczanska said that in Australia's south-east tropical and subtropical species of fish, molluscs and plankton are shifting much further south through the Tasman Sea. In the Indian Ocean, there is a southward distribution of sea birds as well as loss of cool-water seaweeds from regions north of Perth.
"Essentially, these findings indicate that changes in life events and distribution of species indicates we are seeing widespread reorganization of marine ecosystems, with likely significant repercussions for the services these ecosystems provide to humans." She said.
Source: Xinhuanet