Saturday, July 09, 2016
Spectacular 'forests of the sea' kelp fields which span thousands of kilometres and fund a $10 BILLION tourism and seafood industry wiped out by a marine heatwave
Greenies can't help themselves. They can't resist tying any natural disaster to global warming. The dieoff described below happened in 2011, in the middle of a global temperature stasis that had lasted 12 years at that point. Over that period, global temperatures had risen and fallen to the tune of only hundredths of one degree per annum. It was as clear an era of NON-warming as one would ever be likely to find. So global warming CANNOT be responsible for what happened to the kelp: There wasn't any such warming at that time
Hundreds of kilometres of a remarkable kelp forest off the western coast of Australia have been wiped out by marine heatwaves, a study has found.
These 'forests of the sea' make up 90 per cent of the north-western tip of the Great Southern Reef and underpin tourism and fishery industries that pump $10 billion into the Australian economy each year.
About 2,000 kilometres of the Western Australian coastline from Cape Leeuwin in the south to Ningaloo in the north of Western Australia was analysed in a study that spanned 14 years from 2001.
A heatwave in 2011 has been named the primary cause of loss, with 100 kilometres of kelp destroyed, which made up 43 per cent of the kelp in Western Australia. Above-average ocean temperatures in 2012 and 2013 were said to 'compound' these effects.
The demise of the kelp forests is likely permanent researchers have said in a study published in the journal of Science on Thursday.
The forests that covered 70 per cent of shallow rocky reefs in mid-Western Australia have now become 'barren', researcher Dr Scott Bennett told ABC.
Dr Bennett who helped in the survey said he thought his team had initially made an error when they dived into the reefs off Kalbarri.
'We jumped into these waters at sites we've been going to for the past 10 years expecting to see large kelp forests and it was just a desert,' he said.
'We thought we'd made a mistake and got the location wrong. It is just heartbreaking to see such a complex, beautiful, vibrant ecosystem decimated.'
Turf algae had multiplied and tropical fish communities had increased which were preventing the regrowth of the kelp because they were being eaten before they managed to re-establish.
The extensive loss of kelp forests in Western Australia provides a strong warning of what the future might be like for Australia's temperate marine environments.
Climate change was creating more frequent heatwaves helping the southward movement of warmer waters and tropical species to increase in the region.
The survey also revealed that 2.5 degrees Celsius is the 'tipping point' for kelp forests.
Associate Professor Thomas Wernberg, from the University of Western Australia worked alongside Dr Bennett and described the kelp forests as the 'biological engine' of the reef system.
'They are as critical to the Great Southern Reef as corals are to the Great Barrier Reef,' he said.
'They are up to 16 times more productive than our most productive wheat fields and provide the foundations for the ecosystem.'
Species such as abalone and rock lobster thrive in these environments which are some of the most valuable species of marine life for fisheries in Australia.
'The impact has been particularly prominent at northern reefs, where kelp forests have disappeared completely,' Professor Wernberg said.
'Recovery is unlikely because of the large grazing pressure, continued warming and the likelihood of more heatwaves in the future.'
Posted by John J. Ray (M.A.; Ph.D.).