Kelp forests off the coast of Western and South Australia have been severely affected over the past few years, recent research suggests. This is the third study released this week concerning the kelp forests.
Scientists explain that kelp forests can be regarded as the natural engine which provides enough resources for coral reefs. Besides their tremendous ecological importance, they also serve as a powerful economic tool, providing the Australian economy with $10 billion every year.
According to Dr. Adriana Vergés from the Centre for Marine Bio-Innovation at the University of New South Wales, if kelp forests die, there will be a massive environmental imbalance which will affect tourism and fisheries too.
Dr. Vergés and her team monitored kelp from various sites near Coffs Harbour in the Solitary Island Marine Park over a period of ten years. At the end of the study, they established that the kelp forest was decimated by the drummer fish and rabbitfish, two species which feed on kelp.
Also, researchers noticed that the population of both species increased as well during the same period. It is worth mentioning that the study was conducted between 2002 and 2011, so the situation got worse in the past five years.
Dr. Vergés adds that it is hard to find bite marks in kelp because they are dirty seaweeds, but if you see at least one, it means that there are many fish out there feeding on kelp. Six sites were the most affected as kelp coverage plummeted from 70 percent in 2002 to roughly 20 percent in 2008.
In some areas, it disappeared completely after 2010. Since kelp forests are sensitive to temperature changes, just like coral reefs, the team accounted for this possibility as well. Although the scientists couldn’t find a cause-and-effect link between heatwaves and kelp decline, Dr. Vergés explains that warming affects the kelp’s reproductive process.
Therefore, the kelp forests become less resilient to other environmental factors and invasive species. The researchers noted an increase in the surgeonfish population too, which they associated with the kelp decline.
Surgeonfish is a subtropical species which feeds on kelp forests, just like the rabbitfish and the drummer fish. The difference between them is that the surgeonfish consumes microscopic algae, which contains baby kelp, whereas the other two species graze directly on kelp plants.
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