Ocean Sentry
A combination of overfishing and climate change are triggering catastrophic overgrazing of reefs by sea urchins in eastern Tasmania, say researchers.
Professor Craig Johnson of the University of Tasmania and colleagues report their findings today in the Proceedings of the National Academy of Sciences.
Scientists believe climate change is causing stronger winds in the Southern Ocean, which speeds up the rotation of the ocean system that drives the east Australian current. The faster current has caused warmer water to spread further south, to the waters off eastern Tasmania. Research team member Dr Scott Ling also previously discovered that a key predator of the sea urchins is the spiny lobster which is worth $50 million to the fishing industry. The team’s latest research looks at the impact on reefs of the interaction between climate change and the decline in the number of lobster predators due to overfishing.
Professor Johnson and colleagues carried out experiments inside and outside protected marine areas to show that fishing has made reefs more vulnerable to the climate-driven threat of the sea urchin.
The urchins only become a problem when its key predator is overfished, says Professor Johnson…. Read Full Article by Anna e Salleh
