Marine Reserves Enhance Coral Health
Researchers have found that marine reserves on the Great Barrier Reef reduce the risk of coral diseases
Researchers from the ARC Centre of Excellence for Coral Reef Studies at James Cook University found that coral disease levels were four times lower inside no-take marine reserves, where fishing is banned, compared to outside reserves.
'We surveyed more than 80,000 corals around the Whitsunday Islands for six different diseases that commonly harm reef corals around the world,' says study lead author Dr Joleah Lamb from the Coral CoE.
'We found three coral diseases were more prevalent on reefs outside no-take marine reserves, particularly on reefs with high levels of injured corals and discarded fishing line.'
Wounded corals are more vulnerable to disease. Damaged tissue provides sites where pathogens and parasites can invade, particularly as coral immune responses are lowered while they heal.
Dr Lamb says once a pathogen infects a coral, tissue loss typically spreads from the point of entry.
'It's like getting gangrene on your foot and there is nothing you can do to stop it from affecting your leg and ultimately your whole body. Disease outbreaks can take a heavy toll, with losses of up to 95 per cent of coral cover on some reefs in the Caribbean.'
Discarded fishing line has been found to cause damage to coral reefs and also provide ground for pathogens to grow.
'Fishing line not only causes coral tissue injuries and skeleton damage, but also provides an additional surface for potential pathogens to colonise, increasing their capacity to infect wounds caused by entangled fishing line,' Dr Lamb says.
The study is the first one to show that no-take fishing zones protect the health of coral and emphasises the significant role marine protected areas play on the Great Barrier Reef.