Cyclone damage to Great Barrier Reef

By AAP with AG Staff 8 March 2011
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Corals have taken a beating from Yasi, while sea turtles are choking on rubbish washed out to sea by the January floods.

CYCLONE YASI CAUSED serious damage to parts of the Great Barrier Reef but left other areas unscathed, scientists say.

About 13 per cent of the reef, from Cairns to Townsville, was exposed to Yasi’s destructive forces when the category five cyclone crossed the Queensland coast near Mission Beach on 2 February.

Marine specialists from the Great Barrier Reef Marine Park Authority (GBRMPA) and the Queensland Parks and Wildlife Service this week released their initial damage assessments. They found Yasi affected about 300 km of the 2400 km-long reef, leaving varying degrees of damage.

The good news is that the damage to these reefs has been patchy,” says the GBRMPA’s Dr Paul Marshall. “The areas that faced wind gusts of up to 285km/h were the most seriously damaged. Coral has been broken, and torn from the reef and tossed around.”

Patchy impacts

Branching corals have suffered the most, he says, “with the remnants being strewn across the seabed floor, while large plate corals have been snapped off and dumped into deeper water.”

Some corals that were hundreds of years old were tipped on their sides. But Paul says reefs around major tourism hubs have escaped the cyclone’s wrath.

“Yasi tracked between the main tourism sites in Cairns, Port Douglas and the Whitsundays and we were very pleased to find that those areas are still healthy and thriving with marine life,” he says. “It is important to remember while parts of the reef in the path of the cyclone have been damaged, most of the Great Barrier Reef remains unaffected.”

The GBRMPA will closely monitor the recovery of affected reefs. It’s also planning more research on the effects of cyclones and the recent floods on the GBR and the industries and communities it supports.

After Cyclone Hamish tracked along the Queensland coast in 2009, James Cook University researchers found coral trout could “go off the bite”. Paul says that they have received similar reports from fishers between Innisfail and Bowen following Yasi.

Under pressure

In related news, there are concerns for the welfare of sea turtles living off the coast of southeast Queensland as pollution from the Brisbane floods washes out into the ocean.

Dr Kathy Townsend a marine biologist at the University of Queensland says the pollution and rubbish that has washed down the Brisbane River and out to sea during the January floods would cause problems for sea turtles in coming months, as they frequently die after choking on plastic and other debris.

“The additional amount of flood debris that has been washed into Moreton Bay and surrounds … means the turtles are high-risk,” she says.

The turtles are under pressure as it is from collisions with boats, encroachment on nesting beaches and feral animals eating their eggs, says Kathy. “This is just adding another straw to the camel’s back.”