Scientists: To save Great Barrier Reef, kill starfish
The Great Barrier Reef has lost half its coral since the 1980s, scientists say.
October 2nd, 2012
11:37 AM ET

Scientists: To save Great Barrier Reef, kill starfish

Australia's Great Barrier Reef has lost 50% of its coral since the mid-1980s, much of that because of a ravenous species of starfish that can each consume some 12 square yards (10 square meters) of coral in a year, scientists reported Tuesday.

According to a study by the Australian government's Institute of Marine Sciences and the University of Wollongong, the coral cover on the world's largest coral reef ecosystem suffered damage from tropical cyclones (48%), the crown-of-thorns starfish (42%), and coral bleaching (10%).

If current trends continue, the reef will lose another 50% of its coral in the next 10 years, the scientists said.

Stopping the starfish infestation is the one thing humans can do that can save the reef, they said.

"We can't stop the storms, and ocean warming (the primary cause of coral bleaching) is one of the critical impacts of the global climate change," John Gunn, chief executive officer of the institute, said in a press release. "However, we can act to reduce the impact of crown of thorns."

"The study shows that in the absence of crown of thorns, coral cover would increase at 0.89% per year, so even with losses due to cyclones and bleaching there should be slow recovery," Gunn said in the release.

Reacting to the study, the World Wildlife Fund said Australia must reduce fertilizer runoff as a first step to controlling the crown-of-thorns starfish.

“The debate is over. This latest research demonstrates that more decisive action to cut chemical fertilizer is urgently needed to prevent unprecedented and on-going outbreaks of Crown of Thorns starfish, which are in turn converting the Great Barrier Reef into rubble,” WWF-Australia spokesperson Nick Heath said in a statement.

According to the study, the starfish in its larval stage feeds on plankton, populations of which surge when fertilizer runoff floods the coastal ocean waters with nutrients. So plentiful plankton can lead to swarms of hungry starfish.

The starfish consume the corals by climbing onto them, thrusting out their stomachs, and bathing the coral in digestive enzymes, which liquefy it for ingestion. Adult crown-of-thorns starfish, ranging in size from 9 to 18 inches in diameter and with up to 21 arms, can eat nearly a square foot of coral each in a day.

The WWF's Heath said both the Australian government and the state government of Queensland, where much of the reef lies, need to take action now.

“What this report shows is that we need urgent recommitment from both the Commonwealth and Queensland governments that will significantly reduce chemical fertilizer pollution on the Reef,” Heath said in a statement.

“With the right political will we can stop the march of crown-of-thorns starfish in its tracks and save the reef," Heath said.

The starfish threat to the reef is nothing new, according to the institute's report. The starfish have lived on the reef for 8,000 years, and swarms of the coral predators have been recorded as far back as 1962. The last major outbreak of the creatures was seen in the late 1990s.

But pressure from the cyclones and bleaching resulting from climate change exacerbate the damage the starfish can do, the report said.

"The combined effect of these disturbances may result in such regular coral mortality and reduced growth that communities cannot fully recover," it said.

Previous efforts to curb starfish populations have been costly and ineffective, the report said. Those include cutting up the creatures (they tend to regrow their lost appendages) and injecting them with an acid (costs $300,000 a year and divers must inject up to 500 starfish a day).

The WWF said $3 million was spent to control a starfish swarm in 2003 alone.

Besides protecting the environment, WWF said loss of the reef means loss of jobs for Australians.

“Sixty thousand jobs in the tourism industry depend on us acting with urgency over the next few years,” the WWF's Heath said in a statement.

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Filed under: Animals • Australia • Coral • Fish
soundoff (105 Responses)
  1. stagger72

    Find a commercial use for the starfish. Lord knows once a buck can be made off of them, they will be overharvested to extinction... problem solved.

    October 2, 2012 at 3:23 pm | Report abuse |
    • peridot2

      They're toxic and touching them hurts.

      Good luck with that...

      October 2, 2012 at 4:56 pm | Report abuse |
  2. renee@bluedotproductions.org

    creating floating wet lands is working to remove fertilizer from what runoff. If we simply rebuild wetlands and float them on waterways where runoff is present we can even consider growing food on these floating rafts and "feed two birds with one scone" Our greatest limitation is not being able to think the thought we have yet to think!

    October 2, 2012 at 3:28 pm | Report abuse |
  3. 7eni2ss8

    I've read informed and uninformed comments here. As an individual actually on the inside of industry who worked with the USEPA in the 90's to design and implement a 1500 square mile stakeholder watershed pollutant abatement program (phosphorus reduction) in the Kalamazoo River (Michigan, USA), I can directly attest to the fact that stakeholder watershed reduction efforts absolutely work, and absolutely will achieve huge, meaningful and lasting results for the ecosystem in need if done correctly.

    ALL stakeholders contributing to the pollutant(s) identified must be identified, brought to the table, involved, provided a voice and fair forum for exchanging thoughts, ideas and grievances. All given a stake in the process of identifying the source(s) of the pollutant(s). The methodologies and measurement of the pollutant(s) must be done by the scientific method, paid for by the entire stakeholder group (i.e. not funded or controlled by any one stakeholder group), and must be audited by an outside blind party). All stakeholders must have an equal part in designing and implementing the stakeholder-based plan for reduction. It is complex, hard, and yet it’s not. This process definitely works. It gets results, and is the only fair and equitable way of bringing together all of the people who are actually contributing to the problem.

    The old "it's all their fault, they are evil, make them do it" thinking is dead. It does not work. Sit at the same table with industry, farmers, education, city officials, environmentalists, labor, and others for two years and really get to know their problems, their issues, their needs/wants/desires and they yours, and you will find that there is always a middle ground, a way, and in the end, if everyone is heard, has a stake, and a real means of contributing to the solutions, backed by science, they will help.

    No one likes to have a gun to their head. Those farmers out there? They grow your food. Those paper plants out there? They make the paper that we all write on and wipe our bums with. Few of us don't flush toilets. Most drive cars, made by people who really need the jobs. We are as dependent on reefs, fisheries and healthy diverse oceans and ecosystems as the very air we breathe. When we look at it, we live in a giant industrial ecosystem as well as earth ecosystem. We need each other figure it out.

    Everyone must act responsibly within that ecosystem, just as in nature the players must be responsible or it collapses. We must all remain adults and figure out how to help each other – pointing fingers and simply saying it's everyone else that contributes to destruction of the reefs is foolish, untrue, and simplistic thinking. It sets up the “red line” of war. I have never seen anyone truly win at a war. Both sides ultimately lose. SO stop making war on each other, and find ways to work together to make this the kind of world we all want to live in, better than what we got from our parents, and one we will be proud to leave to our children...

    October 2, 2012 at 3:40 pm | Report abuse |
  4. Kyle

    They have to thin out the crown-of-thorns because of the run off, which needs to be addressed. But it will also give the Triton mullusk (crown-of-thorns only predator) a chance to do its job & and keep population in check. Sadly a Triton can only consume about 1 crown-of-thorns per day. So let's hunt some starfish and fix the run off problem. Crown-of-thorn over population is a good start though

    October 2, 2012 at 4:13 pm | Report abuse |
  5. Canopy

    Result: UNINTENDED CONSEQUENCES. Did we not learn in science class about the ecosystem and how things work in a cycle.

    October 2, 2012 at 4:41 pm | Report abuse |
  6. Don Canard

    Environmental absolutism (in this case, insisting on only addressing this situation by "fixing" runoff, and opposing harvesting (killing) of crown-of-thorns) will result in no changes to runoff, and the Barrier Reef passing into human and ecological history. TIme to get practical: harvest and kill the starfish, and make the agricultural industries creating the runoff pay for the program through taxation.

    October 2, 2012 at 5:03 pm | Report abuse |
    • Aud

      Here! Here!

      October 2, 2012 at 5:45 pm | Report abuse |
  7. cpc65

    Easy enough to do. Convince the Chinese that this species of starfish is an ancient remedy for impotence and / or that they make for a really good soup and they'll be extinct in no time.

    October 2, 2012 at 5:13 pm | Report abuse |
  8. Lady in Grey

    So let's relocate some manatees into the area. They flourish on plankton too, and maybe they can help get the excess amount under control so the starfish won't overpopulate so much. And that way we don't have to worry so much about hurting farms' food production and processes. Win for the manatees, Win for the reef, Win for the farmers, and Win to the starfish who don't have to be cut up.

    I don't really know what I'm talking about, lol – just to save myself from fireballs. I just thought, plankton + warm water = happy manatee. There are probably a million reasons that would never work. But you never know....

    October 2, 2012 at 5:21 pm | Report abuse |
    • Lady in Grey

      Ha! Just realized I had it alllll wrong. Plankton + Manatee = Dead Manatee. My bad!

      Let's send the whales in instead! Or something else that's likes plankton!

      October 2, 2012 at 5:34 pm | Report abuse |
    • Adam

      Huff paint much?

      October 2, 2012 at 9:00 pm | Report abuse |
  9. G D

    Reducing fertilizer pollution seems like a good but long-term fix. The infestation going on today also needs to be dealt with or the reef will suffer as a result of past and current practices. So it would seem that a multi-pronged solution is called for, and neither end-member alone would likely work.

    October 2, 2012 at 5:25 pm | Report abuse |
  10. PErickson

    Someone just needs to mount a campaign to convince the Chinese that Crown of Thorns starfish are an exponentially better aphrodisiac than rhino horn. We could solve two problems at the same time.

    October 2, 2012 at 5:30 pm | Report abuse |
  11. Puckles

    Too little too late. Earth is on a downward spiral far past the point of fixing.

    October 2, 2012 at 6:04 pm | Report abuse |
    • Adam

      "Puckles" has spoken.

      October 2, 2012 at 9:01 pm | Report abuse |
  12. Puckles

    Too little too late. Earth is on a downward spiral far past the point of fixing..

    October 2, 2012 at 6:05 pm | Report abuse |
  13. The False Prophet

    There is only one solution to this problem. Subtract humans from the equation and nature's balance will be restored. If we continue to exist we're going to destroy this planet completely. It's only a matter of time. Fortunately for Earth, our leaders are hell-bent on starting WW3, and nuking our species into extinction.

    October 2, 2012 at 6:07 pm | Report abuse |
  14. M.E.

    Are these starfish poisonous? Are they tasty? If the answer is no followed by yes, I vote for sushi!

    October 2, 2012 at 6:12 pm | Report abuse |
  15. joeymom

    How about just pull them out of the water? Let them dry, ship them elsewhere to grind up for natural fertilizer.

    October 2, 2012 at 6:17 pm | Report abuse |
    • joeymom

      To clarify, that is ADDITION to addressing the runoff issue.

      October 2, 2012 at 6:17 pm | Report abuse |
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