Crown of throwns starfish curbed by fishing ban

[DICER]

Coral-killing starfish curbed by fishing ban



26 July 2008
From New Scientist Print EditionIF YOU want to save coral reefs from rapacious starfish, you should ban fishing.
The crown-of-thorns starfish, Acanthaster planci, preys on corals in some of the most biodiverse and threatened reefs in the world, dwarfing coral losses from storms and bleaching. The predator is less devastating in "no-take zones" of Australia's Great Barrier Reef, however, where fishing has been banned since 1989 (Current Biology, vol 18, p R598).
A team led by Hugh Sweatman of the Australian Institute of Marine Science in Townsville, Queensland, found that, between 1994 and 2004, there were only about a quarter as many starfish "outbreaks" in no-take zones as in open areas of the reef.
Sweatman suspects that while the protected fish are unlikely to prey on the starfish directly, they may be eating more of the smaller fish that usually prey on small marine invertebrates, which in turn eat more of the juvenile starfish.
Coral bleaching, caused by rising sea temperatures, remains a long-term threat to corals, but fishing bans could buy time for reefs, says Sweatman.
Endangered species - Learn more about the conservation battle in our comprehensive special report (http://www.newscientist.com/channel/life/endangered-species).
From issue 2666 of New Scientist magazine, 26 July 2008, page 6-7

[Lucky_Phill]

Sweatman suspects that while the protected fish are unlikely to prey on the starfish directly, they may be eating more of the smaller fish that usually prey on small marine invertebrates, which in turn eat more of the juvenile starfish.

I suspect that Aigutso is right as well with his analogy of the relationship of the reduction in Pirate numbers to the increase of sea surface temperatures.

I think qualified research into this is warranted. I rule out nothing until independent research draws educated conclusions, but to simply suspect at this stage is drawing a long bow....


Phill

[Scott nthQld]

geez, everyone but fisho's have their sights set on banning fishing don't they?

One of th biggest problem that used to face the reef, was divers cutting up the crown of thorn starfish in a misguided attempt to control them. But at that time, they didn't know that cutting them up did nothing, but produce 2, 3 or 4 (depending on how many pieces they cut them up into) adult, ready to breed COT, so in an area where there may have been say 50 COT, divers would go down and cut them up, leaving up to 200, fully developed, ready to spawn COT, quadrupling the number of brood stock and therefore producing 4X more offspring than what would've naturally occurred.

Using that logic, we could've banned diving on the reef long ago, but we left them alone, so why can't we be extended the same courtesy?

[JIMBO99]

Somebody Found A Crown Of Thorns Starfish And Said This Would Be A Ripper Tool To Use For Stopping Fishermen From Catching A Feed And The Government Set Sail With Millions Of Our Dollars Prodded Along By The Green Movement And Decided That The Thorny Starfish Would Destroy The Reef In No Time Flat, Whoops !! Not So Mate Do People Really Think Crown Of Thorns Has Just Started To Eat The Coral? It's Been Here For About As Long As The Reef And What Coral It Eats Is Spawned Upon By Live Coral And The Entire Cycle Starts Again I Recon.

[Luc]

Isn't it amazing how any links that involve limiting/banning fishing are so direct and clear cut.

It's a shame that links to polution and environment always seems so tenuous!!

Given the very limited harvesting of the reef by fishermen, other causes should be researched.

Luc

[creature100]

COT are not part of the GBR system they are an introduced pest, possibly introduced through ballast water from international vessels.

[Pirate Pete]

COT are not part of the GBR system they are an introduced pest, possibly introduced through ballast water from international vessels.

"...crown-of-thorns starfish skeletons
have been found in old reef sediments which
suggests that starfish have occurred on the
Great Barrier Reef during the past 3,000 to
7,000 years" Quote from CRC Reef Research Centre

You may want to recheck your facts Creature100

[Mike Delisser]

A little more from the same quote
Spicules from crown-of-thorns starfish skeletons have been found in old reef sediments which suggests that starfish have occurred on the Great Barrier Reef during the past 3,000 – 7,000 years. However, because the sediments become mixed over time and the spicules are difficult to date accurately, it is unclear whether starfish outbreaks are a new phenomenon or not.
The first documented case of large numbers of crown-of-thorns starfish on the Great Barrier Reef was noticed at Green Island off Cairns in 1962. It’s possible that starfish outbreaks are more likely to be noticed now than in the past because of increased tourism and the popularity of SCUBA diving.

The full page is on the link
http://www.reef.crc.org.au/publications/brochures/COTS_web_Nov2003.pdf