Navigation Links
Fishing ban guards coral reefs against predatory starfish outbreaks
Date:7/21/2008

No-take marine reserves where fishing is banned can have benefits that extend beyond the exploited fishes they are specifically designed to protect, according to new evidence from Australia's Great Barrier Reef reported in the July 22nd issue of Current Biology, a Cell Press publication. Researchers have found that outbreaks of large, predatory crown-of-thorns starfish (Acanthaster planci), which can devastate coral reefs, occur less often in protected zones, although they don't yet know exactly why.

" The geographic range of A. planci includes the most biodiverse as well as some of the most threatened reefs on earth," said Hugh Sweatman of the Australian Institute of Marine Science. "This study provides an additional argument for establishment of effective marine protected areas across the range, as refuges from exploitation and other threats and as sources for recolonization of damaged reefs to increase ecological resilience."

The crown-of-thorns starfish in question have up to 20 arms covered in "evil-looking spines," Sweatman said. Not only do they look menacing, but those spines are also extremely sharp and carry a painful toxin.

When outbreaks occur, thousands of starfish dot the reef surface, interspersed by the pure white skeletons of recently consumed coral colonies. Sweatman said that even much lower densities of starfish have a very significant effect on coral cover. Eventually, the starfish on a reef are thought to die of starvation and disease, but their larvae are carried by currents to downstream reefs. "The living coral typically covers about 20 percent of the perimeters of reefs of the Great Barrier Reef. That figure drops to about 5 percent after an outbreak," he added.

Now, Sweatman has found that no-take marine reserves can help prevent that vicious cycle. He compared the frequency of starfish outbreaks on no-take reefs to that on reefs that were open to fishing on the Great Barrier Reef, on the basis of results of an extensive monitoring program.

The initial zoning plan for the Great Barrier Reef Marine Park was fully implemented in 1989, with no-take zones covering 4.5 percent of the region. Subsequent surveys found that the relative frequency of outbreaks on reefs that were open to fishing was 3.75 times higher than on no-take reefs in the mid-shelf region, where most outbreaks occur.

"It had been suggested that exploited fishes eat the juvenile starfish, but there are only one or two anecdotal observations," Sweatman said. "I did not expect to find this pattern at all."

He remains skeptical that exploited fish species are significant predators of starfish, but said there might be a "trophic cascade" where increased numbers of exploited fishes, many of which are carnivores, cause a decline in small predatory fishes that favors larger invertebrates. He speculates that those invertebrates may prey on the starfish when they are very small.

The Great Barrier Reef Marine Park was re-zoned in mid-2004, increasing the no-take zones from 4.5 percent to 33 percent of the area of the park, a move that Sweatman's group reported in the June 23rd Current Biology has led to a rapid comeback of coral trout in the area.

" Whatever the underlying mechanism, this study suggests that this increase should reduce the overall impact of future waves of A. planci outbreaks," he said. "That effect may be amplified if fewer reefs with starfish outbreaks mean less effective propagation of outbreaks from reef to reef."


'/>"/>

Contact: Cathleen Genova
cgenova@cell.com
617-397-2802
Cell Press
Source:Eurekalert

Related biology news :

1. Does fishing on drifting fish aggregation devices endanger the survival of tropical tuna?
2. Can certain metals repel sharks from fishing gear?
3. Fishing throws targeted species off balance, Scripps study shows
4. Oceanic sharks worldwide at serious risk from high-seas fishing, rising demand for shark products
5. Small-scale fishing in Mexico rivals industrial fisheries in accidental turtle deaths
6. Research shows loggerhead sea turtles threatened by small-scale fishing operations
7. Gene guards grain-producing grasses so people and animals can eat
8. New indicator uncovered that can predict coral health
9. Lionfish decimating tropical fish populations, threaten coral reefs
10. 1/3 of reef-building corals face extinction
11. New NOAA coral bleaching prediction system calls for low level of bleaching in Caribbean this year
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:4/14/2016)... TEL AVIV, Israel , April 14, 2016 /PRNewswire/ ... in Behavioral Authentication and Malware Detection, today announced the ... has already assumed the new role. Goldwerger,s ... for BioCatch, on the heels of the deployment of ... In addition, BioCatch,s behavioral biometric technology, which discerns unique ...
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys has ... CEO, Barrett Bready , M.D., who returned to ... the original technical leadership team, including Chief Technology Officer, ... Product Development, Steve Nurnberg and Vice President of Software ... the company. Dr. Bready served as CEO ...
Breaking Biology News(10 mins):
(Date:5/27/2016)... ... ... PBI-Gordon Corporation is pleased to announce Dave Loecke has accepted the position ... PBI-Gordon, Dave has served in a wide variety of roles. His most recent position ... of many of PBI-Gordon’s most successful products. , “Dave has been essential to the ...
(Date:5/26/2016)... and READING, England , May ... http://www.indegene.com ), a leading global provider of clinical, ... and healthcare organisations and TranScrip ( http://www.transcrip-partners.com ), ... throughout the product lifecycle, today announced the extension ... IntraScience.      (Logo: http://photos.prnewswire.com/prnh/20141208/720248 ...
(Date:5/26/2016)... ... May 26, 2016 , ... FireflySci has been manufacturing quartz ... all over the globe. Their cute firefly logo has been spreading to more ... makes spectrophotometer calibration standards that never require recalibration. These revolutionary standards have ...
(Date:5/25/2016)... ... May 25, 2016 , ... ... issued by the Office of the National Coordinator for Health IT (ONC) outlining ... if clinically relevant data were available when and where it was needed. The ...
Breaking Biology Technology: