• UCSB_GradPost twitter avatar
    Utilize the A.S. Media Center's Free Video Cameras and Gear http://t.co/IUeP6NHs07 #UCSB
    5 hours 33 min ago
  • UCSBgauchos twitter avatar
    What a way to start off the season! @UCSBMensSoccer tops No.5 Stanford 1-0 Friday. RECAP >>> http://t.co/gPhjHwqFP0 http://t.co/z7Z90RLG5D
    2 days 30 min ago
  • UCSBgauchos twitter avatar
    The Gauchos start the 2015 season off in style, hold No. 8 Stanford scoreless to win 1-0. @UCSBMensSoccer first win over Stanford since 2004
    2 days 1 hour ago
  • UCSBgauchos twitter avatar
    Stanford trying desperately to get on the board but UCSB's backline can't be beat. Gauchos lead 1-0 with 5 minutes to go
    2 days 1 hour ago
  • UCSBgauchos twitter avatar
    Ahinga Selemani beats his defender to set up Geoffrey Acheampong beautifully in the box, but the lefty's shot goes wide of the post
    2 days 2 hours ago
  • UCSBgauchos twitter avatar
    Stanford with a pair of good chances with just under 30 minutes to go but UCSB still finds a way to keep them off the board and lead 1-0
    2 days 2 hours ago
  • UCSBgauchos twitter avatar
    .@UCSBMensSoccer leading No. 8 Stanford 1-0 at the half thanks to a goal by who else, Nick DePuy. Great first half for the Gauchos
    2 days 2 hours ago
  • UCSBgauchos twitter avatar
    GOAL! Seo-In Kim sends a cross far post and Nick DePuy heads it in to put the Gauchos up 1-0 with 3 minutes left in the half
    2 days 2 hours ago
  • UCSBgauchos twitter avatar
    Women's Soccer: San Jose State 1, UC Santa Barbara 1 (Final - 2OT) UCSB, San Jose State Battle to 1-1 Tie http://t.co/KolrGPE4AY
    2 days 3 hours ago
  • UCSBgauchos twitter avatar
    Big save by Vom Steeg to keep the game scoreless! 25 min left in 1st half @UCSBMensSoccer
    2 days 3 hours ago
  • UCSBgauchos twitter avatar
    Stanford has the advantage in the run of play through 10 minutes but it's still 0-0. @UCSBMensSoccer
    2 days 3 hours ago
  • UCSBgauchos twitter avatar
    WVB: UCSB Opens Season with Back-to-Back Sweeps! #GoGauchos http://t.co/yye1PtugDW
    2 days 3 hours ago
  • UCSBgauchos twitter avatar
    Heres UCSB's starting lineup against Stanford: Vom Steeg, Quezada, Strong, Backus, Jome, Espana, Feucht, Murphy, Acheampong, Selemani, DePuy
    2 days 3 hours ago
  • UCSBgauchos twitter avatar
    Don't miss @UCSBMensSoccer season opener against Stanford. Kickoff in 10 minutes!
    2 days 4 hours ago
  • UCSBgauchos twitter avatar
    @UCSBWomenSoccer ties San Jose St. 1-1 in home season opener behind early goal by Mallory Hromatko
    2 days 4 hours ago

‘Fishy Lawnmowers' Help Save Pacific Corals

Thursday, November 10, 2011 - 16:00
Santa Barbara, CA

2597-1.jpg

Crown-of-thorns sea star feeding on a coral. Photo

Crown-of-thorns sea star feeding on a coral. Photo

Photo Credit: 

Gerick Bergsma

imagetn.aspx_.jpg

Tom Adam

Photo Credit: 

George Foulsham, UCSB Office of Public Affairs and Communications

Can fish save coral reefs from dying? UC Santa Barbara researchers have found one case where fish have helped coral reefs to recover from cyclones and predators.

Coral reefs worldwide are increasingly disturbed by environmental events that are causing their decline, yet some coral reefs recover. UCSB researchers have discovered that the health of coral reefs in the South Pacific island of Moorea, in French Polynesia, may be due to protection by parrotfish and surgeonfish that eat algae, along with the protection of reefs that shelter juvenile fish.

The findings are published in a recent issue of the journal PLoS ONE. The UCSB research team is part of the Moorea Coral Reef Long-Term Ecological Research (MCR LTER) project, funded by the National Science Foundation.

In many cases, especially in the case of severely damaged reefs in the Caribbean, coral reefs that suffer large losses of live coral often become overgrown with algae and never return to a state where the reefs are again largely covered by live coral. In contrast, the reefs surrounding Moorea experienced large losses of live coral in the past –– most recently in the early 1980's –– and have returned each time to a system dominated by healthy, live corals.

"We wanted to know why Moorea's reefs seem to act differently than other reefs," said Tom Adam, first author, research associate with MCR LTER, and postdoctoral fellow at UCSB's Marine Science Institute. "Specifically, we wanted to know what ecological factors might be responsible for the dramatic patterns of recovery observed in Moorea."

The research team was surprised by its findings. The biomass of herbivores on the reef –– fish and other animals that eat plants like algae –– increased dramatically following the loss of live coral. "What was surprising to us was that the numbers of these species also increased dramatically," said Andrew Brooks, co-author, deputy program director of MCR LTER, and associate project scientist with MSI. "We were not simply seeing a case of bigger, fatter fishes –– we were seeing many more parrotfishes and surgeonfishes, all of whom happened to be bigger and fatter. We wanted to know where these new fishes were coming from."

The researchers also found that not all of the coral reefs around Moorea were affected equally by an outbreak of predatory crown-of-thorns sea stars or by cyclones. The crown-of-thorns sea stars did eat virtually all of the live coral on the barrier reef –– the reef that separates the shallow lagoons from the deeper ocean. However, neither the sea stars nor the cyclones had much impact on the corals growing on the fringing reef –– the reef that grows against the island.

 

 

"We discovered that these fringing reefs act as a nursery ground for baby fishes, most notably herbivorous fishes," said Brooks. "With more food available in the form of algae, the survivorship of these baby parrotfishes and surgeonfishes increased, providing more individuals to help control the algae on the fore reef. In effect, the large numbers of parrotfishes and surgeonfishes are acting like thousands of fishy lawnmowers, keeping the algae cropped down to levels low enough that there is still space for new baby corals to settle onto the reef and begin to grow."

A major reason the reefs in the Caribbean do not recover after serious disturbances is because these reefs lack healthy populations of parrotfishes and surgeonfishes, due to the effects of overfishing, explained Adam. "Without these species to help crop the algae down, these reefs quickly become overgrown with algae, a situation that makes it very hard for corals to re-establish themselves," he said.

Managers have tried to reverse the trend of overfishing through the creation of Marine Protected Areas (MPAs), where fishing is severely restricted or prohibited. "Our results suggest that this strategy may not be enough to reverse the trend of coral reefs becoming algal reefs," said Brooks. "Our new and very novel results suggest that it also is vital to protect the fringing reefs that serve as nursery grounds. Without these nursery grounds, populations of parrotfishes and surgeonfishes can't respond to increasing amounts of algae on the reefs by outputting more baby herbivores."

In short, the research team found that by using MPAs, managers can help protect adult fish, producing bigger, fatter fish. "But if you don't protect the nursery habitat –– the babies produced by these bigger fish, or by fish in other, nearby areas –– you can't increase the overall numbers of the important algae-eating fish on the reef," said Brooks.

According to the scientists, it appears that Moorea's reefs may recover. "One final bit of good news is that we are seeing tens of thousands of baby corals, some less than a half-inch in diameter, on the fore reefs surrounding Moorea," said Brooks.

MCR researchers will follow the coral reef recovery process over the next decade or more, in search of additional information that can aid managers of the world's coral reefs.

Additional co-authors are Russell J. Schmitt and Sally J. Holbrook of UCSB's Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology; Peter J. Edmunds and Robert C. Carpenter of California State University, Northridge; and Giacomo Bernardi, of UC Santa Cruz.

 

 


 

 

[RETURN TO TOP]  

 

 

Middle image: Surgeonfish and parrotfish feeding on algae on the fore reef in Moorea, French Polynesia. The algae are growing on the skeletons of corals recently consumed by crown-of-thorns sea stars.
Credit: Eric Dilly

 

Moorea Coral Reef LTER

After reading this article I feel