Joshua Learn, E&E reporter<\/p>\n
Published: Friday, August 22, 2014 <\/p>\n
Coral larvae and fish looking for new homes are able to sniff out and
\navoid areas degraded by overfishing, pollution or other problems,
\naccording to research published yesterday in the journal Science.<\/p>\n
Danielle Dixson, a biology professor at the Georgia Institute of
\nTechnology in Atlanta and the lead author, said the study suggests that
\ndesignating protected marine areas may not always lead to healthier
\nreefs nearby.<\/p>\n
Further intervention may be needed, she said, to help degraded areas
\nrecover.<\/p>\n
Researchers started by testing 15 fish species and three coral species
\nin the lab for their ability to smell healthy reef locations ripe for
\ncolonizing based on seawater they injected into the water.<\/p>\n
“We were really wondering what chemical cues makes them decide where to
\ngo,” Dixson said in a telephone interview, adding that the species
\nshowed “a very strong preference for water taken from the healthy reef
\nareas.”<\/p>\n
The scientists then took tests out to waters in Fiji that have very
\nhealthy and well-protected reef areas next to spots that have suffered
\nhugely from overfishing or other human-related activities.<\/p>\n
“Coral are pretty much a living rock, they can’t move once they’ve
\nsettled,” Dixson said.<\/p>\n
Larvae, she said, will often scout settlement areas out before choosing
\nto lay down their roots and begin forming coral. But in Fiji they
\ntended to avoid areas plagued with too much algae.<\/p>\n
In Fiji, she said, “degraded reefs are pretty much algal parking lots.”<\/p>\n
The discovery is troubling, she said, because marine protected acres
\n(MPAs) are supposed to act as recovery points for wider areas, as fish
\nand other species don’t stick within their borders.<\/p>\n
“The point of a marine protected area is not only to protect what’s
\ninside its area,” she said.<\/p>\n
But in Fiji it’s not happening in some areas because larvae and the
\nfish that follow them once the coral has developed probably don’t ever
\nrecognize that some algae-covered areas are habitat anymore.<\/p>\n
“When two areas are too different from one another, the MPA might not
\nbe working in the way that we think it should be working,” she said.
\n“That feedback loop is just not going to occur.”<\/p>\n
Joana Figueiredo, a marine larval ecologist at the Oceanographic Center
\nat Nova Southeastern University in Fort Lauderdale, Fla., said the
\nstudy’s findings seem reasonable.<\/p>\n
“Just by the scent of the water, the larva decided the water wasn’t
\ngood,” she said, adding that the study is in agreement with things that
\nhave been published before.<\/p>\n
Both Figueiredo and Dixson said that as a result, conservationists need
\nto think about wider strategies than just demarcating protected zones.<\/p>\n
“What she’s showing is that you cannot just protect a little small area
\nand not worry about the condition of all the rest. The overall quality
\nof the area needs to be high,” Figueiredo said. “It’s not just by
\nprotecting one area that you will be able to save a reef.”<\/p>\n
Dixson said ways to do this could include clearing the algae from areas
\nthat would otherwise be appropriate for coral settlement, or even
\nlearning more about the kinds of scents that different coral favor in
\nsettlement, as some species will put up with a smellier home than
\nothers.<\/p>\n
It’s an important area of study, Dixson said, because once reefs go
\npast a certain point, we don’t know what we can do to help them.<\/p>\n
She’s currently working on related studies testing the chemical
\npreferences of Caribbean coral species off the coast of Belize.<\/p>\n","protected":false},"excerpt":{"rendered":"
Joshua Learn, E&E reporter Published: Friday, August 22, 2014 Coral larvae and fish looking for new homes are able to sniff out and avoid areas degraded by overfishing, pollution or other problems, according to research published yesterday in the journal Science. Danielle Dixson, a biology professor at the Georgia Institute of Technology in Atlanta and … Continue reading E&E: Marine protected areas alone unlikely to save degraded reefs — study<\/span>