{"317821":{"#nid":"317821","#data":{"type":"news","title":"Marine protected areas might not be enough to help overfished reefs recover","body":[{"value":"\u003Cp\u003EPacific corals and fish can both smell a bad neighborhood, and use that ability to avoid settling in damaged reefs.\u003C\/p\u003E\u003Cp\u003EDamaged coral reefs emit chemical cues that repulse young coral and fish, discouraging them from settling in the degraded habitat, according to new research. The study shows for the first time that coral larvae can smell the difference between healthy and damaged reefs when they decide where to settle.\u003C\/p\u003E\u003Cp\u003ECoral reefs are declining around the world. Overfishing is one cause of coral collapse, depleting the herbivorous fish that remove the seaweed that sprouts in damaged reefs. Once seaweed takes hold of a reef, a tipping point can occur where coral growth is choked and new corals rarely settle.\u003C\/p\u003E\u003Cp\u003EThe new study shows how chemical signals from seaweed repel young coral from settling in a seaweed-dominated area. Young fish were also not attracted to the smell of water from damaged reefs. The findings suggest that designating overfished coral reefs as marine protected areas may not be enough to help these reefs recover because chemical signals continue to drive away new fish and coral long after overfishing has stopped.\u003C\/p\u003E\u003Cp\u003E\u201cIf you\u2019re setting up a marine protected area to seed recruitment into a degraded habitat, that recruitment may not happen if young fish and coral are not recognizing the degraded area as habitat,\u201d said \u003Ca href=\u0022http:\/\/www.biology.gatech.edu\/people\/danielle-dixson\u0022\u003EDanielle Dixson\u003C\/a\u003E, an assistant professor in the School of Biology at the Georgia Institute of Technology in Atlanta, and the study\u0027s first author.\u003C\/p\u003E\u003Cp\u003EThe study will be published August 22 in the journal \u003Ca href=\u0022http:\/\/www.sciencemag.org\/content\/345\/6199\/892\u0022\u003E\u003Cem\u003EScience\u003C\/em\u003E\u003C\/a\u003E. The research was sponsored by the National Science Foundation (NSF), the National Institutes of Health (NIH), and the Teasley Endowment to Georgia Tech.\u003C\/p\u003E\u003Cp\u003EThe new study examined three marine areas in Fiji that had adjacent fished areas. The country has established no-fishing areas to protect its healthy habitats and also to allow damaged reefs to recover over time.\u003C\/p\u003E\u003Cp\u003EJuveniles of both corals and fishes were repelled by chemical cues from overfished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Both coral and fish larvae preferred certain chemical cues from species of coral that are indicators of a healthy habitat, and they both avoided certain seaweeds that are indicators of a degraded habitat.\u003C\/p\u003E\u003Cp\u003EThe study for the first time tested coral larvae in a method that has been used previously to test fish, and found that young coral have strong preferences for odors from healthy reefs.\u003C\/p\u003E\u003Cp\u003E\u0022Not only are coral smelling good areas versus bad areas, but they\u2019re nuanced about it,\u0022 said \u003Ca href=\u0022http:\/\/labs.biology.gatech.edu\/labs\/hay\/\u0022\u003EMark Hay\u003C\/a\u003E, a professor in the School of Biology at Georgia Tech and the study\u0027s senior author. \u0022They\u2019re making careful decisions and can say, \u0027settle or don\u2019t settle.\u0027\u0022\u003C\/p\u003E\u003Cp\u003EThe study showed that young fish have an overwhelming preference for water from healthy reefs. The researchers put water from healthy and degraded habitats into a flume that allowed fish to choose to swim in one stream of water or the other. The researchers tested the preferences of 20 fish each from 15 different species and found that regardless of species, family or trophic group, each of the 15 species showed up to an eight times greater preference for water from healthy areas.\u003C\/p\u003E\u003Cp\u003EThe researchers then tested coral larvae from three different species and found that they preferred water from the healthy habitat five-to-one over water from the degraded habitat.\u003C\/p\u003E\u003Cp\u003EChemical cues from corals also swayed the fishes\u0027 preferences, the study found. The researchers soaked different corals in water and studied the behavior of fish in that water, which had picked up chemical cues from the corals. Cues of the common coral Acropora nasuta enhanced attraction to water from the degraded habitat by up to three times more for all 15 fishes tested. A similar preference was found among coral larvae.\u003C\/p\u003E\u003Cp\u003EAcropora corals easily bleach, are strongly affected by algal competition, and are prone to other stresses. The data demonstrate that chemical cues from these corals are attractive to fish and corals because they are found primarily in healthy habitats. Chemical cues from hardy corals, which can grow even in overfished habitats, were less attractive to juvenile fishes or corals.\u003C\/p\u003E\u003Cp\u003EThe researchers also soaked seaweed in water and tested fish and coral preferences in that water. Cues from the common seaweed Sargassum polycystum, which can bloom and take over a coral reef, reduced the attractiveness of water to fish by up to 86 percent compared to water without the seaweed chemical cues. Chemical cues from the seaweed decreased coral larval attraction by 81 percent.\u003C\/p\u003E\u003Cp\u003E\u0022Corals avoided that smell more than even algae that\u0027s chemically toxic to coral but doesn\u0027t bloom,\u0022 Dixson said.\u003C\/p\u003E\u003Cp\u003EFuture work will involve removing plots of seaweed from damaged reefs and studying how that impacts reef recovery.\u003C\/p\u003E\u003Cp\u003EA minimum amount of intervention at the right time and the right place could jump start the recovery of overfished reefs, Hay said. That could bring fish back to the area so they settle and eat the seaweed around the corals. The corals would then get bigger because the seaweed is not overgrown. Bigger corals would then be more attractive to more fish.\u003C\/p\u003E\u003Cp\u003E\u0022What this means is we probably need to manage these reefs in ways that help remove the most negative seaweeds and then help promote the most positive corals,\u0022 Hay said.\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis research is supported by the National Science Foundation (NSF), under award number OCE-0929119, and the National Institutes of Health, under award number U01-TW007401. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Dixson et al., \u0022Chemically mediated behavior of recruiting corals and fishes: A tipping\u003Cbr \/\u003Epoint that may limit reef recovery.\u0022 (August 2014, \u003Cem\u003EScience\u003C\/em\u003E).\u0026nbsp;\u003Ca href=\u0022http:\/\/www.sciencemag.org\/content\/345\/6199\/892%20\u0022\u003Ehttp:\/\/www.sciencemag.org\/content\/345\/6199\/892\u0026nbsp;\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EGeorgia Institute of Technology\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003E177 North Avenue\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EAtlanta, Georgia 30332-0181 USA\u003C\/strong\u003E\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/twitter.com\/@GTResearchNews\u0022\u003E\u003Cstrong\u003E@GTResearchNews\u003C\/strong\u003E\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts:\u003C\/strong\u003E Brett Israel (\u003Ca href=\u0022http:\/\/www.twitter.com\/btiatl\u0022\u003E@btiatl\u003C\/a\u003E) (404-385-1933) (\u003Ca href=\u0022mailto:brett.israel@comm.gatech.edu\u0022\u003Ebrett.israel@comm.gatech.edu\u003C\/a\u003E) or John Toon (404-894-6986) (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E)\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EScientific Contacts:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMark Hay\u003C\/strong\u003E\u003Cbr \/\u003E\u003Ca href=\u0022mailto:mark.hay@biology.gatech.edu\u0022\u003Emark.hay@biology.gatech.edu\u003C\/a\u003E \u003Cbr \/\u003EFiji phone numbers: 679-833-3300 or 679-979-5991 (cell). 679-653-0093 (landline)\u003Cbr \/\u003ESkype: Markhaygt\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDanielle Dixson\u003C\/strong\u003E\u003Cbr \/\u003E\u003Ca href=\u0022mailto:danielle.dixson@biology.gatech.edu\u0022\u003Edanielle.dixson@biology.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003EBelize phone: 011-501-532-2392\u003Cbr \/\u003ESkype: Danielle.Dixson\u003C\/p\u003E\u003Cp\u003EWriter: Brett Israel\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Young corals, fish turned off by smell of damaged habitats"}],"field_summary":"","field_summary_sentence":[{"value":"Pacific corals and fish can both smell a bad neighborhood, and use that ability to avoid settling in damaged reefs."}],"uid":"27902","created_gmt":"2014-08-21 13:28:19","changed_gmt":"2016-10-08 03:16:56","author":"Brett Israel","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2014-08-21T00:00:00-04:00","iso_date":"2014-08-21T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"317841":{"id":"317841","type":"image","title":"Testing fish in a choice chamber","body":null,"created":"1449244974","gmt_created":"2015-12-04 16:02:54","changed":"1475895027","gmt_changed":"2016-10-08 02:50:27","alt":"Testing fish in a choice chamber","file":{"fid":"201775","name":"choice_chamer.jpg","image_path":"\/sites\/default\/files\/images\/choice_chamer_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/choice_chamer_0.jpg","mime":"image\/jpeg","size":1987706,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/choice_chamer_0.jpg?itok=KAUw4Jyz"}},"317851":{"id":"317851","type":"image","title":"Snorkeling in Fiji to study marine habitats","body":null,"created":"1449244974","gmt_created":"2015-12-04 16:02:54","changed":"1475895027","gmt_changed":"2016-10-08 02:50:27","alt":"Snorkeling in Fiji to study marine habitats","file":{"fid":"201776","name":"fiji_snorkling.jpg","image_path":"\/sites\/default\/files\/images\/fiji_snorkling_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/fiji_snorkling_0.jpg","mime":"image\/jpeg","size":3185012,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/fiji_snorkling_0.jpg?itok=KGKkq6de"}}},"media_ids":["317841","317851"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"141","name":"Chemistry and Chemical Engineering"},{"id":"154","name":"Environment"},{"id":"146","name":"Life Sciences and Biology"}],"keywords":[{"id":"100721","name":"chemical sensing"},{"id":"100711","name":"coral reefs"},{"id":"100731","name":"corals"},{"id":"79191","name":"Danielle Dixson"},{"id":"94671","name":"field work"},{"id":"4211","name":"fiji"},{"id":"1104","name":"fish"},{"id":"13884","name":"Mark Hay"},{"id":"169448","name":"seaweed"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EBrett Israel\u003C\/p\u003E\u003Cp\u003E404-385-1933\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022http:\/\/www.twitter.com\/btiatl\u0022\u003E@btiatl\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["brett.israel@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}