Temporal and spatial distribution of floating objects in coastal waters of central-southern Chile and Patagonian fjords
Floating objectsaresuggestedtobetheprincipalvectorforthetransportanddispersalofmarineinvertebrateswithdirectdevelopmentaswellascatalystsforcarbonandnutrientrecyclinginaccumulationareas.Thefirststepinidentifyingtheecologicalrelevanceoffloatingobjectsinaspecificarea istoidentifytheirspatio-temporaldis...
Published in: | Continental Shelf Research |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon-Elsevier Science Ltd
2011
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Subjects: | |
Online Access: | https://doi.org/10.1016/j.csr.2010.04.013 http://ecite.utas.edu.au/88826 |
Summary: | Floating objectsaresuggestedtobetheprincipalvectorforthetransportanddispersalofmarineinvertebrateswithdirectdevelopmentaswellascatalystsforcarbonandnutrientrecyclinginaccumulationareas.Thefirststepinidentifyingtheecologicalrelevanceoffloatingobjectsinaspecificarea istoidentifytheirspatio-temporaldistribution.Weevaluatedthecomposition,abundance,distribution,andtemporalvariabilityoffloatingobjectsalongthecontinentalcoastofcentralsouthernChile (33421S) andthePatagonianfjords(42501S) usingshipsurveysconductedinaustralwinter(July/August)andspring(November)oftheyears20022005and2008.Potentialsourcesoffloatingitems wereidentifiedwiththeaidofpubliclyavailabledatabasesandscientificreports.Wefoundthreemain typesoffloatingobjects,namelyfloatingmarinedebris(mainlyplasticobjectsandStyrofoam),wood (trunksandbranches),andfloatingkelps(Macrocystispyrifera and Durvillaea antarctica).Floatingmarinedebriswereabundantalongmostoftheexaminedtransects,withmarkedlylowerabundancestowardthesouthernfjordareas.Floatingmarinedebrisabundancesgenerallycorrespondedtothedistributionofhumanactivities,andwerehighestintheInteriorSeaofChiloe , whereaquacultureactivitiesareintense.Floatingwoodappearedsporadicallyinthestudyarea,oftenclosetothemainrivers. Inaccordancewithseasonalriverrun-off,woodwasmoreabundantalongthecontinentalcoastin winter(rainyseason)andinthePatagonianfjordsduringthespringsurveys(snowmelt).Densitiesofthe twofloatingkelpspeciesweresimilaralongthecontinentalcoast,withoutaclearseasonalpattern.M. pyrifera densitiesincreasedtowardsthesouth,peakinginthePatagonianfjords,whereitwasdominantover D. antarctica. Densitiesof M. pyrifera in thePatagonianfjordswerehighestinspring.Correlationanalysesbetweentheabundancesoffloatingobjectsandthedistancetothenearestsourceswere generallynon-significant,suggestingthatpost-supplyprocessesaffectthedistributionofthefloating objectsinthestudyregion.Theidentificationofseveralmajorretentionzonessupportsthisidea.Accumulationareasoffloatingobjectsappeartobemorecommoninthefjordzones.Ingeneral,the resultsunderscoretheabundanceoffloatingobjectsthroughoutthestudyregionandthefactthatfloating marinedebrissourcesaremostlylocal,whereasfloatingalgaemaybedispersedovergreaterdistances.Futurestudiesshouldfocusontheecologicalroleoffloatingobjectsinbiotadispersalandnutrientcycling. |
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