Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach

Handle URI:
http://hdl.handle.net/10754/621959
Title:
Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach
Authors:
Tietbohl, Matthew ( 0000-0002-1101-8412 )
Abstract:
Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.
Advisors:
Berumen, Michael L. ( 0000-0003-2463-2742 )
Committee Member:
Moran, Xose Anxelu G. ( 0000-0002-9823-5339 ) ; Tester, Mark A. ( 0000-0002-5085-8801 ) ; Thorrold, Simon R. ( 0000-0002-1533-7517 )
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Program:
Marine Science
Issue Date:
Dec-2016
Type:
Thesis
Appears in Collections:
Theses

Full metadata record

DC FieldValue Language
dc.contributor.advisorBerumen, Michael L.en
dc.contributor.authorTietbohl, Matthewen
dc.date.accessioned2016-12-07T05:25:00Z-
dc.date.available2016-12-07T05:25:00Z-
dc.date.issued2016-12-
dc.identifier.urihttp://hdl.handle.net/10754/621959-
dc.description.abstractHerbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.en
dc.language.isoenen
dc.subjectHerbivoresen
dc.subjectfishesen
dc.subjectIsotope Analysisen
dc.subjectcompound-specificen
dc.subjectamino acidsen
dc.subjectCoral Reefsen
dc.titleAssessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approachen
dc.typeThesisen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberMoran, Xose Anxelu G.en
dc.contributor.committeememberTester, Mark A.en
dc.contributor.committeememberThorrold, Simon R.en
thesis.degree.disciplineMarine Scienceen
thesis.degree.nameMaster of Scienceen
dc.person.id142812en
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