title: Effect of light and nutrient availability on the release of dissolved organic carbon (DOC) by Caribbean turf algae.
abstract: Turf algae increasingly dominate benthic communities on coral reefs. Given their abundance and high dissolved organic carbon (DOC) release rates, turf algae are considered important contributors to the DOC pool on modern reefs. The release of photosynthetically fixed carbon as DOC generally, but not always, increases with increased light availability. Nutrient availability was proposed as an additional factor to explain these conflicting observations. To address this proposed but untested hypothesis, we documented the interactive contributions of light and nutrient availability on the release of DOC by turf algae. DOC release rates and oxygen production were quantified in incubation experiments at two light levels (full and reduced light) and two nutrient treatments (natural seawater and enriched seawater). In natural seawater, DOC release at full light was four times higher than at reduced light. When nutrients were added, DOC release rates at both light levels were similar to the natural seawater treatment at full light. Our results therefore show that low light in combination with low nutrient availability reduces the release of DOC by turf algae and that light and nutrient availability interactively determine DOC release rates by this important component of Caribbean reef communities.
authors.affiliation: Royal Netherlands Institute for Sea Research (NIOZ) Department of Marine Microbiology and Biogeochemistry and Utrecht University, P.O. Box 59, 1790AB Den Burg, Texel, The Netherlands.|CARMABI Foundation, Piscaderabaai z/n, P.O. Box 2090, Willemstad, Curaçao.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mueller
authors.affiliation: University of Amsterdam, Department of Aquatic Microbiology, P.O. BOX 94248, 1090 GE Amsterdam, The Netherlands.|Max-Plank Institute for Marine Microbiology (MPI Bremen), Celsiusstr. 1, 28359 Bremen, Germany.
authors.forename: Joost
authors.initials: J
authors.lastname: den Haan
authors.affiliation: University of Amsterdam, Department of Aquatic Microbiology, P.O. BOX 94248, 1090 GE Amsterdam, The Netherlands.
authors.forename: Petra M
authors.initials: PM
authors.lastname: Visser
authors.affiliation: CARMABI Foundation, Piscaderabaai z/n, P.O. Box 2090, Willemstad, Curaçao.|University of Amsterdam, Department of Aquatic Microbiology, P.O. BOX 94248, 1090 GE Amsterdam, The Netherlands.
authors.forename: Mark J A
authors.initials: MJ
authors.lastname: Vermeij
authors.affiliation: Royal Netherlands Institute for Sea Research (NIOZ) Department of Marine Microbiology and Biogeochemistry and Utrecht University, P.O. Box 59, 1790AB Den Burg, Texel, The Netherlands.|CARMABI Foundation, Piscaderabaai z/n, P.O. Box 2090, Willemstad, Curaçao.
authors.forename: Fleur C
authors.initials: FC
authors.lastname: van Duyl
mesh_terms: D000818:Animals; D002244:Carbon / Q000032:analysis*; D017691:Caribbean Region; D000460:Chlorophyta / Q000502:physiology*; D057894:Coral Reefs; D017753:Ecosystem; D008027:Light; D010100:Oxygen / Q000032:analysis; D010788:Photosynthesis; D012623:Seawater / Q000737:chemistry*
chemical_list: D002244:Carbon; D010100:Oxygen