title: Microbial and sponge loops modify fish production in phase-shifting coral reefs.
abstract: Shifts from coral to algae dominance of corals reefs have been correlated to fish biomass loss and increased microbial metabolism. Here we investigated reef benthic and planktonic primary production, benthic dissolved organic carbon (DOC) release and bacterial growth efficiency in the Abrolhos Bank, South Atlantic. Benthic DOC release rates are higher while water column bacterial growth efficiency is lower at impacted reefs. A trophic model based on the benthic and planktonic primary production was able to predict the observed relative fish biomass in healthy reefs. In contrast, in impacted reefs, the observed omnivorous fish biomass is higher, while that of the herbivorous/coralivorous fish is lower than predicted by the primary production-based model. Incorporating recycling of benthic-derived carbon in the model through microbial and sponge loops explains the difference and predicts the relative fish biomass in both reef types. Increased benthic carbon release rates and bacterial carbon metabolism, but decreased bacterial growth efficiency could lead to carbon losses through respiration and account for the uncoupling of benthic and fish production in phase-shifting reefs. Carbon recycling by microbial and sponge loops seems to promote an increase of small-bodied fish productivity in phase-shifting coral reefs.
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Cynthia B
authors.initials: CB
authors.lastname: Silveira
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Silva-Lima
authors.affiliation: Departamento de Engenharia e Meio Ambiente, Universidade Federal da Paraíba, Paraíba, Brasil.
authors.forename: Ronaldo B
authors.initials: RB
authors.lastname: Francini-Filho
authors.affiliation: Laboratório de Ciências Ambientais, Universidade Estadual Norte Fluminense, Rio de Janeiro, Brasil.
authors.forename: Jomar S M
authors.initials: JS
authors.lastname: Marques
authors.affiliation: Laboratório de Ciências Ambientais, Universidade Estadual Norte Fluminense, Rio de Janeiro, Brasil.
authors.forename: Marcelo G
authors.initials: MG
authors.lastname: Almeida
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Cristiane C
authors.initials: CC
authors.lastname: Thompson
authors.affiliation: Laboratório de Ciências Ambientais, Universidade Estadual Norte Fluminense, Rio de Janeiro, Brasil.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Rezende
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Paranhos
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Rodrigo L
authors.initials: RL
authors.lastname: Moura
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Paulo S
authors.initials: PS
authors.lastname: Salomon
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Fabiano L
authors.initials: FL
authors.lastname: Thompson
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000382:microbiology / Q000502:physiology*; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D057894:Coral Reefs; D005399:Fishes / Q000254:growth & development*; D060434:Herbivory; D010933:Plankton / Q000254:growth & development* / Q000378:metabolism; D011161:Porifera / Q000502:physiology*
chemical_list: D002244:Carbon