title: Phase heterogeneity in carbonate production by marine fish influences their roles in sediment generation and the inorganic carbon cycle.
abstract: Marine teleost fish are important carbonate producers in neritic and oceanic settings. However, the fates of the diverse carbonate phases (i.e., mineral and amorphous forms of CaCO3) they produce, and their roles in sediment production and marine inorganic carbon cycling, remain poorly understood. Here we quantify the carbonate phases produced by 22 Bahamian fish species and integrate these data with regional fish biomass data from The Bahamas to generate a novel platform-scale production model that resolves these phases. Overall carbonate phase proportions, ordered by decreasing phase stability, are: ~20% calcite, ~6% aragonite, ~60% high-Mg calcite, and ~14% amorphous carbonate. We predict that these phases undergo differing fates, with at least ~14% (amorphous carbonate) likely dissolving rapidly. Results further indicate that fisheries exploitation in The Bahamas has potentially reduced fish carbonate production by up to 58% in certain habitats, whilst also driving a deviation from natural phase proportions. These findings have evident implications for understanding sedimentary processes in shallow warm-water carbonate provinces. We further speculate that marked phase heterogeneity may be a hitherto unrecognised feature of fish carbonates across a wide range of neritic and oceanic settings, with potentially major implications for understanding their role in global marine inorganic carbon cycling.
authors.affiliation: Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter, EX4 4RJ, UK. m.a.salter@exeter.ac.uk.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Salter
authors.affiliation: Department of Biological Sciences, Florida International University, North Miami, Florida, 33181, USA.|Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, Goddard Building, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Alastair R
authors.initials: AR
authors.lastname: Harborne
authors.affiliation: Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter, EX4 4RJ, UK.
authors.forename: Chris T
authors.initials: CT
authors.lastname: Perry
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
authors.forename: Rod W
authors.initials: RW
authors.lastname: Wilson
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D057486:Carbon Cycle; D002254:Carbonates / Q000737:chemistry / Q000378:metabolism*; D017753:Ecosystem; D005399:Fishes / Q000378:metabolism*; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry; D012623:Seawater; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002254:Carbonates; D002244:Carbon