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Title: Fish Carbonates in the North Atlantic and Their Potential Role in the Carbon Cycle
Abstract Marine fish precipitate carbonates in their intestines that they subsequently excrete as part of an osmoregulatory strategy. While fish carbonates are proposed to be volumetrically significant to the global carbonate budget, no study has presented direct evidence of fish carbonates in the open ocean. Here we examine sediment trap material collected by the Oceanic Flux Program (OFP) in the North Atlantic and observe the episodic occurrence of enigmatic blue particles since 1992. The blue particles are comprised of calcite with unusually high magnesium content (up to 46 mol%) with distinctively depleted δ13C and enriched δ18O compared with calcite produced by common marine calcifiers. Based on the mineralogical, isotopic, and textural similarities between the blue particles and fish carbonates, we propose that the blue particles are produced by pelagic fish. Our data suggest that fish modify their intestinal fluids to create a concentrated, highly supersaturated,13C depleted solution capable of precipitating calcite with high magnesium content and low δ13C. Collectively, our data imply that fish carbonate production is an open‐ocean phenomenon, opening up the possibility that fish contribute to the production, dissolution, and export of carbonates globally.  more » « less
Award ID(s):
2421112 2414704
PAR ID:
10620803
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
AGU
Date Published:
Journal Name:
Global Biogeochemical Cycles
Volume:
39
Issue:
6
ISSN:
0886-6236
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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