Kelp carbon sink potential decreases with warming due to accelerating decomposition

by Karen Filbee-Dexter, Colette J. Feehan, Dan A. Smale, Kira A. Krumhansl, Skye Augustine, Florian de Bettignies, Michael T. Burrows, Jarrett E. K. Byrnes, Jillian Campbell, Dominique Davoult, Kenneth H. Dunton, Jo ão N. Franco, Ignacio Garrido, Sean P. Grace, Kasper Hancke, Ladd E. Johnson, Brenda Konar, Pippa J. Moore, Kjell Magnus Norderhaug, Alasdair O’Dell, Morten F. Pedersen, Anne K. Salomon, Isabel Sousa-Pinto, Scott Tiegs, Dara Yiu, Thomas Wernberg Cycling of organic carbon in the ocean has the potential to mitigate or exacerbate global climate change, but major questions remain about the environmental controls on organic carbon flux in the coastal zone. Here, we used a field experiment distributed across 28 ° of latitude, and the entire range of 2 dominant kelp species in the northern hemisphere, to measure decomposition rates of kelp detritus on the seafloor in relation to local environmental factors. Detritus decomposition in both species were strongly related to ocean temperature and initial carbon content, with higher rates of biomass loss at lower latitudes with warmer temperatures. Our experiment showed slow overall decomposition and turnover of kelp detritus and modeling of coastal residence times at our study sites revealed that a significant portion of this production can remain intact long enough to reach deep marine sinks. The results suggest that decomposition of these kelp species could accelerate with ocean warming and that low-latitude kelp fores...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research