Predators help protect carbon stocks in blue carbon ecosystems

Authors: Trisha B Atwood, Rod M Connolly, Euan G Ritchie, Catherine E Lovelock,
Michael R Heithaus, Graeme C Hays, James W Fourqurean and Peter I Macreadie

Published in: Nature Climate Change, September 2015

Tiger Shark

Tiger sharks in Shark Bay, Western Australia, create a landscape of fear where sea turtles and dugongs preferentially forage in seagrass microhabitats that are lower in predation risk and have allowed Cabon stocks. Image credit Albert Kok via Wikimedia Commons.

Abstract

Predators continue to be harvested unsustainably throughout most of the Earth’s ecosystems.

Recent research demonstrates that the functional loss of predators could have far-reaching consequences on carbon cycling and, by implication, our ability to ameliorate climate change impacts. Yet the influence of predators on carbon accumulation and preservation in vegetated coastal habitats (that is, salt marshes, seagrass meadows and mangroves) is poorly understood, despite these being some of the Earth’s most vulnerable and carbon-rich ecosystems.

Here we discuss potential pathways by which trophic downgrading affects carbon capture, accumulation and preservation in vegetated coastal habitats.

We identify an urgent need for further research on the influence of predators on carbon cycling in vegetated coastal habitats, and ultimately the role that these systems play in climate change mitigation.

There is, however, sufficient evidence to suggest that intact predator populations are critical to maintaining or growing reserves of ‘blue carbon’ (carbon stored in coastal or marine ecosystems), and policy and management need to be improved to reflect these realities.

Atwood TB, Connolly RM, Ritchie EG, Lovelock, CE, Heithaus MR, Hays GC, Fourqurean JM, Macreadie PI (2015) Predators help protect carbon stocks in blue carbon ecosystems, Nature Climate Change PDF DOI