Can seaweed farming in the tropics contribute to climate change through emission of short-lived halocarbons?

Abstract

Volatile halocarbons form a major source of halogen radicals in the atmosphere, which are involved in the catalytic destruction of ozone. Studies show that marine algae release halocarbons, with 70% of global bromoform produced by marine algae (Carpenter et al., 2000). The role of halocarbons in algae is linked to their use as defense against epiphytes and grazing as well as scavengers of strong oxidants (Nightingale et al., 1995). Halocarbon release rates are higher for tropical algae than temperate species (Abrahamsson et al., 1995). The Maritime Continent is a major contributor to emissions of short-lived halocarbons and their transport to the stratosphere due to deep convection. The Coral Triangle situated in the Maritime Continent, is a centre for seaweed farming. The following discusses the potential impact of tropical seaweed emissions of halogenated compounds to climate change.