The Hidden Ecological Power of Seaweed Litter

Seaweed beds are far more than underwater gardens; they are pivotal hubs for the global carbon cycle. A comprehensive review reveals that the 'litter' these plants produce—decaying organic matter—is fundamental to maintaining coastal stability and nourishing sediment-dwelling, or benthic, communities.

The breakdown of this material is influenced by a complex interplay of drivers. While natural factors like temperature and hydrodynamics dictate decay rates, human impacts such as aquaculture and pollution are increasingly significant. Furthermore, the specific chemical composition of the seaweed, including its lignin content, determines how quickly nutrients return to the system.

Scientists predict that climate change will accelerate seaweed growth and subsequent litterfall, potentially altering the microbial communities responsible for decomposition. To safeguard these ecosystems, experts recommend shifting to ecosystem-based management, a holistic approach that considers long-term environmental trends. Additionally, this biological detritus holds untapped potential, with promising applications in sustainable biofuel production and organic fertilisers.