Blue carbon sequestration


This week’s featured research article has just been published in Frontiers in Ecology and the Environment on managing coastal ecosystems to sequester more blue carbon. To promote the sequestration of blue carbon, resource managers rely on best-management practices that have historically included protecting and restoring vegetated coastal habitats (seagrasses, tidal marshes, and mangroves), but are now beginning to incorporate catchment-level approaches. Drawing upon knowledge from a broad range of environmental variables that influence blue carbon sequestration, including warming, carbon dioxide levels, water depth, nutrients, runoff, bioturbation, physical disturbances, and tidal exchange, the researchers discuss three potential management strategies that hold promise for optimising coastal blue carbon sequestration: (1) reducing anthropogenic nutrient inputs, (2) reinstating top-down control of bioturbator populations, and (3) restoring hydrology. By means of case studies, they explore how these three strategies can minimise blue carbon losses and maximise gains. They state that a key research priority is to more accurately quantify the impacts of these strategies on atmospheric greenhouse-gas emissions in different settings at landscape scales. The study investigated key environmental processes that influence blue carbon sequestration and identified three catchment-level processes controllable through resource management: nutrient inputs, bioturbation, and hydrology. The researchers argue that reducing nutrient inputs, avoiding unnaturally high levels of bioturbation, and restoring natural hydrology (freshwater flows and tidal exchange) will maximise blue carbon sequestration and minimise blue carbon losses. The article can be downloaded here.