As the endpoint of the biological carbon pump, the burial of sedimentary carbon in the seafloor represents the ultimate carbon sink in the earth system. In coastal, shelf, slope or deep ocean environments, these reservoirs can act as considerable long-term stores of carbon and as such are globally significant in climate regulation. However, marine sediments are under increasing global pressure from anthropogenic activities and from climate forcing itself, altering carbon reactivity, alkalinity generation, and overall burial efficiency.
Human impacts include, but are not limited to: bottom-contacting fisheries, marine aggregate mining, offshore construction such as offshore wind or tidal power developments or decommissioning, material dumping, and coastal protection. Such activities can modify sedimentary carbon storage through direct disturbance of the seafloor or indirectly by changing carbon supply, physical fields and/or ecosystem functions, including biological assemblage changes. Impacts of climate forcing may manifest in multiple ways, such as changes in riverine carbon export, marine production and temperature driven changes in carbon degradation, as well as increased sediment remobilisation caused by changes in metocean conditions. Although the magnitudes of these impacts, their connection to the global carbon cycle, and implications for marine spatial management strategies have recently been discussed intensively, a consensus has yet to be achieved on the net effects on key carbon parameters and budgets. The goal of this session is to promote this debate on the way to achieve scientific consensus about the vulnerability of sedimentary carbon sequestration to human disturbances across multiple temporal and spatial scales.
In this multidisciplinary session we invite all experimental, observational and modelling studies related to human impacts and climate forcing on subtidal sediments. We especially encourage contributions which seek to resolve interactions between human activities, climate forcing, sediment transport, marine biota and the carbon cycle to inform management and policy questions.