Research Portal

The seabed is one of the key ecological interfaces on the planet, exerting a major influence on global biogeochemical cycles. Biological processes such as bioturbation – the reworking of sediment by activities of benthic fauna – are key in mediating fluxes of nutrients, carbon, and oxygen from the water column into the sediment. To date, most research on bioturbation has focused on the role of sediment-dwelling invertebrates with the contribution of other and often larger organisms such as fish largely overlooked. Here, we highlight the significant and underappreciated role of fish as bioturbators in benthic ecosystems and present the first systematic approach to assess fish bioturbation impact on the seabed based on ecological traits known to

Understanding and mapping seabed sediment distribution in shelf seas is essential for effective coastal management, offshore developments, and for blue carbon stock assessments and conservation. Fine-grained marine sediments, particularly muds, play a key role in long-term organic carbon sequestration, so knowledge of the spatial extent of these carbon-rich deposits is important. Here, we consider how changes in shelf sea tidal dynamics since the Last Glacial Maximum have influenced the development of three mud depocenters in the northwest European shelf seas: the Fladen Ground, the Celtic Deep, and the Western Irish Sea Mud Belt. Using a new high-resolution paleotidal model, we demonstrate how…

Fishing with active bottom-contacting gears (here collectively described as ‘bottom trawling’) is considered the greatest source of anthropogenic disturbance to marine sediments. However, uncertainties are apparent in studies evaluating the severity of their impacts from fishing with these gears at the global scale. A major uncertainty is the estimation of the area of seabed disturbed by applying European-based vessel size to gear footprint (i.e., gear width) relationships to the global fleet, thereby assuming these relations hold worldwide. To test the strength of this assumption, we conducted a structured review to understand global variation in fishing gear parameters and, thus, footprint of bottom trawling gears. While we find a…

The air–sea exchange and oceanic cycling of greenhouse gases (GHG), including carbon dioxide (CO₂), nitrous oxide (N₂O), methane (CH₄), carbon monoxide (CO), and nitrogen oxides (NO_x = NO + NO₂), are fundamental in controlling the evolution of the Earth’s atmospheric chemistry and climate. Significant advances have been made over the last 10 years in understanding, instrumentation and methods, as well as deciphering the production and consumption pathways of GHG in the upper ocean (including the surface and subsurface ocean down to approximately 1000 m). The global ocean under current conditions is now well established as a major sink for CO₂, a major source for N₂O and a minor source for both…