Exploring benthic communities responses along a gradient of fishing intensity in the Southern Tyrrhenian Sea

Marine spatial planning (MSP) is promoted as a more integrated system of management for human activities at sea. In a context of Ecosystem Based Fisheries Management (EBFM), the key to the success of MSP is accurate, timely, and representative spatial information on trawling activities and the pressures they exert on the seabed and related benthic communities. First of all the study provides an assessment of the spatial extent of otter trawling activity to a fishing ground scale in the Southern Tyrrhenian Sea. Afterwards, considering the patchiness of this activity and the resulting bearing on the persistence of benthic communities, the fishing intensity effects were tested on each surveyed epibenthic communities. The high-resolution spatial distribution of fishing effort was evaluated through the Vessel Monitoring System data analysis. The study analysed the non-target epibenthic fraction incidentally caught by a “Maireta” otter trawl net from 2010 to 2013. The presence of a Fishery Exclusion Zone offered the opportunity to explore the benthic communities responses along a gradient of fishing intensity. A significant reduction of vulnerable organisms such as large, slow-growing species and/or fragile bioengineering species was highlighted along a growing gradient of fishing intensity. Contrarily, an increase of resilient species, smaller individuals and species suffer lower mortality rates was recorded in the most exploited areas. The study focus on the continental shelf ecosystem and provides important insights into the responses of benthic communities’ components to trawl disturbance, a necessary step to evaluate the impact of this activity in a context of EBFM.