BUSCADOR RECOLECTA

ABIDES-1 Cruise (29GD20170205) carried out on the Research Vessel García del Cid in 2017, To study the transport processes from the submarine canyon flanks of the Catalan margin to deeper areas caused by the bottom trawling activities and evaluate the impact on the sedimentary substrate.To address several of the specific objectives proposed in this project objectives it will be necessary to carry out three separate oceanographic campaigns six months each other to record time series of oceanographic parameters through the anchorage of several anchors equipped with current meters, turbidimeters and sediment traps located inside submarine canyons . In the first of these campaigns, we will proceed to anchoring the anchors, in the second to the maintenance and in the third to the final recovery of the instruments, to cover an annual cycle of record the sediment transport processes and identify the contribution of the resuspension by trawling to sedimentary flows . In each one of these campaigns will be transects of CTD stations to study the seasonal variability of hydrography and formation of nephelloid layers in the column of water and surface sediment cores will be obtained . Sampling will be done both in open slope environments and in the interior of canyons submarines. The oceanographic vessel chosen for these three campaigns is the B / O García del Cid, which has the right characteristics to carry out the tasks planned and the crew is experienced with anchoring maneuvers and recovery of oceanographic anchors

ABIDES-ROV Cruise (29SG20170905) carried out on the Research Vessel Sarmiento de Gamboa in 2017, The ABIDES (Assessment of Bottom-trawling Impacts in DEep-sea Sediments) project focuses on the study of contemporary sedimentary processes associated to the impact of bottom trawling activities on the deep seafloor. The disturbance of deep-sea environments caused by this fishing practice is considered to be notably higher than all other anthropogenic pressures combined, given its intensity, recurrence and wide geographical distribution. Although the impacts of trawling on coastal and shelf environments have been investigated in the past from the sedimentary point of view, up to date, very few studies have addressed the role of this fishing practice on slope environments, where background energy levels controlling natural sedimentary processes are generally low and where the associated benthic ecosystems are less resilient and more vulnerable. Therefore, the main goal of the ABIDES project is to improve our knowledge of the contemporary sediment erosion, transport and accumulation processes driven by this anthropogenic activity, with the aim to assess the magnitude of the associated impacts in continental slope environments and to provide support for mitigation efforts towards the development of sustainable fisheries. During the ABIDES-ROV cruise we have conducted a morphological and seabed habitat characterization of the continental slope regions that have (and have not) been intensively trawled during decades, both at small- and large-scale with the aim to evaluate the “seafloor integrity”. The main study area has been the NW Mediterranean continental margin, where a bottom trawling fishery has been operating for decades and a good knowledge of the current bottom-trawling footprint exists. ROV footage has been used to determine the small-scale morphological changes and the impact caused by trawling gear on the seafloor habitats through direct visual observations; and detailed multibeam bathymetric mapping will be used to identify large-scale morphological changes caused by persistent trawling activities over major fishing grounds of the study area

ABIDES-2 Cruise (29GD20170603) carried out on the Research Vessel García del Cid in 2017, To study the transport processes from the submarine canyon flanks of the Catalan margin to deeper areas caused by the bottom trawling activities and evaluate the impact on the sedimentary substrate.To address several of the specific objectives proposed in this project objectives it will be necessary to carry out three separate oceanographic campaigns six months each other to record time series of oceanographic parameters through the anchorage of several anchors equipped with current meters, turbidimeters and sediment traps located inside submarine canyons . In the first of these campaigns, we will proceed to anchoring the anchors, in the second to the maintenance and in the third to the final recovery of the instruments, to cover an annual cycle of record the sediment transport processes and identify the contribution of the resuspension by trawling to sedimentary flows . In each one of these campaigns will be transects of CTD stations to study the seasonal variability of hydrography and formation of nephelloid layers in the column of water and surface sediment cores will be obtained . Sampling will be done both in open slope environments and in the interior of canyons submarines. The oceanographic vessel chosen for these three campaigns is the B / O García del Cid, which has the right characteristics to carry out the tasks planned and the crew is experienced with anchoring maneuvers and recovery of oceanographic anchors.

ABIDES-3 Cruise (29GD20171003) carried out on the Research Vessel García del Cid in 2017, It aims to study the current sedimentary processes associated with the activity of trawling, which although it has been investigated in coastal environments, very little is known of those occurring in the continental slope, where the benthic ecosystem is more vulnerable to having reduced capacity for recovery The stress that trawling generates on the seabed is dramatic in areas where fishing activity is intense, continuous and wide geographically, as in the continental strip of the northwestern Mediterranean (coast and slope adjacent to the provinces of Barcelona and Girona). Thus, the main objective of this project is to improve the knowledge of the current mechanisms of erosion, transport and sediment accumulation caused by this form of fishing in the continental slope, with the purpose of identifying the impacts caused on the seabed and get to promote corrective measures to guarantee a sustainable fishery. To do this, time series of currents and sediment concentration in suspension will be recorded by anchoring instrumented anchors in the vicinity of fishing grounds. At the same time, hydrographic profiles will be periodically carried out for the identification of nephelide layers in the water column and surface sediments will be obtained during oceanographic campaigns. Sampling will be carried out both in open slope environments and in the interior of submarine canyons, following a strategy based on the footprint of the fishing effort during the last 10 years. Likewise, a detailed study of the habitats and underwater morphology will be carried out in order to evaluate the status (or level of integrity) of the seabed. The study area will focus on the continental margin of the northwestern Mediterranean, where trawling has been practiced for several decades and where the distribution of fishing effort is known in detail. The specific objectives that are intended to be achieved are 1) monitor sediment transport processes inside submarine canyons and identify the contribution of resuspension by trawling to sedimentary flows; 2) identify the hydrographic structure and the temporal evolution of the distribution of nephelide layers in the water column as indicators of resuspension processes by trawling; 3) evaluate the erosion caused by trawling in the surface sediments of the continental slope and establish sedimentary patterns based on the presence or absence of fishing grounds; 4) determine the sedimentation rhythms inside submarine canyons and evaluate the potential formation of preferential zones of anthropic sedimentary accumulation; 5) quantify the role of trawling in the alteration of organic carbon content in the sedimentary record; 6) to determine, through direct visual observations, small-scale morphological changes and alterations in the habitat and deep benthic ecosystems produced by trawling; and 7) identify large-scale morphological changes in areas of fishing grounds in the study area by performing detailed bathymetries, as well as in other areas of intensive trawling of the Spanish margin from the use of existing bathymetric information