Spatial and temporal characterization (2006-2012) of the trawling activity in the Site of Community Importance "Volcanes de fango del golfo de Cádiz" (southwestern Iberian Peninsula).

Abstract

Event Abstract Back to Event Spatial and temporal characterization (2006-2012) of the trawling activity in the Site of Community Importance "Volcanes de fango del golfo de Cádiz" (southwestern Iberian Peninsula). Emilio González-García1*, Ángel Mateo-Ramírez1, Javier Urra Recuero1, Gerardo Bruque2 and José Rueda1 1 Oceanographic Center of Málaga, Spanish Institute of Oceanography (IEO), Spain 2 Instituto Español de Oceanografía (IEO), Spain Human activity is causing different environmental impacts that accelerate changes in the marine environment both in the species of commercial interest and in the habitats where they occur, promoting a loss of biological diversity (Rice et al., 2016). Fishing, mainly bottom trawling, is one of the activities with the highest negative impact on marine ecosystems. Currently, the use of combined information from logbooks and Vessel Monitoring Systems (VMS) is a booming technique to study the spatial distribution of the fishing activity. This technique allows detailed spatial and temporal analyses of the fishing activity in specific areas (Hintzen et al., 2012). In the present study we analyze the spatio-temporal evolution of the fishing effort of the bottom trawling fleet as well as catches of the main species, both within the Site of Community Importance (SCI) of the "Volcanes de Fango del golfo de Cádiz" and in the external zone of the SCI (adjacent). The resulting data will be taken into account for the development of future SCI management plans in order to promote sustainable fisheries and habitat protection. The SCI is located in Spanish waters of the Gulf of Cadiz between 350 m depth and the upper slope 700 m, and the study focuss mainly in the Shallow Field of Fluid Expulsion (SFFE) of the SCI. Numerous trawlable grounds of important species occur in the SCI such as the Norway lobster (Nephrops norvegicus), the deep-water rose shrimp (Parapenaeus longirostris), European hake (Merluccius merluccius) and blue whiting (Micromesistius poutassou), among others (Ramos et al., 1996). Data from the logbooks and the VMS provided by “Secretaría General de Pesca” have been used for the period 2006-2012 for analyzing the evolution of the spatial distribution of the fishing effort and catches of the main species by the bottom trawling fleet. Regarding the VMS, this localization device sends a signal every 2 hours (ping) and provides data from the vessel itself, fishing status, date, time, position (latitude and longitude), course and speed. This information is previously processed in R software and analyzed using the VMStools package. This package calculates the time and average speed between successive signals and identifies the beginning and end of each fishing trip. The distribution of average speed frequencies was used to delimitate the speed range when vessels were trawling. Subsequently, depending on vessel and date, the data was crossed with the logbooks for analyzing catches of commercial species. The spatial distribution of the fishing effort as well as of the different catches made for the period 2006-2012 was estimated using a grid size of 1 km2 in which the number of hours of trawling and the catch assigned to each ping was calculated. The data obtained were integrated into the ArcGIS desktop software for representing both the fishing effort and the average catches (kilograms) of important commercial species in each 1 km2 cell. The spatial distribution of the trawling activity, both in hours and vessels, extends throughout sedimentary bottoms of the shelf and slope of the northwestern Gulf of Cádiz, with a greater pressure in the shelf throughout the years. High trawling activity areas are mostly located outside the SCI, however specific areas with high trawling were also detected in the SCI, mainly in the northern (around Anastasya mud volcano) and the central parts. The main targeting species in the SCI areas is the Norway lobster. In the deep zones of the SCI (> 700 m depth) as well as in hard bottoms and/or with strong near-bottom current speeds, trawling activity decreases considerably (Figure 1). An overall increase of the trawling activity was detected from 2009 to 2012, possibly due to the closure of the Moroccan fishing grounds and the reorganization of the trawling fleet. The fleet belonging to the Huelva province presented the greatest activity within the SCI, probably related with the technical characteristics of its fleet (e.g. large dimensions, powerful engines). Catches of the commercial species are generally higher outside the SCI. The main target species in the SCI is the Norway lobster with an upward trend throughout the years (3.7t in 2006 to 28t in 2011).The deep-water rose shrimp catches fluctuated between 9t in 2007 and 155t in 2009 and the European hake and monkfishes (Lophius spp) catches were stable during the period with average values of 13.5t and 3.8t respectively. The information on the spatial distribution patterns of the trawling activity and the catches of the main target species throughout the study period represent an important tool in the management measures of SCI. This is of importance for minimizing the impact of bottom trawling fleet and estimating the socio-economic impact of the closure of some areas to trawling. Figure 1. Spatial distribution, with a mesh size of 1 km2, of the trawling activity effort (average annual fishing hours) for 2012 in the SCI and outside the SCI. No color cell indicates no trawling detected. Figure 1 Acknowledgements This study is part of the Action 4 within LIFE PAF INTEMARES project “Gestión integrada, innovadora y participativa de la Red Natura 2000 en el medio marino español” for analizing the effects of fisheries on habitats of the Habitat Directive. References Hintzen N.T., Bastardie F., Beare D., Piet G.J., Ulrich C. et al. (2012). VMStools: Open-source software for the processing, analysis and visualization of fisheries logbook and VMS data. Fish Res. 115, 31-43 Ramos F., Sobrino I., Jiménez M.P. (1996). Cartografía temática de caladeros de la flota de arrastre en el Golfo de Cádiz. Junta de Andalucía, Servicio de Publicaciones y Divulgación Informe Técnico 45/96. Consejería de Agricultura y Pesca. Junta de Andalucía. Rice J., Rosenberg A., Simcock, A. (2016). Overall Assessment of Human Impact on the Oceans. New York, United States. Keywords: Fisheries, Gulf of Cádiz, mud volcanoes, SCI ESZZ12002, trawling activity Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019. Presentation Type: Oral Presentation Topic: Fisheries, Aquaculture and Biotechnology Citation: González-García E, Mateo-Ramírez Á, Urra Recuero J, Bruque G and Rueda J (2019). Spatial and temporal characterization (2006-2012) of the trawling activity in the Site of Community Importance "Volcanes de fango del golfo de Cádiz" (southwestern Iberian Peninsula).. Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00149 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 17 May 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Emilio González-García, Oceanographic Center of Málaga, Spanish Institute of Oceanography (IEO), Málaga, Andalusia, 29016, Spain, emilio.gonzalez@ieo.es Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Emilio González-García Ángel Mateo-Ramírez Javier Urra Recuero Gerardo Bruque José Rueda Google Emilio González-García Ángel Mateo-Ramírez Javier Urra Recuero Gerardo Bruque José Rueda Google Scholar Emilio González-García Ángel Mateo-Ramírez Javier Urra Recuero Gerardo Bruque José Rueda PubMed Emilio González-García Ángel Mateo-Ramírez Javier Urra Recuero Gerardo Bruque José Rueda Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.