Long-term morphological and sedimentological changes caused by bottom trawling on the northern Catalan continental shelf (NW Mediterranean)

Author:

Durán Ruth,Puig Pere,Paradis Sarah,Guillén Jorge,Palanques Albert,Lo Iacono Claudio,Arjona-Camas Marta,Muñoz Araceli,Micallef Aaron

Abstract

Bottom trawling is a fishing method that involves towing of nets along the seafloor to catch demersal species. The dragging of trawling gears along the seafloor results in scraping and ploughing of the surficial sediments, leading to the formation of turbid plumes of resuspended sediments and causing measurable changes in the seabed morphology. High-resolution multibeam data, side scan sonar, sediment grain size and vessel tracking data have been used to investigate the impact of bottom trawling on the seafloor morphology and surficial sediments of the northern Catalan continental shelf (NW Mediterranean), providing new insights into the impact of this anthropogenic activity on the seafloor. Multibeam data evidenced the occurrence of large-scale erosive features as a consequence of repeated scouring by fishing gears in localized areas. They are characterized by elongated (70-300 m wide and up to 8 km long) channelized areas of high backscatter with variable incision (from 0.2 m to 1.2 m). The spatial distribution of these morphologies shows a similar pattern to that observed in the fishing intensity, with maximum values in the areas of increased trawling intensity, corresponding to the main fishing grounds. Side scan sonar data also shows higher densities of trawl marks in these areas than in the surroundings. Sediment cores collected on these features show an upward-coarsening trend in the first 4-5 cm of the core, suggesting that part of the finer fraction resuspended by trawling is winnowed, increasing the sand content of the surface sediment. The identification of such large erosive morphologies in the main fishing grounds evidences that repeated trawling over the same fishing ground during decades can result in deep excavation of the seafloor, leading to permanent large-scale morphological changes. Furthermore, the evolution of these erosive features over a 13-year interval points towards long recovery periods after the cessation of trawling activities.

Funder

HORIZON EUROPE Marie Sklodowska-Curie Actions

Ministerio de Ciencia e Innovación

Generalitat de Catalunya

Publisher

Frontiers Media SA

Subject

Ocean Engineering,Water Science and Technology,Aquatic Science,Global and Planetary Change,Oceanography

Reference61 articles.

1. River mouth plume events and their dispersal in the northwestern Mediterranean Sea;Arnau;Oceanography,2004

2. Effects of beamtrawl fishery on the bottom fauna of the North Sea;Beleidsgericht Ecol. Onderzoek Noordzee,1990

3. Sediment transport rates and sediment disturbance due to scallop dredging in Port Phillip Bay;Black;Mem. Queensl. Mus.,1994

4. Identifying trawl marks in North Sea sediments;Bruns;Geosciences,2020

5. Impacts of fisheries and aquaculture on sediments and benthic fauna: suggestions for new management approaches;Buhl-Mortensen;Fisken og Havet,2013

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3