Changes in the overexploited demersal fish assemblages in the Northwest Atlantic : the Southern Grand Banks and the Flemish Cap

• Main Author: Nogueira Gassent, Adriana
• Other Authors: Gonzalez Castro, Bernardino, Paz Canalejo, Xabier
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Ecoloxía e bioloxía animal 2017
• Subjects: 2510.91 Recursos Renovables; 2401.06 Ecología Animal; 2404.01 Bioestadística; Española; Flota; Northwest Atlantic
• Online Access: http://hdl.handle.net/11093/667

The Northwest Atlantic fishery is one of the most important Spanish fisheries in distant waters. This region has suffered several collapses of the exploited demersal resources, the latest during the period 1985-1993. The thesis aims to determine the impact of fishing and climate variations on the size and species composition of demersal fish communities in two fishing grounds of NAFO (Northwest Atlantic Fisheries Organization) Regulatory Area (Div.3MNO). We propose to identify, describe and map ground fish assemblages in Flemish Cap (Div. 3M of NAFO) and Southern Grand Banks (Div. 3NO of NAFO), and its relation with abiotic variables. Databases of the Spanish bottom trawl surveys conducted in the area: Flemish Cap (NAFO Div.3M: 2004-2013) and Southern Grand Banks (NAFO Div.3NO: 2002-2013) will be used. It is proposed to study the impact of fishing on fish communities. The thesis will define the specific composition of structural assemblages and their persistence over time, on the other hand it will explore community indicators to detect the fishing impact. Also it will intend to compare and to test different methodologies, specially advantages and disadvantages of multivariate techniques and Geographic Information Systems (GIS). Assemblages or sub geographic groupings are appropriate for purposes of modelling and/or management, as they allow investigating the biological variability and the organizational structure within each area and the interactions between areas. Structural association may be useful for monitoring bycatch, the determination of appropriate Marine Protected Area (MPA), and the development of ecosystem models to, ultimately achieving a more sustainable ecosystem. El Atlántico Noroeste es uno de los caladeros más importantes de la flota española de gran altura. Esta región ha sufrido varios colapsos de los recursos demersales explotados, el último en el período 1985-1993. El estudio tiene como objetivo determinar el impacto de la pesca y de las variaciones climáticas en el tamaño y la ...