RIM 20(10): Effects of pollution on fish and presence of marine litter on the seabed of the Basque continental shelf: supporting the Marine Strategy Framework Directive

Author /Editor: Joxe Mikel Garmendia, Nagore Cuevas, Joana Larreta, Izaskun Zorita and Iñaki Quincoces

Year: 2013

Content: The European Marine Strategy Framework Directive (Directive 2008/56/EC), establishes a framework and common objectives for the protection and conservation of the marine environment. This Directive requires the implementation of all measures necessary to achieve the Good Environmental Status by 2020, according to 11 qualitative descriptors: (1) biodiversity, (2) non-native species, (3) commercial species, (4) food webs, (5) eutrophication, (6) seabed integrity, (7) hydrography, (8) pollutants, (9) contaminants in biota, (10) marine litter and (11) energy and noise. With the aim of improving the knowledge of the environmental status of the Basque coast, in relation to the descriptors 1, 2, 3, 4, 6, 8 and 10, a new iteration of the survey Itsasteka 2011 and deployed by AZTI-Tecnalia was carried out, using the Gure Gaskuña vessel. 23 trawls were undertaken and the sampled depth ranged from 25 m to 358 m. The area surveyed with trawls was 6.75 km2. The present work shows the information obtained for descriptors 8 and 10.

Four sentinel species were selected for the assessment of biological effects of contaminants: hake (Merluccius merluccius), small spotted catshark (Scyliorhinus canicula), thickback sole (Microchirus variegatus) and common sole (Solea solea). Contaminant levels in the first three species mentioned follow a different pattern being the hake, in general, the species with the lowest contaminant values. The histopathology study in hake indicates that there are no significant differences among studied zones and, in general, there are no signs of disturbed environmental health. The micronuclei frequency seems to be a promising technique both for the small spotted catshark and for the common sole. However, in this study it is recommended the characterization and set up of the biological effects of contaminants (histopathology and micronuclei frequency in fish) proposed by ICES for the study area of the Bay of Biscay.

With respect to marine litter, in this survey it has been collected an average of 0.068 kg   ha-1 from the marine bottom. The main amount has been found in front of Pasaia and Donostia. In weight, the main litter (63.4%) corresponds to the type “others” (slags, foam mattress, tyre and wood pieces) and plastics (15.1%). In number, this dominance is more distributed between “others” (31.7%) and plastics (29.9%).


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