Line of action:

Status:

Execution date:

The overall objective of the ENCORAT project is to reduce the accidental mortality of the shag in gillnet fishing gear in the North Atlantic Marine Demarcation. To this end, the project focuses on the study of juvenile birds, the age group most affected by mortality in gillnets. During the project, an active gear modification measure will be evaluated in areas with the highest risk of bycatch. The main specific objectives of this project are:

1. To experiment with an active measure to reduce the by-catch of shag in gillnet fishing gear.

2. To estimate the use of space by shag during juvenile dispersal to determine the areas where it is necessary to implement modifications in gillnets

A1. Experimental study of modification of fishing gear to reduce the accidental capture of A2 shags
. Study of the possible effects of the modification of fishing gear on catches of commercial
interest A3. Dissemination of the objectives and results of the A4 project
. Placement of GPS-GSM devices to juvenile shag to know in detail the use they make of the A5 space
. Estimation of priority areas for the promotion of the use of modified gear to reduce the capture of shag

The ENCORAT project has consisted of two specific objectives and five actions. The first objective, the testing of an active measure to reduce the bycatch of the shag in gillnet fishing gear, involved three activities:

Modification of fishing gear (trammel nets) to reduce the catch of cormorants

The analysis of the impact of this measure on the capture of commercial species

Dissemination of project objectives and results

For the estimation of space use by shag during juvenile dispersal, GPS devices were placed on juvenile shag to estimate space use and priority conservation areas for these birds.

For the first time in the North Marine Demarcation, an active measure has been experienced to reduce the accidental capture of seabirds in gillnets, which consisted of the placement of LED lights on the gear. 30 sets were made, 15 with modified rigging and 15 control sets. The results indicate that the use of deterrent lights in gillnets does not have any negative effect on fishing activity, both in terms of the number of catches and the economic yield. During the fieldwork (2 months), a high mortality of cormorants in gillnets (five individuals in three boats) has been observed, including that which occurred during the experimental sets. Mortality was associated with certain environmental conditions, such as wind speed. The deterrent lights had no effect on mortality, although this result should be taken with caution given the low number of individuals captured in the experimental sets.

Previously, a pilot study was carried out, placing three devices in adults, indicating a high interindividual heterogeneity in the feeding areas. 46 devices were placed in juveniles, who registered a total of 18,684 locations. The GPS positioning has made it possible to characterize in detail the use of the space by the juveniles between May and August. Until mid-June, all the juveniles were located within a radius of less than one kilometre from the perches of the breeding colonies and in mid-July they moved away from the colonies, reaching more than seven km from them. Based on the results of the locations, the priority areas for conservation during the post-generation period were delimited.