Line of action:

Status:

Execution date:

General Objective:

To increase the sustainability of artisanal fisheries and to transfer the information obtained for the design of conservation decisions to the managing bodies and the sector involved.

Specific objectives:

• Reduce by-catch and interactions with fixed nets by using the shag as an umbrella species, inside and outside the Natura 2000 Network, with the participation of the fishing sector, achieving mutual benefit.
• Reduce, through an innovative method, ghost fishing gear present at sea and transfer the experience gained to the fishing sector.
• Maintain long-term monitoring of coastal fish communities by using the European Shag diet as a bioindicator.
• To provide information, on new mapping, of the seabed and to determine the habitats selected by cormorants.
• Determine the parasite load of the shag and evaluate which fish species participate in closing the life cycle of the parasites; fish with a higher prevalence of parasites that would reduce their quality for human consumption and that would be the vectors of transfer to the cormorant with effects on their physical condition.
• Determine the load of microplastics and heavy metals fixed in cormorants as a sentinel of the state of the sea.

1. Bycatch and interaction of marine fauna with gillnets.
2. Mapping and extraction of lost fishing gear (ghost fishing).
3. Dynamics of coastal fish populations through the diet of the European shag.
4. Population dynamics, tracking and reproductive parameters of the shag.
5. Obtaining the cartography of the seabed.
6. Parasites, microplastics and pollutants.
7. Dissemination actions (press release, social networks, congresses, scientific articles, workshops and conferences).

The University of Girona has been studying the Mediterranean shag on the Catalan coast over the last few years, confirming the problem of accidental capture of this species, mainly in fixed gillnets.

The DESMARES III project carried out in 2022 is preceded by two projects from previous calls, DESMARES in 2019 and DESMARES II in 2020.
The main objective of the DESMARES III project has been to increase the sustainability of artisanal gillnet fishing and to transfer to the managing bodies and the sector involved, the information obtained for the design of conservation decisions, through the use of the shag as an emblem species and umbrella.
For the first specific objective of reducing bycatch and interactions with fixed nets of the shag and other umbrella species, with the participation of the fishing sector, notebooks have been delivered in the ports of the Catalan and Balearic coasts. It has been used to expand the network of collaboration and communication with artisanal fishermen, allowing an increase in the collection of interaction data, reaching the collection of data on 6 tufted cormorants and a loggerhead turtle entangled only for the duration of the project.

As mitigation measures on accidental catches, some 75 days of testing have been carried out with fixed green LED lights in the net in 6 artisanal fishing vessels, 3 in Catalonia and 3 in the Balearic Islands. Only one shag has been entangled in the net without lights.
No changes in catches of commercial species have been observed with the use of lights. Although in some cases dolphins have interacted with the lights, playing with them.
Hydrophones and photo-identified transects have also been used to increase information on the interaction of cetaceans, mainly bottlenose dolphins, with nets.
For the objective of reducing ghost fishing gear present at sea, in the tests, an innovative method has been used, a remotely operated vehicle (ROV), removing 200m of trammel net and 6 pots, in collaboration with a fishing vessel in the marine area of the Cap de Creus Natural Park. The objective of long-term monitoring of coastal fish communities through the use of the diet of the European shag allows detecting inter- and intra-annual fluctuations, as well as determining differences between areas that are usually linked to the type of existing underwater community. Currently, there are about 4000 pellets, 403 analyzed during this project, reaching 3000 analyzed in the three projects, with a total of 100,000 otoliths identified. To complement and observe the existing fish community, the ROV has been used to carry out fish censuses using visualized transects.

In the action of the population dynamics, tracking and reproductive parameters of the shag, a reproductive monitoring of the breeding population in Catalonia has been carried out, determining a total of 60 occupied nests, of which chicks have been enveloped in 31 nests, with a total of 54 chicks, with a productivity of 0.90. In addition, to study the movements of individuals, GPS has been installed on 15 individuals within the framework of this project, reaching a total of 72 GPS installed to date (DESMARES, DESMARES II and DESMARES III).

An analysis of population dynamics has also been carried out with the marking data of the 300 individuals ringed since 2014. The specific objective for the provision of information, on new mapping, of the seabed and to determine the habitats selected by the cormorants, it has been observed that the cormorants tagged with GPS do not use the meadow areas as a priority for fishing.

In the objective on the parasite load of the shag, the stomachs of 21 individuals from the Catalan coast have been analyzed using visual and molecular techniques, finding nematode parasites of Contracaecum rudolphii sp A. in all but one. And it has been proven that the sandeel and spiderfish are not act as a vector of transmission of the parasite.

Likewise, they also have a high load of microplastics with their presence in 93.75% of cormorant digestive systems and half of the pellets analyzed. Specimens from the central Catalan coast have a higher incidence of microplastics in their digestive systems, compared to those from the Costa Brava. The incidence of heavy metals (Cu, Hg, Pb, Cd, Zn, Se, As) has also been analyzed, observing that individuals with lower reserves have a higher amount of heavy metals.
Finally, various meetings and dissemination actions have been held, both on social networks, as well as various press releases, and the project has appeared on radio and television. In addition, a scientific article has been produced and attendance at a scientific congress has been carried out. Workshops have also been held to disseminate the project with dramatizations aimed at family audiences, a mobile information panel to add to the traveling exhibition and an informative video showing the main advances of the project on microplastics and parasites in the shag.

Conclusions
⎻ The network of collaboration and communication with the fishing sector has been increased, as well as its predisposition and involvement in seeking solutions in the preservation of species.
⎻ Mitigation measures with LED lights have been carried out satisfactorily and the accidental capture of a cormorant has been in the part without lights, but for their implementation it would be necessary to finish evaluating their effectiveness. It should be noted that this measure does not affect commercial catches.
⎻ The remotely operated vehicle (ROV) can be a very valid tool for the extraction of lost fishing gear, especially when they have not been lost on the bottom for a long time and have not accumulated organisms or become attached to sensitive bottoms such as gorgonians and the like.
⎻ The increase in pellet samples and the identification of otoliths to determine the species ingested by the European shag increase knowledge for long-term study to complete a historical series to contribute to the improvement of the knowledge of these communities, as well as to provide information applicable to fisheries management.
⎻ The productivity of the species in the reproductive area of Catalonia is not very high, where the effect of storms with strong waves causes a high loss of nests and therefore the consequent reproductive failure. Although the population of the study area seems to be stable, it is worth paying attention to them due to the various mortality problems, whether natural or anthropic.

⎻ Cormorants prefer to fish on sandy bottoms, probably in search of the sandeel and its companion species, the sandeel being a species that regulates the population of the shag.
⎻ Most stomachs are mainly infected by nematode parasites of the species Contracaecum rudolphii sp. A, and this parasitic load has no clear relationship to the sex, provenance, or age of the shag.
⎻ The presence of microplastics, both at the digestive level and in the pellets, is very high, probably due to the consumption of prey that they have previously ingested.