Saving seabirds from the bycatch threat posed by demersal longliners is easier said than done. In the Mediterranean especially, the variety of fishing methods, the sheer number of target species and numerous types of gears used by the fleet all means that potential mitigation methods need to be adapted case-by-case. Yet one thing remains constant – we must make fishermen fully aware of the negative impact their activity poses for seabird populations. Their taking active responsibility for this conservation problem is our best chance of success in the long term.
Many fishermen wrongly assume that the “occasional” seabird caught in their nets and hooks holds no serious consequences. For them, the problem seems negligible. But this is a problem that adds up fast. The total number of seabird catches that occur annually in each and every one of the fishing boats in the Spanish Mediterranean is such that mortality levels for certain seabird species in the region are unsustainable. That is to say, it poses a real threat to the survival of the species. This is particularly true for species with small populations, such as the critically endangered Balearic shearwater. It is critical that we help fishermen to see the bigger picture through exchange of knowledge and experiences.
The SEO/BirdLife-STF team is working hard to build alliances with fishermen. We’re using different actions, such as workshops, questionnaires, on-board observations, self-reporting logbooks and mitigation methods trials. My own work is primarily focused on mitigation trials. This is possible thanks to project ZEPAMED, which is supported by the Fundación Biodiversidad of the Spanish Ministerio de Transición Ecológica, under Pleamar Programme, cofinanced by the European Maritime and Fisheries Fund (EMFF).
Fishermen are our best allies. As conservationists, we need their years of valuable experience and knowledge to find effective and feasible mitigation methods. Establishing good relationships with them, based on mutual trust and understanding, allows us to work together towards saving seabirds. These collaborations also help us build bridges with the wider fishing sector.
During the last few months, Guillermo Roquer (a fisherman aboard the Catalonian longliner, Llançà) and I have been working on adapting a technique designed in Ecuador for the boats of the Mediterranean – the so-called “NISURI Fastset” system.
The NISURI system is used by the artisanal longliners of Ecuador to reduce seabird bycatch. This consists of a single long PVC pipe that sits along the side of the boat. The pipe has a slot along its length where the hooks with the baits are placed, keeping the baits hidden inside the pipe. The most important advantage of this is the possibility of setting a large number of hooks (around 200 per meter of pipe) very quickly, reducing the risk of birds taking the baited hooks.
After many trials, we have finally built a NISURI system adjusted to the requirements of local boats. Our aim was to allow fishermen to preserve the baits inside the pipe when they are prepared the day before (which reduces the work during the fishing day) or when sudden weather changes force them to return to port. Our NISURI system is now quite different to the original Ecuadorian version. In our case, to set the longline, we use more than one pipe, and each is joined to a box which contains a longline of around 90 hooks (see picture). The pipes are shorter and are set sequentially using a wooden base.
We are still working on improving this way of line setting. After that, we then need to confirm their positive effect on seabird and commercial catches. However, the work done so far has made us cautiously optimistic. We’re quietly hopeful that we will see positive results and it will be well received by fishermen!
There are other effective methods to reduce seabird bycatch in the Mediterranean. The most important method is night setting, which involves the use of less attractive baits for seabirds, and increasing of the sink rate of the hooks. These measures may be used separately or in combination, depending on the fishing practice in use and on the abundance and composition of birds at the fishing grounds. Our ultimate goal is to give fishermen a broad range of methods from which they can choose the method most effective and feasible for their own way of working. After that, we can focus on implementing better surveillance mechanisms to confirm that bycatch solutions are actually being used out on the sea.
The mortality caused by demersal longliners operating in the Balearic Sea is high and may be jeopardizing the viability of the shearwater populations. Therefore, the identification and implementation of mitigation measures is urgently required.
Seabird Task Force 