First bycatch data collected by Seabird Task Force observers in Spain

According to previous information, May and June is the most dangerous time of the year for seabird bycatch in the Western Mediterranean and observer effort has been intensified. The bycatch of the 3 Cory’s shearwaters (Calonectris diomedea) has occurred during three monitored fishing operations. Cory’s shearwater was the main species attending at demersal long-liners during the line setting and hauling.

Cory's shearwater Calonectris diomedea accidentaly captured on a pelagic long-liner
Cory’s shearwater Calonectris diomedea accidentaly captured on a demersal long-liner. Photo: Albert Cama

The analyses of the corpses indicated that some dead birds could be active breeders, showing breeding patch. The internal analysis of one bird indicated that it was an adult female.

See breeding patch on a Cory's shearwater Calonectris diomedea
See breeding patch on a Cory’s shearwater Calonectris diomedea Photo: Albert Cama

In addition to the data collected by SEO/BirdLife observers, fishermen reported the bycatch of other seabirds during the last weeks, including another Cory’s shearwater, 2 Atlantic gannets (Morus bassanus) and up to 40 unidentified shearwaters, including a massive event of 20-30 birds. We should mention that the skipper aborted the line setting due to the big amount of seabirds attacking to bait. Two Mediterranean European shags (Phalacrocorax aristotelis desmarestii) were accidentaly captured on cuttlefish pots. Additionally, 2 Cory’s shearwaters, 2 Yelkouan shearwaters (Puffinus yelkouan) and 5 Balearic shearwaters (Puffinus mauretanicus) were found death in one beach in Tarragona, they did not showed the presence of hooks, but some injuries near the mouth, indicating Long-line bycatch.

We wish to thank the collaboration of fishermen by allowing observers on board and reporting data.

Cory's shearwater Calonectris diomedea eating discarded fish from a demersal Long-liner
Cory’s shearwater Calonectris diomedea eating discarded fish. This has been the most abbundant species attending demersal long-liners. Photo: Albert Cama

New population estimates for the Balearic shearwater: Should we let down our guard?

The Seabird Task Force is working to quantify and reduce bycatch of Balearic Shearwaters. Read Pep Arcos’ (SEO/BirdLife) blog about the critically endangered population, the trends & threats.

European Seabirds Blog

Recently the media and social networks have echoed good news for our most endangered bird species, the Balearic shearwater Puffinus mauretanicus. Indeed, a study published this year in the scientific journal Bird Conservation International points to a global population of about 25,000 birds, roughly doubling the previous estimates. The study is based on data from the Migres Programme, and consists on the census of Balearic shearwaters crossing the Strait of Gibraltar in their outward movement towards the Atlantic, after breeding. The information is consistent with another study of SEO/BirdLife, which followed a different approach (the census of birds in waters off the Iberian Mediterranean in late autumn, when the birds are back from the Atlantic. In fact, both approaches had been already published together, although the new paper provides more detail on the methodology used in the Strait of Gibraltar. The issue is also considered in…

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