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.
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…
BirdLife International is extending its Albatros Task Force, the initiative to reduce seabird bycatch in collaboration with fishermen, to Europe. Here, the so called Seabird Task Force starts at two bycatch hotspots, Lithuania and the Spanish Mediterranean. Reasons to prioritise this latter area deserve some further explanation.
Spain has a wide diversity of seabirds, with over 40 regular species, more than 20 of them breeding, spread across three distinct geographical regions: the Macaronesia, the European Atlantic and the Mediterranean. Of these, the Mediterranean hosts smaller seabird numbers, but a relatively high diversity of species, many of them of conservation concern precisely due to their tiny populations, as well as restricted distribution ranges. Moreover, the Mediterranean region is highly populated and therefore supports high human pressure, which affects seabirds in several ways: coastal development, introduced predators, pollution, fisheries overexploitation, etc. Among these, bycatch appears to be one of the most serious threats for some species.
Of the seabirds of conservation concern, two species deserve particular attention, the Balearic shearwater Puffinus mauretanicus (Critically Endangered) and the Yelkouan shearwater P. yelkouan (Vulnerable). Both are endemic to the Mediterranean, with small global populations and sharp declining trends, that could lead to their extinction in the near future. Although they are affected by introduced predators and other threats in their colonies, the major drivers of their decline seem to occur at sea, and bycatch postulates itself as the most important of them, particularly on longlines.
Balearic shearwater seeking discards behind a fishing vessel
Why these birds are prone to be caught in longlines? Both Balearic and Yelkouan shearwaters are often seen following fishing vessels to capture discards, and can get captured in the longline baited hooks when these are thrown overboard during the setting operations. Demersal longlines are particularly dangerous for them, as they operate over the continental shelf, where both species of shearwaters tend to forage (while pelagic longlines often operate further offshore), and use smaller hooks, as well as more suitable bait (often sardine or similar sized fish, ideal for the shearwaters). Moreover, these seabirds are highly gregarious in their foraging grounds, and can “attack” a longline by the hundreds, with the risk of “massive captures” (several tens or more).
Balearic and yelkouan shearwaters off Roses, Catalonia, NE Spain. The gregarious behaviour of these two species makes them susceptible of “massive” catches, which have been often reported in this area
Information supporting the idea that demersal longline is a major threat for the two small shearwaters endemic to the Mediterranean is still patchy, but increasing. Events of “mass” mortality have been reported by fishermen (up to over 200 small shearwaters in a single line), or deduced from stranded birds on the beach. Questionnaires to fishermen also point in that direction, with a described event of up to 3,900 seabirds reported!!! And observers onboard demersal longlines have reported the regular capture of the shearwaters, though effort is still limited.
The new Seabird Task Force brings the opportunity to reinforce observers’ effort in the Demersal longline fishery operating off Catalonia, NE Spain, one of the main foraging grounds for the Balearic shearwater in winter and spring (pre-breeding and breeding periods), and also the main foraging area for Yelkouan shearwaters in Spain. Other seabirds regularly captured include Scopoli’s shearwater Calonectris diomedea and Audouin’s gull Larus audouinii, both endemic to the Mediterranean. Recent observers’ work has been conducted in the region by a team from the University of Barcelona (and the Spanish Institute of Oceanography in pelagic longlines), plus questionnaires and workshops by SEO/BirdLife, but further effort is necessary to refine the existing information, most important to provide an accurate estimate of bycatch rates, given the high variability observed. During 2015, SEO/BirdLife’s observers will get onboard demersal longliners across the Catalan coast to address these issues. Later, in 2016, mitigation measures will be tested to assess their efficiency at solving the problem. The close collaboration with fishermen will be essential to achieve any success. We’ll keep you posted of future advances with the project.
Main foraging grounds of Balearic (left) and Yelkouan shearwaters (right) off eastern Spain. From blue trough yellow to red, areas low to highly selected. Both species tend to forage in waters over the continental shelf. Sorce: SEO/BirdLife
BirdLife International amplía su Albatros Task Force (o Grupo de Trabajo de Albatros), la iniciativa para reducir la captura accidental de aves marinas en colaboración con los pescadores, a Europa. Aquí, el llamado Seabird Task Force (o Grupo de Trabajo de Aves Marinas) se forma inicialmente en dos zonas de especial preocupación en cuanto a capturas accidentales, Lituania (donde miles de patos marinos y otras aves buceadoras quedan enredadas en redes de fondo) y el Mediterráneo español. Las razones para priorizar esta última zona merecen una explicación más detallada.
España cuenta con una gran diversidad de aves marinas, con más de 40 especies de ocurrencia regular, más de 20 de las cuales son reproductoras, repartidas en tres regiones geográficas distintas: la Macaronesia, el Atlántico europeo y el Mediterráneo. De ellas, el Mediterráneo acoge una elevada diversidad de especies, muchas de ellas prioritarias desde el punto de vista de la conservación, debido a que cuentan con poblaciones relativamente pequeñas y de distribución restringida (muchas son endémicas del Mediterráneo). Por otra parte, la región mediterránea está altamente poblada, lo que se traduce en una elevada presión humana que afecta a las aves marinas de varias maneras: degradación del hábitat asociado al desarrollo costero, presencia de depredadores introducidos en las colonias de cría, contaminación, sobreexplotación pesquera, etc. Entre estas amenazas, las capturas accidentales representan una de las más graves para algunas especies.
Dos especies merecen especial atención por su delicada situación, la pardela balear Puffinus mauretanicus (En Peligro Crítico) y la pardela mediterránea P. yelkouan (Vulnerable). Ambas son endémicas del Mediterráneo, con pequeñas poblaciones globales y que se encuentran en acusado descenso, lo que que podría conducir a su extinción en un futuro próximo. A pesar de que se ven afectados por los depredadores introducidos y otras amenazas en sus colonias, los principales factores responsables impulsores de su declive parecen concentrarse en el mar, y la captura accidental se postula como el más importante de ellos, sobre todo las capturas en palangres.
Pardela balear busca descartes detrás de un pesquero
¿Por qué son estas aves tan propensas a ser capturadas en los palangres? Tanto la pardela balear como la mediterránea suelen asociarse a barcas de pesca para capturar sus descartes (pescado no comercializable, que es devuelto al mar), y pueden quedar enganchadas en los anzuelos cebados de palangre cuando éstos son arrojados por la borda durante la calada del arte. Los palangres demersales son particularmente peligrosos para estas pardelas, ya que operan sobre la plataforma continental, donde ambas especies suelen alimentarse (mientras que los palangres pelágicos suelen operar en aguas más profundas), y usan anzuelos más pequeños (más “adecuados” al tamaño de las dos pardelas), así como cebos más atractivos (a menudo sardina o peces de tamaño similar). Por otra parte, estas aves son muy gregarias en sus zonas de alimentación, y pueden acudir a un palangre durante la maniobra de calada en gran número (cientos), con el riesgo de causar “capturas masivas” (varias decenas o más).
Pardelas baleares y mediterráneas frente a Roses, Catalunya. El comportamiento gregario de estas dos especies las hace susceptibles de captura “masivas”, que han sido documentadas a menudo en esta zona.
La importancia de las capturas accidentales de las dos pardelas “pequeñas” típicas del Mediterráneo se basa en información aún fragmentaria, pero cada vez existen más evidencias que ponen de manifiesto el problema. Así por ejemplo, cada vez son más los casos de capturas “masivas” documentados por los propios pescadores (hasta más de 200 pardelas en una sola línea), o inferidos a partir de orillamientos de estas aves en las playas (con signos de haber sido capturadas en artes de pesca). Las encuestas a pescadores también apuntan en esa dirección, con un caso extremo descrito de hasta 3.900 aves marinas capturadas en una sola línea!!! Y los observadores a bordo palangres demersales confirman también la captura regular de las pardelas, aunque el esfuerzo es aún limitado.
El nuevo Seabird Task Force brinda la oportunidad de reforzar el esfuerzo de observadores en la pesca demersal en aguas catalanas, una de las principales zonas de alimentación para la pardela balear en invierno y primavera (períodos pre-reproductor y reproductor), y también la principal zona de alimentación para la pardela mediterránea en España. Otras aves marinas capturadas regularmente en la zona incluyen a la pardela cenicienta mediterránea Calonectris diomedea y la gaviota de Audouin Larus audouinii, ambas endémicas del Mediterráneo. En años recientes ya ha habido trabajo de observadores en la zona, por parte de un equipo de la Universidad de Barcelona (y del IEO en el caso de palangre pelágico), , así como encuestas y talleres por parte de SEO/BirdLife, pero es necesario intensificar el esfuerzo para refinar la información existente, destacando la necesidad de obtener una estimación precisa de las tasas de captura accidental, dada la alta variabilidad observada. Durante 2015, el Seabird Task Force se concentrará en embarcar observadores de SEO/BirdLife a bordo de palangres demersales en todo el litoral catalán para abordar estas cuestiones. Más adelante, en 2016, se pondrán a prueba diversas medidas de mitigación para evaluar su eficacia y posible implementación. La colaboración con los pescadores será esencial durante todo el proyecto, especialmente en la fase de probar medidas de mitigación. En este blog se irán presentando los avances del proyecto.
Principales areas de alimentación para la pardela balear (izquierda) y la pardela mediterránea (derecha) en aguas del Mediterráneo español durante la época reproductora. Del azul al rojo, pasando por el amarillo, se indica las áreas de menos a más atractivas para estas pardelas. Fuente: SEO/BirdLife.
The European Seabird Task Force is BirdLife’s new team of seabird bycatch experts. We are working with fishermen across Europe to tackle seabird bycatch.
The establishment of the Seabird Task Force means that BirdLife International and our Partners can actively contribute to the understanding of seabird bycatch within Europe and begin to develop and adapt solutions to this problem with fishermen across the region. The Seabird Task Force is the European incarnation of the successful ‘Albatross Task Force’, a team which has been working collaboratively with fishermen to tackle seabird bycatch in southern Africa and South America. Around the world, our approach is simple and all about collaboration- we work with local fishermen to understand the seabird bycatch problem and develop solutions together. This approach builds mutual respect between the team and the fishermen, and allows an effective collaboration to take place to solve a shared environmental and economic problem.As the coordinator of the Seabird Task Force, I am working with a diverse team of seabird, bycatch and policy experts and our on-board observers/instructors (see our team) to tackle this problem. Over the next two years, we will be working in both Spain (Mediterranean) and Lithuania (Baltic Sea). In each country we are working with small, artisanal fishing boats, however we are focused on two different fishing gears-demersal longlines and and bottom set gillnets.
Within the Spanish Mediterranean, we have prioritised working with fishermen using demersal longlines. Many of these small fishing vessels work in the same area as the main Spanish feeding grounds of the critically endangered Balearic Shearwater, and we know that this species is just one which has been caught unintentionally by fishermen. Cost effective and efficient solutions exist for this type of fishery, and once we understand the problem in greater detail, our team will be working with fishermen to understand what methods could work best on-board their vessels.
In Lithuania, small artisanal fishermen use gillnets to catch cod, at the same time that hundreds of thousands of migrating sea ducks visit the Baltic Sea. As they dive and forage underwater many sea duck species are particularly susceptible to being caught in these nets. An estimated 76,000 seabirds are believed to be caught by this type of fishing gear in the Baltic each year. In comparison to longlines, we do not have proven methods to stop seabird bycatch in gillnets, therefore our team- together with local fishermen- will be at the forefront of trialling innovative solutions to see if we can reduce the number of birds caught in nets.
I hope that you will follow our project with interest. If you would like to subscribe to these updates, please register below. Our blogs are available in English, Spanish and Lithuanian. Please do contact us if you would like further information on the project.
