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 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 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. This has been the most abbundant species attending demersal long-liners. Photo: Albert Cama
An international workshop on Marine Important Bird Areas in Malta and the Mediterranean will be held between the 23rd – 25th November 2015 by the LIFE+ Malta Seabird Project and BirdLife International. The workshop will be a key opportunity to gather knowledge and experience on protecting seabirds across national boundaries and international waters of the Mediterranean as well as set the way forward for international collaborations in protecting our common seabird heritage.
Within the Mediterranean seabirds face threats both on land and at sea, such as overfishing, by-catch, invasive predators, habitat destruction from poor planning and marine pollution. However only 4% of the Mediterranean is currently protected through the EU Natura 2000 network in Europe and the Barcelona Convention’s Specially Protected Areas of Mediterranean Importance.
At a regional scale there are still many important gaps to fill in the protected area network for seabirds, particularly for sites at sea. The meeting will enable scientists, nature conservationists and policy makers to further coordinate efforts for seabird protection at a regional scale through capacity building and the sharing of specialist knowledge.
The meeting will start with the presentation of a draft inventory of Marine Important Bird Areas for seabirds in Maltese and international waters identified under the LIFE+ Malta Seabird Project. This will be followed by sessions on knowledge sharing and gap analysis for the entire Mediterranean region, identifying sites within and beyond national jurisdiction, priority areas and policy mechanisms from across the Mediterranean.
Find out more, including to download the registration form, here.
The Spanish team is focused in the Catalan harbours, where different kinds of long-liners operate. The main target of this project is the demersal long-liner fleet, but other boats using artisanal or pelagic long-lines also operate in the area. In fact, in the harbours where we have started our work -Llançà, Roses and Vilanova i la Geltrú- we can find boats using the different long-line types. In this blog post, we will quickly point out the differences between these similar fishing gears.As we know, long-lines are composed by a main line with several hooks attacked to it, but this general configuration can be set in a plethora of different variations which can be grouped in 3 main classes:
– Pelagic long-lines: This fishing gear requires floats to keep the gear close to the sea surface. In the Catalan coast, the fishermen generally target large pelagic predators like swordfish or tunas. They set a few thousand large hooks separated by a distance that can exceed 30 m. In this project we do not pay attention to this fishing method, since the Spanish Oceanographic Institute has an on-going long-term project with on-board observers on these fishing boats.
Example of pelagic longline configuration. Bycatch mitigation factsheet 8. BirdLife
Pelagic longliner at Torredembarra harbour. Photo: Matxalen Pauly
– Demersal long-lines: Targeting bottom species, like hake or breams, the fishing gear is sunk by the use of weights, which are combined with floats to keep the gear on the right placement for the target species. They set a similar amount of smaller hooks, which are spaced very few meters.
Longline box with the hooks, some with the bait. Photo: Pau Calero
Demersal long-liner off central Catalonia
–Artisanal long-lines: The main characteristic of this fishing gear is its small scale. This fishing gear can be very similar to demersal long-liners, but they use a few hundreds of hooks which are set in relatively shallow waters close to the coast line.
After some weeks of continuous northern winds, the 2nd and 3rd of March the first STF surveys on-board of demersal long-liners in Spain were conducted. One observer of SEO/BirdLife shipped on a demersal long-liner based in Llançà, one of northernmost Catalan harbours next to the Spanish-French border. The main target of the fishing boat was the Blackspot seabream Pagellus bogaraveo. These first surveys were worth improving the methodology, getting familiar with it and collecting the first data. We characterised the fishing gear configuration and effort and observed no seabird bycatch. We also enjoyed of a very tasty on-board meal, which was worth recovering strength and knowing the fishermen from a personal point of view.
Black legged kitty-wake Rissa tridactyla following the vessel during the operations
Only very few Yellow-legged gulls Larus michahellis, Mediterranen gulls L. melanocephalus and Kittywakes Rissa tridactyla followed the vessel during the operations. Seabirds ate discarded baits and one kittiwake stole one bait when setting but was not hooked. The shearwaters (only Mediterranean, Puffinus yelkouan) were very scarce during the operations, and most individuals were observed in coastal waters when returning to port.
During the following weeks we will keep contacting long-liner skippers and continue with on-board observations.
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.
