Jose Manuel Arcos

• Biologist
• Manager at SEO/BirdLife

Worldwide, many seabirds are affected by fisheries in opposing ways: as a source of mortality from bycatch, but also by providing discards as a predictable and abundant food resource. This applies to the Balearic shearwater Puffinus mauretanicus, the most endangered European seabird, whose time to extinction was estimated at only ~40 years a decade...

Protected areas play a key role in the preservation of biodiversity, but their implementation at sea is lagged behind terrestrial environments, especially in offshore areas. Here we describe the identification of foraging hotspots off the Mediterranean Iberian coast using three Procellariiform species as examples, and assess the stability of these...

Unprecedented changes to the marine environment and growth of bio-logging science make detailed study of the movement ecology of threatened marine species timely. Here, we study spatial and temporal patterns of marine space use by a critically endangered seabird: the Balearic shearwater Puffinus mauretanicus. Using a suite of bio-logging systems, 6...

Although the breeding ecology of Audouin’s gull has been widely studied, its spatial distribution patterns have received little attention. We assessed the foraging movements of 36 GPS-tracked adult Audouin’s gulls breeding at the Ebro Delta (NW Mediterranean), coinciding with the incubation period (May 2011). This also coincided with a trawling mor...

Animal migrations are unique phenomena involving mass movements of individuals, which pose significant challenges to develop conservation strategies. Migratory seabirds, particularly, face many anthropogenic threats across their distributions, and populations are declining worldwide. We provided a thorough isotopic method to characterise individual...

beached seabirds of 28 different species, 81% of which were Atlantic puffins (N=4043) followed by 5% (n=242) of Razorbills Alca torda (table 1). • The peak of puffins wreck was attained on the 2nd fortnight of January 2023, when nearly 75% of all beached birds were reported (figure 1). A slight delay of this peak was found when comparing Portuguese...

In the north-western Mediterranean there are two breeding species of procellariforms from the Procellariidae family: Scopoli’s shearwater Calonectris diomedea and the Balearic shearwater Puffinus mauretanicus. Long-term monitoring carried out in a number of breeding colonies provides enough data to be able to assess the conservation status of both...

How individual animals respond to climate change is key to whether populations will persist or go extinct. Yet, few studies investigate how changes in individual behavior underpin these population-level phenomena. Shifts in the distributions of migratory animals can occur through adaptation in migratory behaviors, but there is little understanding...

Marine protected areas (MPAs) are widely used tools for conservation and management. Their correct delimitation is challenging, especially when the target species are small, elusive and inconspicuous, as little data are generally available to adequately assess their distribution at sea. Therefore, currently designated MPAs may not effectively cover...

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are h...

Las capturas accidentales en artes de pesca son la mayor amenaza para la supervivencia de varias especies de aves marinas, incluyendo las tres especies de pardela endémicas del Mediterráneo, todas ellas amenazadas. Pero el elevado número de barcas y la alta diversidad de la flota pesquera mediterránea, en su mayoría embarcaciones de artes menores,...

Animals explore and prospect space searching for resources and individuals may disperse, targeting suitable patches to increase fitness. Nevertheless, dispersal is costly because it implies leaving the patch where the individual has gathered information and reduced uncertainty. In social species, information gathered during the prospection process...

Increasing human activities have detrimental consequences on marine ecosystems and their impact can have cumulative effects. Within marine ecosystems, seabirds respond to ecosystem variability and face multiple human pressures, especially threatened species. In long-lived species, juveniles and immatures could represent up to 50% of the total popul...

Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of nation...

Foraging distribution of flying seabirds is constrained by environmental factors influencing individual decision-making. This must be particularly true during the breeding period, when individuals face additional limitations imposed by their central-place foraging behaviour. We used GPS data loggers and Argos PTTs to track the foraging flights of B...

Human fisheries provide scavengers with abundant and predictable feeding opportunities that may schedule their behavioural patterns. Using miniaturized global positioning system (GPS) tracking technology, we evaluated how Audouin’s gull (Ichthyaetus audouinii), a Mediterranean endemic seabird that makes extensive use of feeding opportunities provid...

This identification guide has been developed to support the monitoring of bycatch of vulnerable species in Mediterranean fisheries. The work has been produced within the context of the project “Understanding Mediterranean multi-taxa ‘bycatch’ of vulnerable species and testing mitigation– a collaborative approach” funded by MAVA Foundation through a...

The distributions of migratory species in the ocean span local, national and international jurisdictions. Across these ecologically interconnected regions, migratory marine species interact with anthropogenic stressors throughout their lives. Migratory connectivity, the geographical linking of individuals and populations throughout their migratory...

Healthy and productive marine ecosystems are important means of supporting maximum sustainable yield and blue growth. However, fisheries and other anthropogenic threats (e.g. pollution, habitat pressure, climate change or the introduction of non-indigenous species) can have potentially negative effects on the marine environment and ecosystems. In t...

Shearwaters and petrels (hereafter petrels) are highly adapted seabirds that occur across all the world’s oceans. Petrels are a threatened seabird group comprising 124 species. They have bet-hedging life histories typified by extended chick rearing periods, low fecundity, high adult survival, strong philopatry, monogamy and long-term mate fidelity...

Spatio-temporal variability of surface geostrophic mesoscale currents in the Balearic Sea (western Mediterranean) is characterized from satellite altimetry in combination with in-situ velocity measurements collected, among others, by drifting buoys, gliders and high-frequency radar. Here, we explore the use of tracking data from living organisms in...

Les captures accidentals d’ocells marins en arts de pesca han estat descrites arreu del planeta. La majoria d’estudis es centren a avaluar i mitigar la captura d’aus en pesqueries professionals. Però, existeix molta menys informació sobre la interacció amb la pesca recreativa, que en el cas d’espècies costaneres també és potencialment important. El...

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time se...

This book has been published by the Spanish Society of Ornithology (SEO/BirdLife) in the framework of the MIGRA programme. In this work we analyse the movement ecology and at-sea behaviour of two related seabird species under conservation concern: the Scopoli's and the Cory's Shearwater. It focuses on Spanish populations, covering the entire distri...

Marine megafauna, including seabirds, are critically affected by fisheries bycatch. However, bycatch risk may differ on temporal and spatial scales due to the uneven distribution and effort of fleets operating different fishing gear, and to focal species distribution and foraging behavior. Scopoli's shearwater Calonectris diomedea is a long-lived s...

The accidental capture of seabirds and other marine animals in fishing gear is referred to as ‘bycatch’. Globally, bycatch is known to be one of the most significant threats to seabirds (Croxall et al., 2012). An estimated 700,000 birds are killed globally each year between the long-line and gillnet fisheries (Žydelis et al., 2013; Anderson et al.,...

Seabird trajectories can be used as proxies to investigate the dynamics of marine systems and their spatiotemporal evolution. Previous studies have mainly been based on analyses of long range flights, where birds are travelling at high velocities over long time periods. Such data have been used to study wind patterns, and areas of avian feeding and...

Bycatch mortality in longline fisheries is considered the main threat at sea for numerous seabird species. These incidental catches occur worldwide, but mortality levels are mainly determined by the specific traits of the fishery operating in each area and the feeding behaviour and local abundance of seabirds. In the Mediterranean, demersal artisan...

Fisheries provide an abundant and predictable food source for many pelagic seabirds through discards, but also pose a major threat to them through bycatch, threatening their populations worldwide. The reform of the European Common Fisheries Policy (CFP), which intends to ban discards through the landing obligation of all catches, may force seabirds...

http://www.seo.org/boletin/seguimiento/migracion/01_gaviota_audouin/

Marine protected areas (MPAs) are considered one of the main tools in both fisheries and conservation management to protect threatened species and their habitats around the globe. However, MPAs are underrepresented in marine environments compared to terrestrial environments. Within this context, we studied the Atlantic non-breeding distribution of...

Foraging Destinations of Balearic Shearwaters

Spatially explicit conservation measures are increasingly taking the central stage of conservation strategies, and networks of marine protected areas (hereafter MPAs) are being used to manage fisheries and to protect threatened species and marine habitats around the globe. There is an increasing interest to extend the application of MPAs to encompa...

Fisheries and seabirds are intimately associated as both exploit the same productive areas. Some seabirds take advantage of fishery discards, mostly generated by trawlers, as a supplementary foraging resource, changing their foraging strategies linked to this predictable food. Thus it is expected that any change in fishing practices will have impor...

Three medium-sized Puffinus shearwaters breed in Europe: Manx R puffinus, Yelkouan R yelkouan and Balearic Shearwaters R mauretanicus. These three, considered a single, polytypic species until relatively recently, can be difficult to identify in some situations, notably in a vagrant context. This paper presents a detailed review of the plumage vari...

In, SEO/BirdLife 2012. Atlas de las aves en invierno en España 2007-2010. Ministerio de Agricultura, Alimentación y Medio Ambiente-SEO/BirdLife. Madrid.

Figure S1. (A) Parameter estimate ± standard error for the logistic GLMM to fit the proportion of rice field positions over the total feeding positions. Weekends were used as a reference level in the analysis. (B) 95% CI of the estimated proportion of rice field positions derived from the model. Figure S2. (A) Parameter estimate ± standard error fo...

Some seabird species have learnt to efficiently exploit fishing discards from trawling activities. However, a discard ban has been proposed as necessary in Europe to ensure the sustainability of the seas. It is of crucial importance for the management and conservation purposes to study the potential consequences of a discard ban on the foraging eco...

Esta monografía ha sido resultado de los estudios científicos del proyecto LIFE+ INDEMARES, cofinanciado por la Comisión Europea, y se ha basado en los estudios realizados por el Instituto Español de Oceanografía (IEO), SECAC y SEO BirdLife.

Esta monografía ha sido resultado de los estudios científicos del proyecto LIFE+ INDEMARES, cofinanciado por la Comisión Europea, y se ha basado en los informes realizados por el Instituto Español de Oceanografía (IEO), SECAC y SEO BirdLife.

La monografía de los volcanes de fango del golfo de Cádiz se enmarca en una serie de 10 publicaciones en las que se detallan los resultados de la investigación de las áreas de estudio del proyecto LIFE+ INDEMARES.

La monografía del Sur de Almería-Seco de los Olivos se enmarca en una serie de 10 publicaciones en las que se detallan los resultados de la investigación de las áreas de estudio del proyecto LIFE+ INDEMARES.

El área del “Canal de Menorca” es un corredor marino situado entre las islas de Mallorca y Menorca, del archipiélago de las islas Baleares, que presenta una amplitud mínima entre islas de 36 kilómetros. En sus fondos se desarrollan hábitats representativos de los fondos mediterráneos en un perfecto estado de conservación, pero además es una zona im...

El Banco de Galicia es un monte submarino profundo localizado al noroeste de la península ibérica, a 180 kilómetros de la costa gallega. Su cima se encuentra entre los 650 y los 1.500 metros de profundidad. Sus laderas, de elevadas pendientes, caen desde esta cima hasta las llanuras abisales situadas a 4.000 metros de profundidad. Esta montaña subm...

Aquesta guia, com el seu nom indica, és un llibre que ens ajuda a conèixer de manera fàcil i amena l’entorn natural del nostre territori. El seu format és força adequat per trobar de manera ràpida allò que necessitem saber. Els continguts es divideixen en 12 parts: medi físic, flora i vegetació, fongs, insectes, invertebrats no insectes, invertebra...

CapsuleThe breeding foraging and post-breeding dispersal movements of five satellite-tagged Bulwer's Petrels from the Canary Islands were recorded. Foraging trips lasted 5.6 days in average (n=3), while the mean distance covered was 1261 km, and foraging areas were located over the continental slope and the adjacent pelagic waters, around 1200-2000...

The Balearic shearwater Puffinus mauretanicus is the most threatened seabird in Europe. Several recent research and conservation programmes from different countries (Spain, Portugal, France, UK and Ireland), using various methodologies such as colony monitoring, at-sea surveys, tracking and coastal censuses, brought new information about the popula...

Aim Apical pelagic species forage in predictable habitats, and their movements should signal biologically and ecologically significant areas of the marine ecosystem. Several countries are now engaged in identifying these areas based on animal tracking, but this is often limited to a few individuals from one breeding population, which may result in...

Seabirds are facing a growing number of threats in both terrestrial and marine habitats, and many populations have experienced dramatic changes over past decades. Years of seabird research have improved our understanding of seabird populations and provided a broader understanding of marine ecological processes. In an effort to encourage future rese...

The Balearic Shearwater Puffinus mauretanicus is considered the most threatened seabird in Europe, based on a prediction of extinction within 3 generations in average. Such prediction was computed in 2004, based on a population estimate of 2,000 breeding pairs at that time. However, the breeding population has been recently updated to 3,193 pairs....

La pardela mediterránea cría en islotes e islas en buena parte de la cuenca mediterránea, principalmente en la parte central y oriental, y de manera aislada en el mar Negro (Bourgeois y Vidal, 2008). Entre agosto y febrero hace movimientos dispersivos restringidos también a estas dos cuencas marinas. Las colonias más cercanas a las costas españolas...

El grueso de la población mundial reproductora cría en España, con cerca de 20.000 parejas en el año 2007 (Genovart et al., 2008), pero una parte muy importante de ésta pasa el invierno en las costas norteafricanas atlánticas (De Juana et al., 1987), incluyendo la gran mayoría de las aves jóvenes e in-maduras (Oro y Martínez Vilalta, 1994). En la E...

La pardela balear se reproduce exclusivamente en las islas Baleares, iniciando las puestas a finales de febrero o principios de marzo (Ruiz y Martí, 2004). Tras la reproducción abandona el Mediterráneo y ocupa las aguas atlánticas del suroeste de Europa (Le Mao y Yésou, 1993; Mouriño et al., 2003), pero el grueso de la población se encuentra ya de...

Knowledge of the winter distribution of the Mediterranean Gull Larus melanocephalus is poor. The limited and geographically patchy data on the species’ winter distribution is of concern because current estimates of the wintering population do not agree with those for the global breeding population. We assessed the winter distribution and abundance...

In the winter of 2002–03 the Prestige tanker spilled 60,000 tons of oil over the northern half of the Iberian Coastal Large Marine Ecosystem (northern Portugal to France). Most (c. 85%) of the 22,981 oiled seabirds reported were alcids (i.e., auks): Common Murres (Uria aalge), Razorbills (Alca torda) and Atlantic Puffins (Fratercula arctica). Here...

Bottom trawl fishing provides substantial amounts of normally unavailable demersal prey to seabirds (e.g., discards), affecting their life-history traits and population dynamics, as well as community structure. Within this framework, we studied seabird-trawling interactions throughout the annual cycle in a poorly studied ecosystem in the Mediterran...

Marine censuses of the four species of small procellariforms that breed in the Canary Islands formed part of the fieldwork within the framework of the Project Life Important Areas for Seabirds (IBAs) in Spain and which was carried out by SEO/BirdLife. In total, more than 180 hours of census work was carried out in Canary Islands waters, both aboard...

The results of the censuses of the European Storm-petrel Hydrobates pelagicus carried out within the project Life Important areas for seabirds (IBA) in Spain and carried out by SEO/BirdLife have enabled knowing the distribution and abundance of this species in Spanish peninsular waters after more than 900 hours of censusing. The species shows a pre...

The observations of Madeiran Storm-petrel Oceanodroma castro in waters of northwestern Spain (Galician Bank) during July and, especially, in September are, with the exception of the four accepted records by the Spanish Rarities Committee (CR/SEO), the first in Spanish Peninsular waters. These observations were the result of pelagic embarcations off...

The Balearic Shearwater is regular off the Catalan coast throughout most of the year apart from the post-breeding dispersal period (summer). It is commoner in the southern and central sectors, which are closer to its breeding grounds. In winter it may form thousand-strong flocks, which vary in size from one year to another, probably due to changes...

The regular western limit of the distribution of the Yelkouan Shearwater lies off the Catalan coast, where it is common most of the year. It shows a clear preference for the colder waters of the northern part of the coast, which are closer to its breeding grounds. In winter this shearwater tends to congregate in coastal waters that are particularly...

Unintended mortality in longlines emerged in the early 1990s as one of the most important threats for pelagic seabirds worldwide. Most of the studies were focused on highly developed industrial fisheries, overlooking bycatch in small-scale artisanal fisheries. However, bycatch in smallscale fisheries might have negative effects similar to those of...

Pelagic seabirds obtain food from oceans where the availability of their prey changes rapidly both seasonally and spatially. Here, we investigated changes in the trophic habits of the critically endangered Balearic shearwater (Puffinus mauretanicus) through the breeding season and tested for dietary differences between sexes and age classes. We ana...