The use of European shag pellets as indicators of microplastic fibers in the marine environment

Álvarez, G., Barros, Á. and Velando, A., 2018. The use of European shag pellets as indicators of microplastic fibers in the marine environment. Marine Pollution Bulletin, 137, pp.444-448.

Microplastic particles are abundant marine pollutants that are ingested by many seabirds. Some seabirds regurgitate non-digestible materials in the form of pellets and their analysis may be useful to study the abundance of plastic debris at the local scale. Here, we aimed to provide baseline data for the presence of microplastics in pellets regurgitated by European shags (Phalacrocorax aristotelis) (n = 41) in the Iberia peninsula (NW Spain). We found microplastic fibers in 63% of pellets, suggesting that this type of plastic pollution is prevalent in the study area. According to Fourier Transform Infrared spectrometry, nylon fibers were the most abundant, followed by polyester. We also found that the presence of microplastics was higher in pellets containing remains of benthic fishes. Our results suggest that shag pellets may be useful to monitor microplastic pollution in coastal waters.

Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and National Parks

Zapata, P., Ballesteros-Cano, R., Colomer, P., Bertolero, A., Viana, P., Lacorte, S., Santos, F.J., 2018. Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and national parks. Science of The Total Environment, 633, pp.704-715.

The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compounds studied include polychlorinated biphenyls (PCBs), organochlorinated pesticides (OC pesticides), perfluorooctane sulfonic acid (PFOS) and polybrominated diphenyl ethers (PBDEs), and were analyzed using mass spectrometric based techniques. The results showed a high contamination by PCBs in all colonies, with total levels ranging from 59 to 1278 ng/g wet weight (ww), despite their use is not currently authorized. OC pesticides were also present in all colonies, with a high incidence of 4,4′-DDE in gull eggs at levels up to 218 ± 50 ng/g ww in L. michahellis and 760 ± 412 ng/g ww in L. audouinii from the Ebro Delta natural park. PBDEs and PFOS were also detected at levels up to 91.7 ± 21.3 ng/g ww, which can be attributed to a more recent use. Except for PBDEs, the POP levels in eggs from L. audouinii were higher than in L. michahellis, presumably associated to the fish-based diet of the former. Finally, the effect of POP levels on eggshell parameters (volume, eggshell thickness and desiccation index) were investigated for each colony and gull species in order to evaluate the egg viability and, therefore, the reproduction success.

Cormorán moñudo – Phalacrocorax aristotelis (Enciclopedia Virtual de los Vertebrados Españoles)

Barros, A., Alvarez, D., Velando, A. (2013). Cormorán moñudo – Phalacrocorax aristotelis. En: Enciclopedia Virtual de los Vertebrados Españoles. Salvador, A., Morales, M. B. (Eds.). Museo Nacional de Ciencias Naturales, Madrid.


Álvarez, D. e Pajuelo, M.A.F., 2011. Southern populations of European shag Phalacrocorax a. aristotelis advance their laying date in response to local weather conditions but not to large-scale climate. Ardeola, 58(2), pp.239-250.

La fecha de puesta es un hecho crítico en la vida de las aves, ya que determina en gran medida su éxito reproductor. Los efectos de las condiciones atmosféricas y del clima sobre el inicio de la reproduction han sido ampliamente estudiados en las últimas décadas y el adelanto en la fenología reproductora ha sido confirmado en muchas especies. Hemos investigado esta variación en la fenología de la la reproducción en una población cantábrica de cormorán moñudo durante la última década. Los resultados demostraron que esta especie había adelantado su fecha de puesta casi 40 días en sólo 10 años. Este avance en la época de la reproducción esta muy ligado al calentamiento registrado durante el último siglo. De todas formas, de todas las variables climáticas estudiadas, sólo el índice de anomalía térmica mostró una correlación positiva con la fecha de puesta, mientras que los efectos del NAO y de temperatura superficial del mar (SST) no fueron significativos. Esto sugiere que en este caso, los efectos de las condiciones locales tienen más efecto sobre la fecha de puesta que los efectos climáticos a gran escala.

Anisakid infection in the European shag Phalacrocorax aristotelis aristotelis

Abollo, E., Gestal, C. e Pascual, S., 2001. Anisakid infection in the European shag Phalacrocorax aristotelis aristotelis. Journal of Helminthology, 75(3), pp.209-214.

A total of 100 specimens of the European shag Phalacrocorax aristotelis aristotelis were examined for anisakid infections in the south-east North Atlantic. The taxonomic status of the anisakid nematodes was studied by structural analysis using light and scanning electron microscopy. Two species, Contracaecum septentrionale and C. rudolphii A (Nematoda: Ascaridoidea), occurred in the European shag with high values of prevalence and mean intensities of infection. These constitute new host records for both parasites, widening their known geographical distribution. Although the histopathology associated with the infections indicated that the anisakids did not have the potential to cause bird death, the parasites are capable of contributing to and hastening avian mortality in the case of heavily-parasitized cormorants and when stressed by xenobiotics and/or through a synergetic effect by other bioagressors.

Complex demographic heterogeneity from anthropogenic impacts in a coastal marine predator

Oro, D., Álvarez, D. e Velando, A., 2018. Complex demographic heterogeneity from anthropogenic impacts in a coastal marine predator. Ecological Applications.

Environmental drivers, including anthropogenic impacts, affect vital rates of organisms. Nevertheless, the influence of these drivers may depend on the physical features of the habitat and how they affect life history strategies depending on individual covariates such as age and sex. Here, the long‐term monitoring (1994–2014) of marked European Shags (Phalacrocorax aristotelis) in eight colonies in two regions with different ecological features, such as foraging habitat, allowed us to test several biological hypotheses about how survival changes by age and sex in each region by means of multi‐event capture–recapture modeling. Impacts included fishing practices and bycatch, invasive introduced carnivores and the severe Prestige oil spill. Adult survival was constant but, unexpectedly, it was different between sexes. This difference was opposite in each region. The impact of the oil spill on survival was important only for adults (especially for females) in one region and lasted a single year. Juvenile survival was time dependent but this variability was not synchronized between regions, suggesting a strong signal of regional environmental variability. Mortality due to bycatch was also different between sex, age and region. Interestingly the results showed that the size of the fishing fleet is not necessarily a good proxy for assessing the impact of bycatch mortality, which may be more dependent on the fishing grounds and the fishing gears employed in each season of the year. Anthropogenic impacts affected survival differently by age and sex, which was expected for a long‐lived organism with sexual size dimorphism. Strikingly, these differences varied depending on the region, indicating that habitat heterogeneity is demographically important to how environmental variability (including anthropogenic impacts) and resilience influence population dynamics.

Seguimento das poboacións de aves mariñas no Parque Nacional Marítimo Terrestre das Illas Atlánticas de Galicia: resultados de 2017

Munilla, I. 2017. Seguimento das poboacións de aves mariñas no Parque Nacional Marítimo Terrestre das Illas Atlánticas de Galicia: resultados de 2017. Parque Nacional Marítimo e Terrestre das Illas Atlánticas de Galicia. Decembro 2017.


Corvo mariño (P. aristotelis)

  • A poboación reprodutora de corvo mariño no Parque Nacional en 2017 estimouse en 944 parellas repartidas en oito colonias principais. Esta cifra representa o 67% do censo galego da especie. Dous terzos da poboación do Parque localízanse no arquipélago de Ons, o 25% no arquipélago de Cíes e o 9% restante en Sagres. A colonia máis numerosa é Ons Norte con 485 parellas, a metade das estimadas para o conxunto do Parque.
  • O número de parellas censadas representa un lixeiro aumento con respecto dos datos de 2015 e 2016.
  • A estima do éxito reprodutor no Parque Nacional en 2017 foi de (media ± desviación típica): 0,99 ± 1,06 polos por niño (N = 76 niños), mais con diferenzas moi acusadas entre os tres arquipélagos: Cíes = 0,52 ± 0,75 polos por niño; Ons = 1,21 ± 1,17; Sagres = 1,11 ± 1,08. O éxito reproductor rexistrado en Ons é significativamente superior ao do ano pasado.
  • A análise de tres mostras de egagrópilas recollidas durante o periodo reprodutor nas illas Cíes (O Faro, N= 24), Ons (Cova do Lobo, N= 42) e Sagres de Fora (N= 27) indican que os corvos mariños do Parque Nacional consumiron maioritariamente tres grupos de peixe, por esta orde: lábridos (Labridae), pións (Atherina presbyter), e fanecas (Trisopterus).
  • Este ano rexistrouse unha frecuencia relativamente alta de bolos (Ammodytidae) na mostra de egagrópilas de Cíes o que pode ser indicativo dunha certa recuperación das poboacións dese peixe preto das illas.

Gaivota patiamarela (L. michahellis)

  • O seguimento interanual indica unha diminución da poboación reprodutora de gaivota patiamarela do 21% en relación ás cifras de 2016. A poboación reprodutora ten diminuído en tódolos sectores sen excepción, sendo este o primeiro ano da serie no que esto acontece. O declive anual promedio para o conxunto de sectores ao longo do periodo de seguimento (2011-2017) é considerable (-9,1%). As illas de Sálvora e Vionta acumulan xa dous anos seguidos con declives moi fortes e perderon, en conxunto, máis do 40% da poboación censada en 2015.
  • Neste ano comparouse o éxito reprodutor entre dúas parcelas de estudo representativas dos principais hábitats de cría da gaivota en Cíes, o cantíl de toxo (Cortello do porco, 48 territorios) e as dunas (Muxieiro, 37 territorios). O éxito reprodutor rexistrado no conxunto da mostra de territorios foi baixo (media ± desviación típica = 0,61 ± 0,90 polos a voar por territorio), aínda que algo superior na parcela de duna (0,68 ± 1,03) que na parcela do cantíl (0,56 ± 0,78).
  • En 2017 a incidencia do sindrome de parálise foi moi baixa. Malia o esforzo de prospección ser intenso e estendido no tempo, observáronse só 6 gaivotas con apariencia de ter morto con síntomas de parálise.
  • O contido da mostra de egagrópilas (N= 167) indica que as gaivotas adultas do Parque Nacional basaron a súa dieta en invertebrados mariños cunha frecuencia de aparición do 76,2%. O alimento mellor representado foi o patexo (Polybius henslowii) (50,1%); seguido dos invertebrados do intermareal (25,6%), entre eles o percebe (Pollycipes cornucopia 20,4%) e mexillón (Mytillus galloprovincialis 7,2%). O lixo urbano está presente no 14,3% da mostra, e o alimento de hábitats terrestres no 7,8%. Os peixes apenas están representados. As diferenzas espaciais entre arquipélagos (Cíes, Ons e Sálvora) veñen dadas pola presenza de determinados tipos de alimento pouco ou nada representados no resto.

Gaivota de asa escura (L. fuscus)

  • En 2017 a poboación reprodutora de Larus fuscus nas illas de Sálvora e Vionta foi de 21 TAO, 20 deles en Sálvora. A estima de 2017 é un 25% por cento menor que as estimas de 2015 e 2016.

Gaivotón (L. marinus)

  • A estima da poboación reprodutora de gaivotón no ano 2016 é dunha parella na illa de Vionta, máis non quitaron polos.

Pardela cincenta (C. diomedea)

  • Na colonia de Tropezas, o principal núcleo reprodutor da especie no Parque Nacional, ocupáronse 27 sitios e a poboación reprodutora foi estimada en 17 parellas. Estes valores son os máis altos rexistrados dende a eventual fundación da colonia. Este ano marcáronse 6 sitios novos e constatouse unha expansión da área cuberta pola colonia.
  • Os datos recollidos suxiren que en 2017 as pardelas de Tropezas produciron 17 polos, aínda que non está claro cantos deles conseguiron voar.
  • A resposta das pardelas aos sistemas de atracción social instalados en Cíes foi pobre. O sitio de cría que ven sendo ocupado en Chancelos dende 2013 foi ocupado de novo este ano por unha parella reprodutora, máis o sitio foi posteriormente abandonado.