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Plastic pollution is distributed patchily around the worlds 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 highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.

We present the first assessment of the diet of the blackchin guitarfish Glaucostegus cemiculus (Geoffroy Saint‐Hilaire, 1817) for West Africa using DNA metabarcoding on stomach contents of individuals captured in the Bijagós Archipelago, Guinea‐Bissau. The diet was dominated by crustaceans, particularly caramote prawn Penaeus kerathurus (frequency of occurrence [FO] = 74%, numerical frequency [NF] = 54%) and fiddler crab Afruca tangeri (FO = 74%, NF = 12%). Bony fishes were present in 30% of the stomachs. We highlight the importance of conservation action for intertidal habitats and their associated benthic invertebrates for the survival of the critically endangered blackchin guitarfish. [ABSTRACT FROM AUTHOR]

We investigated inter-annual variability in the breeding performance of six tropical seabirds with different life histories. We further examined the extent to which presumed differences among years in food availability to seabirds were related to large-scale oceanic processes (El Nino Southern Oscillation and Indian Ocean Dipole) or local features around the colony (Sea Surface Temperature--SST, chlorophyll-a concentration, wind patterns, association with underwater predators). Two food shortages were recorded: (1) a short-term event operating at a local-scale, lacking any relationship with any measured oceanographic parameters and affecting only a few seabird species; (2) a generalized and protracted event, strikingly characterized by low SST, possibly induced by a La Nina and/or negative IOD event, and with detrimental impacts in the whole seabird community. Overall, species with inflexible feeding habits and fast chick growth rates were more affected by food shortage events than those with more plastic life-history traits., Introduction Seabirds have been widely considered as monitors of marine ecosystems, as they show behavioural, reproductive and demographic responses to environmental changes impacting prey availability (Furness 1987, Piatt et al. [...]

Summary: The increasing pressure of anthropogenic development in areas with high natural value poses a huge challenge for wildlife conservation worldwide. The Tagus estuary in southern Portugal is among the most important wetlands for migratory shorebirds in the East Atlantic Flyway (EAF). However, in 2020 the Portuguese government approved the construction of the new Lisbon international airport at the heart of the Tagus estuary. Intense aircraft traffic, flying at low altitudes during both approach and take-off, is expected to cross the estuary, overlapping to a great extent the important intertidal foraging areas. Here, we aim to quantify the potential loss of conservation value of the intertidal areas of the Tagus estuary for shorebirds resulting from the disturbance (noise) caused by overflying aircraft. Using a comprehensive dataset of wintering shorebird abundance and distribution in the whole intertidal estuarine area we first identified priority areas for conservation using a spatial prioritization approach. We then performed a replacement cost analysis by excluding the areas likely to become unsuitable or severely underused by birds due to intense air traffic noise. Our results suggest that the implementation of the new Lisbon airport may lead to a loss of up to 30% of the conservation value of the Tagus estuary in terms of intertidal feeding areas of wintering birds alone. The global impact will likely be greater when effects on supratidal roosts, as well as on passage birds, are also considered. The Tagus estuary, which is internationally important for six of the 10 species included in our analysis, is just one of a network of already depleted sites along the EAF. Thus, negative impacts on bird populations on the Tagus estuary will have repercussions and undermine conservation efforts elsewhere. The plight of shorebirds at the Tagus estuary is thus a matter of international conservation concern. [ABSTRACT FROM AUTHOR]

We used pellets and prey dropped near nests to study the diet and feeding ecology of Little Tern (Sterna albifrons) adults and chicks in northern and southern Portugal during 2000 2004. We compared diets among study areas, years, and birds breeding in two main habitat types: sandy beaches and salinas (man-made salt-pans). We also sampled prey fish in one study area and used published data from another area to examine whether the diet of Little Tern adults and chicks corresponded with the abundance of prey found in primary foraging habitats. Adult Little Terns led mainly on sand-smelts (Atherina spp.) and gobies (Pomatoschistus spp.), which were the most abundant fish species in our estuarine and lagoon study areas. Despite some differences among colonies we did not find clear differences in adult diets among study areas and habitat types. Little Tern chicks also ate primarily Atherina spp., but their diet was more diverse than that of the adults, and characterized by a significantly higher proportion of prey with a high energetic value such as sardines (Sardina pilchardus), garfish (Belone belone), and killifish (Fundulus spp.). Chick diets differed significantly between habitat types, which may be a consequence of the limited foraging range of adult breeding birds. Both adult and chick diets matched the abundance of the main prey in our study areas, confirming the opportunistic foraging character of this species. We suggest that annual variation in prey availability may be the most important factor explaining annual variation in adult diets. Key words. diet, estuarine terns, foraging ecology, foraging habitats, Little Tern, Sterna albifrons. Neste trabalho foi estudada a dicta e ecologia alimentar de adultos e filhotes de Sterna albifrons no norte e no sul de Portugal, entre 2000 e 2004, a partir de egagropilas e presas caidas perto dos ninhos. Foram comparadas as dietas de fireas de estudo distintas, entre anos e entre aves que nidificam em dois principais tipos de habitat: praias arenosas e salinas. Para verificar se a dieta de adultos e de filhotes de Chilreta correspondia a abundancia de presas nos principais habitats de alimentacao, amostrou-se a abundancia de peixes em uma das areas de estudo e utilizaram-se dados publicados para outra area de estudo. Os adultos de S. albifrons alimentaram-se sobretudo de Peixe-rei (Atherina spp.) e Bodioes (Pomatoschistus spp.), os quais foram as especies de peixe mais abundantes no estu.ario e na laguna das areas de estudo. Apesar de algumas diferencas entre colonias, nao se obtiveram diferencas significativas na dieta dos adultos entre fireas de estudo e entre tipos de habitat. Os filhotes de S. albifrons tambien consumiram sobretudo Atherina spp. No entanto, a sua dieta foi mais diversificada do que a dos adultos, contendo uma proporcao significativamente maior de presas com alto valor energetico, tais como a Sardinha (Sardina pilchardus), o Peixe-agulha (Belone belone) e a Barrigudinha (Fundulus spp.). A dieta dos filhotes diferiu significativamente entre tipos de habitat, o que pode ser uma consequencia da reduzida area de alimentacao dos adultos. As dietas de adultos e filhotes foram concordantes com a abundancia das presas nas areas de estudo, o que confirma o caracter oportunista desta especie. Sugere-se que a variacao anual na disponibilidade de presas seja o factor mais importante para explicar a variacao anual na dieta dos adultos de S. albifrons.