Percorrer por autor "Casero, Maria"
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- Foraging ecology and fisheries interactions of common bottlenose dolphins (Tursiops truncatus) inferred from strandings in western iberian atlantic watersPublication . Marçalo, Ana; Nicolau, Lídia; Torres‐Pereira, Andreia; Eira, Catarina; Araújo, Helder; Oliveira, Isabel; Santos, Jorge; Casero, Maria; Ferreira, Marisa; Sequeira, Marina; Sá, Sara; Monteiro, Silvia S.; Vingada, José; Giménez, JoanThe common bottlenose dolphin (Tursiops truncatus) is a resident species along the Portuguese mainland coast, yet knowledge of its stranding patterns and feeding ecology is scarce. This study presents a comprehensive assessment of strandings (n=264, from 1980 to 2019) and feeding ecology based on stomach content analysis (n=43 from 1997 to 2019) along the Portuguese mainland coast. Strandings were more frequent in the first half of the year and have increased in recent decades, particularly along the northwestern and southern coasts, likely reflecting improved monitoring efforts. Dietary analysis revealed a predominantly piscivorous diet (>85% by number and weight), with prey including pelagic, meso-pelagic, and demersal fish species. Hake (Merluccius merluccius), conger eel (Conger conger), and blue whiting (Micromesistius poutassou) emerged as the most important prey items. Despite a preference for demersal and mesopelagic fish, dolphins exhibited dietary plasticity, foraging across diverse habitats, likely adapting to local prey availability. The substantial dietary overlap with commercially targeted species, particularly by small-scale and coastal fisheries, suggests potential interactions and competition for shared resources. These findings provide valuable insights into the trophic ecological role of bottlenose dolphins in the region and highlight the need to consider this species in ecosystem-based fisheries management and conservation planning.
- Plastic ingestion in aquatic birds in PortugalPublication . Basto, Marta; Nicastro, Katy; Tavares, Ana I; McQuaid, Christopher D.; Casero, Maria; Azevedo, Fabia; Zardi, Gerardo, IIn modem society, plastic items have become indispensable. The rapid growth of plastic production has led to an increase in the concentration of plastic waste in the environment and, consequently, wildlife has been severely affected. As wide-ranging foragers and predators, aquatic birds are ideal sentinels for monitoring changes in their environment. Plastic found in stomach contents of stranded aquatic birds collected throughout Portugal was examined. Out of the 288 birds processed, 12.9% ingested plastics. Six of the 16 species assessed showed evidence of plastic ingestion. The Lesser Black-backed Gull (18.7%) had the highest incidence while, among those that did ingest plastics, the Northern Gannet (4.8%) had the lowest. User plastics were the most common type of plastic ingested, while microplastics and off/white-clear were the most common size and colour respectively of plastics found. This study sets a first multispecies baseline for incidence of plastic ingestion by aquatic birds in Portugal.
- Unveiling patterns in cetacean strandings along southern atlantic iberia: temporal and spatial trends, seasonality, and causes of deathPublication . Hofman, Jan; Crawford, Sarah; Fialho, Ana; Casero, Maria; Pontes, João; Conceição Alves da Silva, Ana Maria; Nicolau, Lídia; Marçalo, AnaWe compiled 46 years of cetacean strandings in the Algarve, Portugal, describing temporal–spatial patterns, size–sex structure,and causes of death (COD). We analyzed national records and years with a dedicated regional stranding network (SN) to assessannual/seasonal trends, spatial hotspots, and compare biometrics and COD. In total, 1231 strandings were recorded; 73.2% wereidentified to 19 species. Five species comprised almost 68% of events: common dolphins 39.0%, striped dolphins 8.9%, minkewhales 8.0%, bottlenose dolphins 8.0%, and harbor porpoises 4.3%. GAMs confirmed that recorded strandings rose over timeand were higher during SN years (mean 63 yr.−1). Stranding hotspots occurred near Cape Santa Maria (Faro–Olhão), Lagos–Portimão, and Sagres; minke whales and harbor porpoises concentrated east of Cape Santa Maria. Seasonality was significantonly for minke whales (spring peak). Size–sex patterns were largely similar, with exceptions for larger stranded striped dolphinfemales and minke strandings dominated by juveniles. COD assignment improved with monitoring and was assessed for 75.6%of the observed carcasses. Bycatch was the leading COD for common dolphins, bottlenose dolphins, and minke whales. Thisstudy highlights the importance of a regional stranding network and a need for more ecological studies of cetaceans in the region.