First evidence of anthropogenic debris in nests of the Kelp Gull (Larus dominicanus) from a small semi-desert Argentinean coastal ecosystem

A review of plastic debris in the South American Atlantic Ocean coast - Distribution, characteristics, policies and legal aspects

The presence of plastics in the oceans has already become a pervasive phenomenon. Marine pollution by plastics surpasses the status of an emerging threat to become a well-established environmental problem, boosting research on this topic. However, despite many studies on the main seas and oceans, it is necessary to compile information on the South American Atlantic Ocean Coast to identify the lack of research and expand knowledge on marine plastic pollution in this region. Accordingly, this paper conducted an in-depth review of monitoring methods, sampling, and identification of macroplastics and microplastics (MPs) in water, sediments, and biota, including information on legal requirements from different countries as well as non-governmental initiatives. Brazil was the country with the highest number of published papers, followed by Argentina. MPs accounted for 75 % of the papers selected, with blue microfibers being the most common morphology, whereas PE and PP were the most abundant polymers. Also, a lack of standardization in the methodologies used was identified; however, the sites with the highest concentrations of MPs were the Bahía Blanca Estuary (Argentina), Guanabara Bay (Brazil), and Todos os Santos Bay (Brazil), regardless of the method applied. Regarding legislation, Uruguay and Argentina have the most advanced policies in the region against marine plastic pollution due to their emphasis on the life cycle and the national ban on certain single-use plastics. Therefore, considering its content, this expert review can be useful to assist researchers dealing with plastic pollution along the South American Atlantic Ocean Coast.

Prevalence of plastic debris in nests of two cormorant species in Peru

The guanay cormorant (Leucocarbo bougainvilliorum) and red-legged cormorant (Poikilocarbo gaimardi) are known for their prolific nest-building behavior, utilizing a diverse array of materials, including anthropogenic debris, thereby serving as valuable indicators of ocean plastic pollution. To elucidate inter-specific variations in nest plastic occurrence between these two cormorant species, we conducted a comprehensive examination of nests at 12 colonies along the Peruvian coast in 2018-2019. Our findings revealed a significantly higher occurrence of plastic in red-legged cormorant nests (mean 50 ± 27 %, N = 100 nests in 7 colonies) compared to guanay cormorant nests (mean 10 ± 20 %, 3497 nests in 8 colonies). Furthermore, the prevalence of plastic waste varied across colonies within both species. Off-white/clear plastic bags were the predominant color and type of debris found in both cormorant nests. This study is a baseline of plastic marine pollution occurrence along the Peruvian coast.

Anthropogenic nest material use in a global sample of birds

As humans increasingly modify the natural world, many animals have responded by changing their behaviour. Understanding and predicting the extent of these responses is a key step in conserving these species. For example, the tendency for some species of birds to incorporate anthropogenic items-particularly plastic material-into their nests is of increasing concern, as in some cases, this behaviour has harmful effects on adults, young and eggs. Studies of this phenomenon, however, have to date been largely limited in geographic and taxonomic scope. To investigate the global correlates of anthropogenic (including plastic) nest material use, we used Bayesian phylogenetic mixed models and a data set of recorded nest materials in 6147 species of birds. We find that, after controlling for research effort and proximity to human landscape modifications, anthropogenic nest material use is correlated with synanthropic (artificial) nesting locations, breeding environment and the number of different nest materials the species has been recorded to use. We also demonstrate that body mass, range size, conservation status and brain size do not explain variation in the recorded use of anthropogenic nest materials. These results indicate that anthropogenic materials are more likely to be included in nests when they are more readily available, as well as potentially by species that are more flexible in their nest material choice.

Gulls as potential sentinels for urban litter: combining nest and GPS-tracking information

The production of urban waste has increased in the past decades leading to its mishandling. The effects on public health, economy, and wildlife that waste mismanagement can have are forcing governments to increase their efforts in detecting and mitigating the presence of waste. Identifying and monitoring sentinel species to assess the presence of urban litter could be a cost-effective option. Thus, analyzing the nest composition of yellow-legged gulls from an urban population inhabiting a very high populated city (Barcelona, Spain), and combining this information with accurate GPS tracking data, provides a potential tool to monitor the presence of marine and terrestrial litter over time. The results revealed the highest presence of debris in the nests of a seabird ever recorded. All the nests examined contained anthropogenic waste, with plastic items present in all of them. Crossing the nest composition with GPS tracking movements confirmed that the waste to build the nests was collected in the urban area and not in other environments surrounding the city. Then, the nest waste composition may be a good indicator of waste mismanagement and advise the municipalities to improve waste management and recycling strategies for the different types of litter. Using gulls breeding in cities as sentinel species and, in particular, the study of their nest composition, may provide essential data to decision-making stakeholders to adopt a One Health approach and help improve not only the environment's health but also the health of those who live in it.

Anthropogenic debris in Kelp Gull and other seabird nests in northern Patagonia, Argentina

Anthropogenic debris is used as nesting material by many seabirds and may result in negative impacts. We assessed the frequency of occurrence of debris (>5 mm) in Kelp Gull (Larus dominicanus) nests at six locations along 2400 km of the Argentine coast, at different distances from urban centres, and in nests of other seven seabird species nesting syntopically. Frequencies in Kelp Gull nests were in general relatively low, ranging between 3.3 and 37.5%, and differed significantly among colonies. No relationship was found between frequency and distance to urban centres. Debris were recorded with frequencies of less than 19.2% in nests of Olrog's Gulls (L. atlanticus), Dolphin Gulls (L. scoresbii), Imperial Cormorants (Leucocarbo atriceps) and Magellanic Penguins (Spheniscus magellanicus), but not in nests of Neotropical Cormorants (Nannopterum brasilianus), Rock Shags (Leucocarbo magellanicus) and Southern Skuas (Catharacta antarctica). This information obtained along a wide coastal sector provides a baseline for future monitoring.