Anthropogenic Debris Ingestion Research Articles

The impact of chronic and acute problems on sea turtles: The consequences of the oil spill and ingestion of anthropogenic debris on the tropical semi-arid coast of Ceará, Brazil

Sea turtle mortality is often related to materials that reach the coast from different anthropic activities worldwide. This study aimed to investigate whether sea turtle mortality was related to older marine problems, such as solid waste, or one of the largest oil spill accidents on the Brazilian coast, that occurred in 2019. We posed three questions: 1) Are there solid residues in the digestive tract samples, and which typology is the most abundant? 2) Can meso‑ and macro-waste marine pollutants cause mortality? 3) Is the dark material found really oil? A total of 25 gastrointestinal content (GC) samples were obtained, of which 22 ingested waste of anthropogenic origin and 18 were necropsied. These 22 samples were obtained during or after the 2019 oil spill, of which 17 specimens were affected, making it possible to suggest oil ingestion with the cause of death in the animals that could be necropsied. Macroscopic data showed that the most abundant solid waste was plastic (76.05 %), followed by fabrics (12.18 %) and oil-like materials. However, chemical data confirmed only three specimens with oil levels ranging from remnants to high. It was possible to infer possible causes of death in 16 of the total 18 necropsied cases: Most deaths were due to respiratory arrest (62.5 %), followed by pulmonary edema (12.5 %), cachexia syndrome (12.5 %), circulatory shock (6.25 %), and head trauma (6.25 %), which may have been caused by contact with solid waste, oil, or both. The study showed that not all dark material found in the GCs of turtles killed in oiled areas is truly oil, and in this sense, a chemical analysis step to prove the evidence of oil must be added to international protocols.

High microplastic and anthropogenic particle contamination in the gastrointestinal tracts of tiger sharks (Galeocerdo cuvier) caught in the western North Atlantic Ocean

Few studies have documented microplastics (<5 mm) in shark gastrointestinal (GI) tracts. Here, we report microplastic contamination in the tiger shark (Galeocerdo cuvier), an apex predator and generalist feeder, at several different life stages. We examined seven stomachs and one spiral valve from eight individuals captured off the United States Atlantic and Gulf of Mexico coasts (eastern US) and conducted a literature review of publications reporting anthropogenic debris ingestion in elasmobranchs. Specimens were chemically digested in potassium hydroxide (KOH) and density separated using calcium chloride (CaCl2) before quantifying and categorizing suspected anthropogenic particles (>45 μm) by size, morphology, and colour. Anthropogenic particles were found in the stomachs and spiral valve of all sharks. A total of 3151 anthropogenic particles were observed across all stomachs with 1603 anthropogenic particles observed in a single specimen. A subset of suspected anthropogenic particles (14%) were chemically identified using Raman spectroscopy and μ-Fourier Transform Infrared spectroscopy to confirm anthropogenic origin. Overall, ≥95% of particles analyzed via spectroscopy were confirmed anthropogenic, with 45% confirmed as microplastics. Of the microplastics, polypropylene (32%) was the most common polymer. Diverse microparticle morphologies were found, with fragments (57%) and fibers (41%) most frequently observed. The high occurrence and abundance of anthropogenic particle contamination in tiger sharks is likely due to their generalist feeding strategy and high trophic position compared to other marine species. The literature review resulted in 32 studies published through 2022. Several methodologies were employed, and varying amounts of contamination were reported, but none reported contamination as high as detected in our study. Anthropogenic particle ingestion studies should continue in the tiger shark, in addition to other elasmobranch species, to further understand the effects of anthropogenic activities and associated pollution on these predators.

Identification of anthropogenic debris in the stomach and intestines of giant freshwater prawns from the Trang River in southern Thailand.

Anthropogenic waste, especially microplastics, is becoming more prevalent in the environment and marine ecosystems, where it has the potential to spread through food chains and be consumed by humans. Southeast Asian countries are home to giant freshwater prawns, a common freshwater species that is eaten around the world. Microplastic pollution in river water, sediment, and commercially significant aquatic species such as fish and mollusks has been observed, yet few studies have been conducted on giant freshwater prawns in the rivers of southern Thailand, where microplastics may contaminate prawns via the food they ingest. The purpose of this research was to investigate the accumulation of anthropogenic material in the organs of river prawns (Macrobrachium rosenbergii). Microplastics in the stomachs and intestines of giant freshwater prawns were the focus of this study. Samples were digested with 30 ml of 10% potassium hydroxide (KOH), heated for 5 min at 60°C, and then digested at room temperature. The quantity, color, and appearance of microplastics were assessed using a stereomicroscope after 12 h. Furthermore, polymers were examined using a Fourier transform infrared spectrophotometer (FTIR). Microplastic counts were compared between sexes. A T-test was used to compare male and female microplastic counts in the stomach and intestine, and the Pearson correlation was used to compare the association between microplastic counts in the stomach and intestine and carapace length (CL), length of abdomen (LA), and body weight (BW) of male and female giant freshwater prawns. The threshold of significance was fixed at p<0.05. Based on the study results, a total of 370 pieces of anthropogenic debris were discovered in the stomachs and intestines of both female and male prawns. The average number of microplastics per individual was 4.87 ± 0.72 in female stomachs and 3.03 ±0.58 in male stomachs, and 1.73 ±0.36 in female intestines and 2.70 ±0.57 in male intestines. The majority of microplastics found in females were within the <100 µm range, while males contained microplastics in the range of 100-500 µm. Both male and female prawns contained fibers (72.70%) and fragments (27.30%). Various polymers were identified, including cotton, rayon, and polyvinyl chloride (PVC). The study also explored the relationship between carapace length, length of abdomen, body weight, stomach weight, and the number of microplastics. The findings reveal a significant association between the number of microplastics and stomach weight in male prawns (R=0.495;p=0.005). These findings provide alarming evidence of anthropogenic debris ingestion in prawns and raise concerns about the future effects of anthropogenic pollution on giant freshwater prawns.

Anthropogenic debris ingestion in a tropical seabird community: Insights from taxonomy and foraging distribution

Oceans have been considered as an unlimited supply of goods and services, but resource extraction and waste disposal became ubiquitous and have been damaging the health of marine ecosystems. Finding suitable sentinel species of the human impacts on the oceans is thus imperative, since they may work as early warnings of disruptive situations. In this study, we investigated how taxonomy and foraging distribution influenced the occurrence of anthropogenic debris among five seabird species inhabiting the tropical Atlantic region. Occurrence of anthropogenic debris was assessed using faeces of breeding individuals as a proxy of ingestion. A total of 268 particles were extracted from all samples. The categories “fragments” and “fibres”, as well as the colour “blue”, were the most prevalent characteristics across species. There was a high diversity of polymers from cellulosic particles to synthetic plastics (Anthropogenic Cellulosic 26.9 %; Polyester 7.7 %; Varnish 5.8 %; Polypropylene 1.9 %). Species with a more coastal foraging strategy exhibited higher occurrence and number of anthropogenic debris when compared to species foraging comparably more in pelagic areas. This suggests that anthropogenic debris are more prevalent in coastal foraging areas, where human activities occur in higher number and frequency (e.g., fisheries) and sources of freshwater input from inland are at close distance. These results provide more evidence to the growing perception on the ubiquity and diversity of anthropogenic debris in the marine environment, and further support the usefulness of using seabirds as bio-indicators of anthropogenic pollution in both neritic and oceanic regions.

Feeding Habits and the Occurrence of Anthropogenic Debris in the Stomach Content of Marine Fish from Pattani Bay, Gulf of Thailand.

Simple SummaryIn this work, the feeding behaviour of fish from a natural bay environment and the ingested anthropogenic fragments in a fish community in relation to their feeding habits and habitats were investigated. The identification of 34 fish species and analysis of their stomach content by visual inspection were carried out. The ingestion of anthropogenic debris by fish differed between season and their feeding features. The planktivorous fish having higher ingestion of anthropogenic debris than other species were found. The study results enhance the understanding of the spatiotemporal variation of feeding habits of fish communities and support future alerts relating to the risk of anthropogenic pollution in marine food webs. This study assessed the feeding habits and ingestion of anthropogenic debris in 34 marine fish species from the southern Gulf of Thailand. A total of 5478 fish samples of 12 families were categorised into seven groups: planktivore, Lucifer feeder, fish feeder, Acetes feeder, shrimp feeder, piscivore, and zoobenthivore fish. A total of 2477 anthropogenic debris items were extracted from 12 fish species by visual inspection. Their ingestion of anthropogenic debris was influenced by season (p < 0.0001), with the highest ingestion during the northeast monsoon season. Furthermore, planktivorous fish displayed more ingested anthropogenic debris than the other investigated species (p = 0.022). Blue-coloured anthropogenic debris was commonly detected in the stomachs of fish and significantly differed between species (p > 0.001). Water depth and season significantly influenced the availability of food types (AF) for fish (p < 0.001). These findings provide evidence of the ingestion of anthropogenic debris by fish inhabiting a natural bay and signal the future anthropogenic pollution of marine fish.

Ingestion of plastics and other debris by coastal and pelagic birds along the coast of Espírito Santo, Eastern Brazil

Although the ingestion of plastics and other anthropogenic debris by seabirds is a global problem, few studies have employed standardized protocols to quantify and classify the debris ingested by seabirds in the Southwest Atlantic. We evaluated the ingestion of marine debris (items >0.1 mm) by 126 coastal and pelagic birds (19 species) along the coast of Espírito Santo, Eastern Brazil. Debris were found in 30% of birds examined (11 species). Particles <1 mm accounted for 35% of all debris items. Most ingested debris were plastics (97%). Ingestion of >0.1 g of plastic debris was recorded in five species: Atlantic yellow-nosed albatrosses (Thalassarche chlororhynchos), Cory's shearwaters (Calonectris borealis), Manx shearwaters (Puffinus puffinus), brown boobies (Sula leucogaster), and Magellanic penguins (Spheniscus magellanicus). Our findings suggest that the ingestion of marine debris, especially plastics, is a common problem for coastal and pelagic birds in tropical Southwest Atlantic waters.

Ecological Traits Influencing Anthropogenic Debris Ingestion by Herbivorous Reef Fishes

One of the most conspicuous marks of the Anthropocene worldwide is the ubiquitous pollution by long lifespan materials (e.g., plastic). In marine habitats, anthropogenic debris are observed from floating on the surface to deposited on the substrate or ingested by wildlife at different food web levels. However, the link between feeding strategy types and debris ingestion by reef fishes remains poorly explored. We analyzed the gut contents of three nominally herbivorous fishes along the Brazilian coast: the doctorfish Acanthurus chirurgus, the parrotfish, Sparisoma axillare, and the chub Kyphosus vaigiensis. Individual [i.e., total length (TL)] and species-level functional traits, as well sites with distinct environmental features (i.e., tourism activity intensity, fishing pressure, and distance from the coast), were tested as predictors of the concentration of debris found inside individual fish guts. Debris found were quantified, measured, and classified accordingly to color and shape. We found debris in 52.7% of individuals. Debris ranged from 0.10 to 11.75 mm, and the frequency of occurrence and ingestion rate (number of debris per individual) varied among species, being higher for the scraper species S. axillare (95.7% and 4.9 ± 1.2, respectively) and A. chirurgus (74.6% and 1.64 ± 0.34), than for the browser K. vaigiensis (55.8% and 0.83 ± 0.24). TL, scraping feeding mode, and the most impacted location were positively related to debris ingestion rate. Our work revealed a higher vulnerability of an ecologically important trophic group to debris ingestion and of an already threatened species according to Brazilian red list. Besides the increasing number of species contaminated by anthropogenic debris, its effect on fish biology and physiology remains poorly understood. Understanding these links would improve conservation planning as species contamination could act as a proxy for environmental pollution on marine habitats.

Ingestion of anthropogenic debris by marine fishes around New Zealand

ABSTRACT A summary is presented of the anthropogenic debris recorded up to 2020 in stomachs of marine fishes from New Zealand waters. This material (mainly plastics) was found in the stomachs of 28 species, with 24 of these species identified in two studies alone. Most of the New Zealand records were not identified in recently published global assessments of plastic ingestion by fish; the likely reasons for this are discussed. Consumption of anthropogenic debris by fish in New Zealand waters is probably a widespread phenomenon, particularly for inshore demersal species with an algal dietary component and for offshore pelagic species that prey on gelatinous biota. Based on currently available data, this behaviour may occur relatively less frequently in deeper water demersal habitats, although no studies investigating the ingestion of microplastic particles by fish in this section of the New Zealand marine environment have yet been completed. The likelihood of identifying plastics in fish diets is strongly dependent on the analytical method used.

Ingestion of anthropogenic materials by yellow-legged gulls (Larus michahellis) in natural, urban, and landfill sites along Portugal in relation to diet composition.

Pollution is a global concern, increasing rapidly throughout marine and terrestrial ecosystems, and affecting many species. Urbanization enhances waste production, leading to the opening of landfills that constitute a spatially and temporally predictable food source for opportunistic species. Several species of gulls are known to exploit and breed in urban areas, taking advantage of accessible and diverse food resources. The exploitation of anthropogenic food subsidies at sea (e.g. fishery discards), urban sites, and landfills leads to debris ingestion by gulls with potential negative effects. Here we characterize anthropogenic debris ingested by yellow-legged gulls (Larus michahellis) along Portugal, by analysing the content of pellets collected in (1) natural and urban breeding locations, and in (2) urban and landfill resting sites, to assess seasonal patterns in the ingestion of anthropogenic debris. We also relate diet with the presence of anthropogenic debris. Debris materials were found in 28.8% of pellets from breeding locations (natural and urban) and in 89.7% of pellets from resting sites (urban and landfill). Gulls from the most urbanized breeding location exhibited higher levels of ingested materials during the entire breeding cycle, however, gulls from a natural breeding site also ingested high levels of debris during the pre-breeding season. At resting sites, small seasonal differences were detected in the number and mass of debris items ingested, which were both higher during spring and summer. Gulls that typically fed on pelagic fish had significantly less sheet and fragment plastics in their pellets. The presence of certain debris categories in gull pellets was positively related to the presence of some prey items, suggesting that gulls may accidentally ingest debris while foraging at multiple habitats. The quantity of anthropogenic materials ingested by gulls from urban locations and landfills indicates a need for improved waste management.

Anthropogenic debris in the digestive tract of a southern right whale (Eubalaena australis) stranded in Golfo Nuevo, Argentina

Over the past fifty years, interactions between anthropogenic debris and a wide range of marine species have increased. In cetaceans, the most frequent interactions have occurred through ingestion and/or entanglement, with results ranging from minor injuries to death in affected animals. While debris ingestion is widely documented in odontocetes, records are scarcer in mysticetes. This study describes the finding of plastic litter in the digestive tract of a southern right whale (Eubalaena australis) juvenile male, which was found dead on the shores of Golfo Nuevo, Chubut, Argentina in 2014. During the examination of intestinal contents, anthropogenic waste was found and classified as macro-debris (25 mm-1 m). Although this whale likely died of causes not related to this finding, it is the first record of anthropogenic debris ingestion for this species. This event adds information about the potential impact of human-made debris on a variety of aquatic species and ecosystems.

Ingestion of anthropogenic debris by migratory barnacle geese Branta leucopsis on a remote north-eastern Atlantic island

Although seabirds are frequently used as sentinel species for anthropogenic pollution, the extent and impacts of synthetic debris ingestion remains poorly studied for many water bird species. Here, we assess ingestion of synthetic particles (≥0.5 mm) by barnacle geese, Branta leucopsis, wintering on a remote island. Faecal samples were collected over a period of four wintering seasons. In total, 71 individual samples were assessed, with 79% of samples displaying at least one debris particle (maximum lengths 0.5–5 mm) from anthropogenic sources. The recovered synthetic debris were identified as micro-fibres (n = 166) and micro-fragments (n = 165). The number of synthetic particles detected per sample was generally low at 4.7 ± 0.9, 43 (mean ± SE, maximum): micro-fibres 2.3 ± 0.3, 10; micro-fragments 2.3 ± 0.8, 40. Particle numbers detected per gram of faecal sample differed amongst wintering seasons. Our results suggest that non-marine water birds can frequently ingest low quantities of synthetic particles in remote coastal habitats.

Seasonal ingestion of anthropogenic debris in an urban population of gulls

Gulls are generalist seabirds, increasingly drawn to urban environments where many species take advantage of abundant food sources, such as landfill sites. Despite this, data on items ingested at these locations, including human refuse, is limited. Here we investigate ingestion of prey and anthropogenic debris items in boluses (regurgitated pellets) from Pacific Gulls (Larus pacificus). A total of 374 boluses were collected between 2018 and 2020 in Tasmania. Debris was present in 92.51% of boluses (n = 346), with plastic (86.63%, n = 324) and glass (64.71%, n = 242) being the most prominent types. An abundance of intact, household items (e.g., dental floss, food wrappers) suggest the gulls regularly feed at landfill sites. In addition, the boluses are deposited at a roosting site located within an important wetland, thus we propose that the gulls may be functioning as a previously unrecognised vector of anthropogenic debris from urban centres to aquatic environments.

Debris ingestion and nutritional niches in estuarine and reef green turtles

Little attention has been drawn toward the effects of marine debris ingestion in relation to nutrient acquisition and fitness consequences. We tested whether anthropogenic debris ingestion influence the nutritional niches of endangered green turtles (Chelonia mydas) in estuarine and reef habitats on the Brazilian coast. Our results showed that estuarine turtles consumed diets with lower proportional wet mass composition of protein (P) and water (W) than their reef conspecifics. The amounts of debris, mostly plastics, retrieved from the digestive tracts of estuarine turtles were higher compared with those individuals from reefs. The realized nutritional niche from estuarine turtles was subject to the debris density in the environment, lack of benthic food resources available and the surface foraging behavior, likely preventing them from reaching their nutritional goals and resulting in lower fitness. The study provides critical information for the management and conservation of ecologically threatened individuals, populations, and their natural habitats.

Seashell and debris ingestion by African penguins

ABSTRACTAfrican penguins (Spheniscus demersus) are pursuit-diving seabirds endemic to the coast of southern Africa. In this study, we investigate the presence of seashells and anthropogenic debris (e.g. plastic, glass, nylon) in the stomach contents of adult African penguins, as determined from sampling of live penguins through the water off-loading technique (n = 4,793) and from post-mortem examination of penguin carcases (n = 159). Seashells were present in stomach contents sampled from 106 live (2.2%) and three dead (1.9%) penguins. Seashells originated from a variety of intertidal and subtidal organisms including molluscs, barnacles and bryozoans, and the eroded condition of the shell fragments suggests that they were picked up from shell deposits on the beach or in the surf zone. Seashell ingestion appears to be more frequent in the months of peak egg laying. A subset of stomach samples from known-sex individuals revealed that seashells were only present in the stomachs of adult females. In post-mortem examination, the presence of seashells in the stomach was accompanied by anatomical evidence that egg laying was imminent or had recently occurred. Anthropogenic debris was found in one (0.6%) and eight (0.2%) stomach content samples obtained from dead and live penguins, respectively. In some cases, the ingestion of anthropogenic debris co-occurred with that of seashells, and their size and shape were similar. Our findings demonstrate that adult female African penguins occasionally ingest seashells, possibly as a calcium supplementation strategy, and raise concern that in doing so they may also accidentally ingest anthropogenic debris.

Ultrasound examination of coelomic viscera through the plastron in stranded green sea turtles (Chelonia mydas).

Many projects have been developed in the last years for the conservation of sea turtles. Young green turtles (Chelonia mydas) often nest on the Brazilian coast. Because they nest in beaches along the coastline and islands, green turtles are susceptible to fishing and accidental ingestion of anthropogenic debris. Early detection of ingested debris is crucial for the survival of rescued sea animals. Ultrasound (US) has emerged as a viable imaging technique for visceral examination in veterinary medicine. Previous studies have suggested the left and right cervicobrachial, axillary, pre- and post-femoral areas as the only viable approaches for US examination, but the acoustic windows available for imaging of coelomic structures are limited. It is important to notice that a detailed evaluation of all gastrointestinal tracts, especially the duodenum, is crucial for detecting foreign bodies and intestinal obstructive processes, as well as obtaining essential information such as intestinal motility and heart frequency. Intestinal motility and heartbeats are not detected through radiographic examination or through the acoustic windows available so far. This study aimed to establish the viability of US examination of coelomic viscera through the plastron in stranded green turtles. Eleven young green turtles rescued by the GREMAR Institute were examined. Turtles were placed in the dorsal decubitus position during US examination, which did not require anesthesia. Even though the plastron is constituted of bones and cartilage, the present research has proven the viability of obtaining US images through it, making it possible to visualize structures undetectable through the acoustic windows previously suggested. The following organs were evaluated through the plastron: heart, stomach, duodenum, jejunum, colon, liver, gallbladder, kidneys, bladder, and spleen (in case of splenomegaly). US imaging through the plastron is a viable approach for detecting ingested artificial debris, which represents one of the leading causes of death among sea turtles.

Two decades of monitoring in marine debris ingestion in loggerhead sea turtle, Caretta caretta, from the western Mediterranean

Anthropogenic marine debris is one of the major worldwide threats to marine ecosystems. The EU Marine Strategy Framework Directive (MSFD) has established a protocol for data collection on marine debris from the gut contents of the loggerhead sea turtle (Caretta caretta), and for determining assessment values of plastics for Good Environmental Status (GES). GES values are calculated as percent turtles having more than average plastic weight per turtle. In the present study, we quantify marine debris ingestion in 155 loggerhead sea turtles collected in the period 1995–2016 in waters of western Mediterranean (North-east Spain). The study aims (1) to update and standardize debris ingestion data available from this area, (2) to analyse this issue over two decades using Zero-altered (hurdle) models and (3) to provide new data to compare the only GES value available (off Italian waters). The composition of marine debris (occurrence and amounts of different categories) was similar to that found in other studies for the western Mediterranean and their amounts seem not to be an important threat to turtle survival in the region. Model results suggest that, in the study area, (a) period of stranding or capture, (b) turtle size and (c) latitude are significant predictors of anthropogenic debris ingestion (occurrence and amount) in turtles. The GES value for late juvenile turtles (CCL>40 cm) has decreased in the last ten years in the study area, and this is very similar to that obtained in Italian waters. We also provide a GES value for early juvenile turtles (CCL≤40 cm) for the first time. Recommendations arising from this study include ensuring use of (1) the standardized protocol proposed by the MSFD for assessing marine debris ingestion by loggerhead sea turtles and (2) the ecology of the turtles (neritic vs oceanic), rather than their size, to obtain GES values.

Differential impact of marine debris ingestion during ontogenetic dietary shift of green turtles in Uruguayan waters

Anthropogenic debris ingestion has been reported for green turtles in all their life stages worldwide. The aim of the present study is to evaluate the marine debris ingestion by green turtles stranded in Uruguayan coast between 2005 and 2013. Debris items were categorized and quantified by frequency of occurrence, relative weight, volume and number of items. A total of 96 dead stranded turtles were analyzed and 70% presented debris in their guts. The majority of debris found were plastic, being hard plastics the most abundant in weight. We found no differences in debris ingestion in stranded turtles a long the Uruguayan coast. However we detected a negative correlation between the presence of debris and turtle's size. Smaller turtles are new recruits to neritic grounds indicating that the early juvenile stage of this species is the most vulnerable to this threat in the Southwestern Atlantic.

Seasonal encounter rate, life stages and main threats to the loggerhead sea turtle (Caretta caretta) in the Aeolian Archipelago (southern Thyrrenian Sea)

Abstract Annual and seasonal encounter rates, life stages and the main threats to loggerhead sea turtles (Caretta caretta) in the Aeolian Archipelago (southern Italy) were studied. Dedicated boat surveys resulted in 258 surface observations and 138 captures of healthy (n = 309), ailing (n = 66) and dead (n = 21) turtles from 2009 to 2013. Loggerheads were encountered at the sea water surface while resting (87%) or feeding on pelagic prey (13%). The loggerhead encounter rate (observations per km surveyed) was higher during the autumn, suggesting the presence of potential foraging/overwintering habitats in the area. The mean (± SD) curved carapace length (CCL) was 48.8 ± 10.7 cm, with 65% of the individuals ranging from 40–70 cm in size. Smaller turtles were encountered more frequently during the spring months, probably as a result of the abundant pelagic prey within the coastal area. During the colder season, larger turtles were more common in the afternoon than in the morning, suggesting that the time needed for rewarming might increase with turtle size. Ingestion of anthropogenic debris was reported in 48.5% of the rescued turtles. Individual mortality was mainly related to longline fishing (70.6%), with debris entanglements/ingestion frequently associated with these records. Longline bycatch and boat collisions were higher in summer, whereas debris ingestion was highest in spring. Different threats might affect particular life stages because the longline bycatch was more frequent for larger turtles, whereas boat collisions were more frequent with smaller individuals. Migratory patterns, habitat characteristics and seasonal changes in sea temperature and currents might influence the seasonal occurrence of loggerhead turtles in this area. These results increase the current ecological knowledge of the factors driving loggerhead turtle life and are important for implementing management plans for its conservation in the Mediterranean Sea.

Anthropogenic Debris Ingestion by Avifauna in Eastern Australia.

Anthropogenic debris in the world’s oceans and coastal environments is a pervasive global issue that has both direct and indirect impacts on avifauna. The number of bird species affected, the feeding ecologies associated with an increased risk of debris ingestion, and selectivity of ingested debris have yet to be investigated in most of Australia’s coastal and marine birds. With this study we aim to address the paucity of data regarding marine debris ingestion in Australian coastal and marine bird species. We investigated which Australian bird groups ingest marine debris, and whether debris-ingesting groups exhibit selectivity associated with their taxonomy, habitat or foraging methods. Here we present the largest multispecies study of anthropogenic debris ingestion in Australasian avifauna to date. We necropsied and investigated the gastrointestinal contents of 378 birds across 61 species, collected dead across eastern Australia. These species represented nine taxonomic orders, five habitat groups and six feeding strategies. Among investigated species, thirty percent had ingested debris, though ingestion did not occur uniformly within the orders of birds surveyed. Debris ingestion was found to occur in orders Procellariiformes, Suliformes, Charadriiformes and Pelecaniformes, across all surveyed habitats, and among birds that foraged by surface feeding, pursuit diving and search-by-sight. Procellariiformes, birds in pelagic habitats, and surface feeding marine birds ingested debris with the greatest frequency. Among birds which were found to ingest marine debris, we investigated debris selectivity and found that marine birds were selective with respect to both type and colour of debris. Selectivity for type and colour of debris significantly correlated with taxonomic order, habitat and foraging strategy. This study highlights the significant impact of feeding ecology on debris ingestion among Australia’s avifauna.

Plastics and other anthropogenic debris in freshwater birds from Canada

Plastics in marine environments are a global environmental issue. Plastic ingestion is associated with a variety of deleterious health effects in marine wildlife, and is a focus of much international research and monitoring. However, little research has focused on ramifications of plastic debris for freshwater organisms, despite marine and freshwater environments often having comparable plastic concentrations. We quantified plastic and other anthropogenic debris in 350 individuals of 17 freshwater and one marine bird species collected across Canada. We determined freshwater birds' anthropogenic debris ingestion rates to be 11.1% across all species studied. This work establishes that plastics and other anthropogenic debris are a genuine concern for management of the health of freshwater ecosystems, and provides a baseline for the prevalence of plastic and other anthropogenic debris ingestion in freshwater birds in Canada, with relevance for many other locations.