Evaluation of meso- and microplastic ingestion by the northern fulmar through a non-lethal sampling method.

An increasing number of organisms from the polar regions are reported contaminated by plastic. Rarely a non-killing sampling method is used. In this study we wanted to assess plastic levels using stomach flushing and evaluate the method suitability for further research and monitoring. The stomach of 22 fulmars from Bjørnøya, Svalbard, were flushed with water in the field. On return to the laboratory, the regurgitated content was digested using potassium hydroxide. The extracted plastics were visually characterised and analysed with spectroscopy. Only three birds had plastics in their stomach, totaling 36 particles, most of them microplastics (< 5 mm). The plastic burdens are much lower than previously reported in Svalbard. The stomach flushing is assumed not to allow the collection of the gizzard content. This is a major limitation as most of the plastics accumulate in the fulmar's gizzard. However, the method is still useful for studies investigating plastic ingestion dynamics, allowing to sample the same individuals over time.

Hydroclimatic influence on the trophic ecology of Atlantic goliath grouper juveniles (Epinephelus itajara) in a tropical estuary using non-lethal methodologies.

The Atlantic goliath grouper Epinephelus itajara is the largest species of groupers in the Atlantic Ocean, reaching over 2 m total length and 400 kg. It has an ontogenetic migration, with adults using nearshore and offshore marine areas and juveniles inhabiting estuarine/mangrove areas. Despite of its high ecological relevance and classification as a threatened species for several decades in the IUCN red lists, critical phases of its life cycle, like juveniles inhabiting estuaries, are still poorly investigated. In this study, we evaluated if hydroclimatic changes may affect the trophic ecology of juveniles in a tropical estuary. We described their diet composition, isotopic niche area, food assimilation, and trophic position of juveniles across seasons using two non-lethal techniques: stomach content analysis using a stomach flushing procedure and stable isotope analysis using a dermal biopsy. A total of 87 individuals with TL ranging from 38 to 331 mm had their stomachs analyzed, of which 31 had food content. We identified 11 prey items, shrimp being the most abundant prey group (IRI% = 88.4), followed by fish (6.6), blue crab (2.8), and crab (2.2). A total of 93 specimens had their muscle's carbon (δ13C) and nitrogen (δ15N) stable isotope ratios analyzed (38-332 mm TL). Average δ13C values showed statistically significant changes across seasons, but no significant changes were observed for δ15N. As initially predicted, isotopic niche size of juveniles changed consistently along the entire hydroclimatic cycle, reaching its peak at the end of the wet season. We also observed changes in the proportion of prey assimilation by juveniles between seasons. Shrimp (92.1%) was the most assimilated prey group during the late dry season, whereas tidal crabs (36.7%), blue crab (27.8%), and shrimp (25.1%) were the most important in the late wet season. Average trophic position of juveniles remained similar across wet (3.32 ± 0.10) and dry (3.23 ± 0.11) seasons. These findings provide important information to help decision makers to promote more efficient management and conservation legislations to protect early life stages of the Atlantic goliath grouper in tropical estuaries.

Availability and assessment of microplastic ingestion by marsh birds in Mississippi Gulf Coast tidal marshes.

Millions of tons of plastic enter the environment every year, where much of it concentrates in environmental sinks such as tidal marshes. With prior studies documenting harm to marine fauna caused by this plastic pollution, the need to understand how this novel type of pollution affects estuarine fauna is great. Yet, research on the fate and uptake of plastic pollutants in estuarine ecosystems is sparse. Therefore, we quantified plastic prevalence and ingestion by two species of resident marsh bird, Clapper Rails (Rallus crepitans) and Seaside Sparrows (Ammospiza maritima), in coastal marsh ecosystems within Mississippi. We detected microplastics (plastics smaller than 5 mm) in 64% of marsh sediment samples, 83% of Clapper Rail and 69% of Seaside Sparrow proventriculus samples. Dominant types of microplastics detected in sediment and bird samples were fibers. This study provides the first evidence of microplastic ingestion by marsh birds and its distribution in coastal marshes within Mississippi.

Stomach flushing technique applied to quantify microplastics in Crocodilians.

The impact of microplastics on wildlife is a recent problem for which methods to evaluate exposure still need development. Being able to identify and quantify microplastics (particles < 5 mm) in the gastric contents of live crocodiles allows us to evaluate exposure, at both individual and population level, and also its contribution as transporter of other contaminants. The method was validated to determine and quantify microplastics in crocodile stomach contents recovered during an experiment where a known amount of this contaminant was given to crocodiles via oral administration. Through stomach flushing we were able to recover more than 80 % of the total volume of microplastic administrated to each crocodile. In summary, the method used during the experiment consists of 1) immobilization of the crocodile; 2) extraction of microplastics from stomach contents obtained through stomach flushing; 3) separation, identification and quantification of recovered microplastic fragments using microscopy and FTIR. •Low cost method that uses a small number of materials, does not take long to produce results and can easily be performed in the field or the laboratory.•Effective in extracting stomach contents (95 %).•High (>80 %) and good (>60 %) recovery efficiencies within two and four days after ingestion of microplastics by crocodiles.

Gastric nematode diversity between estuarine and inland freshwater populations of the American alligator (Alligator mississippiensis, daudin 1802), and the prediction of intermediate hosts.

We examined the variation of stomach nematode intensity and species richness of Alligator mississippiensis from coastal estuarine and inland freshwater habitats in Florida and Georgia, and integrated prey content data to predict possible intermediate hosts. Nematode parasitism within inland freshwater inhabiting populations was found to have a higher intensity and species richness than those inhabiting coastal estuarine systems. This pattern potentially correlates with the difference and diversity of prey available between inland freshwater and coastal estuarine habitats. Increased consumption of a diverse array of prey was also correlated with increased nematode intensity in larger alligators. Parasitic nematodes Dujardinascaris waltoni, Brevimulticaecum tenuicolle, Ortleppascaris antipini, Goezia sp., and Contracaecum sp. were present in alligators from both habitat types. Dujardinascaris waltoni, B. tenuicolle, and O. antipini had a significantly higher abundance among inland inhabiting alligators than hosts from estuarine populations. Our findings also suggest that host specific nematode parasites of alligators may have evolved to infect multiple intermediate hosts, particularly fishes, crabs, and turtles, perhaps in response to the opportunistic predatory behaviors of alligators.

Impacto antrópico na dieta do cágado-de-barbicha [Phrynops geoffroanus - Chelidae] no rio Uberabinha, Uberlândia, Minas Gerais, Brasil / Human impact on the diet of geoffroy's toadhead turtle [phrynops geoffroanus - Testudines, Chelidae] in the river Uberabinha, Uberlândia, Minas gerais, Brazil / Impacto antropico en la dieta de la tortuga de barbilla, [Phrynopsgeoffroanus - Testudines, Chelidae] en el rio Uberabinha, uberlândia, Minas Gerais, Brasil

Os Testudines (répteis caracterizados pela presença de uma carapaça) são uns dos principais componentes das redes tróficas dos rios, apesar disto, ainda é rara a observação dos cágados se alimentando em condições naturais. De maio a outubro de 2011 foi capturado um total de 110 espécimes de (cágado-de-barbicha) [Phrynops geoffroanus, Schweigger, 1812] do rio Uberabinha Minas Gerais, em três áreas distintas e também as presas em potenciais (peixes, macroinvertebrados e invertebrados terrestres). A coleta dos itens ingeridos foi realizada por meio de lavagem estomacal e para a coleta das presas em potencial foi utilizado armadilha tipo pitfall, rede D e armadilha tipo covo. Os itens da dieta foram fixados, identificados, separados em categorias e tiveram seus volumes aferidos. Para verificar se as diferentes áreas interferiram na dieta realizou- -se uma ANOVA Fatorial. Uma das áreas (área 3) não foi incluída nos testes estatísticos pela grande discrepância entre o número de fêmeas e machos capturados. Considerando a dieta como um todo, não houve diferença significativa entre as áreas 1 e 2 (F=3,342, p=0,068), mas ao se analisar separadamente cada categorias de itens alimentares, os espécimes da área 1 consumiram mais vertebrados aquáticos e menos itens de origem antrópica quando comparados com os espécimes da área 2 (F=65,419, p<0,01). Com relação ao sexo, não houve diferença estatística na área 1 (F=0,561, p= 0,454), mas houve na área 2 (F= 9,410, p=0,02), sendo que as fêmeas consumiram maior volume de itens de origem antrópica do que os machos (F= 34,276, p<0,001). A dieta diversificada e a adaptação a ambientes impactados demonstram que P. geoffroanus é uma espécie com grande plasticidade.

The Testudines (reptiles characterized by the presence of a shell) are a major component of trophic networks in rivers. Nonetheless, it is still rare to see turtles feeding in natural conditions. From May to October 2011, a total of 110 specimens of P. geoffroanus were captured in River Uberabinha, in three distinct areas, as well as capturing their potential prey (fish, macro-invertebrates and terrestrial invertebrates). The collection of ingested items was performed by stomach flushing, and the collection of potential prey was made with pitfall traps, D nets and “Covo” trap. The dietary items were fixed, marked, separated into categories, and their volumes were measured. In order to verify if the different areas affect the diet, ANOVA factorial was performed. One of the areas (area 2) was not included in the statistical tests due to the large discrepancy between the number of females and males captured. Considering the diet as a whole, there were no significant differences between areas 1 and 2 (F=3.342, p=0.068), but when they were analyzed separately for each food item categories, the specimens from area 1 consumed more aquatic vertebrates and fewer items from anthropogenic origin when compared to specimens from area 2 (F=65.419, p<0.01). Regarding gender, no statistical differences were found in area 1 (F=0.561, p= 0.454), but statistical difference was found in area 2 (F= 9.410, p=0.02), being that females consumed a greater volume of items from anthropogenic origin than males (F= 34.276, p<0.001). The diversified diet and adaptation to impacted environments demonstrate that P. geoffroanus is a species with high plasticity.

Los Testudines (reptiles caracterizados por la presencia de un caparazón) son algunos de los principales componentes de las redes tróficas de los ríos, a pesar de esto, todavía es rara la observación de las tortugas alimentándose en condiciones naturales. De mayo a octubre de 2011 fueron capturados un total de 110 especímenes de tortuga de barbilla (Phrynopsgeoffroanus, Schweigger, 1812) del río Uberabinha – Minas Gerais, en tres áreas distintas y también las presas potenciales (peces, macroinvertebrados e invertebrados terrestres). La colecta de los ítems ingeridos se ha realizado por medio de lavaje estomacal y para la colecta de las presas potenciales se ha utilizado una trampa tipo “pitfall”, “red D” y trampa tipo “embudo”. Los ítems de la dieta fueron fijados, identificados, separados en categorías y tuvieron sus volúmenes medidos. Para verificar si las diferentes áreas interfirieron en la dieta se realizó un ANOVA Factorial. Una de las áreas (área 3) no fue incluida en los testes estadísticos debido gran discrepancia entre el número de hembras y de machos capturados. Considerando la dieta como un todo, no hubo diferencia significativa entre las áreas 1 y 2 (F=3,342, p=0,068), pero al analizar separadamente cada categoría de ítems alimenticios, los especímenes del área 1 consumieron más vertebrados acuáticos y menos ítems de origen antrópica comparados con los especímenes del área 2 (F=65,419, p<0,01). Con relación al sexo, no hubo diferencia estadística en el área 1 (F=0,561, p= 0,454), pero hubo en el área 2 (F= 9,410, p=0,02), siendo que las hembras consumieron mayor volumen de ítems de origen antrópica que los machos (F= 34,276, p<0,001). La dieta diversificada y la adaptación a ambientes impactados demuestran que P. geoffroanus es una especie con gran plasticidad.