The green turtle (Chelonia mydas) is listed as a globally endangered species and is vulnerable to anthropogenic threats, including environmental pollution. This study investigated the antimicrobial resistance of Gram-negative bacteria isolated from wild green turtles admitted to a sea turtle rehabilitation center in Taiwan. For this investigation, cloacal and nasal swab samples were collected from 28 green turtles between 2018 and 2020, from which a total of 47 Gram-negative bacterial isolates were identified. Among these, Vibrio spp. were the most dominant isolate (31.91%), and 89.36% of the 47 isolates showed resistance to at least one of 18 antimicrobial agents tested. Isolates resistant to one (6.38%), two (8.51%), and multiple (74.47%) antimicrobials were observed. The antimicrobial agents to which isolates showed the greatest resistance were penicillin (74.47%), followed by spiramycin, amoxicillin, and cephalexin. The antimicrobial-resistance profiles identified in this study provide useful information for the clinical treatment of sea turtles in rehabilitation facilities. The results of our study also imply that wild green turtles may be exposed to polluting effluents containing antimicrobials when the turtles traverse migratory corridors or forage in feeding habitats. To benefit sea turtle conservation, future research should focus on (1) how to prevent pollution from antimicrobials in major green turtle activity areas and (2) identifying sources of antimicrobial-resistant bacterial strains in coastal waters of Taiwan.

Investigating environmental pollution is important to understand its impact on endangered species such as green turtles (Chelonia mydas). In this study, we investigated the accumulation and potential toxicity of selected persistent organic pollutants (POPs) and naturally occurring MeO-PBDEs in liver, fat, kidney and muscle of turtles (n = 30) of different gender, size, year of death, location and health status. Overall, POP concentrations were low and accumulation was highest in liver and lowest in fat which is likely due to the poor health of several animals, causing a remobilization of lipids and associated compounds. PCBs and p,p’-DDE dominated the POP profiles, and relatively high MeO-PBDE concentrations (2′-MeO-BDE 68 up to 192 ng/g lw, 6-MeO-BDE 47 up to 79 ng/g lw) were detected in all tissues. Only few influences of factors such as age, gender and location were found. While concentrations were low compared to other marine wildlife, biological toxicity equivalences obtained by screening the tissue extracts using the micro-EROD assay ranged from 2.8 to 356 pg/g and the highest values were observed in muscle, followed by kidney and liver. This emphazises that pollutant mixtures found in the turtles have the potential to cause dioxin-like effects in these animals and that dioxin-like compounds should not be overlooked in future studies.

A program to reintroduce the Northern Aplomado falcon (Falco femoralis septentrionalis) in south Texas and the southwestern United States was initiated in the late 1970s. Fledgling Aplomado falcons were first released in the Laguna Atascosa National Wildlife Refuge in 1993 and the first nesting pair in the area was recorded by 1995. During 2004–2017 we collected addled eggs from nesting pairs in the Laguna Atascosa National Wildlife Refuge and Matagorda Island in south Texas, to determine if environmental contaminants in Aplomado falcon eggs had decreased over time and if eggshell thickness values were similar to those in the pre-DDT era. We analyzed organochlorine pesticides, PCBs, and PBDEs in 60 egg homogenates by gas chromatography-mass spectrometry. Eggshells were measured to determine thickness and to correlate with contaminant concentrations. Mean concentration in eggs were 244 ng/g ww for p,p’- DDE, 270 ng/g ww for PCBs and 10 ng/g ww for PBDEs. These values were lower than those reported in a previous study for eggs collected between 1999 and 2003, with a mean of 821 ng/g ww for p,p’-DDE and 1228 ng/g ww for total PCBs. Eggshell thickness ranged from 0.206 mm to 0.320 mm (n = 156). Overall, contaminant concentrations in eggs of Aplomado falcons were low, at levels not likely to impact the recovery of the species. Data from this and previous studies indicate that DDE has decreased significantly in eggs of Aplomado falcons over the last 25 years in south Texas. Breeding populations have been steady at over 30 breeding pairs in south Texas since 2011, although they decreased to 24 pairs in 2018 following Hurricane Harvey.

Elasmobranchs are particularly prone to accumulating contaminants due to their life history patterns and relatively high trophic position. However, several compounds, especially contaminants of emerging concern, have still not been well studied in this group. Here, we aimed to determine the occurrence and concentrations of several inorganic and organic contaminants in different tissues of the Brazilian guitarfish Pseudobatos horkelii. This species is a critically endangered species, endemic from the Southwest Atlantic which uses southern Brazilian waters as a nursery habitat. Polycyclic aromatic hydrocarbons (PAHs), emerging pesticides, pharmaceutical and personal care products (PPCPs) and trace metals were determined in five biological tissues in order to assess the accumulation and organotropism of these compounds. Except for chlorothalonil and triclosan, all compounds were detected in, at least, one tissue, mostly in liver samples. All compounds differed among tissues, with liver presenting the higher concentrations of several contaminants, followed by muscle and gills. PAHs and PPCPs were the most detected analytes and presented the highest concentrations among tissues. Diclofenac levels were determined, for the first time in elasmobranchs, and were relatively high, when compared to other fishes. Finally, relatively high concentrations of PAHs, dichlofluanid and octocrylene in muscle might be suggestive of chronic exposure, presenting also human health implications. Regarding trace metals, contrary to most elasmobranch studies, Hg levels were low in all tissues, whereas Cd and Pb here higher in liver, and gills and blood samples, respectively. Our results indicate that P. horkelii is exposed to several organic and inorganic which might affect this species in a long-term scale. Concerning the determination of emerging contaminants, it is likely that other elasmobranchs are also exposed to these compounds and special attention should be given to this issue in order to predict future effects on this group.

In the Northern coast of Rio de Janeiro State is located the major urban centers of the oil and gas industry of Brazil. The intense urbanization in recent decades caused an increase in human use of the coastal areas, which is constantly impacted by agricultural, industrial and wastewater discharges. Franciscana dolphin (Pontoporia blainvillei) is a small cetacean that inhabits coastal regions down to a 30 m depth. This species is considered the most threatened cetacean in the Western South Atlantic Ocean. This study investigated the levels of 52 PCB congeners and 9 PBDE congeners in liver of nine individuals found stranded or accidentally caught between 2011 and 2012 in the Northern coast of Rio de Janeiro. PCB mean levels ranged from 208 to 5543 ng g⁻¹ lw and PBDEs mean concentrations varied between 13.84 and 36.94 ng g⁻¹ lw. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and penta-BDE mixtures in Brazil. While still few studies have assessed the organic contamination in cetaceans from the Southern Hemisphere, including Brazil, the levels found in this study could represent a health risk to these endangered species.

Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species.

Increasing heavy metal pollution in wetland ecosystems around the world pose significant health risks to waterbirds, especially the endangered species. We analyzed heavy metal pollution in bird foraging area of Caohai wetland in Guizhou Plateau (China), and used an integrated exposure risk model for assessing heavy metal (Cd, Pb, Cr, Ni, Zn, Sb) exposure risk in birds from the soil, water, plants and benthic invertebrates. There is considerable variation in the extent of heavy metal contamination across the different sampling sites, and Cd and Sb are the main contaminants. The mussel Anodonta showed greater heavy metal accumulation (except for Zn) compared to the snail species C. cathayensis. The different plant species also varied in terms of amount for accumulated heavy metals. The phytophagous together with omnivorous birds were exposed to Cd, Pb, Zn and Ni through plants rather than the soil, whereas the maximum Zn exposure in the omnivorous and carnivorous birds was through consumption of benthic invertebrates. Furthermore, the phytophagous black-necked cranes (Grus nigricollis) were less risk to heavy metal exposure compared to the omnivorous bar-headed goose (Anser indicus) and carnivorous ruddy shelducks (Tadorna ferruginea). The exposure risk of Cr (8.1) was highest, followed by Pb (5.1), Zn (3.8), Sb (1.0), Cd (0.33) and Ni (0.28). The heavy metal assessment heavy metal exposure risk for migratory birds should take into account the exposure from food and soil. Our findings provide new insights into developing measures to minimize heavy metal contamination in migratory birds.

Modification of nighttime light levels by artificial illumination (artificial light at night; ALAN) is a rapidly increasing form of human disturbance that affects natural environments worldwide. Light in natural environments influences a variety of physiological and ecological processes directly and indirectly and, as a result, the effects of light pollution on species, communities and ecosystems are emerging as significant. Small prey species may be particularly susceptible to ALAN as it makes them more conspicuous and thus more vulnerable to predation by visually oriented predators. Understanding the effects of disturbance like ALAN is especially important for threatened or endangered species as impacts have the potential to impede recovery, but due to low population numbers inherent to at-risk species, disturbance is rarely studied. The endangered Stephens’ kangaroo rat (SKR), Dipodomys stephensi, is a nocturnal rodent threatened by habitat destruction from urban expansion. The degree to which ALAN impacts their recovery is unknown. In this study, we examined the effects of ALAN on SKR foraging decisions across a gradient of light intensity for two types of ALAN, flood and bug lights (756 vs 300 lumen, respectfully) during full and new moon conditions. We found that ALAN decreased probability of resource patch depletion compared to controls. Moreover, lunar illumination, distance from the light source and light type interacted to alter SKR foraging. Under the new moon, SKR were consistently more likely to deplete patches under control conditions, but there was an increasing probability of patch depletion with distance from the source of artificial light. The full moon dampened SKR foraging activity and the effect of artificial lights. Our study underscores that ALAN reduces habitat suitability, and raises the possibility that ALAN may impede the recovery of at-risk nocturnal rodents.

We monitor pollutant accumulation and investigate associated changes at the physiological level within the population of an obligate avian scavenger, the Egyptian Vulture (Neophron percnopterus), from Catalonia (NE Spain). This population is expanding its range, presumably because of the use of human waste disposal sites as food resource. We hypothesized that habitat urbanization, presumably associated with feeding from human wastes, could influence the accumulation of persistent organic pollutants and metals. The aim of this study was to explore the relationship between accumulated pollutants and biochemical parameters in nestling blood. We used the proportion of urban surface within an 8 km radius of each nest as a proxy to study the relationship between anthropic influence and pollutant accumulation. Observed blood levels of metals, organochlorine pesticides, polychlorinated biphenyls (PCBs), per- and polyfluoroalkylated substances (PFAS) and polybrominated diphenyl ethers (PBDEs) were relatively low, as expected for nestling individuals due to short-term exposures. CB-180 and PBDEs were associated with variations in blood biochemistry parameters; hexa-BDEs appeared positively associated with activities of the enzymes aspartate aminotransferase and lactate dehydrogenase, whereas CB-180 accumulation was associated with an increased activity of creatine phosphokinase and elevated glutathione levels. Increased CB-180 levels were also related to decreased blood concentrations of calcium, cholesterol, α-tocopherol and lutein. A proportion of urban surfaces as low as 6.56% within a radius of 8 km around the nest appears related to the accumulation of CB-180, the majority of analysed PFAS and of PBDE congeners 99 and 209, and increased urbanization was also associated with decreased plasma levels of α-tocopherol and carotenoids. These associations suggest that changes in blood profiles of vitamins, carotenoids or other analytes, despite related to increased plasma levels of CB-180, would be consequence of exploitation of artificial food sources rather than of a direct effect of the pollutants.