Ranking terrestrial vertebrate species for utility in biomonitoring and vulnerability to environmental contaminants

The importance of recognizing Buffer Zones to lands being developed, restored, or remediated: on planning for protection of ecological resources

Environmental management relies on many types of information before making decisions regarding remediation, restoration, or other land use decisions, including ecological data, such as risks to species, populations, communities, and ecosystems. The aim of this investigation was to describe the ecological information required within the context of making environmental decisions and providing visual communication tools for regulators, conservationists, and the public to understand the risk to ecological resources on- and off-site. It is suggested that ecological information used in environmental decisions is required to be transparent throughout the planning and execution of a project, which needs to include: 1) ecological information and evaluations within development areas or units (in this case, watersheds), and 2) resources in adjacent areas (Buffer Zones) that might be affected. The Melton Valley administrative watershed (Oak Ridge Reservation, TN) is used as a case study because this site still has active facility development and environmental remediation, and there are important ecological resources on and off-site. Data indicate that although there are important resources on Melton Valley administrative watershed, there are also significant resources in the Buffer Zone around the watershed. Compared to the Melton Valley administrative watershed, the Buffer Zone contains more Interior (and Buffer) Forest and greater value resources. The point is made that when remediation, restoration, or development occurs, it is equally important to consider resources that are adjacent to the site in a Buffer Zone, particularly when remediation and development might continue for many years or decades.

A multi-taxonomic framework for assessing relative petrochemical vulnerability of marine biodiversity in the Gulf of Mexico

A fundamental understanding of the impact of petrochemicals and other stressors on marine biodiversity is critical for effective management, restoration, recovery, and mitigation initiatives. As species-specific information on levels of petrochemical exposure and toxicological response are lacking for the majority of marine species, a trait-based assessment to rank species vulnerabilities to petrochemical activities in the Gulf of Mexico can provide a more comprehensive and effective means to prioritize species, habitats, and ecosystems for improved management, restoration and recovery. To initiate and standardize this process, we developed a trait-based framework, applicable to a wide range of vertebrate and invertebrate species, that can be used to rank relative population vulnerabilities of species to petrochemical activities in the Gulf of Mexico. Through expert consultation, 18 traits related to likelihood of exposure, individual sensitivity, and population resilience were identified and defined. The resulting multi-taxonomic petrochemical vulnerability framework can be adapted and applied to a wide variety of species groups and geographic regions. Additional recommendations and guidance on the application of the framework to rank species vulnerabilities under specific petrochemical exposure scenarios, management needs or data limitations are also discussed.

Bald eagle mercury exposure varies with region and site elevation in New York, USA

Freshwater fish in several regions of New York State (NYS) are known to contain concentrations of mercury (Hg) associated with negative health effects in wildlife and humans. We collected blood and breast feathers from bald eagle (Haliaeetus leucocephalus) nestlings throughout NYS, with an emphasis on the Catskill region to determine their exposure to Hg. We assessed whether habitat type (lake or river), region (Delaware-Catskill region vs. rest of NY) or sample site elevation influenced Hg concentrations in bald eagle breast feathers using ANCOVA. The model was significant and accounted for 41% of the variability in log₁₀ breast feather Hg concentrations. Mercury concentrations in nestling breast feathers were significantly greater in the Delaware-Catskill Region (geometric mean: 14.5 µg/g dw) than in the rest of NY (7.4 µg/g, dw), and greater at nests located at higher elevations. Habitat type (river vs. lake) did not have a significant influence on breast feather Hg concentrations. Geometric mean blood Hg concentrations were significantly greater in Catskill nestlings (0.78 µg/g ww) than in those from the rest of NY (0.32 µg/g). Mercury concentrations in nestling breast feathers and especially blood samples from the Delaware-Catskill region were generally greater than those reported for most populations sampled elsewhere, including areas associated with significant Hg pollution problems. Bald eagles can serve as valuable Hg bioindicators in aquatic ecosystems of NYS, particularly given their broad statewide distribution and their tendency to nest across all major watersheds and different habitat types.

In ovo exposure to brominated flame retardants Part II: Assessment of effects of TBBPA-BDBPE and BTBPE on hatching success, morphometric and physiological endpoints in American kestrels

Tetrabromobisphenol A bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTPBE) are both brominated flame retardants (BFRs) that have been detected in birds; however, their potential biological effects are largely unknown. We assessed the effects of embryonic exposure to TBBPA-BDBPE and BTBPE in a model avian predator, the American kestrel (Falco sparverius). Fertile eggs from a captive population of kestrels were injected on embryonic day 5 (ED5) with a vehicle control or one of three doses within the range of concentrations that have been detected in biota (nominal concentrations of 0, 10, 50 or 100 ng/g egg; measured concentrations 0, 3.0, 13.7 or 33.5 ng TBBPA-BDBPE/g egg and 0, 5.3, 26.8 or 58.1 ng BTBPE/g egg). Eggs were artificially incubated until hatching (ED28), at which point blood and tissues were collected to measure morphological and physiological endpoints, including organ somatic indices, circulating and glandular thyroid hormone concentrations, thyroid gland histology, hepatic deiodinase activity, and markers of oxidative stress. Neither compound had any effects on embryo survival through 90% of the incubation period or on hatching success, body mass, organ size, or oxidative stress of hatchlings. There was evidence of sex-specific effects in the thyroid system responses to the BTBPE exposures, with type 2 deiodinase (D2) activity decreasing at higher doses in female, but not in male hatchlings, suggesting that females may be more sensitive to BTBPE. However, there were no effects of TBBPA-BDBPE on the thyroid system in kestrels. For the BTPBE study, a subset of high-dose eggs was collected throughout the incubation period to measure changes in BTBPE concentrations. There was no decrease in BTBPE over the incubation period, suggesting that BTBPE is slowly metabolized by kestrel embryos throughout their ∼28-d development. These two compounds, therefore, do not appear to be particularly toxic to embryos of the American kestrel.

Morphological and physiological assessments reveal that freshwater turtle (Mauremys leprosa) can flourish under extremely degraded-polluted conditions

Freshwater turtles are long-lived sedentary organisms used as biological sentinels to assess anthropogenic perturbations in freshwater-ecosystems; notably because pollutants tend to accumulate in their tissues. Pollution has detrimental effects in sea turtles, but studies in freshwater turtles have provided contrasted results: several species have been impacted by habitat perturbation and pollution while others not. It is important to explore this issue since freshwater turtles are threatened worldwide. We compared two populations of the stripe necked terrapin (Mauremys leprosa) in a relatively pristine area (piedmont of the Atlas mountain) versus an extremely degraded-polluted area (sewers of a large city) in Morocco. All morphological and physiological proxies showed that turtles were able to cope remarkably well with highly degraded-polluted habitat. Population density, body size, and body condition were higher in the sewers, likely due to permanent water and food availability associated with human wastes. Stress markers (e.g. glucocorticoids) provided complex results likely reflecting the capacity of turtles to respond to various stressors. Reproductive parameters (testosterone level, indices of vitellogenesis) were lower in the relatively pristine area. The deceptive overall image provided by these analyses may hide the disastrous human impact on rivers. Indeed, Mauremys leprosa is the only aquatic vertebrate able to survive in the sewers, and thus, might nonetheless be a pertinent indicator of water quality, providing that the complexity of eco-physiological responses is considered.

A low dose of an organophosphate insecticide causes dysbiosis and sex-dependent responses in the intestinal microbiota of the Japanese quail (Coturnix japonica)

Organophosphate insecticides have been directly or indirectly implicated in avian populations declining worldwide. Birds in agricultural environments are commonly exposed to these insecticides, mainly through ingestion of invertebrates after insecticide application. Despite insecticide exposure in birds occurring mostly by ingestion, the impact of organophosphates on the avian digestive system has been poorly researched. In this work we used the Japanese quail (Coturnix japonica) as an avian model to study short-term microbial community responses to a single dose of trichlorfon at low concentration in three sample origins of the gastrointestinal tract (GIT): caecum, large intestine and faeces. Using next-generation sequencing of 16S rRNA gene amplicons as bacterial markers, the study showed that ingestion of insecticide caused significant changes in the GIT microbiome. Specifically, microbiota composition and diversity differed between treated and untreated quail. Insecticide-associated responses in the caecum showed differences between sexes which did not occur with the other sample types. In caecal microbiota, only treated females showed significant shifts in a number of genera within the Lachnospiraceae and the Enterobacteriaceae families. The major responses in the large intestine were a significant reduction in the genus Lactobacillus and increases in abundance of a number of Proteobacteria genera. All microbial shifts in faeces occurred in phylotypes that were represented at low relative abundances. In general, changes in microbiota possibly resulted from contrasting responses towards the insecticide, either positive (e.g., biodegrading bacteria) or negative (e.g., insecticide-susceptible bacteria). This study demonstrates the significant impact that organophosphate insecticides have on the avian gut microbiota; showing that a single small dose of trichlorfon caused dysbiosis in the GIT of the Japanese quail. Further research is necessary to understand the implications on birds’ health, especially in females.

HEMATOLOGY IN AN EASTERN MASSASAUGA (SISTRURUS CATENATUS) POPULATION AND THE EMERGENCE OF OPHIDIOMYCES IN ILLINOIS, USA

Disease events are threatening wildlife populations across North America. Specifically, mortality events due to Ophidiomyces (snake fungal disease; SFD) have been observed recently in snakes in Illinois, US. We investigated the health of a population of eastern massasaugas ( Sistrurus catenatus ) in south-central Illinois using 1) a meta-analysis of hematologic findings from 2004, 2011, 2013, and 2014; 2) a determination of the prevalence of SFD in snakes examined in 2013 and 2014; and 3) the examination of 184 museum specimens collected from 1999-2013 for signs and presence of SFD. For the meta-analysis and prevalence of SFD, hematologic analytes were reduced to three principle components that explained 67.5% of the cumulative variance. There were significant differences among one principle component (total white blood cell counts, monocytes, lymphocytes, and basophils) across years when it was highest in 2004 and 2014. The top general linear model explaining the difference in principle components included the main effects of year and stage, body condition index (BCI), and the interaction between stage and BCI. The prevalence of SFD was 18% (n=7) in 2013 and 24% (n=11) in 2014, and no hematologic analytes were associated with SFD. In museum specimens, Ophidiomyces DNA was first detected from an individual collected in 2000. Studies such as these, integrating multiple modalities of health, can elucidate the epidemiology of diseases that may pose conservation threats.