Spatiotemporal Trends Spanning Three Decades Show Toxic Levels of Chemical Contaminants in Marine Mammals.

Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures. Using one of the world's largest marine mammals strandings data sets, we combine published and unpublished data to examine pollutant concentrations in 11 species that stranded along the coast of Great Britain to quantify spatiotemporal trends over three decades and identify species and regions where pollutants pose the greatest threat. We find that although levels of pollutants have decreased overall, there is significant spatial and taxonomic heterogeneity such that pollutants remain a threat to biodiversity in several species and regions. Of individuals sampled within the most recent five years (2014-2018), 48% of individuals exhibited a concentration known to exceed toxic thresholds. Notably, pollutant concentrations are highest in long-lived, apex odontocetes (e.g., killer whales (Orcinus orca), bottlenose dolphins (Tursiops truncatus), and white-beaked dolphins (Lagenorhynchus albirostris)) and were significantly higher in animals that stranded on more industrialized coastlines. At the present concentrations, POPs are likely to be significantly impacting marine mammal health. We conclude that more effective international elimination and mitigation strategies are urgently needed to address this critical issue for the global ocean health.

Cetacean Intracytoplasmic Eosinophilic Globules: A Cytomorphological, Histological, Histochemical, Immunohistochemical, and Proteomic Characterization.

The nature, etiopathogenesis, and clinicopathologic relevance of the prevalent intracytoplasmic eosinophilic globules (IEGs) within hepatocytes of cetaceans are unknown. This study aims to evaluate the presence and characterize the IEGs in the hepatocytes of cetaceans using histochemical and immunohistochemical electron microscopy, Western blot, lectin histochemistry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry techniques. A total of 95/115 (83%) animals (16 species) exhibited histologically evident intracytoplasmic round to oval, single to multiple, hyaline eosinophilic globules within the hepatocytes. These globules were largely PAS-positive, diastase resistant, and were immunopositive for fibrinogen (FB, 97%), albumin (Alb, 85%), and α1-antitrypsine (A1AT, 53%). The IEG positivity for FB and A1AT were correlated with live-stranding, hepatic congestion and a good nutritional status. The cetaceans lacking IEGs were consistently dead stranded and had poor body conditions. The IEGs in 36 bycaught cetaceans were, all except one, FB-positive and A1AT-negative. The IEGs exhibited morphologic and compositional variations at the ultrastructural level, suggesting various stages of development and/or etiopathogenesis(es). The glycocalyx analysis suggested an FB- and A1AT-glycosylation pattern variability between cetaceans and other animals. The proteomic analyses confirmed an association between the IEGs and acute phase proteins, suggesting a relationship between acute stress (i.e., bycatch), disease, and cellular protective mechanisms, allowing pathologists to correlate this morphological change using the acute hepatocytic cell response under certain stress conditions.

Evaluation of a marine mammal status and trends contaminants indicator for European waters.

Marine mammals are vulnerable to the bioaccumulation, biomagnification and lactational transfer of specific types of pollutants, such as industrial polychlorinated biphenyls (PCBs), due to their long-life spans, feeding at a high trophic level and unique fat stores that can serve as depots for these lipophilic contaminants. Currently, European countries are developing indicators for monitoring pollutants in the marine environment and assessing the state of biodiversity, requirements under both Regional Seas Conventions and European legislation. As sentinel species for marine ecosystem and human health, marine mammals can be employed to assess bioaccumulated contaminants otherwise below current analytical detection limits in water and lower trophic level marine biota. To aid the development of Regional Seas marine mammal contaminants indicators, as well as Member States obligations under descriptor 8 of the EU Marine Strategy Framework Directive, the current study aims to further develop appropriate methodological standards using data collected by the established UK marine mammal pollutant monitoring programme (1990 to 2017) to assess the trends and status of PCBs in harbour porpoises. Within this case study, temporal trends of PCB blubber concentration in juvenile harbour porpoises were analysed using multiple linear regression models and toxicity thresholds for the onset of physiological (reproductive and immunological) endpoints were applied to all sex-maturity groups. Mean PCB blubber concentrations were observed to decline in all harbour porpoise Assessment Units and OSPAR Assessment Areas in UK waters. However, a high proportion of animals were exposed to concentrations deemed to be a toxicological threat, though the relative proportion declined in most Assessment Units/Areas over the last 10 years of the assessment. Recommendations were made for improving the quality of the assessment going forward, including detailing monitoring requirements for the successful implementation of such an indicator.

Interventions to Reduce Pesticide Exposure from the Agricultural Sector in Africa: A Workshop Report.

Despite the fact that several cases of unsafe pesticide use among farmers in different parts of Africa have been documented, there is limited evidence regarding which specific interventions are effective in reducing pesticide exposure and associated risks to human health and ecology. The overall goal of the African Pesticide Intervention Project (APsent) study is to better understand ongoing research and public health activities related to interventions in Africa through the implementation of suitable target-specific situations or use contexts. A systematic review of the scientific literature on pesticide intervention studies with a focus on Africa was conducted. This was followed by a qualitative survey among stakeholders involved in pesticide research or management in the African region to learn about barriers to and promoters of successful interventions. The project was concluded with an international workshop in November 2021, where a broad range of topics relevant to occupational and environmental health risks were discussed such as acute poisoning, street pesticides, switching to alternatives, or disposal of empty pesticide containers. Key areas of improvement identified were training on pesticide usage techniques, research on the effectiveness of interventions targeted at exposure reduction and/or behavioral changes, awareness raising, implementation of adequate policies, and enforcement of regulations and processes.

Budd-Chiari-like pathology in dolphins.

Nearly two decades ago, pathologic examination results suggested that acoustic factors, such as mid-frequency active naval military sonar (MFAS) could be the cause of acute decompression-like sickness in stranded beaked whales. Acute systemic gas embolism in these whales was reported together with enigmatic cystic liver lesions (CLL), characterized by intrahepatic encapsulated gas-filled cysts, tentatively interpreted as "gas-bubble" lesions in various other cetacean species. Here we provide a pathologic reinterpretation of CLL in odontocetes. Among 1,200 cetaceans necropsied, CLL were only observed in four striped dolphins (Stenella coeruleoalba), with a low prevalence (2%, N = 179). Together, our data strongly suggest that CLL are the result of the combination of a pre-existing or concomitant hepatic vascular disorder superimposed and exacerbated by gas bubbles, and clearly differ from acute systemic gas embolism in stranded beaked whales that is linked to MFAS. Budd-Chiari-like syndrome in dolphins is hypothesized based on the present pathologic findings. Nonetheless, further researched is warranted to determine precise etiopathogenesis(es) and contributing factors for CLL in cetaceans.

Systemic Erysipelothrix rhusiopathiae in seven free-ranging delphinids stranded in England and Wales.

Microbiology records for 1127 cetaceans stranded on English and Welsh beaches and examined at the Institute of Zoology between 1990 and 2019 were reviewed to identify cases of Erysipelothrix rhusiopathiae, an uncommon but potentially fatal zoonotic pathogen. Once cases were identified, prevalence was calculated, corresponding postmortem reports were reviewed, common gross and histopathological findings were identified, and antibiotic susceptibilities were determined. Overall prevalence for E. rhusiopathiae was 0.62% (7/1127; 95% CI: 0.30-1.28%). It was isolated from 3 bottlenose dolphins Tursiops truncatus, 3 harbor porpoises Phocoena phocoena, and 1 short-beaked common dolphin Delphinus delphis, with a prevalence of 21.4% (3/14; 95% CI: 7.6-47.9%), 0.39% (3/779; 95% CI: 0.13-1.13%), and 0.47% (1/212; 95% CI: 0.08-2.62%) for each species, respectively. E. rhusiopathiae resulted in septicemia in all cases from which it was isolated. Gross necropsy findings included pulmonary edema (5/7), hemorrhage (5/7) and/or congestion of various organs (4/7), and serosanguineous effusion (3/7; pericardial: 3/7, pleural: 2/6, abdominal: 2/6). Congestion (5/5), bacterial emboli (4/5), and hemorrhage (4/5) were commonly observed on histopathology, and acute renal tubular injury (2/5) and pulmonary edema (2/5) were occasionally observed. Routine bacterial cultures were vital in identifying E. rhusiopathiae, since gross lesions were often subtle and nonspecific. The liver, kidney, and brain were key organs from which E. rhusiopathiae was consistently isolated. Antibiotic resistance was uncommon and was only observed for amikacin and trimethoprim sulfonamide. Penicillins were consistently effective, along with fluoroquinolones, macrolides, clindamycin, cephalexin, and oxytetracycline.

Decompressive Pathology in Cetaceans Based on an Experimental Pathological Model.

Decompression sickness (DCS) is a widely known clinical syndrome in human medicine, mainly in divers, related to the formation of intravascular and extravascular gas bubbles. Gas embolism and decompression-like sickness have also been described in wild animals, such as cetaceans. It was hypothesized that adaptations to the marine environment protected them from DCS, but in 2003, decompression-like sickness was described for the first time in beaked whales, challenging this dogma. Since then, several episodes of mass strandings of beaked whales coincidental in time and space with naval maneuvers have been recorded and diagnosed with DCS. The diagnosis of human DCS is based on the presence of clinical symptoms and the detection of gas embolism by ultrasound, but in cetaceans, the diagnosis is limited to forensic investigations. For this reason, it is necessary to resort to experimental animal models to support the pathological diagnosis of DCS in cetaceans. The objective of this study is to validate the pathological results of cetaceans through an experimental rabbit model wherein a complete and detailed histopathological analysis was performed. Gross and histopathological results were very similar in the experimental animal model compared to stranded cetaceans with DCS, with the presence of gas embolism systemically distributed as well as emphysema and hemorrhages as primary lesions in different organs. The experimental data reinforces the pathological findings found in cetaceans with DCS as well as the hypothesis that individuality plays an essential role in DCS, as it has previously been proposed in animal models and human diving medicine.

Novel Presentation of DMV-Associated Encephalitis in a Long-Finned Pilot Whale (Globicephala melas).

Cetacean morbillivirus (CeMV) is an important global cause of morbidity and mortality in cetacean populations, with four pathological presentations including non-suppurative encephalitis. We describe an unusual case of dolphin morbillivirus (DMV)-associated non-suppurative encephalitis in a long-finned pilot whale (Globicephala melas), in which the lesions were orientated on the periventricular white matter and comprised prominent multifocal syncytia formation in the absence of systemic lesions. DMV RNA was detected in brain tissue by qRT-PCR and immunohistochemistry for morbillivirus antigen yielded intense labelling of syncytia in periventricular sites, with sparse involvement of the deeper neuroparenchyma. The pattern of lesions raises the possibility of viral dissemination through the cerebrospinal fluid, as described for canine distemper virus, suggesting that similar pathogenic mechanisms may be implicated in lesion development. Further investigation is required to establish the pathogenesis of CeMV encephalitis and the behaviour of the virus within the central nervous system of cetaceans.

Uncovering assets in Brazilian national parks.

Protected areas (PAs) are the cornerstone of global conservation policy and have expanded dramatically over the last century. Though unequivocally beneficial for biodiversity, gazetting land for protecting nature can also be seen as an 'opportunity cost' that some politicians are unwilling to pay. One of the most effective strategies to increase the political resilience of PAs in the face of such threats is to demonstrate their broader value to society. This is one of the objectives of the recently proposed 'PA asset framework'. The framework conceptualizes PAs as being composed of suites of biophysical, human, infrastructure, institutional and cultural assets that interact with individuals and institutions to generate different forms of tangible and intangible value. Here, we test the utility of the framework by conducting an asset-based analysis of Brazilian National Parks (NPs) at two different scales (NP system and NP unit). Assets were identified at the system level through a systematic review of 49 Management Plans (MPs) using a typology of PA asset classes as a tool for characterising the presence and state of assets in or associated with NPs. At the NP unit level, assets were identified through semi-structured interviews with local managers of the Chapada Diamantina National Park. Biophysical and infrastructure assets were the most represented asset classes at both scales. Our analysis successfully revealed: (i) which assets can be managed to generate wider forms of values at local scale (e.g. natural spectacles, iconic species, park volunteers) (ii) relational values between assets (e.g. trails and outdoor recreational features), and (iii) value generating practices (VGPs) to capture values from the interaction between different assets (i.e. restoration of degraded areas through voluntary programmes, etc.). We conclude by discussing how the PA asset framework can be operatively integrated into NP management to improve the future allocation of limited financial resources.

Polychlorinated biphenyls are associated with reduced testes weights in harbour porpoises (Phocoena phocoena).

Polychlorinated biphenyls (PCBs) are highly toxic and persistent aquatic pollutants that are known to bioaccumulate in a variety of marine mammals. They have been associated with reduced recruitment rates and population declines in multiple species. Evidence to date documents effects of PCB exposures on female reproduction, but few studies have investigated whether PCB exposure impacts male fertility. Using blubber tissue samples of 99 adult and 168 juvenile UK-stranded harbour porpoises (Phocoena phocoena) collected between 1991 and 2017, here we show that PCBs exposures are associated with reduced testes weights in adults with good body condition. In animals with poor body condition, however, the impact of PCBs on testes weights was reduced, conceivably due to testes weights being limited by nutritional stress. This is the first study to investigate the relationship between PCB contaminant burden and testes weights in cetaceans and represents a substantial advance in our understanding of the relationship between PCB exposures and male reproductive biology in cetaceans. As testes weight is a strong indicator of male fertility in seasonally breeding mammals, we suggest the inclusion of such effects in population level impact assessments involving PCB exposures. Given the re-emergent PCB threat our findings are globally significant, with potentially serious implications for long-lived mammals. We show that more effective PCB controls could have a substantial impact on the reproductive health of coastal cetacean species and that management actions may need to be escalated to ensure adequate protection of the most vulnerable cetacean populations.

iEcology: Harnessing Large Online Resources to Generate Ecological Insights.

Digital data are accumulating at unprecedented rates. These contain a lot of information about the natural world, some of which can be used to answer key ecological questions. Here, we introduce iEcology (i.e., internet ecology), an emerging research approach that uses diverse online data sources and methods to generate insights about species distribution over space and time, interactions and dynamics of organisms and their environment, and anthropogenic impacts. We review iEcology data sources and methods, and provide examples of potential research applications. We also outline approaches to reduce potential biases and improve reliability and applicability. As technologies and expertise improve, and costs diminish, iEcology will become an increasingly important means to gain novel insights into the natural world.

Selection of pesticides to reduce human and environmental health risks: a global guideline and minimum pesticides list.

BACKGROUND: Pesticides present widespread risks to human and environmental health, yet selection criteria for end-users that factor in differences in risk between compounds are scant. We developed a system to classify pesticide risks and hazards with respect to human and environmental health and produce a minimum (lower risk) pesticide list. METHODS: We classified 659 pesticides by acute and chronic risks to human health (eg, respiratory and carcinogenic effects) and by environmental risks, including biomagnification and atmospheric ozone depletion and risks to aquatic life, terrestrial wildlife, and pollinators. From this analysis, we produced a guideline for selection of lower risk pesticides. The classification of highly hazardous and high-risk compounds has been tested in more than a million farm households in the tropics, and in US integrated pest management (IPM) programmes. The full classification, including the minimum pesticide list, has been used in management of the fall armyworm (Spodoptera frugiperda) throughout Africa and Asia. FINDINGS: Our analysis developed a stand-alone guideline for selection of lower risk pesticides. When classifying pesticides in current use against the fall armyworm in Africa, our guideline identified chemicals that are effective and of lower risk to human and environmental health. We argue that a minimum (lower risk) pesticides list, which meets IPM needs, could be developed from our classification system. INTERPRETATION: As far as we are aware, our analysis is the first to propose a method for implementing the idea of a minimum pesticide list and the first to outline lower risk candidate compounds. Currently accepted criteria for defining highly hazardous pesticides do not adequately protect human bystanders, aquatic life, terrestrial wildlife, and pollinators. FUNDING: The Sustainable Agriculture Network, the Rainforest Alliance, the US Department of Agriculture-National Institute of Food and Agriculture, the US Department of Agriculture, the Foreign Agricultural Service, the US Agency for International Development, the International Maize and Wheat Improvement Center, and the UN Food and Agriculture Organization.

Levels of Polychlorinated Biphenyls Are Still Associated with Toxic Effects in Harbor Porpoises (Phocoena phocoena) Despite Having Fallen below Proposed Toxicity Thresholds.

Polychlorinated biphenyls (PCBs) are toxic, persistent, and lipophilic chemical compounds that accumulate to high levels in harbor porpoises (Phocoena phocoena) and other cetaceans. It is important to monitor PCBs in wildlife, particularly in highly exposed populations to understand if concentrations are declining and how levels relate to toxicological thresholds and indices of health like infectious disease mortality. Here we show, using generalized additive models and tissue samples of 814 U.K.-stranded harbor porpoises collected between 1990 and 2017, that mean blubber PCB concentrations have fallen below the proposed thresholds for toxic effects. However, we found they are still associated with increased rates of infectious disease mortality such that an increase in PCB blubber concentrations of 1 mg kg-1 lipid corresponds with a 5% increase in risk of infectious disease mortality. Moreover, rates of decline and levels varied geographically, and the overall rate of decline is slow in comparison to other pollutants. We believe this is evidence of long-term preservation in the population and continued environmental contamination from diffuse sources. Our findings have serious implications for the management of PCB contamination in the U.K. and reinforce the need to prevent PCBs entering the marine environment to ensure that levels continue to decline.

Pleistocene Arctic megafaunal ecological engineering as a natural climate solution?

Natural climate solutions (NCS) in the Arctic hold the potential to be implemented at a scale able to substantially affect the global climate. The strong feedbacks between carbon-rich permafrost, climate and herbivory suggest an NCS consisting of reverting the current wet/moist moss and shrub-dominated tundra and the sparse forest-tundra ecotone to grassland through a guild of large herbivores. Grassland-dominated systems might delay permafrost thaw and reduce carbon emissions-especially in Yedoma regions, while increasing carbon capture through increased productivity and grass and forb deep root systems. Here we review the environmental context of megafaunal ecological engineering in the Arctic; explore the mechanisms through which it can help mitigate climate change; and estimate its potential-based on bison and horse, with the aim of evaluating the feasibility of generating an ecosystem shift that is economically viable in terms of carbon benefits and of sufficient scale to play a significant role in global climate change mitigation. Assuming a megafaunal-driven ecosystem shift we find support for a megafauna-based arctic NCS yielding substantial income in carbon markets. However, scaling up such projects to have a significant effect on the global climate is challenging given the large number of animals required over a short period of time. A first-cut business plan is presented based on practical information-costs and infrastructure-from Pleistocene Park (northeastern Yakutia, Russia). A 10 yr experimental phase incorporating three separate introductions of herds of approximately 1000 individuals each is costed at US$114 million, with potential returns of approximately 0.3-0.4% yr-1 towards the end of the period, and greater than 1% yr-1 after it. Institutional friction and the potential role of new technologies in the reintroductions are discussed. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.

Phylogenomic Resolution of the Cetacean Tree of Life Using Target Sequence Capture.

The evolution of cetaceans, from their early transition to an aquatic lifestyle to their subsequent diversification, has been the subject of numerous studies. However, although the higher-level relationships among cetacean families have been largely settled, several aspects of the systematics within these groups remain unresolved. Problematic clades include the oceanic dolphins (37 spp.), which have experienced a recent rapid radiation, and the beaked whales (22 spp.), which have not been investigated in detail using nuclear loci. The combined application of high-throughput sequencing with techniques that target specific genomic sequences provide a powerful means of rapidly generating large volumes of orthologous sequence data for use in phylogenomic studies. To elucidate the phylogenetic relationships within the Cetacea, we combined sequence capture with Illumina sequencing to generate data for $\sim $3200 protein-coding genes for 68 cetacean species and their close relatives including the pygmy hippopotamus. By combining data from $>$38,000 exons with existing sequences from 11 cetaceans and seven outgroup taxa, we produced the first comprehensive comparative genomic data set for cetaceans, spanning 6,527,596 aligned base pairs (bp) and 89 taxa. Phylogenetic trees reconstructed with maximum likelihood and Bayesian inference of concatenated loci, as well as with coalescence analyses of individual gene trees, produced mostly concordant and well-supported trees. Our results completely resolve the relationships among beaked whales as well as the contentious relationships among oceanic dolphins, especially the problematic subfamily Delphinidae. We carried out Bayesian estimation of species divergence times using MCMCTree and compared our complete data set to a subset of clocklike genes. Analyses using the complete data set consistently showed less variance in divergence times than the reduced data set. In addition, integration of new fossils (e.g., Mystacodon selenensis) indicates that the diversification of Crown Cetacea began before the Late Eocene and the divergence of Crown Delphinidae as early as the Middle Miocene. [Cetaceans; phylogenomics; Delphinidae; Ziphiidae; dolphins; whales.].

Juvenile harbor porpoises in the UK are exposed to a more neurotoxic mixture of polychlorinated biphenyls than adults.

Polychlorinated biphenyls (PCBs) are a group of 209 persistent and bio-accumulative toxic pollutants present as complex mixtures in human and animal tissues. Harbor porpoises accumulate some of the highest levels of PCBs because they are long-lived mammals that feed at a high trophic level. Studies typically use the sum of a suite of individual chlorobiphenyl congeners (CBs) to investigate PCBs in wildlife. However, toxic effects and thresholds of CB congeners differ, therefore population health risks of exposure may be under or over-estimated dependent on the congener profiles present. In this study, we found congener profiles varied with age, sex and location, particularly between adult females and juveniles. We found that adult females had the highest proportions of octa-chlorinated congeners whilst juveniles had the highest proportions of tri- and tetra-chlorinated congeners. This is likely to be a consequence of pollutant offloading between mothers and calves during lactation. Analysis of the individual congener toxicities found that juveniles were exposed to a more neurotoxic CB mixture at a time when they were most vulnerable to its effects. These findings are an important contribution towards our understanding of variation in congener profiles and the potential effects and threats of PCB exposure in cetaceans.

Forensic microbiology reveals that Neisseria animaloris infections in harbour porpoises follow traumatic injuries by grey seals.

Neisseria animaloris is considered to be a commensal of the canine and feline oral cavities. It is able to cause systemic infections in animals as well as humans, usually after a biting trauma has occurred. We recovered N. animaloris from chronically inflamed bite wounds on pectoral fins and tailstocks, from lungs and other internal organs of eight harbour porpoises. Gross and histopathological evidence suggest that fatal disseminated N. animaloris infections had occurred due to traumatic injury from grey seals. We therefore conclude that these porpoises survived a grey seal predatory attack, with the bite lesions representing the subsequent portal of entry for bacteria to infect the animals causing abscesses in multiple tissues, and eventually death. We demonstrate that forensic microbiology provides a useful tool for linking a perpetrator to its victim. Moreover, N. animaloris should be added to the list of potential zoonotic bacteria following interactions with seals, as the finding of systemic transfer to the lungs and other tissues of the harbour porpoises may suggest a potential to do likewise in humans.

Are Protected Areas undervalued? An asset-based analysis of Brazilian Protected Area Management Plans.

When effectively managed, Protected Areas (PAs) are capable of generating multiple forms of value, both tangible and intangible, for individuals and institutions. However, the value-generating potential of many PAs may be going unrecognized and underutilized due to a limited view of management objectives as codified within the parks' Management Plan. Here, we test the hypothesis that PAs are undervalued by evaluating the degree to which Management Plans from four different Brazilian designations (National Parks, Ecological Stations, Environmental Protected Areas and National Forests) recognize different categories of nature-related assets (entities, attributes and relationships that can be protected, managed and/or invested in to generate forms of value). Based on a recently proposed PA Asset Framework, we identify what assets are mentioned by Management Plans and what assets are under-represented. Our results indicate that Human and Cultural assets are the least represented of the major asset classes (Biophysical, Human, Infrastructural, Institutional and Cultural) and that many asset sub-categories that should reasonably be expected to be present in Management Plans are frequently not mentioned. Assets that are not being considered in Management Plans are, by extension, less likely to be managed and/or invested in. Given the strong similarities between PA Management Plans in different countries, these results probably reflect a general trend. A simple way to ensure that PAs maximize the value generating potential (within the context of their designation) would be to survey their assets and generate a 'PA Asset Management and Investment Plan' to supplement and support existing planning documentation.