Shallow diving air-breathing animals face the challenge of maximising oxygen stores to extend dive duration while being subject to rapid pressure changes, especially in the first 10 m. Buoyancy control is integral to managing the physiological and physical challenges of shallow water diving. Dugongs (Dugong dugon) are shallow diving megaherbivores and must spend extended periods foraging on shallow benthic seagrass communities. Thus, balancing the locomotor activity associated with diving and limited oxygen stores is critical for dugongs, making the dugong a valuable model for investigating buoyancy control in shallow diving marine mammals. We used multi-sensor tags to investigate the buoyancy control of seven mature dugongs (three female, four male; deployments lasting 10–35 hours) in New Caledonia, 2019 (n=2) and the Exmouth Gulf, Western Australia, 2021 (n=5). Our study demonstrates that dugongs regulate their buoyancy by controlling their inhaled lung volume prior to diving, a strategy that contrasts with some other deeper diving marine mammals (e.g. phocid seals), which dive on exhalation. For the dugongs, the depth at which gliding commenced, a proxy for the animal’s buoyancy shifting from positive to negative, increased with maximum dive depth during descent and ascent. This is a strong indication for inhaled air volume increasing with maximum dive depth. Body angle, fluke beat frequency and activity during descents and ascents increased in unison. This evidence suggests that dugongs utilise lung-mediated buoyancy control to maximise the time spent at depth, while minimising the locomotory costs associated with buoyancy while diving.

The ingestion of plastic debris has been reported in all seven marine turtle species, affecting vital processes throughout their entire life cycle and key habitats. Consequently, this emerging threat has been recognized as a priority conservation concern. The potential health impacts range from cryptic sublethal effects to severe injury and death. A comprehensive understanding of these impacts and the processes involved, at both the individual and population levels, is crucial for evaluating the vulnerability of marine turtles to plastic pollution. Aiming to guide researchers and stakeholders from the initial stages of project development, this study discusses essential components for establishing and achieving research on plastic ingestion in marine turtles. Drawing on diverse efforts globally, this manuscript compiles the most common approaches and established methodologies, while evaluating resource availability and capabilities, to outline a globally applicable best practice framework for designing and implementing research and monitoring initiatives on plastic ingestion impacts to marine turtles.

The Sindhudurg coast in Maharashtra, India, supports diverse fisheries and is a vital habitat for the Indian Ocean humpback dolphin Sousa plumbea , a species found nearshore along the west coast of India. Here, dolphins cause economic losses to fishermen by competing for catch and damaging fishing gear. Dolphins are also affected by entanglement in or ingestion of parts of fishing nets. There is a need for a systematic assessment of the distribution of risks to dolphins and the specific fisheries most impacted by interactions with dolphins. To bridge this information gap, we (1) analysed the behaviour and locations of dolphin groups in the absence and presence of fishing vessels (2012-2015) and (2) mapped the spatial overlap of dolphins and fishing vessels (2014-2015) to determine high-risk areas for dolphins. We observed 175 dolphin groups, of which 75 groups (43%) engaged in foraging behaviours. Dolphins occurred in approximately 50% (164 km 2 ) of the total survey area, and fishing vessels were observed in 100% of the total survey area (333 km 2 ). The proportion of dolphin groups engaged in foraging behaviours was significantly higher when fishing vessels were present compared to when absent. Gillnet (55%) and trawl (32%) accounted for the majority of observed fishing vessels when dolphins were present. Gillnet vessels had a 95% spatial overlap with dolphin habitat, and trawl and purse-seine vessels each had 86%. We identified 8 high-risk areas that were within ~500 m of the coastline, coinciding with high-density dolphin habitat near estuaries. These results have the potential to inform marine mammal conservation and fishery management in Sindhudurg.

The Great Barrier Reef (GBR) region supports globally significant populations of the dugong, a medium-sized coastal marine mammal and a seagrass community specialist. The dugong has evolved morphological and sensory adaptations to its life as a strictly marine herbivore, and its perceptions of its environment are very different from those of other marine mammals in the region. Dugongs perceive their environment largely through touch, hydrodynamic reception, and hearing; vision and taste are less important components of their sensory repertoire, and it is likely that dugongs have very limited capacity to smell. Dugongs also apparently rely on socially transmitted knowledge learned from their mothers during the years of calf dependency. They have good spatial cognition. The important elements of their biophysical environment include the drivers of the distribution, abundance, species composition, biomass of seagrass communities, and the environmental parameters that influence dugongs directly such as water depth, light, temperature, tides, waves, currents, coastline features, and predation risk. The most profound effects of climate change on dugongs in the GBR are likely to be short- and long-term changes to the distribution, species composition, and biomass of seagrass habitats, which, in turn, will affect dugong life history parameters, movements, and habitat use. Multidisciplinary research is required to progress our understanding of the interactions between dugongs and their biophysical environment. This research should include (1) modelling to investigate the relationships between the distribution and relative abundance of dugongs and seagrass presence, biomass, community type, and environmental parameters; (2) anatomical studies of the dugong sensory structures relevant to its ecology; (3) investigations of the sensory capacities of captive animals; and (4) field studies of (a) the effects of feeding, particularly in cropping mode, on the biomass, community structure, and nutritional qualities of various seagrass species and (b) presence (using eDNA), movements, diving behavior, habitat use (using telemetry tags), vocalizations, three-dimensional habitat use, and social interactions (using acoustic receivers).

Context The dynamic habitat use by dugongs (Dugong dugon) in small coral reef lagoon systems spatially limited by tides is not well understood and has hampered adaptive management. Aims We investigated how dugongs locally used a high conservation value coral-reef lagoon system during different seasons and tides to support local management. Methods We conducted local-scale aerial surveys to document the seasonal and tidal changes in the distribution and number of dugongs over seagrass and non-seagrass coral reef habitats in a small lagoon in New Caledonia. The surveys were conducted fortnightly over 18 months in different seasons and at different tides. Temperature loggers and existing local footage of dugong herding behaviour were used to study the habitat use and behaviour of the animals in the area. Key results More dugongs were sighted in Cap Goulvain during the cool season than during the warm season. As tides restricted access to the intertidal seagrass meadows and during the cool season, more dugongs were sighted outside the lagoon on the fore reef shelf outside the lagoon. Dugongs were resting in large aggregations during their use of this non-seagrass habitat. Conclusions Our study emphasises the importance of non-seagrass habitats for dugongs in spatially restricted coral reef environments as well as the importance of considering outer lagoon habitats as key dugong management areas. This study also adds evidence of behavioural thermoregulation in dugongs. Implications The development of dynamic management strategies is essential, especially where different habitats should be protected at different times of the year.

Context and challenges The Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) focuses Australian Government interests on the protection of matters of national environmental significance. Many of these matters were affected by the 2019-20 wildfires. Given the impacts of these fires, responses to prevent extinction and support recovery needed to be made urgently and targeted towards those species and ecological communities that were in most need of such management. Determining this response required rapid assessment of impacts. Main findings The Australian Government committed an initial $2 billion National Bushfire Recovery Fund to support a wide range of responses to the 2019-20 wildfires; this included a $200 million investment for the recovery of native wildlife and their habitats. This funding provided the foundational support for many post-fire emergency responses to prevent extinction and support recovery of fire-affected species and ecological communities. The Australian Government responded rapidly to the biodiversity losses caused by the 2019-20 wildfires. This response was characterised by a high degree of consultation and collaboration with state/territory conservation agencies, conservation non-government organisations (NGOs), researchers and many other stakeholders. The response was substantially informed by an independent advisory panel established by the Minister for the Environment. Largely as informed by this panel, the Australian Government Department of Agriculture, Water and the Environment ('the Department') rapidly developed priority listings of the ecological communities, plants and animals that were most affected by the 2019-20 wildfires, with such listings then used to help allocate investments in recovery efforts. The Australian Government undertook a series of regional consultative workshops in the most fire-affected areas to develop, fund and implement priority actions at regional scale for the recovery of fire-affected biodiversity. The Australian Government supported the independent Threatened Species Scientific Committee to prioritise and undertake an expedited assessment of the conservation status of a large set of fire-affected species and ecological communities most in need of conservation and management. The Australian Government established a Royal Commission into National Natural Disaster Arrangements, and the Department's evidence encompassed the impacts of the fires on biodiversity, measures to reduce impacts of future fires and assist recovery, the respective roles of the Commonwealth and the states in environmental management, and options for improvement around data, mapping, and species distribution modelling. These contributions to the Commission were one way in which the biodiversity impacts, issues and response were integrated with broader policy considerations following the fires. The Australian Government supported in principle the Commission's recommendation relating to biodiversity. The Department worked closely with the National Bushfire Recovery Agency (now National Recovery and Resilience Agency) to maintain a focus on biodiversity impacts and response among other Australian Government actions. Recognising that shortcomings in national coordination and availability of critical data constrained assessment of the impacts of these fires on biodiversity, the Australian Government supported a suite of projects and initiatives to improve data availability and fill some key knowledge gaps. Such evidence will increase preparedness for any future comparable event.

Despite the lack of obvious physical barriers and their ability to travel significant distances, many marine mammals exhibit substantial population structuring over relatively short geographical distances. The dugong (Dugong dugon), the only extant representative of family Dugongidae, is listed as Vulnerable to Extinction globally. We investigated the genetic population structure of dugongs in the shallow coastal waters along >2,000 km of the eastern Queensland coast, including the Great Barrier Reef region. Microsatellite genotypes for 22 loci in 293 dugongs, SNP genotypes based on 10,690 loci in 43 dugongs, and 410 bp mitochondrial control-region sequences from 639 dugongs were analyzed. Clustering analysis techniques consistently identified an abrupt genetic break in the Whitsunday Islands region (20.3 degrees S), which interrupts an overall pattern of isolation-by-distance. Geographic distance was relatively more important than sea-surface temperature and seagrass distribution in explaining pairwise microsatellite genetic distances. The cause of reduced dispersal across this region is unknown but might relate to an unusual tidal and current mix, termed the "sticky-water" effect, and/or a break in the geographical distribution of off-shore seagrass meadows. The genetic structure suggests distinct breeding units north and south of the Whitsunday Islands region for consideration in further developing management plans for Queensland dugongs.

The ivory trade is of global interest due to its impacts on elephant conservation. Thailand permits the domestic trade of ivory from domesticated elephants. Knowledge of the supply chain is important for managing this market in order to achieve sustainable benefits for both wildlife conservation and human livelihoods. We interviewed elephant owners and ivory manufacturers to conduct an analysis of the Thai ivory supply chain. Five key actor groups operate in this supply chain: elephant owners, intermediaries, manufacturers, retailers, and ivory consumers. Factors influencing the supply of raw ivory vary with harvesting, use, and sale destination but the financial needs of elephant owners and market factors are particularly influential. Elephant owner decisions also depend on elephant management, sentimental values, ivory beliefs, tusk forms, and legal awareness. These findings have the potential to inform the design of monitoring the Thai ivory market.

The General Assembly of States Parties to the World Heritage Convention adopted a policy and strategy on climate change in 2007. Many of its actions remain to be delivered. Climate change has highlighted the limits of a system under stress to respond to an immense challenge. The General Assembly is again considering the issue, and a second World Heritage climate change policy is being developed to provide high-level guidance on response measures. The draft second policy emphasises the role of individual States Parties in addressing climate impacts on their World Heritage sites but says less about the responsibilities of the World Heritage Committee, World Heritage Centre or Advisory Bodies to the Convention in meeting the goals of climate action and achieving an equitable, international and shared response. Nor does it tackle issues related to Outstanding Universal Value, the core of any response to climate change. We develop a conceptual framework for substantive reform and propose actions to enable the World Heritage system to effectively respond to climate change and support the resolution of longstanding, systemic issues. Meaningful response to climate change needs to involve strategic as well as operational elements in a staged response with measurable outcomes and outputs.

Marine mammal interactions with fisheries, such as bycatch and depredation, are a common occurrence across commercial and small-scale fisheries. We conducted a systematic review to assess the management responses to marine mammal interactions with fisheries. We analyzed literature between 1995 and 2021 to measure research trends in studies on direct and indirect interactions for: (i) high and low to middle-income countries, (ii) fishery operations (commercial and small-scale), and (iii) taxonomic groups. Management responses were categorized using the framework described previously in peer-reviewed studies. Marine mammal bycatch remains a major conservation concern, followed by marine mammal depredation of fishing gear. A high proportion of studies concentrated on commercial fisheries in high-income countries, with an increase in small-scale fisheries in low to middle-income countries between 1999 and 2020. The insufficient understanding of the social dimensions of interactions and the inevitable uncertainties concerning animal and human behaviors are major challenges to effective management. Despite the key role of human behavior and socioeconomics, we found only eight articles that incorporate human dimensions in the management context. Integrating social dimensions of marine mammal interactions with fisheries could help in setting pragmatic conservation priorities based on enhanced understanding of critical knowledge gaps. An area-specific adaptive management framework could be an effective tool in reducing the risk to marine mammals from fisheries by coupling technical solutions with socio-economic and political interventions. We conclude that despite the vast body of literature on this subject, a “silver bullet” management solution to marine mammal interactions with fisheries does not yet exist.

Wild animals are captured or taken opportunistically, and the meat, body parts, and/or eggs are consumed for local subsistence or used for traditional purposes to some extent across most of the world, particularly in the tropics and subtropics. The consumption of aquatic animals is widespread, in some places has been sustained for millennia, and can be an important source of nutrition, income, and cultural identity to communities. Yet, economic opportunities to exploit wildlife at higher levels have led to unsustainable exploitation of some species. In the literature, there has been limited focus on the exploitation of aquatic non-fish animals for food and other purposes. Understanding the scope and potential threat of aquatic wild meat exploitation is an important first step toward appropriate inclusion on the international policy and conservation management agenda. Here, we conduct a review of the literature, and present an overview of the contemporary use of aquatic megafauna (cetaceans, sirenians, chelonians, and crocodylians) in the global tropics and subtropics, for species listed on the Appendices of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). We find that consumption of aquatic megafauna is widespread in coastal regions, although to varying degrees, and that some species are likely to be at risk from overexploitation, particularly riverine megafauna. Finally, we provide recommendations for CMS in the context of the mandate of the Aquatic Wild Meat Working Group.

Sirenians are culturally significant to traditional and contemporary human communities throughout their ranges. They live in tropical and sub-tropical coastal, riverine, and lacustrine habitatsHabitats,, including many sites of high human use. ManateesManatee and dugongsDugong (Dugong dugon) nurse their calves over prolonged periods via axillary teatsAxillary Teats and their mammary glandsMammary glands have often been likened to human breasts, fostering the widespread belief that sirenians are the basis of mermaidMermaid myths and much folkloreFolklore and magic. For thousands of years, humans have used their knowledge of the predictabilityPredictability of sirenian habitatHabitats, use and behavior, to captureCapture them for their meat and other products using simple equipment such as a harpoonHarpoon. Nonetheless, the acuity of sirenian hearing means that capturing them requires specialized skills, and many cultures have developed complex captureCapture ritualsRitual. Sirenians do not require wilderness per se and can persist in highly disturbed habitatsHabitats,. DugongsDugong (Dugong dugon) and manateesManatee can be both wary and curious. Some curious animals initiate interactions with fishers and divers. ManateesManatee are highly tactile, chew on lines, and manipulate them with their flippers. The predictable nature of sirenian behavior and habitatHabitats, use increases their likelihood of encountering, tangling, and dying in fishing gears, particularly gill netsNets gill nets , a major cause of mortalityMortality. Swim-with-sirenian programs have developed in some areas with clear water and some habituatedHabituated animals have become local tourist attractions. Sirenians, particularly Florida manateesFlorida manatee (Trichechus Manatus Latirostris), are vulnerable to injury and mortalityMortality from vessel strikes. Almost all adult Florida manateesFlorida manatee (Trichechus Manatus Latirostris) bear scars from such encounters, with about a quarter showing evidence of being hit on at least ten occasions. Sirenians accumulate contaminantsContaminants because they feed on large quantities of aquatic plants. However, none of the persistent contaminantsContaminants identified in sirenian tissues have been definitively associated with mortalityMortality, morbidity or changes in behavior. Anecdotal information suggests that sirenians give birthParturition (Birth) in quiet shallow waters and exhibit natal philopatryNatal philopatry. The lossLoss, of traditional birthingBirthing and rearing habitatsHabitats, has apparently increased the risk of dependent calves becoming separated from their mothers and subsequently stranding. DugongsDugong (Dugong dugon) and manateesManatee exhibit behavioral thermoregulationThermoregulation behavioral at the high latitude limits of their ranges. Florida manateesFlorida manatee (Trichechus Manatus Latirostris) form transient aggregationsAggregation in natural and artificial warm water sanctuariesRefuge (sanctuary), the latter resulting in the animals coming into close contact with industrial facilities. Amazonian and African manateesAfrican manatee (Trichechus senegalensis) living in floodplain environments make seasonal migrations along rivers. DamsDams isolate populations and prevent animals from reaching their feedingFeeding and breeding grounds. Despite the frequency and variety of interactions between humans and sirenians, large gaps persist in our understanding of sirenian ethology and behavioral ecology in relation to human activitiesActivity.

The legal and moral imperatives for incorporating indigenous knowledge into natural resource management are now widely recognized. Many consider the integration of indigenous knowledge to be an essential component of successful solutions for conserving resources valued by indigenous peoples, including marine mammals. The effective integration of indigenous knowledge requires an understanding of what it is. Indigenous elders from five very different parts of the world briefly explain their knowledge of local marine mammals including: ika-moana (large whales) of Aotearoa, New Zealand; dhangal (dugongs) of Torres Strait between northern Australia and Papua New Guinea; river dolphins and manatees of Amazonia; beluga whales, Atlantic walrus, bearded seals and harp seals of the Nunavik region of north Quebec in the Canadian Arctic; and sea otters, spotted or larga seals, northern fur seals and Steller sea lions of the Commander Islands, Russia. These accounts illustrate the complexity and temporal dynamism of indigenous knowledge. To help identify the themes in these accounts, we used an extension of Houde's typology (in Ecol Soc 12(2):34, 2007) of indigenous knowledge, which we envisaged as a hexagon with worldview at the core and cosmology, factual observations, management systems, past and present uses, ethics and values, and culture and identity on its faces. We hope that this chapter will help marine mammal scientists who work in research partnerships with indigenous peoples, to build trust, respect, and mutual understanding of each other’s knowledge systems. This understanding should help marine mammal scientists to work successfully across the “cultural interface to achieve true progress in marine mammal conservation and coexistence.”

Aim:Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW). Location:Global. Taxon:All extant mammal species. Methods:Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species). Results:Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use. Main conclusion:Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

The Asian elephant Elephas maximus is of cultural significance for the Thai people. The development of legal protection for elephants in Thailand dates back to the 17th century, reflecting concerns about both human livelihoods and elephant conservation. The legal status of privately owned, captive elephants differs from that of wild individuals, with consequences for the lawful use of ivory from captive animals. Prior to 2015, the lack of comprehensive measures to control the Thai ivory market enabled the laundering of illegally sourced ivory in the country. The Thai government introduced legal reforms in 2015, imposing strict controls over the possession and domestic trade of ivory from captive Asian elephants, and aligning the protection of African elephants and their ivory with CITES regulations. Nonetheless, the sustainable use of Thai ivory remains disputed, and international pressure to close the commercial trade in domestic ivory persists. Here we review this complex situation, aiming to inform future reforms. Consolidation of laws related to elephants and ivory would facilitate law enforcement and compliance. Use of an electronic database would improve the monitoring of ivory movements and aid the implementation and enforcement of laws.

Climate changeClimate change stressors are already affecting the subtropical and tropical coastal, estuarine, and riverine habitatsHabitats, of sirenians with consequential changes to their ethology and behavioral ecology. Climate changeClimate change is causing temperature increases, sea level riseSea level rise, changes in water chemistryWater chemistry and qualityWater quality, increase in the intensity and nature of extreme weather eventsExtreme weather events, and changes in rainfall patternsPatterns,. These stressors are predicted to increase over the coming decades and will be exacerbated by co-stressorsCo-stressor including harmful algal bloomsHarmful Algal Blooms (HABS), damDams construction, hardeningCoastal hardening coastlines, phasing out coastal power plantsPower plant, land clearingLand clearing, and human food insecurityHuman food insecurity. The cumulative impactsCumulative impacts on all sirenian habitatsHabitats, will be locally variable but changes in habitatHabitats, extent and continuity are likely to be widespread. Important features of some key manateeManatee habitatsHabitats, such as warm water refugesRefuge (sanctuary), freshwater sources, and navigable migration routesMigration routes are expected to be reduced or lost. ForagingForaging and movement behaviorsMovement behavior of all species will change in response to alterations in community composition of feedingFeeding habitatsHabitats,, and the temporary lossLoss, of such habitatsHabitats, resulting from the increased intensity of extreme events, including the expansion of polar vorticesPolar vortex, marine heatwavesMarine heatwave, tropical cyclonesCyclones, floodsFlood, droughtsDrought, and harmful algal bloomsHarmful Algal Blooms (HABS). These extreme events are expected to increase sirenian mortalityMortality and reduce fecundityFecundity, local population sizePopulation size, and genetic diversityGenetic diversity. The locations of essential resources and the cues triggering the timingMovement timing of movements are expected to alter rapidly as the climate changesClimate change. Some coastal habitatsCoastal habitats may become unsuitable for manateesManatee because of the salinizationSalinization of sources of fresh water forFreshwater drinking drinkingFreshwater drinking. The capacity of sirenians to alter their behavior in response to climate changeClimate change will be essential to their survival.