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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. [ABSTRACT FROM AUTHOR]

People in 114 countries have consumed meat and other products from ~ 87 species of marine mammals since 1990. Nonetheless, assessment of the sustainability of most harvests is very difficult because information on the target populations and harvest numbers is inadequate. Dugongs have been harvested by the indigenous peoples of Torres Strait between Australia and Papua New Guinea, for at least 4000 years; the harvest has been substantial for at least the last 400–500 years. We use several lines of evidence to re-evaluate the sustainability of this harvest in the absence of robust data on the absolute size of this dugong population or the harvest. The evidence suggests that the harvest is sustainable. Dugong relative density was significantly higher in 2013 than in any other survey year and their Area of Occupancy has trended slightly upward since 1987. The proportion of calves in 2013 was the highest recorded. Genetic diversity is high. Dugongs are caught in only 5.0% of the 5268 km 2 of very high dugong density habitat as the result of the controls on the harvest and socio-economic factors. Nonetheless, many in the wider Australian community disapprove of this harvest and demand that hunting be banned. Enhancing culturally-appropriate spatial controls may be a more practical approach to managing this harvest than a more data-demanding Total Allowable Catch approach and may also be appropriate for some other indigenous harvests of marine mammals. [ABSTRACT FROM AUTHOR]

Knowledge of the distribution and relative abundance of seagrass communities in the Coral Triangle is limited, despite their global significance and the vital ecosystem services they perform for local human populations, threatened species such as dugongs and green turtles, as well as the role of being a globally significant carbon stock. To address this gap and investigate cost-effective methods in data-poor regions, we conducted seagrass mapping near two islands off the coast of Sabah in Malaysia: Banggi Island (7°15'N, 117°12'E) and Mantanani Island (6°43'N, 116°21'E). We used a staged approach that included: (1) interview surveys, (2) manta tow and spot surveys, and (3) comprehensive transect surveys. Approximately 415ha and 112ha of seagrass meadows were mapped off Banggi Island and Mantanani Island respectively. We found 10 species of seagrasses from two families: Halophila ovalis, Halodule uninervis (broad and thin leaf varieties), Thalassia hemprichii, Cymodocea rotundata, Halophila decipiens, Halophila spinulosa, Cymodocea serrulata, Syringodium isoetifolium, Enhalus acoroides and Halophila sp. nov. Our methodology proved cost-effective and the resultant information should be relevant to conservation planners. [ABSTRACT FROM AUTHOR]

In human-dominated landscapes, interactions and perceptions towards wildlife are influenced by multidimensional drivers. Understanding these drivers could prove useful for wildlife conservation. We surveyed the attitudes and perceptions of fishers towards threatened Irrawaddy dolphins ( Orcaella brevirostris) at Chilika Lagoon India. To validate the drivers of fisher perceptions, we : (1) observed dolphin foraging behavior at stake nets, and (2) compared catch per unit effort (CPUE) and catch income of fishers from stake nets in the presence and absence of foraging dolphins. We found that fishers were mostly positive towards dolphins, believing that dolphins augmented their fish catch and using culture to express their perceptions. Foraging dolphins were observed spending half their time at stake nets and were associated with significantly higher catch income and CPUE of mullet ( Liza sp.), a locally preferred food fish species. Wildlife conservation efforts should use the multidimensional drivers of human-wildlife interactions to involve local stakeholders in management. [ABSTRACT FROM AUTHOR]

Australian snubfin and Indo-Pacific humpback dolphins co-occur throughout most of their range in coastal waters of tropical Australia. Little is known of their ecology or acoustic repertoires. Vocalizations from humpback and snubfin dolphins were recorded in two locations along the Queensland coast during 2008 and 2010 to describe their vocalizations and evaluate the acoustic differences between these two species. Broad vocalization types were categorized qualitatively. Both species produced click trains burst pulses and whistles. Principal component analysis of the nine acoustic variables extracted from the whistles produced nine principal components that were input into discriminant function analyses to classify 96% of humpback dolphin whistles and about 78% of snubfin dolphin calls correctly. Results indicate clear acoustic differences between the vocal whistle repertoires of these two species. A stepwise routine identified two principal components as significantly distinguishable between whistles of each species: frequency parameters and frequency trend ratio. The capacity to identify these species using acoustic monitoring techniques has the potential to provide information on presence/absence, habitat use and relative abundance for each species. [ABSTRACT FROM AUTHOR]

Context: Systematic conservation planning is increasingly used to identify priority areas for protection in marine systems. However, ecosystem-based approaches typically use density estimates as surrogates for animal presence and spatial modeling to identify areas for protection and may not take into account daily or seasonal movements of animals. Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective. This study aims to demonstrate an evidence-based method to inform the biological basis for co-management of two sympatric species, dugongs and green sea turtles. This approach can then be used in conservation planning to delineate areas to maximize species protection. Methodology/Results: Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Dugong and green turtle home-ranges significantly overlapped in both locations. However, both species used different core areas and differences existed between regions in depth zone use and home-range size, especially for dugongs. Both species used existing protection areas in Shoalwater Bay, but only a single tracked dugong used the existing protection area in Torres Strait. Conclusions/Significance:: Fast-acquisition satellite telemetry can provide evidence-based information on individual animal movements to delineate relationships between dugongs and green turtles in regions where they co-occur. This information can be used to increase the efficacy of conservation planning and complement more broadly based survey information. These species also use similar habitats, making complimentary co-management possible, but important differences exist between locations making it essential to customize management. This methodology could be applied on a broader scale to include other sympatric and inter-related species. [ABSTRACT FROM AUTHOR]

The challenge of developing environmental outcomes acceptable to stakeholders with different values is well documented. Discourse analysis provides insights into how the views of different stakeholders affect decision making. We studied the discourses of key actors associated with the implementation of a Turtle and Dugong Hunting Management Plan developed by Hope Vale Aboriginal community in the Great Barrier Reef World Heritage Area, Australia. The discourses of the environmental managers and community members were very different. Hope Vale people prioritized cultural well-being; the staff of management agencies prioritized biodiversity outcomes. These differences precluded effective outcomes despite considerable investment in hunting management over more than 20 years by both groups. Understanding the discursive terrain within environmental management domains can inform environmental decision making and the implementation of agreed management arrangements, enabling biodiversity objectives and Indigenous cultural aspirations to be met in a socially just, economically viable, and environmentally sustainable way. [ABSTRACT FROM AUTHOR]

Abstract: The extensive sea grass meadows in Torres Strait enable it to be a globally important habitat for the dugong, Dugong dugon, a marine mammal of cultural and dietary significance to Torres Strait Islanders and the basis for the substantial island-based fishery in the Torres Strait Protected Zone. Torres Strait sea grass communities are subjected to episodic diebacks which are now believed to be largely natural events. Information on dugong life history was obtained from specimens obtained from female dugongs as they were butchered for food by Indigenous hunters at two major dugong hunting communities in Torres Strait: Daru (9.04°S, 143.21°E) in 1978–1982 (a time of sea grass dieback and recovery) and Mabuiag Island (9.95°S, 142.15°E) in 1997–1999 (when sea grasses were abundant). Dugongs sampled in 1997–1999 had their first calf at younger ages (minimum of 6 cf. 10 years), and more frequently (interbirth interval based on all possible pregnancies 2.6±0.4 (S.E.)yr cf. 5.8±1.0yr) than the dugongs sampled in 1978–1982. Pregnancy rates increased monotonically during 1978–1982, coincident with sea grass recovery. The age distribution of the female dugongs collected in 1997–1999 also suggested a low birth rate between 1973 and 1983 and/or or a high level of mortality for animals born during this period. These results add to the evidence from other regions that the life history and reproductive rate of female dugongs are adversely affected by sea grass loss, the effect of which cannot be separated from a possible density-dependent response to changes in dugong population size. Many green turtles in Torres Strait were also in poor body condition coincident with the 1970s sea grass dieback. The impacts of future sea grass diebacks need to be anticipated when management options for the traditional Torres Strait fisheries for dugongs and green turtles are evaluated. [Copyright &y& Elsevier]

Allocating money for species conservation on the basis of threatened species listings is not the most cost-effective way of promoting recovery or minimizing extinction rates. Using ecological and social factors in addition to threat categories, we designed a decision-support process to assist policy makers in their allocation of resources for the management of native wildlife and to clarify the considerations leading to a priority listing. Each species is scored on three criteria at the scale of the relevant jurisdiction: (1) threat category, (2) consequences of extinction, and (3) potential for successful recovery. This approach provides opportunity for independent input by policy makers and other stakeholders (who weight the relative importance of the criteria) and scientists (who score the species against the criteria). Thus the process explicitly separates societal values from the technical aspects of the decision-making process while acknowledging the legitimacy of both inputs. We applied our technique to two Australian case studies at different spatial scales: the frogs of Queensland (1,728,000 km2; 116 species) and the mammals of the Wet Tropics bioregion (18,500 km2; 96 species). We identified 7 frog and 10 mammal species as priorities for conservation. The frogs included 1 of the 9 species classified as endangered under Queensland legislation, 3 of the 10 species classified as vulnerable, 2 of the 22 species classified as rare, and 1 of the 75 species classified as least concern. The mammals identified included 3 of the 6 species classified as endangered, 1 of the 4 species classified as vulnerable, 5 of the 11 species classified as rare, and 1 of the 75 species classified as least concern. The methods we used to identify species were robust to comparisons across the two taxonomic groups. We concluded that (1) our process facilitates comparisons of data required to make transparent, cost-effective, and strategic management decisions across taxonomic groups and (2) the process should be used to short-list species for further discussion rather than for allocating resources per se. [ABSTRACT FROM AUTHOR]

Abstract: Disturbance from boats has been documented for many species of marine mammals, especially cetaceans, but has never been quantified for dugongs. Dugongs depend on seagrass for food. This food mostly occurs in shallow coastal areas where boat traffic is high. Thus there is potential for boats to alienate dugongs from critical habitat areas. Using an overhead video observation system (‘blimp-cam’), we observed the behaviour of focal dugongs during controlled boat pass experiments and while no boats were present. The percentage of time focal dugongs spent feeding and travelling was unaffected by boat presence, the number of boat passes and whether a pass included a stop and restart (pass continuity). The duration, distance and direction of a focal dugong''s subsurface behaviour were unaffected by number, continuity or distance of boat passes. However, focal dugongs were less likely to continue feeding if the boat passed within 50 m, than if the boat passed at a greater distance. Mass movements of dugong feeding herds in response to experimental and opportunistically observed boats were timed on 42 occasions but only lasted an average of 122 s. These movements occurred in response to boats passing at a range of speeds, and at distances of less than 50 m to over 500 m. The levels of boat traffic we observed may reduce dugongs'' feeding time budget by a maximum of 0.8–6%. Thus at present boats appear unlikely to be having a substantive effect on the energy intake of dugong populations at our study site on the Moreton Banks near Brisbane, Australia. However, boat traffic is likely to increase in this fast growing region, raising concern about the future impact of boats on this and other dugong populations. [Copyright &y& Elsevier]

The probability of detecting an animal in a sampled area during a survey consists of 2 components: 1) the probability of an animal being available for detection (availability), which can be highly variable in heterogeneous environments; and 2) the probability of an animal being detected, conditional on its being available for detection (perception). Many surveys only estimate the latter probability because modeling the availability process requires information collected external to the survey. We illustrate estimation of both probabilities in an application to aerial surveys of dugongs (Dugong dugon) in Northern Australian coastal waters where water clarity varies greatly over relatively small spatial scales. Using artificial dugong models and timed depth recorders deployed on 15 wild dugongs to obtain dive profiles, we carried out experiments to determine zones of detectability for dugongs at the range of depths, turbidities, and sea states that spanned the environmental heterogeneity encountered on dugong surveys. Resulting probability estimates were heterogeneous and dependent on the measured conditions. To estimate perception probability, we used a tandem team of 2 observers on either side of the aircraft. This permitted fitting generalized Lincoln­Petersen models with Program MARK. We then used the generalized Horvitz­Thompson estimator, based on the overall detection probability for each individual dugong, to generate population estimates. We also developed a new simulation-based method for estimating standard errors and confidence intervals. We contrast absolute abundance estimates of dugongs in the Torres Strait and Northern Great Barrier Reef regions using both the new and original approaches (Marsh and Sinclair 1989a). For Torres Strait, the new method produced a substantially smaller estimate (11,956 vs. 14,106 dugongs) and a very much smaller standard error (1,189 vs. 2,314 dugongs), whereas the new method produced slightly larger estimates (mean 9,855 vs. 9,193 dugongs, standard error 1,184 vs. 917 dugongs) for the Northern Great Barrier Reef survey. [ABSTRACT FROM AUTHOR]

Although most countries have ethical guidelines for research involving human subjects and other sentient animals, the ethical issues associated with field research have received little attention. Most experimental marine biologists and ecologists operate without ethical guidelines or scrutiny, despite intermittent community concern about their activities. We offer suggestions on how marine biologists and ecologists can protect the future of research involving the field collection and experimental manipulation of organisms by developing mechanisms to address community concerns that such research is ethically responsible. We urge experimental marine biologists and ecologists to take pre-emptive initiatives by encouraging: (1) institutional animal ethics committees to broaden their terms of reference to include environmental ethics; (2) scientific societies to develop codes of ethics to guide the environmental research conducted by their members; (3) editorial boards of journals to require the research they publish to conform to an appropriate code of ethics, and (4) management agencies that issue permits for field research to establish an ethics committee to advise them on the ethical issues raised by specific research proposals. We conclude that the resultant administrative burden on scientists would be low but that the penalties of operating without such protection can be high. [Copyright &y& Elsevier]

Investigates the patterns of mammal assemblage structure in tropical rain forest in Australia. Relationship between mammal assemblage structure and habitat structure; Effects of spatial habitat heterogeneity on small-mammal assemblage.

Marine migratory species require collaborative decision‐making because individuals move across jurisdictional boundaries within and between countries. However, governance of these species is not always harmonized or truly collaborative. We analyzed the Recovery Plan for Marine Turtles in Australia 2017 (the Plan) and three of its subsidiary plans for evidence of collaborative governance using a two‐part gap analysis and interviews with environmental managers, scientists, and other stakeholders involved in the development of the Plan and in managing marine migratory species in Australia more generally. We applied existing adaptive and collaborative governance frameworks, which focused mainly on the social components of collaborative governance, and identified a need for a new, interdisciplinary framework for the collaborative governance of marine turtles in Australia. We applied our new framework to the Plan and identified that while the biological components of the Plan were well‐developed, stakeholder analysis and engagement details were largely missing. We recognize that recovery plans are inevitably silent about certain issues but suggest that plans would benefit from including better guidance on stakeholder engagement and analysis. Our framework is directly relevant to harmonizing the management of marine turtles across jurisdictions in Australia but it could also be applied to managing threats towards other migratory species that inhabit large marine jurisdictions. [ABSTRACT FROM AUTHOR]

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. The dugong's (Dugong dugon) habitat use in small coral reef lagoon systems, constrained by tides, is poorly understood, hindering adaptive management. Through aerial surveys, we examined seasonal and tidal variations in dugong utilisation in a high conservation value coral reef lagoon. This study reveals significant temporal variations in dugong habitat use, influenced by tides and seasons. It underscores the importance of outer reef habitats devoid of seagrass for the species. Additionally, it contributes evidence of behavioural thermoregulation in dugongs. This article belongs to the Collection Marine Mammals in the Pacific. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Signatory states of the Convention on Biological Diversity must ‘protect and encourage the customary use of biological resources in accordance with traditional cultural practices that are compatible with conservation or sustainable use requirements’. Thus the management of traditional hunting of wildlife must balance the sustainability of target species with the benefits of hunting to traditional communities. Conservation policies usually define the values associated with wild meats in terms of income and nutrition, neglecting a wide range of social and cultural values that are important to traditional hunting communities. We elicited the community-defined benefits and costs associated with the traditional hunting of dugongs Dugong dugon and green turtles Chelonia mydas from communities on two islands in Torres Strait, Australia. We then used cognitive mapping and multidimensional scaling to identify separable groups of benefits (cultural services, provisioning services, and individual benefits) and demonstrate that traditional owners consider the cultural services associated with traditional hunting to be significantly more important than the provisioning services. Understanding these cultural values can inform management actions in accordance with the Convention on Biological Diversity. If communities are unable to hunt, important cultural benefits are foregone. Based on our results, we question the appropriateness of conservation actions focused on prohibiting hunting and providing monetary compensation for the loss of provisioning services only. [ABSTRACT FROM PUBLISHER]

The geographic range of sea kraits encompasses one of the geologically most-complex regions of the world. At its center lies Wallacea (the transition between the terrestrial biotas of the Asian and Australian tectonic plates) and the Indonesian Throughflow (nexus of the equatorial marine biotas of the Indian and Pacific oceans). The aim of this study was to elucidate the role of paleogeography, paleoclimatology, and oceanic currents in the evolution and distribution of sea kraits across these major biogeographic crossroads and beyond. A recent assessment of times of taxonomic divergence was projected against paleogeographic reconstructions to produce a parsimonious, hypothetical model of events critical for the origin, dispersal, and differentiation of this taxon. Times and degree of divergence of taxa suggested by recent morphological and molecular studies are in accord with various climatological and geologic events. The model postulates that the distribution of sea kraits was neither greatly affected by tectonics, other than the approach of the Australian Plate to the Asian one, nor dominated by the historic barriers to dispersal of terrestrial fauna across Wallacea, or by the Indonesian Throughflow. Rather, the model suggests that two major factors-paleogeographic alteration of the configuration of land and sea, and the directions of sea currents, past and present-provide an explanation of how these amphibious snakes (1) originated from a terrestrial Asian elapid ancestor, (2) subsequently generated the venomous Australian land snakes and their derivatives the true sea snakes, and (3) differentiated into the species complexes, species, and infraspecific entities of the genus Laticauda. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Cross-cultural knowledge sharing in natural resource management is receiving growing academic attention. Further consideration is necessary regarding how indigenous and Western knowledges are understood and validated by resource managers. Using a marine co-management case study in northern Australia, we explored how indigenous and nonindigenous managers engage with indigenous and Western scientific knowledge. Interview participants discussed the utility of empirical information within each knowledge system, but engaged less with the beliefs and worldviews framing knowledge. Based on interview responses, we developed a typology that describes the main ways resource managers engage with indigenous and Western scientific knowledge in this management system. We suggest several steps to help achieve a more integrative approach to knowledge utilization in indigenous co-management contexts. Ensuring that resource managers understand and respect multiple ways of knowing will improve stakeholder collaboration engagement across cultures. [ABSTRACT FROM AUTHOR]

Background: Conservation planning and the design of marine protected areas (MPAs) requires spatially explicit information on the distribution of ecological features. Most species of marine mammals range over large areas and across multiple planning regions. The spatial distributions of marine mammals are difficult to predict using habitat modelling at ecological scales because of insufficient understanding of their habitat needs, however, relevant information may be available from surveys conducted to inform mandatory stock assessments. Methodology and Results: We use a 20-year time series of systematic aerial surveys of dugong (Dugong dugong) abundance to create spatially-explicit models of dugong distribution and relative density at the scale of the coastal waters of northeast Australia (∼136,000 km2). We interpolated the corrected data at the scale of 2 km * 2 km planning units using geostatistics. Planning units were classified as low, medium, high and very high dugong density on the basis of the relative density of dugongs estimated from the models and a frequency analysis. Torres Strait was identified as the most significant dugong habitat in northeast Australia and the most globally significant habitat known for any member of the Order Sirenia. The models are used by local, State and Federal agencies to inform management decisions related to the Indigenous harvest of dugongs, gill-net fisheries and Australia's National Representative System of Marine Protected Areas. Conclusion/Significance: In this paper we demonstrate that spatially-explicit population models add value to data collected for stock assessments, provide a robust alternative to predictive habitat distribution models, and inform species conservation at multiple scales. [ABSTRACT FROM AUTHOR]

Quantifying the factors influencing behaviors of aquatic mammalian grazers may enhance the generic understanding of grazer ecology. We investigated diel and tidal patterns in movements of the dugong (Dugong dugon) by Global Positioning System--tracking 12 animals in 5 inshore--intertidal and 3 offshore--subtidal habitats along the coast of Queensland, Australia. We examined effects of tide height and time of day on the dugong's distance from 1) the nearest coast, 2) water >3 m deep, 3) actual water depth (bathymetry + tide ht) experienced, and 4) distribution of the directions of movements. Both tidal and diel cycles influenced dugong movement. Tracked dugongs tended to be closer to shore at high tide than at low tide and closer to shore at night than during the day. Onshore movement was more prevalent on incoming tides and in the afternoon and evening. Offshore movement was more prevalent on outgoing tides and from midnight through the morning until midday. Tidal and diel variation in water depths used by the inshore--intertidal dugongs was small, but probably underestimated, hidden by a sampling bias in the telemetry equipment. Onshore movement at high tide allowed dugongs to exploit intertidal seagrass beds. Dugongs are closer to shore in afternoons and evenings than in mornings. This behavior may be related to the avoidance of predators or watercraft. Our findings can be used to predict spatial patterns of dugongs within areas of conservation management significance and to assess, avoid, and mitigate adverse effects of anthropogenic disturbance. [ABSTRACT FROM AUTHOR]

Abstract: A 24km2 seagrass meadow in Hervey Bay, Queensland, Australia, was confirmed as important dugong habitat by a satellite tracking study. Marine videography, near-infrared spectroscopy (NIRS) and geographic information systems (GIS) were used to survey, analyse and map seagrass species composition, nutrient profile and patch structure at high resolution (200m). Five species of seagrass covered 91% of the total habitat area. The total above and below-ground seagrass biomass was estimated to be 222.7±19.6t dry-weight. Halodule uninervis dominated the pasture (81.8%, 162.2t), followed by Halophila ovalis (35.3%, 16.5t), Zostera capricorni (15.9%, 22.2t), Halophila spinulosa (14.5%, 21.9t), and traces of Halodule pinifolia. Because seagrass distributions overlapped, their combined percentage totalled >100% of the survey area. The seagrass formed a continuous meadow of varying density. Abiotic variables explained relatively little of the spatial patterns in the seagrass. For all seagrass species, the above-ground component (shoots and leaves) possessed greater total nitrogen than the below-ground component (roots and rhizomes), which possessed greater total starch. Because of the relatively low intraspecific variation in nutrient composition, nutrients were concentrated according to seagrass biomass density. Halodule uninervis was the most nutritious seagrass species because of its superior whole-plant nitrogen (1.28±0.05% DW) and starch (6.42±0.50 DW %) content. Halodule uninervis formed large, clustered patches of dense biomass across the pasture and thus nitrogen and starch were concentrated where H. uninervis was prevalent. This seagrass meadow appears to be utilised well below its potential dugong carrying capacity. The survey and analytical techniques used enabled rapid, economical and accurate quantification and characterisation of seagrass habitat at scales relevant to a large forager. [Copyright &y& Elsevier]

Abstract: Seventy dugongs were fitted with satellite PTTs and/or GPS transmitters in sub-tropical and tropical waters of Queensland and the Northern Territory, Australia. Twenty-eight of the 70 dugongs were also fitted with time-depth recorders. The dugongs were tracked for periods ranging from 15 to 551 days and exhibited a large range of individualistic movement behaviours; 26 individuals were relatively sedentary (moving <15 km) while 44 made large-scale movements (>15 km) of up to 560 km from their capture sites. Male and female animals, including cows with calves, exhibited large-scale movements (LSM; >15 km). Body length of travelling dugongs ranged from 1.9 to 3 m. At least some of the movements were return movements to the capture location, suggesting that such movements were ranging rather than dispersal movements. LSMs included macro-scale regional movements (>100 km) and meso-scale inter-patch local movements (15 to <100 km) and were qualitatively different from tidally-driven micro-scale commuting movements between and within seagrass beds (<15 km). The mean±S.E. macro-scale movement distance per individual was 243.8±35.4 km (N =14 individuals that travelled >100 km), with a mean±S.E. travel time of 179.8±29.0 h. The mean±S.E. meso-scale movement distance per individual was 49.7±3.3 km (N =28 individuals that made movements of 15–100 km), with a mean±S.E. travel time of 52.3±7.1 h. LSMs were rapid and apparently directed (mean±S.E. travel speeds for GPS tagged animals; meso-scale movements=1.3±0.11 km/h, min=0.3, max=3.0; macro-scale movements=1.6±0.16 km/h, min=0.8, max=1.3). Tracked dugongs rarely travelled far from the coast (mean±S.E. max distance=12.8±1.3 km). Dive profiles from the time-depth recorders suggest that dugongs make repeated deep dives while travelling rather than remaining at the surface, increasing their likelihood of capture in bottom set gill nets. Some animals caught in the high latitude limits of the dugongs'' range on the Australian east coast in winter apparently undertook long distance movements in response to low water temperatures, similar to migrational movements by Florida manatees. Our findings that dugongs frequently undertake macro-scale movements have implications for management at a range of scales, and strengthen the aerial survey and genetic evidence for management and monitoring at ecological scales that cross jurisdictions. [Copyright &y& Elsevier]

Abstract: Very little is known about the ecology of snubfin Orcaella heinsohni and Indo-Pacific humpback dolphins Sousa chinensis in Australian waters. We used photo-identification data collected between 1999 and 2002 in Cleveland Bay, northeast Queensland, to estimate abundance, site fidelity and residence patterns of these species in order to make recommendations for their effective conservation and management. Our abundance estimates indicate that less than a hundred individuals of each species inhabit this coastal area. Even with relatively unbiased and precise abundance estimates population trends will be extremely difficult to detect in less than three years unless changes in population size are very high (>20% p.a.). Though both species are not permanent residents in Cleveland Bay, they both used the area regularly from year to year following a model of emigration and reimmigration. Individuals of both species spend periods of days to a month or more in coastal waters of Cleveland Bay before leaving, and periods of over a month outside the study area before entering the bay again. Because of their small population sizes and movement patterns, snubfin and humpback dolphins are particularly vulnerable to local extinction. Our results illustrate that: (1) detection of population trends should not be a necessary criterion for enacting conservation measures of both species in this region, and (2) efforts to maintain viable populations of both species in Cleveland Bay must include management strategies that integrate anthropogenic activities in surrounding areas. [Copyright &y& Elsevier]

The elephant ivory trade remains controversial because of concerns about the extinction risk of elephants and the different needs of CITES member states. Thailand's situation is particularly contentious because of the different legal status among types of elephant ivory. Thai law allows the local sale of ivory from domesticated Asian elephants, which creates challenges for Thai enforcement officers in identification of ivory provenance. We investigated the capacity of non‐destructive Near Infrared (NIR) spectroscopy (600–1700 nm), combined with Partial Least Squares Discriminant Analysis (PLS‐DA), to discriminate between ivory from African, wild Asian and domesticated Asian elephants. Ivory spectra of 64 elephants were divided randomly into calibration and validation datasets. We were able to determine elephant ivory provenance at both the interspecies (African and Asian elephant ivory), and within species (wild and domesticated Asian elephant ivory) classifications with 100% accuracy. These results showed the potential use of handheld NIR spectrometers for rapid assessments of ivory provenance, as well as a forensic tool for wider enforcement. [ABSTRACT FROM AUTHOR]

Abstract Many species of marine mammals have evolved behavioural adaptations to minimize heat loss to the surrounding water. We tracked 21 dugongs (Dugong dugon Müller 1776) using acoustic and satellite/GPS transmitters in 2012, 2013 and 2014 in Moreton Bay, Queensland at the high latitude limit of the species' winter range in eastern Australia to examine if there was a relationship between movements and environmental temperature that might suggest behavioural thermoregulation. Oceanic waters immediately outside the bay where the dugong's seagrass food is unavailable exhibited temperatures from 5.5 °C warmer to 3 °C cooler than the Eastern Banks, the major dugong habitat in the bay. All tracked dugongs made at least one (and up to 66) return trip(s) from the Eastern Banks to the adjacent oceanic waters. The probability of making an outgoing trip was highest in 2014 and lowest in 2013 when the water temperature inside the bay was higher than the other two years. The odds of making an outgoing trip were lower when temperature differences (outside minus inside) were small or negative but increased by a factor of up to 2.12 for each 1 °C positive difference. Individual dugongs were most likely to travel out of the bay between midnight and noon on an outgoing tide or at slack high water and return to the bay on an incoming tide or slack low water between noon and midnight. The amount of time a dugong spent outside the bay on each trip was relatively short with an overall median of 5.9 h. The dugongs' individual activity spaces generally declined as winter progressed suggesting a change in the cost-effectiveness of moving outside the bay. Our analysis adds to the evidence that dugongs undertake behavioural thermoregulation at least at the high latitude limits of their range. Highlights • Dugongs undertake behavioural thermoregulation at high latitude limits of their range • Dugongs move outside protected inshore bay habitats to access warmer oceanic waters • Dugongs saved energy by taking advantage of tidal flow in and out of the bay • Dugongs were more likely to travel out of Moreton Bay between midnight and noon [ABSTRACT FROM AUTHOR]

Assessing wildlife tourism sustainability in developing countries is crucial, but few studies analyse the sustainability of dolphin-based wildlife tourism in this context. We measure multiple indicators within the human dimensions of wildlife tourism, including tourist visitation numbers, satisfaction, preferences, perceptions, background and specialisation, to ascertain the extent to which the dolphin-watching industry at Chilika Lagoon, in rural India might be considered sustainable. Our methods included participant observation, tourist surveys, and the use of secondary data on visitation over 10 years. We found that the growth rate of tourist visitation over 10 years was beginning to decline. Tourists were mostly inexperienced, and dissatisfied with their dolphin-watching experience. Tourist preferences and perceptions showed useful insights and shortcomings in the way in which the industry was being conducted and managed, and reflected the expectations of non-specialist visitors. Our study highlights drawbacks in the way that wildlife tourism is managed in a rural, developing world context, which draws the sustainability of the dolphin-watching industry in Chilika into question. Future development of an early warning system that addresses combined governance or managerial, social, economic and ecological indicators, and an integrated management plan for conservation and wildlife tourism could contribute to the sustainable management of such industries. [ABSTRACT FROM AUTHOR]

The probability of an aquatic animal being available for detection is typically <1. Accounting for covariates that reduce the probability of detection is important for obtaining robust estimates of the population abundance and determining its status and trends. The dugong (Dugong dugon) is a bottom-feeding marine mammal and a seagrass community specialist. We hypothesized that the probability of a dugong being available for detection is dependent on water depth and that dugongs spend more time underwater in deep-water seagrass habitats than in shallow-water seagrass habitats. We tested this hypothesis by quantifying the depth use of 28 wild dugongs fitted with GPS satellite transmitters and time-depth recorders (TDRs) at three sites with distinct seagrass depth distributions: 1) open waters supporting extensive seagrass meadows to 40 m deep (Torres Strait, 6 dugongs, 2015); 2) a protected bay (average water depth 6.8 m) with extensive shallow seagrass beds (Moreton Bay, 13 dugongs, 2011 and 2012); and 3) a mixture of lagoon, coral and seagrass habitats to 60 m deep (New Caledonia, 9 dugongs, 2013). The fitted instruments were used to measure the times the dugongs spent in the experimentally determined detection zones under various environmental conditions. The estimated probability of detection was applied to aerial survey data previously collected at each location. In general, dugongs were least available for detection in Torres Strait, and the population estimates increased 6–7 fold using depth-specific availability correction factors compared with earlier estimates that assumed homogeneous detection probability across water depth and location. Detection probabilities were higher in Moreton Bay and New Caledonia than Torres Strait because the water transparency in these two locations was much greater than in Torres Strait and the effect of correcting for depth-specific detection probability much less. The methodology has application to visual survey of coastal megafauna including surveys using Unmanned Aerial Vehicles. [ABSTRACT FROM AUTHOR]

Fisheries bycatch is a widespread and serious issue that leads to declines of many important and threatened marine species. However, documenting the distribution, abundance, population trends and threats to sparse populations of marine species is often beyond the capacity of developing countries because such work is complex, time consuming and often extremely expensive. We have developed a flexible tool to document spatial distribution and population trends for dugongs and other marine species in the form of an interview questionnaire supported by a structured data upload sheet and a comprehensive project manual. Recognising the effort invested in getting interviewers to remote locations, the questionnaire is comprehensive, but low cost. The questionnaire has already been deployed in 18 countries across the Indo-Pacific region. Project teams spent an average of USD 5,000 per country and obtained large data sets on dugong distribution, trends, catch and bycatch, and threat overlaps. Findings indicated that >50% of respondents had never seen dugongs and that 20% had seen a single dugong in their lifetimes despite living and fishing in areas of known or suspected dugong habitat, suggesting that dugongs occurred in low numbers. Only 3% of respondents had seen mother and calf pairs, indicative of low reproductive output. Dugong hunting was still common in several countries. Gillnets and hook and line were the most common fishing gears, with the greatest mortality caused by gillnets. The questionnaire has also been used to study manatees in the Caribbean, coastal cetaceans along the eastern Gulf of Thailand and western Peninsular Malaysia, and river dolphins in Peru. This questionnaire is a powerful tool for studying distribution and relative abundance for marine species and fishery pressures, and determining potential conservation hotspot areas. We provide the questionnaire and supporting documents for open-access use by the scientific and conservation communities. [ABSTRACT FROM AUTHOR]

Prioritisation methods have been adopted for >20 years to inform resource allocation in species conservation. The academic literature on prioritisation focuses on technical matters, with little attention to the socio-political factors affecting the uptake of priorities. We investigated the policy instruments employed to promote uptake, and the structural factors affecting the uptake of priorities, using as our case study a species prioritisation method adopted by the Queensland Government (Australia). We interviewed 79 key informants and analysed policy documents and plans. The Queensland Government relied on 'information delivery' as a policy instrument to foster uptake. We identified communication channels to assist 'information delivery' between Government and intended users, but also found that several structural factors limited their use: fragmentation of policies, the relative strength of alternative priorities and centralisation of power in decision-making. We discuss the results in relation to other conservation planning initiatives and suggest how structural barriers can be addressed. [ABSTRACT FROM AUTHOR]

Background: A substantial period of life after reproduction ends, known as postreproductive lifespan (PRLS), is at odds with classical life history theory and its causes and mechanisms have puzzled evolutionary biologists for decades. Prolonged PRLS has been confirmed in only two non-human mammals, both odontocete cetaceans in the family Delphinidae. We investigate the evidence for PRLS in a third species, the false killer whale, Pseudorca crassidens, using a quantitative measure of PRLS and morphological evidence from reproductive tissues. Results: We examined specimens from false killer whales from combined strandings (South Africa, 1981) and harvest (Japan 1979-80) and found morphological evidence of changes in the activity of the ovaries in relation to age. Ovulation had ceased in 50% of whales over 45 years, and all whales over 55 years old had ovaries classified as postreproductive. We also calculated a measure of PRLS, known as postreproductive representation (PrR) as an indication of the effect of inter-population demographic variability. PrR for the combined sample was 0.14, whereas the mean of the simulated distribution for PrR under the null hypothesis of no PRLS was 0.02. The 99th percentile of the simulated distribution was 0.08 and no simulated value exceeded 0.13. These results suggest that PrR was convincingly different from the measures simulated under the null hypothesis. Conclusions: We found morphological and statistical evidence for PRLS in South African and Japanese pods of false killer whales, suggesting that this species is the third non-human mammal in which this phenomenon has been demonstrated in wild populations. Nonetheless, our estimate for PrR in false killer whales (0.14) is lower than the single values available for the short-finned pilot whale (0.28) and the killer whale (0.22) and is more similar to working Asian elephants (0.13). [ABSTRACT FROM AUTHOR]

Environmental issues are often highly politicized. Indigenous peoples may be reluctant to participate in research due to a history of colonization and negative experiences with researchers—described as a “chronic conflict”. We present a case where an acute conflict (an event that creates intense mistrust among stakeholders) occurred during a research project. The project studied a contentious issue: the sharing of dugong and turtle meat by Indigenous Australians. The chronic conflict of colonial history and Western research was exacerbated by media coverage of related issues when the project was starting, making participants unwilling to participate in our research. We adapted established Indigenous engagement protocols and—both literally and figuratively—set the table in response to the sociopolitical context of the research. This engagement process enabled us to establish trusting relationships with participants, and could benefit most researchers seeking to engage people, irrespective of Indigeneity or context. [ABSTRACT FROM AUTHOR]

The hunting and trade of bushmeat is a significant issue. The sharing of marine bushmeat between Australian Torres Strait Islanders and their mainland urban diaspora was documented from a diaspora perspective by collecting quantitative and qualitative data from communities in three mainland cities. Motivations for sharing dugong and turtle meat were almost exclusively cultural and mostly occurred when a diaspora member visited Torres Strait, when Torres Strait Islanders visited their mainland family, during Islander ceremonies, or when goods were exchanged as gifts. Each respondent consumed relatively little dugong and turtle meat (<1–2% of annual meat consumption, or < 1 kg per person per annum). Sharing bushmeat strengthened social capital and reinforced cultural identity. Harnessing the social capital generated from the sharing of bushmeat to engage the urban diaspora in dugong and turtle management activities in the Torres Strait could enhance the legitimacy and effectiveness of such initiatives. [ABSTRACT FROM PUBLISHER]

Knowledge of the relationships between environmental forcing and demographic parameters is important for predicting responses from climatic changes and to manage populations effectively. We explore the relationships between the proportion of sea cows (Dugong dugon) classified as calves and four climatic drivers (rainfall anomaly, ], NINO 3.4 sea surface temperature index, and number of tropical cyclones) at a range of spatially distinct locations in Queensland, Australia, a region with relatively high dugong density. Dugong and calf data were obtained from standardized aerial surveys conducted along the study region. A range of lagged versions of each of the focal climatic drivers (1 to 4 years) were included in a global model containing the proportion of calves in each population crossed with each of the lagged versions of the climatic drivers to explore relationships. The relative influence of each predictor was estimated via Gibbs variable selection. The relationships between the proportion of dependent calves and the climatic drivers varied spatially and temporally, with climatic drivers influencing calf counts at sub-regional scales. Thus we recommend that the assessment of and management response to indirect climatic threats on dugongs should also occur at sub-regional scales. [ABSTRACT FROM AUTHOR]

Marine protected areas (MPAs) are a powerful tool for conserving marine biodiversity when designed using ecological information and conservation goals and targets. Dugongs (Dugong dugon) were not an explicit target in the design of the network of MPAs in New Caledonia, despite being one of the region’s World Heritage values. Our study retrospectively assessed the capacity of the New Caledonia MPA network to protect dugongs from anthropogenic threats. We developed a spatially explicit model of dugong distribution and relative density based on information collected from ∼10 years of aerial surveys. We quantified the amount of overlap between areas supporting high densities of dugongs and MPAs. We found that most of the important dugong habitats of New Caledonia had a low coverage of MPAs that provide high levels of restriction on anthropogenic activities. We identified several important dugong habitats along the west and the north-east coast that were not covered by MPAs and should be a priority for future management. The spatial mismatch between MPAs and dugongs was likely caused by weaknesses in the planning process, including the: (1) lack of explicit conservation goals and targets; (2) omission of spatial information on species’ distribution; (3) mismatch of spatial scales; (4) cost considerations; and (5) incorrect application of the IUCN protected area categories. We provide guidance on how these shortcomings can be avoided for marine species of conservation concern in New Caledonia and other regions. [ABSTRACT FROM AUTHOR]

Marine animals face increased pressure through expanded shipping and recreational activities. Effective conservation and management of large species like marine mammals or sea turtles depend on knowledge of movement and habitat use. Previous studies have used data collected from either satellite or acoustic telemetry but rarely both. In this study, data from satellite and acoustic technologies were used to: determine the efficacy of satellite and acoustic telemetry to define dugong movement patterns; compare the benefits and limitations of each approach; examine the costs of each approach in relation to the amount and type of data provided; and relate telemetry data to the boundaries of a Go Slow area designed to protect dugongs and turtles from vessel strike within an urbanised coastal embayment (Moreton Bay, Queensland, Australia). Twenty-one dugongs were captured in seagrass habitats on the Eastern Banks of Moreton Bay in July–September 2012 and July 2013 and fitted with GPS and acoustic transmitters. Both satellite and acoustic telemetry produced reliable presence and movement data for individual dugongs. When the dugongs were within the range of the acoustic array, there was relatively good correspondence between the overall space use measures derived from GPS and acoustic transmitters, demonstrating that acoustic tracking is a potentially valuable and cost-effective tool for monitoring local dugong habitat use in environments equipped with acoustic receiver arrays. Acoustic technology may be particularly useful for species that establish home ranges with stable residency especially near large urban or port environs. However, the relative merits of the two technologies depend on the research question in the context of the species of interest, the location of the study and whether the study site has an established acoustic array. [ABSTRACT FROM AUTHOR]

The number of cetacean watching tourism operations in developing countries has doubled in the past decade. Practices are typically unregulated and not informed by research, especially research into the human dimensions of the tourist experience. Dolphin watching tourism at Lovina, Bali, started in the late 1980s when local fishers formed self-regulating cooperatives. Up to 180 dedicated operators use small fishing vessels to carry passengers to watch dolphins close to shore. Most tourists come from western countries, although the industry also attracts Asian visitors. Most visitors are tertiary-educated. Tourist satisfaction ranges from low to medium. While there was no significant difference between the average satisfaction of western and Asian tourists, the associated variables were different. The satisfaction of western tourists was associated with encounter management, preferred number of boats and the number of dolphins seen. Encounter management was the only variable associated with the satisfaction of Asian tourists. Satisfaction was positively associated with willingness to recommend the tour: western respondents who felt neutral to very comfortable with their dolphin encounters were more likely to promote the tour. Better understanding of the tourist experience is crucial in designing sustainable marine wildlife tourism in developing countries; such research appears to be rare. [ABSTRACT FROM AUTHOR]

Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18–20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and failure to orient. Acclimation does not seem to be in this species’ repertoire. In the water column, marine snakes track water temperature; on land, sea kraits can thermoregulate by basking, selecting favorable locations, and by kleptothermy. Laticauda colubrina adjusts its reproductive cycle geographically in ways that avoid breeding in the coldest months. Mean voluntary diving time is not temperature-dependent within the normal range of temperatures experienced by marine snakes in the field, but is reduced in water colder than 20°C. On land, much as while diving in the sea, sea kraits maintain long periods of apnea; intervals between breaths are inversely related to temperature. [ABSTRACT FROM AUTHOR]

This study examined the direct economic impacts of dolphin watching tourism in Lovina, north Bali (Indonesia). The study applied the direct expenditure approach to tourists who went on dolphin tours in Lovina in 2008 and 2009. This industry depends on predictable access to coastal dolphins, attracts at least 37,000 overnight visitors per annum (~60% of the region's overnight tourists) and contributes at least 46% of the total direct expenditures (USD 4.1 million p.a.) for accommodation, meals, transportation, communication and souvenirs. The 179 boatmen enjoy an above average income and thus have little financial incentive to leave the industry. Nonetheless, trip fees constitute only 3% of the total expenditures generated by dolphin watching tourism. The remainder e.g., for accommodation, restaurants and transport is spent with local businesses which become the substantial beneficiaries and hence these stakeholders should also be consulted prior to any management intervention. This profitable industry supports 35–100 tour boats operating daily. The number of boats should be regulated to address concerns over their impacts on the dolphins and visitor satisfaction. [Copyright &y& Elsevier]

Abstract: Knowledge of the diving behaviour of aquatic animals expanded considerably with the invention of time–depth recorders (TDRs) in the 1960s. The large volume of data acquired from TDRs can be analyzed using dive analysis software, however, the application of the software has received relatively little attention. We present an empirical procedure to select optimum values that are critical to obtaining reliable results: the zero-offset correction (ZOC) and the dive threshold. We used dive data from shallow-diving coastal dugongs (Dugong dugon) and visual observations from an independent study to develop and test a procedure that minimizes errors in characterizing dives. We initially corrected the surface level using custom software. We then determined the optimum values for each parameter by classifying dives identified by an open-source dive analysis software into Plausible and Implausible dives based on the duration of dives. The Plausible dives were further classified as Unrecognized dives if they were not identified by the software but were of realistic dive duration. The comparison of these dive types indicated that a ZOC of 1m and a dive threshold of 0.75m were the optimum values for our dugong data as they gave the largest number of Plausible dives and smaller numbers of other dive types. Frequency distributions of dive durations from TDRs and independent visual observations supported the selection. Our procedure could be applied to other shallow-diving animals such as coastal dolphins and turtles. [Copyright &y& Elsevier]

The ingestion of anthropogenic marine debris can lead to injuries in the digestive system of marine turtles through blockages, lacerations and enteritis, as well as sub-lethal effects from bioaccumulation of adhered chemicals and toxic substances leached out into tissues and blood. The early detection of these impacts is central for the treatment and recovery of turtles in a rehabilitation setting. In this study, we provide baseline data on gastrointestinal transit times in healthy green turtles (Chelonia mydas) to enable non-intrusive detection of digestive motility disorders. We conducted two experiments with juvenile green turtles (N = 14) (curved carapace length range 33.7–47.0 cm) using inorganic (inert plastic discs) and organic (corn kernels) markers respectively, in order to estimate gastrointestinal transit times and assess the effectiveness of each marker type in recording them. Gastrointestinal transit times for the inorganic marker trial group (n = 6 turtles) ranged from 14.6 ± SD 3.6 days for the first markers recovered to 22.5 ± SD 4.2 days for the last markers recovered. The corresponding data for the organic marker trial group (n = 8 turtles) ranged from 6.63 ± SD 1.6 days to 17.3 ± SD 3.3 days respectively. We obtained 96% recovery success of markers in the inorganic marker trial versus 72.5% in the organic marker trial. Thus, inorganic markers proved to be more efficient in reporting gastrointestinal transit times because they do not degrade or discolour as they pass along the digestive process, enabling higher recovery success. Opportunistically, veterinarians diagnosed an obstruction caused by plastic fragments, which had been swallowed in the wild prior to the trial, in one of the experimental animals after we failed to recover any markers. This incident is evidence that gastrointestinal transit time assessment is a useful approach for providing early warning of digestive system blockages. Furthermore, this knowledge on transit times could be of interest for toxicology studies regarding exposure to chemicals lixiviated from debris ingested, as an index of the time spent by these substances inside the organism. • Gastrointestinal transit times can last up to 22 days in juvenile green turtles. • Transit times are a proxy for detecting digestive motility disorders. • Inert plastic markers are highly efficient in reporting transit times. • Baseline data to inform toxicology studies on chemicals lixiviated from debris ingested. [ABSTRACT FROM AUTHOR]

Grazing by dugongs and cropping by green turtles have the capacity to alter the subsequent nutritional quality of seagrass regrowth. We examined the effects of simulated light and intensive grazing by dugongs and cropping by turtles on eight nutritionally relevant measures of seagrass chemical composition over two regrowth periods (short-term, 1–4 months; long-term, 11–13 months) at two seagrass communities (a mixed species community with Zostera capricorni, Halophila ovalis, Halodule uninervis, Cymodocea rotundata and C. serrulate; and a monospecific bed of Halodule uninervis) in tropical Queensland, Australia. The concentrations of organic matter, total nitrogen, total water-soluble carbohydrates, total starch, neutral detergent fiber, acid detergent fiber, acid lignin, as well as the in vitro dry matter digestibility (IVDMD) were measured in the leaves and below-ground parts of each species using near-infrared reflectance spectroscopy (NIRS). Regrowth of preferred species such as H. ovalis and H. uninervis from simulated intensive dugong grazing after a year exhibited increased (by 35 and 25%, respectively, relative to controls) whole-plant N concentrations. Similarly, regrowth of H. ovalis from simulated turtle cropping showed an increase in the leaf N concentration of 30% after a year. However, these gains are tempered by reductions in starch concentrations and increases in fiber. In the short-term, the N concentrations increased while the fiber concentrations decreased. These data provide experimental support for a grazing optimization view of herbivory in the tropical seagrass system, but with feedback in a different manner. Furthermore, we suggest that in areas where grazing is the only major source of natural disturbance, it is likely that there are potential ecosystem level effects if and when numbers of dugongs and turtles are reduced. [ABSTRACT FROM AUTHOR]

The diving behaviour of 15 dugongs (Dugong dugon) was documented using time–depth recorders (TDRs), which logged a total of 39,507 dives. The TDRs were deployed on dugongs caught at three study sites in northern Australia: Shark Bay, the Gulf of Carpentaria and Shoalwater Bay. The average time for which the dive data were collected per dugong was 10.4±1.1 (S.E.) days. Overall, these dugongs spent 47% of their daily activities within 1.5 m of the sea surface and 72% less than 3 m from the sea surface. Their mean maximum dive depth was 4.8±0.4 m (S.E.), mean dive duration was 2.7±0.17 min and the number of dives per hour averaged 11.8±1.2. The maximum dive depth recorded was 20.5 m; the maximum dive time in water >1.5 m deep was 12.3 min. The effects of dugong sex, location (study site), time of day and tidal cycle on diving rates (dives per hour), mean maximum dive depths, durations of dives, and time spent ≤1.5 m from the surface were investigated using weighted split-plot analysis of variance. The dugongs exhibited substantial interindividual variation in all dive parameters. The interaction between location and time of day was significant for diving rates, mean maximum dive depths and time spent within 1.5 m of the surface. In all these cases, there was substantial variation among individuals within locations among times of day. Thus, it was the variation among individuals that dominated all other effects. Dives were categorised into five types based on the shape of the time–depth profile. Of these, 67% of dives were interpreted as feeding dives (square and U-shaped), 8% as exploratory dives (V-shaped), 22% as travelling dives (shallow-erratic) and 3% as shallow resting dives. There was systematic variation in the distribution of dive types among the factors examined. Most of this variation was among individuals, but this differed across both time of day and tidal state. Not surprisingly, there was a positive relationship between dive duration and depth and a negative relationship between the number of dives per hour and the time spent within 1.5 m of the surface after a dive. [Copyright &y& Elsevier]