61 research outputs found
Using habitat suitability models in an industrial setting: the case for internesting flatback turtles
To predict and manage ecological impacts of anthropogenic activities effectively, an understanding of at-risk species spatial ecology is first required. This is particularly difficult in the marine environment due to limited offshore access and wide-ranging movements of some species. Flatback turtles are a protected species potentially at risk from hazards associated with the resource sector in Australia, yet their at-sea spatial ecology is not well understood. We use habitat suitability modeling to identify environmental variables that influence flatback turtle internesting movement; identify areas of suitable internesting habitat; and determine overlap of identified internesting habitat with resource sector hazards. Internesting movements of 47 female flatback turtles, from five rookeries in the North West Shelf region of Western Australia, were recorded using platform terminal transmitters between 2006 and 2010. Environmental variables including sea surface temperature (SST), bathymetry, magnetic anomalies, distance from coastline, slope, and ruggedness index were combined with the tracking data from each rookery in an ecological niche model. We used the positions of resource sector vessels to represent areas of potential impact from resource sector hazards and identified overlap with suitable internesting habitat areas as a representative of the likelihood of impact. The primary environmental variables that influenced flatback internesting movement were bathymetry, distance from coastline, and SST. Suitable areas of internesting habitat were located in close proximity to many known flatback turtle rookeries across the region. Areas of suitable internesting habitat overlapped resource sector hazards in close proximity to four of the five rookeries and at other known flatback turtle rookeries. The cumulative overlap across the overall study area indicates a high potential for interaction with resource sector hazards, demonstrating the need for regional protection measures in these areas. This study provides a capability for regulators and developers to determine the potential offshore presence of internesting flatback turtles within the region, allowing for protection measures to be targeted appropriately as industrial development continues
Impacts of artificial light at night in marine ecosystemsâA review
The globally widespread adoption of Artificial Light at Night (ALAN) began in the mid-20th century. Yet, it is only in the last decade that a renewed research focus has emerged into its impacts on ecological and biological processes in the marine environment that are guided by natural intensities, moon phase, natural light and dark cycles and daily light spectra alterations. The field has diversified rapidly from one restricted to impacts on a handful of vertebrates, to one in which impacts have been quantified across a broad array of marine and coastal habitats and species. Here, we review the current understanding of ALAN impacts in diverse marine ecosystems. The review presents the current state of knowledge across key marine and coastal ecosystems (sandy and rocky shores, coral reefs and pelagic) and taxa (birds and sea turtles), introducing how ALAN can mask seabird and sea turtle navigation, cause changes in animals predation patterns and failure of coral spawning synchronization, as well as inhibition of zooplankton Diel Vertical Migration. Mitigation measures are recommended, however, while strategies for mitigation were easily identified, barriers to implementation are poorly understood. Finally, we point out knowledge gaps that if addressed would aid in the prediction and mitigation of ALAN impacts in the marine realm
Impacts of artificial light at night in marine ecosystemsâA review
The globally widespread adoption of Artificial Light at Night (ALAN) began in the mid-20th century. Yet, it is only in the last decade that a renewed research focus has emerged into its impacts on ecological and biological processes in the marine environment that are guided by natural intensities, moon phase, natural light and dark cycles and daily light spectra alterations. The field has diversified rapidly from one restricted to impacts on a handful of vertebrates, to one in which impacts have been quantified across a broad array of marine and coastal habitats and species. Here we review the current understanding of ALAN impacts in diverse marine ecosystems. The review
presents the current state of knowledge across key marine and coastal ecosystems (sandy and rocky shores, coral reefs and pelagic) and taxa (birds and sea turtles), introducing how ALAN can mask seabirds and sea turtles navigation, cause changes in animals predation patterns and failure
of coral spawning synchronization, as well as inhibition of zooplankton Diel Vertical Migration. Mitigation measures are recommended, however, while strategies for mitigation were easily identified, barriers to implementation are poorly understood. Finally, we point out knowledge gaps
that if addressed would aid in the prediction and mitigation of ALAN impacts in the marine real
The potential of unmanned aerial systems for sea turtle research and conservation: A review and future directions
This is the final version. Available on open access from Inter Research via the DOI in this recordThe use of satellite systems and manned aircraft surveys for remote data collection has been shown to be transformative for sea turtle conservation and research by enabling the collection of data on turtles and their habitats over larger areas than can be achieved by surveys on foot or by boat. Unmanned aerial vehicles (UAVs) or drones are increasingly being adopted to gather data, at previously unprecedented spatial and temporal resolutions in diverse geographic locations. This easily accessible, low-cost tool is improving existing research methods and enabling novel approaches in marine turtle ecology and conservation. Here we review the diverse ways in which incorporating inexpensive UAVs may reduce costs and field time while improving safety and data quality and quantity over existing methods for studies on turtle nesting, at-sea distribution and behaviour surveys, as well as expanding into new avenues such as surveillance against illegal take. Furthermore, we highlight the impact that high-quality aerial imagery captured by UAVs can have for public outreach and engagement. This technology does not come without challenges. We discuss the potential constraints of these systems within the ethical and legal frameworks which researchers must operate and the difficulties that can result with regard to storage and analysis of large amounts of imagery. We then suggest areas where technological development could further expand the utility of UAVs as data-gathering tools; for example, functioning as downloading nodes for data collected by sensors placed on turtles. Development of methods for the use of UAVs in sea turtle research will serve as case studies for use with other marine and terrestrial taxa
Biochemical indices and life traits of loggerhead turtles (Caretta caretta) from Cape Verde Islands
The loggerhead turtle (Caretta caretta) is an endangered marine reptile for whom assessing population health requires
knowledge of demographic parameters such as individual growth rate. In Cape Verde, as within several populations, adult
female loggerhead sea turtles show a size-related behavioral and trophic dichotomy. While smaller females are associated
with oceanic habitats, larger females tend to feed in neritic habitats, which is reflected in their physiological condition and in
their offspring. The ratio of RNA/DNA provides a measure of cellular protein synthesis capacity, which varies depending on
changes in environmental conditions such as temperature and food availability. The purpose of this study was to evaluate
the combined use of morphometric data and biochemical indices as predictors of the physiological condition of the females
of distinct sizes and hatchlings during their nesting season and how temperature may influence the physiological condition
on the offspring. Here we employed biochemical indices based on nucleic acid derived indices (standardized RNA/DNA
ratio-sRD, RNA concentration and DNA concentration) in skin tissue as a potential predictor of recent growth rate in nesting
females and hatchling loggerhead turtles. Our major findings were that the physiological condition of all nesting females
(sRD) decreased during the nesting season, but that females associated with neritic habitats had a higher physiological
condition than females associated with oceanic habitats. In addition, the amount of time required for a hatchling to right
itself was negatively correlated with its physiological condition (sRD) and shaded nests produced hatchlings with lower sRD.
Overall, our results showed that nucleic acid concentrations and ratios of RNA to DNA are an important tool as potential
biomarkers of recent growth in marine turtles. Hence, as biochemical indices of instantaneous growth are likely
temperature-, size- and age-dependent, the utility and validation of these indices on marine turtles stocks deserves further
study.The authors thank the Cape Verde Ministry of Environment (General Direction for the Environment), INDP (National Fisheries Institution), the Canary
Islands Government (D.G. Africa and D.G. Research and Universities), ICCM (Canarian Institution for Marine Sciences), the Andalusian Government (Andalusian
Environmental Office) and AEGINA PROJECT (INTERREG IIIB) for funding and hosting them during this study. The authors also thank the European Regional
Development Fund (ERDF) through the COMPETE - Operational Competitiveness Programme, and national funds through FCT - PEst-C/MAR/LA0015/2011 for
supporting the biochemical analysis
Futurecasting ecological research: the rise of technoecology
Increasingly complex research questions and global challenges (e.g., climate change and biodiversity loss) are driving rapid development, refinement, and uses of technology in ecology. This trend is spawning a distinct subâdiscipline, here termed “technoecology.” We highlight recent groundâbreaking and transformative technological advances for studying species and environments: bioâbatteries, lowâpower and longârange telemetry, the Internet of things, swarm theory, 3D printing, mapping molecular movement, and lowâpower computers. These technologies have the potential to revolutionize ecology by providing “nextâgeneration” ecological data, particularly when integrated with each other, and in doing so could be applied to address a diverse range of requirements (e.g., pest and wildlife management, informing environmental policy and decision making). Critical to technoecology\u27s rate of advancement and uptake by ecologists and environmental managers will be fostering increased interdisciplinary collaboration. Ideally, such partnerships will span the conception, implementation, and enhancement phases of ideas, bridging the university, public, and private sectors
Movement, distribution and marine reserve use by an endangered migratory giant
Aim Understanding the spatial and temporal variation in the distribution of migratory species is critical for management and conservation efforts. However, challenges in observing mobile marine species throughout their migratory pathways can impede the identification of critical habitat, linkages between these habitats and threat-mitigation strategies. This study aimed to gain insight into the long-term residency and movement patterns of the whale shark (Rhincodon typus) and to reveal important habitat in the context of R. typus usage of existing Marine Protected Areas (MPAs). Location South-eastern Indian Ocean. Methods Satellite telemetry was used to remotely track the long-term movements of 29 R. typus, and to quantify shark usage of the existing MPA network. From the tracking data and environmental predictors, nonlinear models were developed to predict suitable R. typus habitat throughout the south-eastern Indian Ocean. Results This study includes the first documented complete return migrations by R. typus to Ningaloo Marine Park, which was found to be an important area for R. typus all year-round. We found that while existing MPAs along Australia's west coast do afford some protection to R. typus, telemetry-based habitat models revealed large areas of suitable habitat not currently protected, particularly along the Western Australian coast, in the Timor Sea, and in Indonesian and international waters. Main conclusions Animal-borne telemetric devices allowed the gathering of long-term spatial information from the elusive and highly mobile R. typus, revealing the spatial scale of their migration in the south-eastern Indian Ocean. Suitable habitat was predicted to occur inside conservation areas, but our findings indicate that the current MPA network may not sufficiently protect R. typus throughout the year. We suggest that telemetry-based habitat models can be an important tool to inform conservation planning and spatial management efforts for migratory species
Leatherback hatchling sea-finding in response to artificial lighting: Interaction between wavelength and moonlight
Green and hawksbill turtles in the Lesser Antilles demonstrate behavioural plasticity in inter-nesting behaviour and post-nesting migration
Satellite transmitters were deployed on three green turtles, Chelonia mydas, and two hawksbill turtles, Eretmochelys imbricata, nesting in the Lesser Antilles islands, Caribbean, between 2005-2007 to obtain preliminary information about the inter-nesting, migratory and foraging habitats in the region. Despite the extremely small dataset, both year-round residents and migrants were identified; specifically (1) two green turtles used local shallow coastal sites within 50 km of the nesting beach during all of their inter-nesting periods and then settled at these sites on completion of their breeding seasons, (2) one hawksbill turtle travelled 200 km westward before reversing direction and settling within 50 km of the original nesting beach and (3) one green and one hawksbill turtle initially nested at the proximate site, before permanently relocating to an alternative nesting site over 190 km distant. A lack of nesting beach fidelity was supported by flipper tag datasets for the region. Tagging datasets from 2002-2012 supported that some green and hawksbill individuals exhibit low fidelity to nesting beaches, whereas other females exhibited a high degree of fidelity (26 turtles tagged, 40.0km maximum distance recorded from original nesting beach). Individual turtles nesting on St Eustatius and St Maarten appear to exhibit behavioural plasticity in their inter-nesting behaviour and post-nesting migration routes in the Eastern Caribbean. The tracking and tagging data combined indicate that some of the green and hawksbill females that nest in the Lesser Antilles Islands are year-round residents, while others may nest and forage at alternative sites. Thus, continued year-round protection of these islands and implementation of protection programmes in nearby islands could contribute towards safeguarding the green and hawksbill populations of the region
Linking loggerhead locations: using multiple methods to determine the origin of sea turtles in feeding grounds
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