Satellite tracking in sea turtles: How do we find our way to the conservation dividends?

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.As species of conservation concern, sea turtles have historically been difficult to study because of their elusive nature and extensive ranges, but improvements in telemetry have facilitated insights into life histories and behaviours which can potentially inform conservation policies. To date, there have been few assessments of the impact of satellite tracking data on species conservation, and it is difficult to clearly gauge whether the dividends justify the costs. Through an extensive review of the literature (369 papers, 1982-2014) and a questionnaire-based survey of 171 sea turtle tracking researchers, we evaluate the conservation dividends gained thus far from tracking and highlight conservation successes. We discuss who is tracking and where, where biases in effort exist, and evaluate the impact of tracking data on conservation. Conservation issues are increasingly being considered. Where research recommends policy change, the quality of advice varies and the level of uptake is still uncertain, with few clearly described examples of tracking-data actually influencing policy. The means to increase the conservation impact are discussed, including: disseminating findings more widely; communicating and collaborating with colleagues and stakeholders for more effective data sharing; community liaison, and endeavouring to close the gaps between researchers and conservation practitioners

Take only photographs, leave only footprints: novel applications of non-invasive survey methods for rapid detection of small, arboreal animals

This is the final version of the article. Available from the publisher via the DOI in this record.The development of appropriate wildlife survey techniques is essential to promote effective and efficient monitoring of species of conservation concern. Here, we demonstrate the utility of two rapid-assessment, non-invasive methods to detect the presence of elusive, small, arboreal animals. We use the hazel dormouse, Muscardinus avellanarius, a rodent of conservation concern, as our focal species. Prevailing hazel dormouse survey methods are prolonged (often taking months to years to detect dormice), dependent on season and habitat, and/or have low detection rates. Alternatives would be of great use to ecologists who undertake dormouse surveys, especially those assessing the need for mitigation measures, as legally required for building development projects. Camera traps and footprint tracking are well-established tools for monitoring elusive large terrestrial mammals, but are rarely used for small species such as rodents, or in arboreal habitats. In trials of these adapted methods, hazel dormice visited bait stations and were successfully detected by both camera traps and tracking equipment at each of two woodland study sites, within days to weeks of installation. Camera trap images and footprints were of adequate quality to allow discrimination between two sympatric small mammal species (hazel dormouse and wood mouse, Apodemus sylvaticus). We discuss the relative merits of these methods with respect to research aims, funds, time available and habitat.The work in this study was undertaken as part of a self-funded PhD and the authors have no support or funding to report for the work outlined in this manuscript

Growth rates of adult sea turtles

This is the final version of the article. Available from Inter Research via the DOI in this record.Indeterminate growth, i.e. growth that persists throughout life, is common in longlived reptiles. Because fecundity and body size tend to be correlated in such species, individuals face a life-history trade-off at sexual maturity. Saturation tagging and intensive monitoring at nesting grounds can potentially provide opportunities to accumulate data on individual measurements and reproductive output. Until recently, however, shortcomings from these methods have prevented the testing of theories on resource allocation between growth and reproduction at sexual maturity in wild populations of sea turtles. Here, we review the state of knowledge of growth rates in adult sea turtles and potential life-history trade-offs. We found that post-maturity growth rates varied among ocean basins. They appeared highest in the Atlantic Ocean for both green turtles Chelonia mydas and hawksbill turtles Eretmochelys imbricata, and highest in the Mediterranean Sea for loggerhead turtles Caretta caretta. For other species, there are too few studies at present to allow for intraspecific comparison. Additionally, we found no significant difference in mean female compound annual growth rates among species and ocean basins. Although captive studies have provided great insight into changes in energy allocation at sexual maturity and life-history trade-offs, this review highlights the lack of data on wild animals regarding changes in post-maturity growth rates and reproductive output over time. Such data are desirable to further our understanding of energy allocation, growth and ageing in wild sea turtles. They are further required to assess the status of species and to understand population dynamics for both conservation and management

Media framing of the Cayman Turtle Farm: implications for conservation conflicts

 This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordConflicts over natural resource use and management often arise where groups have different goals or priorities. The media can play an important dual role in these conflicts; article content might offer insights about public opinion, whilst media may shape debates and how issues are perceived by the public and decision-makers. Wildlife farming is a contentious conservation tool attracting the attention of worldwide media, and associated conflicts among different interest groups may undermine its applicability. We investigated the media’s portrayal of the Cayman Turtle Farm (CTF), a facility in the Cayman Islands which breeds green sea turtles (Chelonia mydas) for human consumption, to investigate how the media presents information about wildlife farming (i.e. framing), consider its potential roles influencing conflicts and explore how it can be used for conservation conflict management. Content analysis was used to compare framing, article valence, and stakeholder representation in 634 newspaper articles from the international and local media. These media stories were framed in terms of: tourism, conflict, conservation, culture/community, management, and utilisation. International articles most often described CTF as a tourism facility. However, during a media campaign by an international animal welfare group, CTF was also often depicted as a source of controversy. Trade in turtle products was mostly debated in older articles. Local media mainly had a financial focus. Conflict framing was associated with a negative article valence, and conflict framed articles were significantly more likely to contain no conservation information. Mentions of environmental interest groups were significantly associated with negative articles, whereas academics were significantly more likely to be mentioned in positive articles. Conservationists must consider stakeholder objectives from the outset of interventions and be aware of the multiple roles the media might play. Media analysis and effectively harnessing the potential of media outlets should be considered as tools for managing conservation conflicts.Darwin Initiativ

Global review of shark and ray entanglement in anthropogenic marine debris

This is the final version. Available on open access from Inter Research via the DOI in this recordNumerous marine taxa become entangled in anthropogenic marine debris, including cartilaginous fishes (class: Chondrichthyes, e.g. elasmobranchs [sharks, skates and rays], holocephalans [chimaeras]). Here we review research that has been conducted on the susceptibility of these taxa to entanglement in marine debris by conducting a systematic literature review complemented by novel data collection from the social media site Twitter. Our literature review yielded 47 published elasmobranch entanglement events (N = 557 animals) in 26 scientific papers, with 16 different families and 34 species in all 3 major ocean basins affected. The most common entangling objects were ghost fishing gear (74% of animals) followed by polypropylene strapping bands (11% of animals), with other entangling materials such as circular plastic debris, polythene bags and rubber tyres comprising 1% of total entangled animals. Most cases were from the Pacific and Atlantic oceans (49 and 46%, respectively), with a bias towards the USA (44% of animals), the UK (30% of animals) and South Africa (10% of animals). While investigating Twitter, we found 74 cases of elasmobranch entanglement, representing 14 families and 26 species. On Twitter, ghost fishing gear was again the most common entangling material (94.9% of animals), with the majority of entanglement records originating from the Atlantic Ocean (89.4% of total entangled animals). Entanglement in marine debris is symptomatic of a degraded marine environment and is a clear animal welfare issue. Our evidence suggests, however, that this issue is likely a far lesser threat to this taxon than direct or indirect take in marine fisheries. We highlight a relative paucity of scientific data on this subject and recommend a standardisation of reporting in an attempt to accurately quantify elasmobranch entanglement risks and locate interaction hotspots

So excellent a fishe: A global overview of legal marine turtle fisheries

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordAim: We provide a global assessment of the current legal direct take of marine turtles, including the scale and species breakdown at country level, and investigate the significance of legal take to marine turtle populations within the wider context of global threats. Location: World-wide. Methods: We undertook a comprehensive review of the literature (>500 publications) and contacted over 150 in-country experts to collate data for countries that permit the legal take of marine turtles (as of 1 January 2013). Current annual take for each country and species was estimated, and estimates were generated for the 1980s, 1990s and 2000s. Results: Currently, 42 countries and territories permit direct take of turtles and collectively take in excess of 42,000turtles per year, the majority of which (>80%) are green turtles Chelonia mydas (Linnaeus 1758). Ten countries account for more than 90% of legal take each year with Papua New Guinea (36.1%) and Nicaragua (22.3%) accounting for more than half of the total global take. Since 1980, we estimate that more than 2million turtles have been legally taken in these countries, with current levels <60% of those in the 1980s. Main conclusions: Our results provide the most comprehensive global synthesis of the legal take of turtles in recent years and suggest that legal take has the potential to be a driver of marine turtle population dynamics, comparable to mortality estimates through recorded bycatch. However, it is likely that illegal take, along with bycatch, is significantly under-recorded and far greater than the total level of directed legal take. This hampers the ability to assess the relative impacts of these threats to marine turtles

Seismic surveys and marine turtles: An underestimated global threat?

Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have been largely neglected both in terms of research and their inclusion in mitigation policies. Few studies have investigated the potential for seismic surveys to cause behavioural changes or physical damage, indicating a crucial knowledge gap. Possible ramifications for turtles include exclusion from critical habitats, damage to hearing and entanglement in seismic survey equipment. Despite this, the policy comparison revealed that only three countries worldwide currently include turtles in their seismic mitigation guidelines and very few of the measures they specify are based on scientific evidence or proven effectiveness. Opinions obtained from stakeholder groups further highlight the urgent need for directed, in-depth empirical research to better inform and develop appropriate mitigation strategies. As seismic surveying is becoming increasingly widespread and frequent, it is important and timely that we evaluate the extent to which marine turtles, a taxon of global conservation concern, may be affected.This work was supported by NERC (QBEX code NE/J012319/1) and the Darwin Initiative (DI 20-009)

Basking shark breaching behaviour observations West of Shetland

This is the author accepted manuscript. The final version is available from BioMed Central via the DOI in this record.This study reports observations of basking sharks (Cetorhinus maximus) sighted during an offshore geophysical survey conducted in July and August 2013, west of Shetland, UK. During the 38-day survey, trained and dedicated marine wildlife observers recorded 19 sightings of basking sharks (n=22 individuals). Of these observations, 17 were of single sharks, with one observation of two sharks and one observation of three sharks. All surface sightings occurred in water with depths between 129 and 199 m, predominantly prior to noon local time (79%), and were mostly of sharks 6-8 m in length, although a young (2 m) individual was also recorded. Breaching behaviour was observed on 14 occasions, by individuals or in small groups. Breaching has been proposed as a male-male competitive behaviour during courtship displays and female basking sharks may breach to signal their readiness for mating. Aggregations of basking sharks at frontal systems are well documented and linked to the occurrence of prey patches; however, these oceanographic features may also be of importance to courtship. The high number of sightings of sharks recorded during a relatively short time frame in addition to breaching behaviour and presence of young individuals, suggest that this area west of Shetland may be an important habitat for the basking shark

Investigating microplastic trophic transfer in marine top predators

Microplastics are highly bioavailable to marine organisms, either through direct ingestion, or indirectly by trophic transfer from contaminated prey. The latter has been observed for low-trophic level organisms in laboratory conditions, yet empirical evidence in high trophic-level taxa is lacking. In natura studies face difficulties when dealing with contamination and differentiating between directly and indirectly ingested microplastics. The ethical constraints of subjecting large organisms, such as marine mammals, to laboratory investigations hinder the resolution of these limitations. Here, these issues were resolved by analysing sub-samples of scat from captive grey seals (Halichoerus grypus) and whole digestive tracts of the wild-caught Atlantic mackerel (Scomber scombrus) they are fed upon. An enzymatic digestion protocol was employed to remove excess organic material and facilitate visual detection of synthetic particles without damaging them. Polymer type was confirmed using Fourier-Transform Infrared (FTIR) spectroscopy. Extensive contamination control measures were implemented throughout. Approximately half of scat subsamples (48%; n ¼ 15) and a third of fish (32%; n ¼ 10) contained 1e4 microplastics. Particles were mainly black, clear, red and blue in colour. Mean lengths were 1.5mm and 2mm in scats and fish respectively. Ethylene propylene was the most frequently detected polymer type in both. Our findings suggest trophic transfer represents an indirect, yet potentially major, pathway of microplastic ingestion for any species whose feeding ecology involves the consumption of whole prey, including humans

Evidence of overfishing in small-scale fisheries in Madagascar

This is the final version. Available from the publisher via the DOI in this record.The datasets generated for this study are available on request to the corresponding authorSmall-scale fisheries are an important source of food, income and cultural identity to millions of people worldwide. Despite many fisher people observing declining catches, a lack of data remains a barrier to understanding the status of small-scale fisheries and their effective management in many places. Where data exist, complex analyses and stock assessments are often beyond the capacity and budgets of local managers. Working with small-scale fisheries in western Madagascar, we analyze landings data to provide a description of the fishery and evaluate the top twenty most commonly caught species for evidence of overfishing. Using length composition data, we use Froese’s three simple rules: Let them spawn, let them grow and let the mega-spawners live, as well as Cope and Punt’s decision tree to infer if spawning biomass is less than target reference points. We then use length-based parameters to calculate fishing mortality and compare with published estimates of natural mortality to assess overfishing (F > M). Over 17,000 fishing trips were registered over a 2-year period (2010–2012), landing just short of 2 million individual fish. Length data were recorded for a sample of over 120,000 individuals. Fish comprised 95% of landings, with the remainder comprised of other groups including crustaceans (mostly shrimp, crab, and lobster), cephalopods, and holothurians. We provide some of the first evidence that fish species caught in the small-scale fisheries of the Menabe region of Madagascar are experiencing overfishing. The most notable result is that for 13 of the 20 most common species, fishing mortality exceeds natural mortality. Many species had a large proportion of individuals (in some cases 100%) being caught before they reached maturity. Very few species were fished at their optimal size, and there were low numbers of large individuals (mega-spawners) in catches. Overfishing in western Madagascar presents a serious threat to the income, food security and well-being of some of the most vulnerable people in the world. The results of this paper support the call for improved management. However, management approaches should take account of overlapping fisheries and be inclusive to ensure the impacts of management do not undermine the rights of small-scale fishers. Further data are needed to better understand the trends and to improve management but should not hinder pragmatic action.European Union’s Regional Coastal Management Programme of the Indian Ocean Countrie