Sympathy for the Devil: A Conservation Strategy for Devil and Manta Rays

Background  International trade for luxury products, medicines, and tonics poses a threat to both terrestrial and marine wildlife. The demand for and consumption of gill plates (known as Peng Yu Sai, “Fish Gill of Mobulid Ray”) from devil and manta rays (subfamily Mobulinae, collectively referred to as mobulids) poses a significant threat to these marine fishes because of their extremely low productivity. The demand for these gill plates has driven an international trade supplied by largely unmonitored and unregulated catches from target and incidental fisheries around the world. Scientific research, conservation campaigns, and legal protections for devil rays have lagged behind those for manta rays despite similar threats across all mobulids. Methods  To investigate the difference in attention given to devil rays and manta rays, we examined trends in the scientific literature and updated species distribution maps for all mobulids. Using available information on target and incidental fisheries, and gathering information on fishing and trade regulations (at international, national, and territorial levels), we examined how threats and protective measures overlap with species distribution. We then used a species conservation planning approach to develop the Global Devil and Manta Ray Conservation Strategy, specifying a vision, goals, objectives, and actions to advance the knowledge and protection of both devil and manta rays. Results and Discussion  Our literature review revealed that there had been nearly 2.5-times more “manta”-titled publications, than “mobula” or “devil ray”-titled publications over the past 4.5 years (January 2012–June 2016). The majority of these recent publications were reports on occurrence of mobulid species. These publications contributed to updated Area of Occupancy and Extent of Occurrence maps which showed expanded distributions for most mobulid species and overlap between the two genera. While several international protections have recently expanded to include all mobulids, there remains a greater number of national, state, and territory-level protections for manta rays compared to devil rays. We hypothesize that there are fewer scientific publications and regulatory protections for devil rays due primarily to perceptions of charisma that favour manta rays. We suggest that the well-established species conservation framework used here offers an objective solution to close this gap. To advance the goals of the conservation strategy we highlight opportunities for parity in protection and suggest solutions to help reduce target and bycatch fisheries

Balanced X autosome translocation suggests association of AMMECR1 disruption with hearing loss short stature bone and heart alterations

Univ Fed Sao Paulo, Dept Morphol & Genet, Sao Paulo, BrazilUniv Geneva, Dept Genet Med & Dev, Geneva, SwitzerlandUniv Lausanne, Ctr Integrat Genom, Lausanne, SwitzerlandBaylor Coll Med, Dept Mol & Human Genet, Houston, TX 77030 USAHop Jeanne De Flandre, Clin Genet, Lille, FranceUniv Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilUniv Sao Paulo, Dept Pathol, Sao Paulo, BrazilFriedrich Schiller Univ, Inst Human Genet, Jena, GermanyHop Jeanne De Flandre, Inst Genet Med, Lille, FranceUniv Fed Sao Paulo, Dept Morphol & Genet, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilWeb of Scienc

Cetaceans in the global centre of marine biodiversity

Indonesia has a diverse range of cetacean species, yet there are few records of their distribution, especially from remote regions. Incidental sightings from aerial surveys were conducted in 2006 and boat-based surveys were conducted from 2006–2011 in Raja Ampat in the Bird's Head Seascape, Indonesia. This paper is the first to provide a species list and an indication of the spatial and temporal distribution of cetaceans in central and southern Raja Ampat. Seven dolphin and six whale species were documented, including Indo-Pacific humpback dolphins Sousa chinensis, Bryde's Balaenoptera edeni, sperm Physeter macrocephalus, killer Orcinus orca and pygmy killer Feresa attenuata whales. Temporal differences in sightings suggest Raja Ampat is an important area for migratory whale species and resident populations of Indo-Pacific humpback Sousa chinensis, spinner Stenella longirostris and common bottlenose Tursiops truncatus dolphins. Cetacean diversity was highest in the months of January–February, May and October–November, with most sightings recorded in Kofiau marine protected area and Dampier and Sagewin Straits. Diversity and species distribution data are critical for managing cetaceans in Indonesia. Emerging threats to cetaceans in Raja Ampat include seismic surveys for seabed oil and gas exploration, potential strikes from increasing ship traffic, entanglement in fishing nets and increasing discharge of plastic pollution from urban areas. In addition to regulations for marine protected areas, a wider conservation strategy is required to address or better manage emerging threats to Raja Ampat, and to ensure the long-term protection of resident and migratory dolphin and whale species

Immature individuals dominate elasmobranch fisheries of the Bali Strait

Elasmobranchs play an important role in the functioning of marine ecosystems and top-down control in food webs. However, overexploitation threatens elasmobranch populations worldwide. Indonesia is currently the leading elasmobranch fishing nation, yet elasmobranch management in Indonesia is challenging because of the paucity of data on elasmobranch fisheries, especially at a species level. This study examined the elasmobranch fisheries of the Bali Strait by describing the species, sex and size composition of the elasmobranch catch landed at a major port in Eastern Java, Indonesia. Data were collected between August 2017 and March 2018 in Muncar. Elasmobranchs were identified to species level and sexed. The disc width and length of 301 rays and the precaudal length and fork length of 1657 sharks were measured. In all, 53 species were identified, many of which are at conservation risk, including species with national and international protection. Vulnerability to fishing gear varied across sex and size of each species, with immature individuals dominating the catch of most species. The findings emphasise the need for improved management of elasmobranchs in Indonesia and could help identify priorities or form strategies. Additional regional and fisheries-specific research is recommended to develop efficient and locally adapted management strategies

Motivations for compliance in Peruvian manta ray fisheries

Fishermen's compliance with fisheries legislation is influenced by a combination of economic, calculated, normative, and social motivations. Compliance can be enhanced by fishers’ inclusiveness within management directives. Since the 2015 fishing ban on the giant oceanic manta ray (Mobula birostris) in Peru, there has been no significant decline in the catch of this protected species. Structured questionnaires were administered to small-scale fishers in two fishing communities in northern Peru, exploring their perspectives and attitudes towards compliance motivations as indicators influencing their non-compliant behaviour. Compliance was mostly hindered due to economic hardship, lack of legitimacy towards authorities driven by corruption and low social influence to comply. The diverging motivations to comply in both communities suggest the engagement of fishermen in fisheries management through local policy changes could lead to increased compliance. This study contributes to understanding fishers’ non-compliant behaviour in fisheries of lower commercial value

Predicting mobulid ray distribution in coastal areas of Lesser Sunda Seascape: Implication for spatial and fisheries management

The Lesser Sunda Seascape (LSS) is considered one of the regions with the largest mobulid fisheries in Indonesia, although their spatial distribution and habitat preference in the LSS is still largely unknown. The goal of the present study was to describe the habitat preference and distribution of the oceanic manta rays, spinetail devil rays, and Chilean devil rays in the coastal area of LSS. We used multiple data sources of mobulid ray sightings and selected significant environmental predictors to execute the maximum entropy model. The model performed well in predicting mobulid ray habitat in the coastal area of LSS and indicated that sea-surface chlorophyll-a (SSC-a), sea-surface temperature (SST), sea-surface salinity (SSS), distance to the 200-m isobath, distance to the 3000-m isobath, and slope were all significant environmental predictors of their distribution. This study confirms that the habitat preference of mobulid rays were in the areas that close to the 200-m isobath and with higher chlorophyll-a concentration as proxy for their prey density. Combining habitat models with fisheries activity records indicated that the areas where these overlaps may represent key mobulid habitats. This study highlights a critical need for species-specific and populations-level management measures for Indonesian mobulid rays, whereas current MPA design has focused on a broad-scale coastal ecosystem management approach, which may have limited effectiveness in practice. This study provides valuable information for the improvement of MPA design and fisheries management tools, through maximum entropy modeling as a powerful means to describe species’ distributions and habitat preference. We recommend that future efforts focus on documenting and incorporating data from large-scale commercial fisheries to improve our knowledge of habitat preference and distribution models in offshore areas and the high seas, and to assess the preference for coastal versus oceanic habitats

Preliminary insights into the population characteristics and distribution of reef (Mobula alfredi) and oceanic (M. birostris) manta rays in French Polynesia

In French Polynesia, both currently recognized manta ray species, Mobula alfredi and M. birostris, are observed. Despite being an important cultural asset and generating significant economic benefits through manta ray watching tourism, published data on the ecology and threats to these species in the region are scarce. Based on an 18-year dataset of sighting records collected by citizen scientists and during two scientific expeditions, this study provides the first insights into the population characteristics and regional distribution of the two manta ray species in French Polynesia. A total of 1347 manta ray photographs (1337 for M. alfredi and 10 for M. birostris) were examined for the period January 2001–December 2017, with photo-identification techniques leading to the successful identification of 317 individual M. alfredi and 10 individual M. birostris throughout the Society, Tuamotu and Marquesas Islands. We provide the first confirmation of sympatric distribution of both species in the Society Islands. Our results highlight strong and long-term site fidelity of M. alfredi individuals to certain aggregation sites (> 9 years for 16 individuals) and reveal some degree of connectivity between populations, with 10 individuals recorded moving between islands located up to 50 km apart. Analysis of photographs of individuals bearing sub-lethal injuries (n = 68) suggests that M. alfredi are more likely to be injured at inhabited islands (Maupiti or Bora Bora; 75% of all injured individuals) than at uninhabited islands, with 75% of injuries related to boat propeller strikes and fishing gear entanglements. Our findings emphasize the need for further research to allow for a comprehensive evaluation of population structure, size and threats to manta rays in this region

Protecting the million-dollar mantas; creating an evidence-based code of conduct for manta ray tourism interactions

Manta ray tourism is estimated to contribute US$ 140 million annually to the global economy. The multitudes of tourists potentially disturb the animals, yet the effect of human behaviour on feeding manta rays has not been quantified. Using videos collected at feeding sites in the Maldives, we found that only 44% of observed human-manta interactions complied with existing guidelines. Human behaviours; accidental obstruction, diving too near/in front, chasing, and approaching from the front, all had a statistically significant negative effect on behaviour, resulting in feeding cessation, while passive interactions resulted in significantly less disturbance and cessation reactions. Interactions within three metres caused significantly increased avoidance behaviours. These findings support the guidelines provided by the Manta Trusts’ code of conduct, which aims to develop legislation to minimise disturbance by tourism. Our key recommendations aim to ensure that the manta ray tourism industry remains sustainable and non-detrimental to the animals’ natural behaviour. Visit https://swimwithmantas.org/ for video abstract