Participatory Risk Assessment of Humpback Whale (Megaptera novaeangliae) and Leatherback Turtle (Dermochelys coriacea) Bycatch in Northern Peru

Uncertainties about the magnitude of bycatch in poorly assessed fisheries impede effective conservation management. In northern Peru, small-scale fisheries (SSF) bycatch negatively impacts marine megafauna populations and the livelihoods of fishers which is further elevated by the under-reporting of incidents. Within the last decade, accounts of entangled humpback whales (HBW) (Megaptera novaeangliae) off the northern coast of Peru have increased, while Eastern Pacific leatherback turtles (LBT) (Dermochelys coriacea) have seen over a 90% decline in nesting populations related in large part to bycatch mortality. By leveraging the experience and knowledge of local fishers, our research objectives were to use a low-cost public participation mapping approach to provide a spatio-temporal assessment of bycatch risk for HBW and LBT off two Peruvian fishing ports. We used an open-source, geographic information systems (GIS) model, the Bycatch Risk Assessment (ByRA), as our platform. Broadly, ByRA identifies high bycatch risk areas by estimating the intersection of fishing areas (i.e., stressors) with species habitat and evaluating the exposure and consequence of possible interaction between the two. ByRA outputs provided risk maps and gear risk percentages categorized as high, medium, and low for the study area and seven subzones for HBW in the austral winter and LBT in the austral summer. Overall, the highest bycatch risk for both species was identified within gillnet fisheries near the coast. Bycatch risk for most gear types decreased with distance from the coast. When we separated the ByRA model by port, our map outputs indicate that bycatch management should be port specific, following seasonal and spatial variations for HBW, and specific fishing gear impacts for HBW and LBT. Combined with direct bycatch mitigation techniques, ByRA can be a supportive and informative tool for addressing specific bycatch threats and marine megafauna conservation goals. ByRA supports a participatory framework offering rapid visual information via risk maps and replicable methods for areas with limited resources and data on fisheries and species habitat.

Occurrence and diet analysis of sea turtles in Korean shore

Background Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.

MENDUKUNG UPAYA PERLINDUNGAN PENYU BELIMBIMG (Dermochelys coriacea) MELALUI PENDIDIKAN (PROGRAM KKN WAU-WEYAF, ABUN)

ABSTRACT Wau-Weyaf Beach is the nesting ground of six species of turtles, including the world's largest turtle, the leatherback turtle (Dermochelys coriacea). The University of Papua (UNIPA) Manokwari, since 2009 has been directly involved in the turtle nesting area protection program by involving the students of UNIPA through the Community Service Program (KKN). In 2016, students carried out the KKN Program starting from June 30th to August 16th in Kampung Wau-Weyaf, one of the leatherback turtles’ egg-laying locations in Abun. This paper is a part of the Community Service Program which is carried out in the said village. The activities conducted during the KKN include both formal and non-formal education, religious education, and environmental education. Education-based KKN directly helps to improve public awareness which, in turn, supports the efforts to protect and save the leatherback turtles (Dermochelys coriacea) on the coast of Abun, Tambrau. The same approach is also able to improve the calistung (the capability to read, write, and count) ability of school children along with their awareness to maintain the cleanliness of their homes, school, and village environment. Keywords: Education; Conservation; Turtle; Wau-Weyaf ABSTRAK Pantai Wau-Weyaf merupakan tempat bertelur bagi 6 jenis penyu, termasuk penyu terbesar di dunia, Penyu Belimbing (Dermochelys coriacea). Universitas Papua (UNIPA) Manokwari, sejak tahun 2009 telah terlibat secara langsung dalam program perlindungan kawasan peneluran penyu ini melalui pelibatan mahasiswa melalui program Kuliah Kerja Nyata (KKN). Pada tahun 2016, mahasiswa Universitas Papua (UNIPA) melaksanakan program KKN yang dilaksanakan antara tanggal 30 Juni sampai dengan 16 Agustus 2016 di Kampung Wau-Weyaf. Tulisan ini merupakan bagian dari pelaksanaan kegiatan KKN yang dilaksanakan di kampung Wau-Weyaf sebagai salah satu lokasi peneluran telur penyu belimbing di Abun. Kegiatan yang dilakukan meliputi pendidikan formal dan non-formal, pendidikan agama, dan pendidikan lingkungan. KKN berbasis pendidikan yang dilakukan secara langsung membantu meningkatkan penyadar tahuan masyarakat yang menunjang usaha perlindungan dan penyelamatan penyu belimbing (Dermochelys coriacea) di pesisir Abun, Tambrau. Pendekatan yang sama juga mampu meningkatkan kemampuan calistung anak-anak sekolah dan kesadaran menjaga kebersihan lingkungan rumah, sekolah dan kampung. Kata kunci: Pendidikan; Konservasi; Penyu; Wau-Weyaf

Leatherback turtles (Dermochelys coriacea) in the Gulf of Venezuela: An update stranding assessment 2001-2014

Leatherback turtle (Dermochelys coriacea) is highly impacted by fisheries’ bycatch worldwide. This study updates and estimates the leatherback turtle stranding records from 2001 to 2014 in the Gulf of Venezuela. Eighty-six stranded leatherback turtles were documented in the coast of the Gulf of Venezuela. Immature leatherback turtles were the most affected (85.1%) and the highest number of strandings were recorded during the dry season (55.8%). Our findings represent the minimum estimate of stranding events for the Gulf of Venezuela, especially considering the current lack of fisheries regulations. This is the latest update for the leatherback turtle strandings in the Gulf of Venezuela and could help to create new management solutions in the area aiming to minimize the impact on leatherback turtle populations in the Caribbean.

First documented record of the leatherback turtle (Dermochelys coriacea) from Djibouti waters

A subadult leatherback turtle was documented in the Gulf of Goubet (Djibouti) during a research expedition. This sighting confirms for the first time previous anecdotal observations of the occurrence of the leatherback turtle, Dermochelys coriacea (Vandelli, 1761), in Djibouti waters. Coupled with observations from fishers, this finding underlines the urgent need to carry out research programs to evaluate the species habitat use within Djibouti waters, and to review the species distribution in the Gulf of Aden. Although marine turtles are protected in Djibouti, illegal harvest and entanglement in fishing gear pose a threat to their survival, and conservation measures should be implemented.

First study of sea turtle strandings in Algeria (western Mediterranean) and associated threats: 2016–2017

Between December 2015 and December 2017 a total of 63 sea turtles were recorded as being stranded along the Algerian coast. The loggerhead sea turtle Caretta caretta was the most commonly stranded species (n = 44) (69.8%), followed by the leatherback Dermochelys coriacea (n = 18) (28.6%) and the green turtle Chelonia mydas (n = 1). There was a slight dominance of the adult size class for stranded loggerhead turtles, while, for the leatherback, late juveniles and adults prevailed. Most loggerhead turtles stranded during the summer months (July and August), whereas most leatherbacks stranded during winter. The breakdown of the strandings by region shows a slight dominance along the western and central shores for C. caretta and a clear dominance in the west for D. coriacea. The primary cause of death was determined in 50.8% of the stranded turtles. Regarding the evidence of interactions with humans the major cause of stranding in loggerhead turtles was incidental catch by artisanal fisheries, followed by boats’ collisions. The main causes of leatherback strandings were boats’ collisions. Algerian data show that human activities affect loggerhead turtles and also prove a significant presence of the leatherback turtle on this coast.

Survival and breeding interval of an endangered marine vertebrate, the leatherback turtle Dermochelys coriacea, in French Guiana

In the context of global change, endangered species such as sea turtles undergo strong population dynamics changes. Understanding demographic processes inducing such changes is critical for developing appropriate measures for conservation and management. Nesting females of the French Guiana population of leatherback sea turtles Dermochelys coriacea represented 40% of the world’s total in 2001; today, they represent only 10%. Here, we analyze data from the long-term monitoring program of leatherbacks in French Guiana, based on 28 yr of capture-mark-recapture data from 46051 individuals in northwestern French Guiana. We used multievent models (multistate capture-recapture models with state uncertainty) to represent the main peculiarity of the life cycle, intermittent reproduction, and to take advantage of the use of several different types of marks to account for mark loss and incomplete detection. The average annual adult survival probability (mean ± SE) 0.789 ± 0.009 is low compared to published estimates for this species. By combining the estimates of departure and return probabilities, we provide an estimate of the interval among laying seasons equal to 2.777 ± 0.118 yr, which matches previous findings. Taking survival into account, this interval translates into an average of 1.704 ± 0.034 further reproductive seasons for an adult female having just bred, which is remarkably low compared to other long-lived vertebrates. The representation of the life cycle and mark loss in our models provides a sound structure for broader and richer analyses to extract biological information from marked individuals and offers an invaluable source of demographic information on leatherbacks, a species for which only a small segment of the population is accessible to intermittent sampling.