ecOceánica

The Mobulidae family comprises nine extant manta and devil ray (mobulid) species in the monogeneric genus Mobula, of which five occur in Peruvian waters. In this study, we assessed mobulid ray landings and trade along the coast of Peru by analysing historical captures, monitoring landing sites, and conducting interviews with fishers (n = 37) and traders (n = 21). A total of 7444.9 tons of mobulids were reported from 2000 to the end of 2023 in artisanal fisheries through data collected by the Marine Institute of Peru. Between 2013 and 2023, mean yearly mobulid ray landings for northern Peru were approximately 11,520 individuals (7414 M. munkiana, 3126 M. mobular, and 981 M. thurstoni) based on species-specific estimates of weight at maturity. This ranks Peru among the top mobulid fisheries globally. Of great concern was a 75.05% decline in mobulid ray landings between 2013 and 2023 relative to 2000–2012. Additionally, six key mobulid landing sites in the Tumbes and Piura region were monitored between April 2017 and February 2019, sampling 257 mobulid ray specimens for detailed morphometric data. In these surveys, the most abundant species was M. mobular (n = 156, 60.7%), followed by M. thurstoni (n = 47, 18.3%), M. munkiana (n = 24, 9.3%), and M. birostris (n = 4, 1.6%). Interviews suggest the highest mobulid landings occur during the warm season (December to May). Although M. birostris has been protected in Peruvian waters since 2016, and recent legislation extends protection to all mobulid species, this study reinforces that all mobulid species are globally threatened. Therefore, the large number of mobulid rays landed in Peru annually is a major concern and requires urgent attention by fisheries management authorities to determine the necessary regulations required to conserve these highly vulnerable species.

The Eastern South Pacific Right Whale (SRW) (Eubalaena australis) population has gained interest due to its Critically Endangered conservation status. So far, this population has been confirmed only along the coasts of Chile (18°20’S to 56°30’S) and from southern to central Peru (17°38’S to 12°11’S). Recent records have extended the species’ known range, highlighting its geographic distribution, now reaching 1500 km north. Here, we report six recent records, consisting of five sightings and one stranding, that expand the documented range to northern Ecuador (0.6°N). The northern extension of the population may be associated with the unusual three-year-long cold phase (La Niña) of the El Niño Southern Oscillation (ENSO) in the eastern South Pacific, population expansion, movement and re-distribution of the species, increased monitoring effort, or a combination of these factors. These observations raise hope for the Critically Endangered SRW population, as the occurrence of mother-calf pairs may indicate a potential for population recovery. Nevertheless, these findings intensify concerns for what is still the least abundant SRW population, underscoring the urgency for more targeted research and conservation measures.

Peru is experiencing a “gastronomic boom” that is increasing the demand for seafood. We investigated two implicit assumptions of two popular sustainable seafood consumer-based initiatives: (1) seafood is labelled correctly, and (2) the recommended species are healthy for consumers. We used DNA barcoding to determine the taxonomic identity of 449 seafood samples from markets and restaurants and analysed the concentration of total mercury (THg) in a sub-sample (271 samples) of these. We found that a third of seafood is mislabelled and that over a quarter of all samples had mercury levels above the upper limit recommended by the US EPA (300 ng/g ww). Additionally, 30% of samples were threatened and protected species. Mislabelling often occurred for economic reasons and the lack of unique common names. Mislabelled samples also had significantly higher mercury concentrations than correctly labelled samples. The “best choice” species compiled from two sustainable seafood guides had less mislabelling, and when identified correctly through DNA barcoding, had on average lower mercury than the other species. Nevertheless, some high mercury species are included in these lists. Mislabelling makes the efforts of seafood campaigns less effective as does the inclusion of threatened species and species high in mercury.

Megamouth Shark, Megachasma pelagios Taylor, Compagno & Struhsaker, 1983, is one of the least-known shark species worldwide. We report the encounters of four megamouth sharks: one caught in a driftnet off Piura (November 2016; sex indeterminate), one landed in Los Organos (July 2018; female), one stranded in El Ñuro (July 2018; sex indeterminate, ca 300 m total length), and one caught in a purse seine off Lambayeque (June 2019; female, total length ca 300 cm). These are the first records from Peru and expand the species’ known southern limit by 415 km. With the addition of M. pelagios, there are 67 species of sharks in Peru.

Inshore bays are key foraging grounds for immature green turtles Chelonia mydas. At these confined areas, capturemarkrecapture (CMR) programs generate valuable informa- tion that can be used to estimate vital rates, essential for the effective conservation of this endan- gered species. We compiled the CMR history profiles of 273 individuals from 13 yr of in-water sur- veys and employed the Cormack-Jolly-Seber model to estimate the survival probabilities of green turtles in 2 neritic bays at Culebra municipality, Puerto Rico. The CMR profiles were grouped into 2 size classes: juvenile and subadult. No adults were captured during the study. We found no sig- nificant differences in survival probability between the green turtles occupying each bay. We also assessed the survival probability of fibropapillomatosis (FP)-afflicted turtles versus FP-free turtles and found no significant differences among these groups. However, there was a significant differ- ence in survival between the 2 size classes. Juveniles showed a higher survival probability (0.8322, 95% CI = 0.7875 to 0.8690) than subadults (0.5290, 95% CI = 0.3851 to 0.6682). The low survival of subadults is potentially biased by the permanent emigration of some of these individu- als. Previous studies have shown that larger immatures leave shallow protected bays and occupy deeper open waters, sometimes associated with adults. Juveniles seem to be resident, and their survival rate can serve as a reference value for viability analysis. This is the first study on the survival of green turtles in the West Indies.