Searching for Chondrichthyans in the Depths of Guatemala’s Caribbean

Determining fishery impact and promoting the protection of deep-water chondrichthyans in the Guatemalan Caribbean.

Efforts to protect deep-water chondrichthyan species in the Guatemalan Caribbean are progressing. In April, the project initiated fishery-independent surveys using scientific longline sets to continue characterizing deep-water sharks and fill critical knowledge gaps about these vulnerable species.

Six longline sets were deployed during the first field trip to catch deep-water sharks, yielding partial but insightful results. Careful handling protocols were followed to minimize harm to the organisms. Each shark was held securely in the water by three team members while essential data—including total length, sex, and species identification—were recorded. Four individuals of the gulper shark (Centrophorus granulosus)—a focal species of the project, given its IUCN status as Endangered (EN)— and one Cuban dogfish (Squalus cubensis) were captured at depths of 428 m. Remarkably, all the gulper sharks captured were immature females, based on their recorded total length (92 cm LT), suggesting a potentially heightened sex-biased vulnerability of this species to deep-water fishing activities. The sharks were tagged with Floy tags, which will allow the team to gather crucial information if the tagged sharks are recaptured. This data could provide insights into the distance traveled from the tagging site, survival rates, size variations, shifts in sexual maturity, and, ultimately, growth rates.

Cuban dogfish (Squalus cubensis) caught during the fishery-independent surveys with scientific longline. Photo © Yuliana Ortega

The support of local fishers from El Quetzalito has been key to the success of this work. Their logistical assistance ensured the feasibility of the fieldwork. By maintaining direct communication, the project team and fishers were able to assess weather conditions and coordinate sampling activities effectively. Moreover, their expertise in handling fishing gear and managing the captured organisms played a crucial role in the safe tagging and data collection processes.

Local fishers assisting with the deployment of scientific longline sets during the surveys. Photo © Ana Cristina Hernandez

Fishery-dependent surveys have also been carried out with the support of youth participants in the Citizen Science program, who collect biological data from chondrichthyans captured in local deep-sea artisanal fishing. By documenting the species encountered in daily fishing activities, these surveys complement the data from fishery-independent efforts, providing insights into the diversity and frequency of deep-water chondrichthyan catches. Since the start of the project in March, only one gulper shark and one Atlantic sixgill shark (Hexanchus vitulus) have been recorded. While these numbers highlight the challenges of studying deep-water species, they also underscore the value of these efforts in addressing information gaps about the chondrichthyans most vulnerable to fishing in the study area.

The project faced challenges due to several tropical storms in October and November 2024, which brought heavy rains and strong winds, disrupting fishing activities and delaying sampling trips. Despite these obstacles, maintaining open communication with the fishers has been crucial for monitoring conditions and determining the best times to safely and efficiently resume activities. If conditions improve, a second tagging expedition using scientific longlines is planned for early December 2024.

By involving local fishers and youth participants in data collection and adapting to environmental challenges, the project is generating valuable data that will serve for developing sustainable conservation strategies in the Guatemalan Caribbean’s deep-water ecosystems.

A young participant from the citizen science program recording data on sharks landed from artisanal fishing. Photo © Yuliana Ortega