By Jamal Galves, 9th September 2022
The Belize Marine Mammal Stranding Network comprises representatives from two government agencies and 12 national NGOs, as well as scientists, veterinarians and volunteers. The members of the network are regularly trained and equipped to respond to stranding incidents. Since 1995, the Belize Marine Mammal Stranding Network and its members have documented stranding events. Belize is known to be the world’s last stronghold for the Endangered Antillean manatees, making this population critical to the species’ survival throughout its range. However, the Belize population faces serious anthropogenic threats that have led to increased manatee strandings, raising concern for the future of the species. We wanted to determine the main threats to these manatees, what this means for the future of the species and to outline necessary conservation actions.
Before 1997, poaching was the number one threat to manatees in Belize. However, since 2010, the main cause of known strandings has been watercraft collisions, with the annual average increasing from 10 before 2010, to 25. Our findings also show a strong and direct correlation between strandings and increased tourism, with its resulting boat traffic. Other threats facing manatees in Belize include habitat destruction, entanglement in fishing gear, pollution, and climate change. Although habitat loss has become a serious threat to manatees in Florida and is tied to the recent spike in manatee deaths there, habitat loss due to unsustainable coastal development is quickly becoming a concern for the Antillean manatees of Belize as well.
During the 23 years covered by this article, our team has successfully rescued 24 injured or orphan manatees that were admitted for rehabilitation. The purpose of this study was to analyse the documented manatee stranding reports for Belize and to explore the occurrence and patterns of the threats affecting this species during 1997–2019.
Stranding data were collected in the five districts. Trained members of the Belize Marine Mammal Stranding Network, upon receipt of a call from the public regarding any marine mammal believed to be in distress or dead, collected preliminary information on the state of the animal and the exact location before verification and examination in situ. Stranding reports were classified as either verified, or not verified. When possible, a field necropsy was carried out on dead manatees, following a manual of procedures for the salvage and necropsy of carcasses of the West Indian manatees. Biological material, including tissue samples and parasite specimens, were also collected where possible for histological analysis, and photographs for identification.
Stranding records were verified, stored in a database and exported for analysis. We examined any differences in the cause of death between male and female manatees. We created a map of the locations of all strandings, which were recorded with a GPS. We calculated the potential biological removal for the Belize manatee population using both minimum and maximum growth rates,and used the number of visitors per year as a proxy for tourism activity.
Left: Rescued manatee with boat strike cuts being treated. Photo: CMARI-Belize. Right: Dead manatee being carried away for examination. Photo: Clearwater Marine Aquarium Marine Aquarium Research Institute-Belize.
Rescue and rehabilitation programmes have also proven to be effective long-term strategies for manatee conservation, and improving these efforts will help raise awareness of threats facing these marine mammals. Based on our study, we recommend the implementation of consistent population assessments and further research to determine the impact of watercraft collisions on the species and to estimate the potential biological removal of manatees in Belize. Enforcement and implementation of boating regulations, like no-wake zones, as well as public education and outreach, are also vital. Our findings are critical for monitoring threats to manatees and collecting the long-term data needed to guide strategies for the conservation of this species. We hope our article will help protect not only the future of the Belizean manatees but also other populations throughout its range.
Baby manatee rescued after a hurricane in Belize. Photos: CMARI-Belize.
The article Analysis of a long-term dataset of Antillean manatee strandings in Belize: implications for conservation is available in Oryx—The International Journal of Conservation.
