Throughout much of the world, and particularly in tropical and subtropical regions, large wild aquatic animals – such as manatees, turtles and dolphins – are hunted and traded. This is not a new phenomenon. The meat of aquatic animals has been eaten and sometimes used as medicine or in traditional ceremonies throughout history.
This type of consumption is widespread. In some places, this wild meat is an important source of nutrition, income and cultural identity. Yet opportunities to exploit wildlife for economic gain – often illegally – are increasing the number of animals hunted in some places. Coupled with the growth of human populations, this has led to the unsustainable exploitation of certain species.
Understanding the scope and potential threat of aquatic wild meat exploitation is an important first step towards appropriate conservation actions and policies.
We are part of a large international team of conservation researchers and practitioners who recently published an article on this subject. We conducted a literature review on the use of large aquatic animals (excluding fish) – what we call “aquatic megafauna” – for wild meat in tropical and subtropical regions of the world. This topic is extremely understudied, so this review represents one of the most thorough assessments of the topic to date.
We focused on 37 species of conservation concern that are listed in the Appendices of the Convention on the Conservation of Migratory Species of Wild Animals. The list includes several species of whales, dolphins and porpoises (cetaceans), manatees and dugongs (sirenes), sea turtles (chelonians) and crocodiles (crocodilians).
Twelve of these species inhabit the oceans and rivers of West, Central and East Africa. These are areas that were in the tropics and subtropics and where there are concerns about hunting, consumption and trade.
We found that the consumption of these aquatic animals is widespread in coastal regions, to varying degrees. Some species are likely to be threatened by overexploitation, especially species living in rivers and freshwater areas.
For most monitored species, a major problem is that animals are accidentally caught as bycatch during fishing. They are then opportunistically killed and eaten or sold, instead of being released alive.
Dolphins, manatees and turtles
We found evidence of the use of cetaceans (whales, dolphins and porpoises) in most tropical African countries, particularly in West Africa. Their meat was used for a variety of purposes, including food, shark bait, and traditional medicine.
One species considered particularly endangered is the Atlantic humpback dolphin (Sousa teuszi). Distributed only along the Atlantic coast of Africa, it is one of the least known coastal dolphins in the world. Because it has such a small population size and lives close to shore – where it can be caught by small-scale fishermen – it is very vulnerable.
African manatees (Trichechus senegalensis), distributed exclusively in West and Central Africa, and dugong (Dugong dugon), whose range extends into East Africa, are legally protected in almost all countries where they occur. However, the team found evidence that they were used for a variety of purposes, including food and traditional medicine to some extent in all countries. Most manatee populations cannot sustain human-induced mortality because their populations are very sensitive to changes in adult survival. In recent years, heavy losses of African manatee populations have been reported.
Turtles face a similar threat. The capture and consumption of adult sea turtles, as well as the harvesting of their eggs, is ubiquitous across most of the species’ ranges. This includes mainland Africa and the African islands. However, as with other aquatic megafauna, larger scale monitoring is needed to assess impacts and sustainability.
Risks to fluvial megafauna – those that live in rivers – related to harvesting can be particularly high, even if opportunistic, as these species face multiple threats in the same restricted area. Threats include dams, intensive fishing and pollution where human population density is high. In Africa, this is the case for African manatees and freshwater turtles (which were not assessed in the study, but which are widely hunted).
Riverine megafauna may suffer from a lack of management and research, and will require increased conservation efforts. This is because they are neither considered terrestrial species nor fish, so it is often unclear at the national level who is responsible for their conservation and management.
In tropical and subtropical regions, there are clearly differences in local circumstances between regions. Drivers of hunting and consumption, hunting technologies used, human density and other threats to animals and their habitats, and their evolution over time, will influence the sustainability of the harvest.
Nevertheless, it is clear that the use of aquatic megafauna for meat is likely to be much more widespread in terms of frequency and species than indicated in the review. Indeed, monitoring and reporting are limited. Also because many species are protected by national laws or are charismatic, their use is therefore secret.
The transboundary nature of the harvest and associated trade of these oceanic, coastal and riverine species requires increased international attention and cooperation.