1. Traditional hunting practices: Manta rays have been traditionally hunted by certain communities in various regions for food and cultural purposes. In some areas, manta ray meat and fins are consumed locally, while in others, they are traded as commodities. Historically, manta rays have been valued for their meat, which is often dried or salted for preservation, as well as their skin, which can be processed into leather.
2. Bycatch: Manta rays often become unintended victims of fishing activities, particularly when they encounter non-selective fishing gear. Manta rays can get caught in driftnets, gillnets, and trawling nets set for other species. Once entangled, manta rays may suffer serious injuries or drown. Bycatch poses a significant threat to manta rays, as it can result in high mortality rates and disrupt their populations.
3. Gill rakers trade: Manta rays possess unique structures called gill rakers, which are located on the underside of their mouths and serve as a filter-feeding apparatus. In recent years, there has been a demand for manta ray gill rakers, especially in some Asian markets, where they are falsely believed to have medicinal properties. This demand has driven targeted fishing of manta rays for their gill rakers, contributing to their population decline.
4. Aquarium trade: Manta rays have also been targeted for the aquarium industry, although this trade is relatively limited compared to other marine species. Manta rays are sought after for public aquariums and private collectors due to their graceful movements and large size. However, capturing and keeping manta rays in captivity can be stressful and challenging, and these animals often have low survival rates in aquariums.
5. Superstitions and beliefs: In some cultures, manta rays are associated with superstitions or negative beliefs, which can contribute to their persecution. For instance, in certain regions, manta rays are believed to be dangerous or harmful to humans, and this perception may lead to indiscriminate killing or avoidance of manta ray areas.
It's important to recognize that these reasons for killing manta rays are often driven by demand and economic incentives, leading to unsustainable practices that threaten their populations. Conservation efforts, scientific research, education, and management regulations play crucial roles in protecting manta rays and ensuring their survival.