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Faces of FADs: Manta Rays

by Campaign for Eco-Safe Tuna
October 8, 2013

Faces of FADs: Manta Rays

Our Faces of FADs series introduces you to the marine species most often injured or killed by fish aggregating devices (FADs) commonly used in unregulated commercial fishing.

The latest edition comes courtesy of Blue Planet Society, which suggested we profile manta rays.

An endangered species, manta rays are one of the largest members of the eagle ray family. The larger species of manta rays, the giant oceanic manta ray, is the largest ray in the world. Despite their association with the ominously-named devil and sting rays, manta rays do not have a stinging spine and are harmless to humans.

Victim III: Manta Ray

Type: Fish

Diet: Filter-feeder – manta rays can strain food particles from water and eat mostly plankton which they swallow as they swim.

Average life span in the wild: 40+ years (estimated)

Size: 9.8 to 11.5 ft. (reef manta rays), up to 30 ft. (giant manta rays)

Conservation Status: Vulnerable

Interesting Fact: Manta rays have the largest brain-to-body ratio of any shark or ray on Earth.

Profile: Despite their large size, manta rays are one of the ocean’s most graceful swimmers. Manta rays have distinctive pectoral fins which help form its triangular-shaped body. Manta rays have a dark color with pale coloring typically appearing on the shoulders.

Generally solitary creatures, manta rays cleanse themselves by visiting coral reefs where smaller fish feed on their parasites. The courtship process for manta rays can last several days as males will follow a female in what is known as a “mating train.” Eventually, one of the males will grasp the female’s pectoral fin in its teeth and the two will mate belly-to-belly. Their gestation period lasts about one year.

Threat from FADs: Although manta rays are docile and of no threat to humans, the same cannot be said of FAD fishermen. Fish aggregating devices (FADs) are on the major threats facing manta rays today. The manta ray’s large size and relatively slow speed make it highly susceptible to being caught in FADs as bycatch. As a result, it is believed that thousands of manta rays are killed each year. The amount of bycatch from FADs is unsustainable for the species, which also suffers from a low birth rate.

Marine Protected Areas have been established to provide legal protection for manta rays from fishermen around Hawaii, Mexico, the Philippines, Ecuador and New Zealand. Overall protection for manta rays remains poor, however.

In 2011, the Manta Trust was established to coordinate global research and conservation efforts. The Manta Trust works closely with tourists, local communities, businesses and governments to ensure the preservation of manta rays through science, education, community-based initiatives and government legislation.