media release

Majestic manta ray designated vulnerable species

November 14, 2011

Nick Dulvy, 604.936.1166, 778.782.4124 (w),, Coquitlam resident
Lucy Harrison, 778.999.6237,, Vancouver resident
Carol Thorbes, PAMR, 778.782.3035,

Diving with the majestic manta ray is an eco-tourist’s dream come true that may soon be experienced only by viewing pictures and videos of the shark family’s graceful giants.

The International Union for Conservation of Nature (IUCN) Shark Specialist Group (SSG), based at Simon Fraser University, has added the Giant and Reef manta rays to its Red List of Threatened Species.

The IUCN SSG, a worldwide network of scientists co-chaired by SFU biologist Nick Dulvy, has declared manta rays Vulnerable with an elevated risk of extinction. Intense fishing fuelled by international demand is wiping out these iconic species by the hundreds.

Until recently, known as one species, the Giant (Manta birostris) and Reef (Manta alfredi) are among the largest fish in the world. The Giant manta ray can grow to more than seven metres across.

Swimming, diving and filming expeditions with manta rays, the top stars in eco-tourism, especially in developing countries, reportedly generate $100 million annually, worldwide.

Manta rays migrate vast distances, crossing international boundaries, in search of food. Increased fishing is depleting their far-flung feeding stations and fishers seeking their food-gathering gill rakers have become manta rays’ greatest predators.

“Given that manta rays have a very low reproduction rate — they give birth to an average of one offspring every two years — they are very vulnerable to overexploitation,” says Dulvy. “They are a long-lived species with little capacity to cope with modern fishing methods and globalized demand from rising human populations.”

“Increasing demand for these fishes’ filter-feeding system for traditional Chinese medicinal purposes, especially in Hong Kong, is rapidly driving down their population everywhere,” says Lucy Harrison. An SFU alumna and biologist, Harrison is the program officer for IUCN SSG.

Mantra ray populations are in steep decline in several regions, with a reduction in numbers by as much as 80 per cent during the last 75 years. Globally, the decline is believed to be more than 30 per cent.

“We can save manta rays — the solution is in our hands,” says Dulvy. He and his IUCN SSG colleagues recommend the creation of international conservation treaties to protect manta rays. They also recommend the following:

  • Using the Convention on Migratory Species (CMS) and the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITIES) to monitor and regulate the trade and exploitation of manta rays.
  • Enacting legislation in countries to reduce and eventually prevent fishing pressures on manta rays through controlled trade.

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Backgrounder: IUCN Red List

Headquartered in Geneva, Switzerland and comprised of more than 1,000 member organizations in 140 countries, including government and non-government organizations, the IUCN is the world’s largest professional conservation network.

A Nov. 10, 2011 IUCN Red List update shows that more than 61,900 species have been assessed to date.

Updated twice a year, the IUCN Red List is the world’s most comprehensive information source on the global conservation status of plant and animal species. It is based on an objective system for assessing the risk of extinction of a species should no conservation action be taken.

The IUCN Red List keeps pace with scientific discoveries—for example, until recently only one species of manta ray was known. New comparisons of field observations now reveal that there are actually two species of manta: the Reef manta ray (Manta alfredi) and the Giant manta ray (Manta birostris), both of which are now classified as vulnerable.

The Giant manta ray is the largest living ray, which can grow to more than seven meters across. Manta ray products have a high value in international trade markets and targeted fisheries hunt them for their valuable gill rakers used in traditional Chinese medicine. Monitoring and regulation of the exploitation and trade of both manta ray species is urgently needed, as well as protection of key habitats.

“Mantas are important as they are some of the largest fish in the ocean,” says Andrea Marshall, IUCN SSG assessment leader. “As iconic species they are tremendously valuable for eco-tourism and they continue to inspire people about the beauty and diversity of the ocean as one of the most featured animals in marine documentaries.”

Images are available upon request. Email Lucy Harrison at

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