Oceanic Manta Ray Conservation Status Downgraded on IUCN Red List
The conservation status of the giant (also known as oceanic) manta ray (Mobula birostris) on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species has been downgraded to 'Endangered', according to a 10 December report from the Marine Megafauna Foundation, the world's foremost manta research organisation.
The new status means that oceanic manta now join more than 16,000 other species assessed to as seriously endangered. Together, at least 30 per cent of all sharks and rays are now threatened with extinction.
Manta rays are targeted for their gill plates, with which they filter tiny zooplankton from the water to feed. The gill-rakers are used in 'traditional' medicines in a chiefly Asian market. However, these so-called traditional remedies using manta gill rakers are relatively new. The increasing demand for manta body parts over the last twenty years has impacted the giant manta particularly hard, with unsustainable harvesting decimating their populations across the globe.
Dr Andrea Marshall, co-founder of the Marine Megafauna Foundation (MMF), who lead-authored this newest assessment for the IUCN, and who has been involved in the assessments since 2003, said: 'The giant manta ray is a classic example of a species that is quickly succumbing to human-induced pressures. When we first assessed manta rays in 2003 there simply was not enough information on the species to determine their conservation status and they were listed as ‘Data Deficient’, but on each of the subsequent assessments, their conservation status increased steadily from Near-Threatened, to Vulnerable and now to Endangered. Their current status is a direct result of unsustainable pressure from fishing, which now threatens to destabilize their populations across the globe.'
To curb the burgeoning trade in their body parts to Asia and to encourage more comprehensive conservation strategies for their populations around the world, the giant manta ray was listed on two of the most important global conservation treaties, the Convention on Migratory Species (CMS) in 2011 and the Convention on the International Trade in Endangered Species (CITES) in 2013. However, neither has provided the necessary protection and the number of manta rays has continued to decline.
'Manta rays simply cannot withstand such pressures on their populations,' said Dr Marshall. 'They reach sexual maturity relatively late in life, they give birth to a single offspring every few years in the wild, they do not look after or defend their young and the offspring themselves are vulnerable when they are small and may not survive. In other words, as a species, they simply cannot reproduce fast enough to build back their numbers once they are depleted.'
This iconic species is not only extremely important from an ecological perspective, giant mantas also provide vast economic benefits to tourism industries around the world. 'Interactions with manta rays are highly sought after by dive and snorkel tourists globally and contribute millions of dollars to tourism economies each year, particularly in developing nations,' said Dr Stephanie Venables, senior scientist and manta ray expert at MMF. 'At this pivotal time, recognizing their economic value may help to encourage the protection of this enigmatic and now endangered species.'
The giant manta ray was only formally described by Dr Marshall and colleagues in 2009. At the time it was one of the largest species to be described in our oceans and the announcement was met with excitement around the globe. The discovery was covered by the BBC that year in the first-ever documentary on manta rays.
'It is such an honour to have been able to study and describe this species,' said Dr Marshall. 'The realization that the giant manta ray is now in danger of extinction is a hard pill to swallow. We are still busy learning about this extraordinary creature and we have only scratched the surface. There is so much more we need to understand, but at this stage, we have put that all aside in favour of protecting the last remaining populations of giant mantas across the globe.'
This article originally appeared on the Marine Megafauna Foundation news page. To help preserve these magnificent animals (and other megafauna such as whale sharks), please consider making a donation to the MMF's ongoing 'Giving Tuesday' fundraiser: www.marinemegafaunafoundation.org/giving-tuesday