Manta Madness in Mexico

February 2020

The Revillagigedo Archipelago off the Pacific coast of Mexico is home to one of the most famous populations of oceanic manta rays.

Dr. Guy Stevens and I led a recent Manta Expeditions trip to the Revillagigedo Archipelago nearly 400km off the Pacific coast of Mexico. The archipelago is made up of 3 islands and an islet however the more remote Clarion island is less regularly visited. Situated at the junction of two major current systems; the Equatorial current and the Californian current, this remote archipelago is teaming with pelagic life.

Unsurprisingly, the focus of our trip was the oceanic manta ray population. This site is studied by our affiliate project at the Pacific Manta Research Group (PMRG) who have been collecting data on the manta rays on the Pacific coast of Mexico for over three decades! They have documented over 800 different oceanic manta rays, with around a third of them re-sighted more than once. The oceanic manta rays at this location were one of the driving factors behind the listing of the site as a UNESCO World Heritage site in 2016.

Check out the video below to see some of the highlights of the trip which also included incredible shark and dolphin encounters!

Without a dedicated research boat, PMRG are limited to collecting data from citizen scientists and on occasional dedicated research expeditions. Therefore, the chance for a Manta Expeditions trip to the region to collect additional data was very valuable.

Dr. Guy Stevens and myself joined around 20 diving enthusiasts on the Nautilus Explorer for a week of diving. We collected ID shots of 31 different individuals and even re-sighted some of the same mantas during the trip. Around 25% of the manta rays we encountered were black morphs (a colour variation seen in manta rays with excessive black skin pigmentation) which is about normal for this population. We have passed on all the sightings data to the PMRG team and are just waiting to hear back about how many new individuals we encountered.