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Roca Partida, a small sea mount in the pacific

provides an incredible back drop for a cruising

oceanic manta ray.


Lying on the surface of the water face down I take another deep breath, filling my lungs as deeply as I can as waves crash around me. One more breath and then descend. Kicking through the water we enter the blue in our most natural form, no breathing equipment just a single breath. As I descend deeper a whole new world opens before me, the visibility clearing to reveal a stunning volcanic landscape not apparent from the waters surface. Hanging in the blue an Oceanic manta ray approaches at first keeping its distance but then coming closer meeting the free divers eye to eye as if asking; What are you? Why are you here? Another diver takes a breath and swims under the Manta capturing its ventral side on a GoPro for later identification. After determining the sex a biopsy is taken, the manta ray roles in response but continues to hang around watching the divers with curiosity.

This latest expedition to La Paz and the Revillagigedo Archipelago organised by The Watermen Project brought a group of scientists, free divers and ocean explorers in contact with some of the oceans biggest giants. The Watermen Project is an organization that uses its breath holding and photography skills to collect scientific data in the form of tagging, biopsies and identification photos. As well as the scientific goals this organization also works to create inspiring images highlighting the beauty of our oceans inspiring a future generation of ocean explorers and conservationists.

William Winram, world champion free diver and founder of The Watermen Project, hangs poised in the water gripping a satellite tagging gun which is fitted with a tag destined for a female scalloped hammerhead.

A Mexican Ponga used for free diving stands in calm water. Snorkeling with La Paz’s juvenile whale shark population has become a popular tourist activity, unfortunately this practice is not maintained sustainably and it is not uncommon to see whale sharks cruising through the area with severe wounds due to Pongas not obeying speed regulations. Local marine biologists such as Andrea featured in this photo are working with local tour operators to regulate these practices and ensure La Paz’s coasts maintain a sustainable whale shark nursery ground.

Andrea Asunsolo a young marine biologist receives some free diving pointers from project leader William Winram during

a training session in her home town of La Paz before embarking on the expedition to the Revillagigedos. Asunsolo uses

freediving as a tool for her research on shark baselines in marine reserve Cabo Pulmo.

Marine Biologist and Young ambassador to The Watermen Project Lucas Muller Dives under a juvenile whale shark in an attempt to determine the sex of one of the worlds largest gentle giants.

Professional safety freediver Francois Leduc Swims beside a juvenile whale shark showing the immense size of these incredible animals even in their earliest years of life.

Roca Partida is the smallest of a series of sea mounts found within the Archipelago de Revillagigedo. It is theorized that these seamounts serve as landmarks for migratory species such as the scalloped hammerhead. The Seamounts of Revillagigedo also support a large abundance of life and support many species that are considered to be critically endangered. These secluded sea mounts are located in the Pacific ocean over a 24 hour boat ride from the coast of Mexico. It is this exclusivity that has allowed them to act as a refuge for endangered species that were previously abundant on the Baja coast. By tagging the populations that visit Roca Partida we can gain valuable data that can be used to ensure the conservation of its incredible inhabitants.

Two Oceanic Manta rays swim past while free divers observe from the surface. The research carried out by The Watermen Project is greatly reliant on the funding provided by participants who join the expedition for the opportunity to observe the research taking place, learn more about marine conservation and have interactions with marine megafauna.

An oceanic manta hangs in the water at eye level observing a diver before continuing on its journey. Acoustic tags are used to decipher these rays movements between the 3 main islands (San Benedicto, Socorro and Roca Partida) during their visits to Revillagigedo Archipelago.

Each Manta Ray has a unique pattern on their ventral side. By taking high definition photos of the manta from below we can identify individuals. Marine biologists 

studying the Manta ray populations of 

Revillagigedo work closely with dive  operators to collect these images from visiting tourists and researches allowing them to develop their database and determine the movement of these individuals between dive sites in a non invasive way. When collecting biopsy samples it is important to take these identification photos so researches are aware of which individual from the population is being analyzed.

Two Manta rays swim creating mirror images. The oceanic Manta ray (Manta birostris) is listed as vulnerable by the IUCN. The Revillagigedo Archipelago is one of the last locations Oceanic manta rays can be seen in abundance. By collecting biopsy samples of these stunning rays we can conduct stable isotope tests and conduct DNA analysis assisting in the conservation of these amazing animals.

Tagging endangered species such as the Oceanic Manta ray and scalloped hammerhead allow scientists a better insight into the movements of these migratory species. Understanding the distribution of these species will allow scientists and policy makers to produce the most beneficial conservation plans to protect these beautiful animals.

Previously tagging has been an invasive practice that often requires the animal to be captured in order to place the tag. A study conducted on Long Line fishing techniques used to catch scalloped hammerheads for tagging procedures showed an increase in mortality of 50% within the first two hours of release and a mortality rates of almost 100% after 24hrs despite good vital signs during the procedure. The high mortality rate is believed to be the cause of high stress levels created during capture. Free diving provides an alternative to this invasive procedure. Due to the lack of bubbles free divers are able to approach animals in a way not possible on SCUBA opening an entirely new area of opportunities for marine research. However it is not without its challenges; intense currents, limited visibility and a limited window of time due to working on one breath mean the free divers need to work with the utmost precision.

Over the years The Watermen Project has lead expeditions to tag a variety of species including, Whale sharks, Bull Sharks, Lemon Sharks, Tiger Sharks, Great Hammerheads, Scalloped hammerheads, Manta rays and even Great White Sharks. The Oceanic environment is one of the most breathtaking and challenging environments to call your office due to constantly changing conditions but each expedition results in an increase in knowledge and a growing understanding of these magnificent animals. The demand for tagging via free diving is steadily growing due to its incredible retention rates and we look forward to it becoming a more prevalent method in the future.

Photos and Story by Inka Cresswell All photos rights belong to Inka Cresswell 


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