They say good things come to those who are patient. I never really gave this saying too much thought until just recently…In the name of manta research I have spent six solid weeks (during the winter of 2009 and winter of 2010) diving a remote offshore rock called Laje de Santos in the south of Brazil looking for the elusive giant manta (Manta birostris). Until today, I have searched in vain. I was the one that actually chose this location for part of the worldwide study on this newly discovered species of ray, as this little spec of a rock is the largest documented aggregation site for this species in the southern Atlantic Ocean. But, to tell you the truth, despite my normal determined outlook when working in the field, I was really beginning to loose hope (and that’s pretty bad, since my current international research campaign is ironically named “Ray of Hope’).
But that’s the funny thing about marine field research and, I suppose, diving in general. It doesn’t matter what the ocean throws at you…countless hours of searching, dozens of dives in cold, green water, boat trip after boat trip on rough, windy seas…all of the excruciating effort and disappointment literally seems melt away the second the animal that you have been searching for appears. Your breath catches in your throat, time stands still and everything seems to make sense in the world. And this is why we divers torture ourselves by squeezing into unbearably uncomfortable wetsuits, why we swim around the sea covered in all kinds of tanks and hoses, and why we spend all of our money and time bobbing around in the middle of the ocean. It is precisely for this sensation and these encounters with special marine creatures. For the majority of us, the most precious encounters are with large, elusive megafauna like sharks, whales and dolphins. The object of my affection, of course, is the manta ray.
<Photo, right: Andrea in the field at Laje.
So, as I was saying… all hope seemed lost when about five days into my latest expedition to Brazil a huge storm hit. It poured rain for a week, the wind howled across the sea and the swell was unrelenting, turning the clear, blue, offshore water into the kind of green that divers have nightmares about. When we finally were able to return to the sea, the visibility was only a few meters and the water was bitterly cold. Our only recourse was to patrol up and down the tiny offshore rock… searching for a miracle.
And then one appeared, literally out of the gloom, and it was coming straight for us. It felt like a dream. He was massive, a large mature male manta, and he was ready to be the ambassador for manta ray conservation in Brazil.
Almost as if he understood what was needed of him, he swam right up to us (hovering momentarily to get his belly tickled by our bubbles) and patiently allowed me to take an ID photo him and place a single satellite tag on his dorsal surface. Watch a video of us sat tagging the first giant manta ray in Brazil! Without even the slightest flinch, he continued to swim with us after the tag was inserted, allowing me to check that the tag was secure and more importantly allowing me to get to know him a little better. For several minutes I took detailed images of every important feature from every conceivable angle. I was amazed by the gentle tolerance of this individual; the experience reminded me how incredibly privileged I am to work on them and how much they deserve our respect and protection.
Then without warning he slowly began to move back off into the gloom, ready to lead us on one of the most exciting journeys of my career. The tag that I placed on was archival, meaning that it functions like a mini laboratory, constantly sampling the outside environment and storing the data for me as the manta ray swims around the ocean.
Amazingly, it records the temperate of the surrounding water, the depth the manta is in as it moves along or makes deep dives, light levels (which are used to determine the actual track of the manta) and GPS positioning should he come to the surface periodically. I manually programmed the tag to automatically detach after 180 days (6 months) at which point it will float to the surface and begin to download all of the stored data to the ARGOS satellites. At this stage, ARGOS will magically beam this information to my computer. Just thinking about this process makes me love being a scientist in the 21st century. To have the technology to be able to ask and then answer difficult questions is such a joy.
At this stage, all we have to do is sit back and wait. For the next six months this individual will roam the cold waters of the Atlantic Ocean storing the secrets of his lifestyle and behaviour; secrets that have eluded us until now.
Over the next few months, we will begin to see things from his perspective. Photo © Andrea Marshall
But already this particular manta ray is a part of history. He is the first manta ray to be satellite tagged in South America or in the southern Atlantic Ocean for that matter and the information that he will contribute with be both unique and invaluable.
This particular individual happened to be a re-sighted male, which had been previously encountered at Laje back in 2007. He had not been seen since his first encounter, but this is not entirely unusual for the area. It is thought that manta rays only make brief stopovers to this offshore oasis before moving off into the unknown. The ‘Mantas do Brasil’ project (Laje Viva Institute), managed by Guilherme Kodja, is specifically trying to address this mystery and have teamed up with my Foundation (Marine Megafauna Foundation) to answer some key questions.
Where do these giants come from? Where do they go when they leave this little rock? Why do they mysteriously appear each winter and what are they coming to do? How are humans impacting their movements and their natural behaviour? Are they affected by the massive amount of shipping traffic that occurs in the region? How many are caught each year in gillnet fisheries along the coastline? With next to nothing known about their lives in this part of the world, these answers could prove invaluable to our ability to manage the manta ray population in the region and protect them from anthropogenic threats.
Success! Our first tagged manta ray in South America. Photo © Andrea Marshall
As we continue to learn more about these ocean giants, I also continue to learn and grow as a scientist. Patience is an important skill in field research as is the determination to see difficult projects through to completion. In the end, persistence will pay off, and although we sometimes feel that we are racing against time, we are ultimately at the mercy of the animals that we study and the elements of nature. Sometimes sitting back and waiting for them to come to us is the only solution.