Queen Of Mantas

MY LIFE IN THE BLUE

Brazilian Ocean Oasis

August 9, 2010
By Andrea Marshall
Andrea-with-baby-ROV_630_467_70

As I left Brazil, after spending nearly a month in the field, I was informed of the passing of one of my friends in a diving accident in South Africa. He was a great man and he will be deeply missed, but his passing reminded me what a curiously unforgiving place the ocean can be. I find that the ocean’s wild beauty often belies its fierce nature. In reality our oceans are vast, their waters often relentlessly rough and turbulent.

Many parts of these great expanses of water are distinctly inhospitable, however, scattered within this liquid eternity are tiny oases of hope, life and refuge. Laje de Santos is precisely one of those places. This little barren rock juts out from a largely desolate seafloor like a proud sentinel in what I often found to be a stormy and chaotic Brazilian sea. As you approach you cannot shake the uncomfortable feeling that this rock is really out in the middle of nowhere. Once moored and looking down into its surrounding cold, green water, your apt to think, “what am I doing out here?”

But one giant leap into the chilly waters of the Atlantic reveals a very different reality. This rock is actually home to an incredible amount of life. While it is only approximately 300 meters or so long, Laje de Santos is an amazing refuge to at least 196 species of fish including some magically rare animals such as hairy carangid fish (Alectis ciliaris), Halichoeres sazimai, and an endemic species of tube dwelling Cerianthos anenome.

<Andrea-with-fish-school-and-wreck_630_429_70Diving at Laje de Santos.

Laje is also rich in elasmobranch fauna (particularly rays) and during my short time there I was fortunate enough to dive with a couple of friendly sand tiger sharks as well as many eagle rays, butterfly rays, thorny stingrays and of course the elusive giant manta ray! While all of these animals are relatively frequent visitors or inhabitants to this small island, Laje also provides sanctuary, on occasion, to animals passing through on ocean voyages such as Bryde’s whales, Mola mola, penguins and whale sharks. And yes, I did say penguins and whale sharks in the same sentence! Oddly enough these two animals have actually been seen on the same day at this location before (one of the most unbelievable things I have ever seen by the way!).

But this island has really drawn its fame from the giant manta rays that pass though every year during the winter months. Divers are regularly treated to VERY close encounters with what may be some of the friendliest manta rays I have ever seen in my life. The experience is miraculous! So, religiously, these brave Brazilian divers make the one and a half hour boat ride out to the island, diving in rain or shine, to observe these rays and the rest of the marine life at this small island refuge.

Born out of their fierce love for this destination and its animal inhabitants, some of the more devoted divers formed a small research institute, which is dedicated to both scientific study and the monitoring of the park itself. Founded by one of the most passionate animals lovers I have ever met, Ana-Paula Balboni, this group of naturalist, scientists and divers have produced many international scientific papers and have various projects underway including their flagship project, “Mantas do Brazil”.

I have been working with the Laje Viva Institute on the ‘Mantas do Brazil’ project since 2009. This project, headed up by Guilherme Kodja, monitors the population visiting Laje each year in addition to gathering information on any sightings of these giant rays along the Brazilian coastline. This winter, our mission was to attach satellite tags to individual rays to determine where they travel on their clear seasonal migrations along the coast. In addition to being a part of my worldwide study on the movements and behaviour of the newly described giant manta, this project has clear local conservation objectives as well. It has become relatively clear to our team thus far that the population of giant manta rays in southern Brazil may be very small, with only 69 individuals identified since 2006.

CIMG0452_629_392_70Gauntlet of shipping boats surrounding Laje.

With very little basic knowledge about how these animals live their lives (e.g. where these manta rays spend most of their time, where their major feeding grounds are, where they mate and give birth, etc.), it is very difficult to regulate or protect them effectively. But because of their annual visitation to this tiny offshore island, Laje is quickly becoming one of the best places in the world, especially in the Atlantic, where these questions can be asked and answered effectively.

Unfortunately, as it is located off the mouth of one of the largest natural marine ports in Brazil, the positioning of this remote island couldn’t be worse for manta rays or other large pelagics like whales, turtles and whale sharks. Hundreds of massive transport vessels and fishing boats pass this tiny marine protected area on a weekly basis, forming a gauntlet of danger for any animal that is obliged to come to the surface.

Plastics and pollution from these large boats are seen strewn across the sea on a daily basis, as are large off-cuts of fishing nets, hooks and buoys. It is just a disaster area, and it is not uncommon for divers to cut manta rays out of nets and fishing line. But despite this, life at Laje de Santos continues to flourish, aided considerably by the degree of protection it is afforded by its protected area status, which was awarded in 1993. If nothing else, Laje de Santos is a mighty testament to the effectiveness of these types of marine sanctuaries, which allow natural fauna to thrive without most of the pressures or influences of man. But clearly these small reserves do not afford larger, migratory or pelagic species the protection they desperately need.

So with a goal of safeguarding this population throughout their wider home range, we headed out to Laje to try and shed some light on the mysterious question of where they go when they leave this tiny island and how they spend most of their time. Armed with the coolest technology in the business, ranging from satellite tags to mini underwater ROVs, we began to try and tackle these questions. Luckily the conditions this year were far more favorable than last year, and despite having an accident mid-way through my trip that put me out of action for a week, we managed to spend many wonderful days out at the island observing mantas and contemplating their future along this coastline.

Out team was successful in placing on two satellite tags before I left (with another 2 planned for later in the season) and the Brazilian manta ray sighting database steadily grew through our ‘citizen science’ program, generating range extensions both to the north and south of Laje. What once seemed like a lone aggregation site for manta rays now appears to be a wider range of habitats (from shallow estuaries to offshore islands) strung together along a massive expanse of coastline.

It is likely that these giant manta rays are exploiting different planktonic resources in these habitats at different times of the year in order to feed their insatiable diets.

But, with some of the tags programmed to come off in only 6 months time, we will now have to sit back and patiently await the results to determine if this theory is correct. If true, it will give us remarkable new evidence of their exceptionally large home ranges, while at the same time highlighting the critical need for habitat protection, as many of these areas face threats from pollution, coastal development, shipping traffic, and fishing pressure.

Green-Turtle-Face-Full-Frame_629_449_70Green Turtle encounter at Laje. Photo © Andrea Marshall

What is immediately clear to me though, and it is a strong call to action for the rest of us out there, is that the passion and commitment of a few individuals can be more powerful that we could ever imagine. In my few weeks here, I have seen enraged divers single handedly apprehend illegal fishing boats in marine protected waters, I have seen the determination of a community banding together to protect a small sanctuary for these magnificent creatures, I have seen naturalists (not scientists) pushing the boundaries of what we know about these animals out of sheer curiosity and concern, and I have seen ordinary citizens rise up and take on the monumental challenge of conservation with out a hint of apprehension or fear. I have seen it happen with my own eyes and I am seeing them succeed. What will you do for your favorite ocean oasis?

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