By Carlos Hiller
The tug on the line is strong and the fisherman – who is actually a park ranger – immediately begins to pull it in by hand.
Seconds later, we see the shark beneath the boat’s strong beacon light. “It’s a big one!” says angler Mikel. We all become alert as we take our positions. Each delicate maneuver requires exact precision; although the hook is modified to cause minimum stress on the fish, the creature can get loose from even the smallest slip or oversight on any of our parts.
Andres, a marine biologist, hoists the white tip reef shark (Triaenodon obesus) overboard with a net - this is my cue to hurl myself on top of it. Although this action is in complete opposition to every basic instinct I have, it’s my job to physically restrain the powerful animal. The texture of its skin is odd and course like sandpaper, having evolved over the centuries to withstand contact with sharp corals and rocks.
Once we have the shark under control, the measuring phase begins. Then its sex is verified, as well as its sexual maturity. Lastly, we tag its dorsal fin and release it back into the waters just off Cocos Island, one of the last and most important diving frontiers on the planet. One shark down, 18 to go. Total time: less than 2 minutes. At this rate, our database would be filled with information in no time.
Misión Tiburon, or Mission Shark, is a Costa Rican NGO dedicated to the conservation and responsible use of marine resources. I first got to know the organization by way of its mascot, Yiyo, a charismatic and inflatable hammerhead shark that spreads knowledge and positive messages about his kind to schools in coastal areas. It’s hard and impassioned work, but somebody’s got to change negative attitudes about these unreasonably feared and largely misunderstood beings.
Ilena Zanella, marine biologist and president of Misión Tiburón, explains that we currently know practically nothing about the growth, habits, abundance and distribution of this fascinating species. With one of the healthiest and most unhindered populations of white tip reef sharks in the world, the waters around Cocos Island are a perfect starting point for learning about local white tip populations.
In a mere 4 days our team managed to place numbered tags on more than 40 sharks; these markers will be used as a reference to monitor the population for future sightings and recaptures. We observed over 25% of the sharks that were tagged on the first expedition three months prior – a testament to the project’s success. Measuring previously marked animals is what allows experts to see just how much the species is affected by stressors like climate change and contamination of their natural habitat – the coral reef ecosystem.
Misión Tiburón’s Project White Tip is associated with Cocos Island National Park. New expeditions to the island are in the planning stages, and this initiative will soon be spreading to other regions in Costa Rica. If you see a tagged shark while snorkeling or scuba diving, rest assured that scientists are active in the area. Please report sightings to info@misiontiburon.org. You can also help the cause by making a donation of equipment or funds. Visit www.misiontiburon.org for more info.
Carlos Hiller is a Guanacaste artist specializing in underwater murals and paintings (
www.carloshiller.com)