Diving in Cocos Islands – Costa Rica

27.09.2018 by ricardo

Between schools of hammerhead sharks and hundreds of reef sharks – diving on Cocos Island, the remote national park island off Costa Rica, stands for spectacular sightings!

Countless stories about pirate treasures entwine around the island. But divers don’t draw the pirate treasures to the island, but the still largely healthy shark stocks. Together with the Galapagos Islands and Malpelo, Cocos represents the third point of the “shark triangle” in the Eastern Pacific. Nowhere you have better chances to see hammerhead sharks and whitetip reef sharks. Also Galapagos, silk and even tiger sharks.

First dive on Cocos Island

Stony corals greet us in the 10-meter area. Swarms of snappers and soldier fish form colorful clouds over the reef. Hardly in the water, a marble stingray swims by. He directs our attention to a sleeping whitetip reef shark. Already after a few minutes you feel like looking for mushrooms: Once the first one has been discovered, it’s time to go one by one. After a lot of reef sharks the harmless cartilaginous fish seem almost boring. 🙂

Cocos Iceland lives up to its reputation

The legendary reputation of Cocos as an exceptional dive site is confirmed during the next dive. Although the hammerhead sharks don’t really come close, they are still beautiful to look at. Then suddenly a shadow appears that nobody expected. Wide figure and stripe pattern – a tiger shark! With a length of about 4 meters it makes the bowhead hammerhead sharks appear tiny. In peace it glides past us. The wide ventral fins make him the “she” – our tiger shark is a female.

A noticeable current prevents the pursuit. But this is not necessary, because 10 minutes later the lady shark honors us again. This time she comes much closer. Only an arm’s length away she passes us. Orange frogfish, stingrays and hammerhead sharks are forgotten. Only the tiger shark encounter counts.

Tiger Shark – The newcomer

Tiger sharks have only been sighted 6 years before coconut. With markings one could prove that they stay up to 9 months before Cocos. Before they disappear then again in the high sea. The animals sometimes cover thousands of kilometres. But they can also stay in one place for months.

As omnivores, they are not choosy. On Cocos they seem to be particularly attracted by rays and turtles. Because since the appearance of the tiger sharks increasingly fewer of them are sighted. Of course, not all must have been eaten. As a reaction to the bag pressure they can also have evaded to less dangerous regions. 

Shark research on Cocos

180 hammerhead sharks have been marked on Cocos in the past 13 years. They have been found to swim back and forth between the Galapagos, Malpelo and Cocos archipelagos. For the distance of 800 kilometres between Cocos and Galapagos they only needed two days! Marked animals were also caught along the coast from Guatemala to northern Peru. Probably this is one huge group of hammerhead sharks. It is mainly found on the islands. For feeding and mating. To give birth they come then to the mainland. There the young are born and spend their first years of life. 

Alarming realization: If large quantities of hammerhead sharks are caught somewhere in the East Pacific, this concerns the protection zones and national parks. So the popular diving destinations Galapagos, Malpelo and Cocos! That means: Well controllable fish prohibition zones are useless in this case, since the hammerhead sharks undertake regular migrations.