San José, Costa Rica, since 1956

Marine life behavior alters after drilling

The blue-water pelagic ecosystem offshore of southwestern Costa Rica’s Isla del Caño Biological Reserve and Corcovado National Park took serious one-two punches during the past few months, and it remains to be seen whether things will ever return to conditions of the past. The area around, not inside, the two protected areas is probably Costa Rica’s most critical dolphin and whale breeding and feeding waters. But the whales are gone, and the dolphins have changed. The fishing has been off, and boats are headed elsewhere to find fish.

Shawn Larkin

Shawn Larkin

The first few months of the year shaped up to be one of the best seasons for marine life in Costa Rican waters in recent memory. The cool currents of La Niña stoked a profusion of big pelagic species like dolphins, whales, tuna, turtles and giant mantas. Divers and snorkelers from the Southern Zone reported more giant mantas seen at Caño Island in February and March than in the past 15 years put together. Flights and boats searching for marine life in the area were finding dolphin superpods, groups of dolphins numbering in the hundreds to thousands, all over the area. There were many mating and birthing humpback whales, a large pod of false killer whales, orcas, fin whales and even three blue whales, including a baby, feeding on giant bait balls of small fish brought up from the depths during the normal strong upwelling at this time of year. There were uncountable hectares of turtles, tuna and billfish. There were even a few big sharks.

Then, a giant foreign ship showed up and began drilling deep holes in the ocean floor not far from Caño Island, in the name of scientific research. Within a day, the whales were gone. Search time for dolphins from a plane went from a half hour or less to two hours or more. Most dolphin superpods broke into smaller groups and headed north toward offshore Quepos. Others broke into smaller groups and moved inshore, closer to the coast. Dolphins that stayed in the area developed a strange skin rash.

The spewing ship kept at it for a month. Great areas of waters turned from marine blue to metallic brown and green. The day after the ship left, a new one showed up towing many kilometers of giant air guns blasting extremely loud sounds repetitively. A week later they were still at it. Drake Bay ecotourism and sportfishing boats foolish enough to still be looking in their favorite hot spots were told to leave the area by burly men on a yacht out of Quepos. Scuba divers at Caño Island could hear the giant booms of the guns during their dives.

No environmental impact study was done for the area. No dolphin and whale observers were onboard to look out for cetacean safety. There were no Costa Ricans onboard until someone noticed. Many questions were never answered. No notice was given to area residents of what was going to happen.

Since the drilling, no whales have been reported in the area – the longest period without whale sightings that anglers and guides in Drake Bay can remember. No large dolphin superpods have been seen. The fishing is bad. No wonder so few tourists seem to want to visit the area right now.

This serious lack of ocean oversight has left locals wondering what is next. There are reports of making a permanent drilling riser here and of laying an undersea cable from the mainland to Caño Island and then offshore to the rig.

Let’s hope an environmental impact study is involved and that locals dependent on the area’s marine life are given some notice so they can find new jobs. Because what’s next could be the knockout punch for a good chunk of Costa Rica’s famous marine life: whales, dolphins, turtles – and fishers and divers.

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