State of the Coral Reefs of Costa Rica
A version of this article appeared in 2004 in The Tico Times, central america's leading English language newspaper. www.ticotimes.net
The coral reefs of Costa Rica are slowly dying. Last year many locations around the entire Caribbean Sea recorded surface temperatures that broke all records. South Caribbean divers here saw some coral turn white and then later die beneath a blanket of quick growing seaweed. But warm waters are not the only factor killing the reef; chances are you might be playing a part.
Reef building corals do not live alone. Corals are little animals that, under the right conditions, each slowly make their own little shelter made out of calcium. The tiny tentacles of each coral animal, or polyp, grab minute sea life drifting by to eat and survive. But these wee creatures could not build a reef without some help. So they share their shelter with some plants known as alga.
The petite plants photosynthesize from the sun and get a sheltered place to live. The wastes the plants produce nurture the corals with just what they need to make reef. All reef building corals depend on plants that, in turn, rely on the corals. This relationship of mutual benefits demonstrates one of the most fantastic examples in nature of what is called symbiosis.
When things heat up the coral and algae do not get along. Rising water temperatures cause coral to kick out their roommates. Without the plants the corals turn white, a phenomenon divers and coral researchers call “bleaching.” The corals cannot live for very long without their alga buddies but if the waters cool enough the alga return and the reef grows.
The reefs grow so well that they are the biggest animal made structures on the planet. The barrier reef growing on Costa Rica’s south Caribe, known as Long Shoal to locals, stretches for several kilometres offshore of the Gandoca Manzanillo National Wildlife Refuge and on towards the fringing reef off Cahuita. Some of the many patch reefs growing inshore towards the beach from the barrier reef are larger than a city block. Other patch reefs, some just a few fin kicks off the beaches, are about as big as your dinner table.
A lot of things on your dinner table here in Costa Rica might have arrived there with the help of the coral reef. Many lobster, fish, shellfish, shrimp and crab, and more spend at least part, if not all, of their life cycles hiding within the protection of the coral. Coral reefs are the most diverse marine ecosystems on earth and an enormous number of other species depend on them for food, from sponges to dolphins. When not eating reef species, people studying them gain insight that leads to many medical advances such as artificial bone.
Without the reefs many surfers and divers would simply go somewhere else. Reefs cause waves to break overhead in a spectacular fashion and that is why Puerto Viejo’s Salsa Brava wave, caused by the coral reef below, is considered by many surfers to be one of the best in the world. There are many other surfing waves, reef breaks, in the south Caribe as well. The resulting draw to surfers brings Limon, and Costa Rica, a lot of money. Divers as well come for the reef, and its accompanying marine life, and like surfers they spend money on transportation, accommodations, food and services all over Costa Rica.
We do not get just money and food from the reef, the reef also protects Costa Ricans from tsunamis, massive waves usually caused by earthquakes. Manzanillo residents who were here for the devastating big shake of 1991 recall watching a massive tsunami break offshore over the Long Shoal barrier reef. The wave spending its deadly energy on the Long Shoal coral reef is probably why parts of the south coast received a slowly rising wave of foam and not a high speed crushing impact. The reefs also create shallow pools and lagoons that are protected from surf and are perfect for swimming. The reefs and pools together form what many people consider to be the most beautiful beaches in Costa Rica.
This source of food, money, medicine, beaches and protection for the nation is now under threat. Rapid development of the tourism industry is dumping contamination, cutting bush and draining wetlands. Irresponsible agriculture does the same thing. All affect the reef with increased sediments in the water. Sediments make the water murky and prevent the reef from growing. The plants that live with coral need plenty of light which can only pass through clear water. Cutting forest and draining land for habitation stops a natural filtration process. Dirty water reaches the reef in hours instead of spending time oozing through the land and leaving many of its sediments.
Another major threat for corals in Costa Rica is water that is too warm. Last year was the worst Caribbean bleaching I have seen in more than twenty years diving the region. Much of the bleached coral is coloured again this year but some of it has died for good. Bleaching corals were documented over most of the Caribbean Sea by the end of the summer last year, the warmest year on record for this body of water.
This year the Caribbean Sea is heating up as the northern hemisphere’s summer advances. According to the United States National Oceanic and Atmospheric Administration, or NOAA, parts of the north Caribbean are already as hot as they normally would be at the end of summer. Costa Rica’s water usually remains warmer longer than the north Caribbean and cools off with the winds of November blowing down water from the north. That’s still months of summer heating to come and that does not bode well for Costa Rica’s Caribbean reef or the marine life and people who depend on coral.
Don’t think dying coral does not affect you if you enjoy just the Pacific coast of Costa Rica. Reef building coral does not grow usually grow as profusely on the western side of continents due to ocean circulation patterns but here in Costa Rica, Pacific divers know that plenty of coral grows on the rocks in some areas and that there are even some rare eastern tropical pacific reefs. These pacific corals provide the habitat for little fish that bring in the big stuff Pacific sport fishers and divers come to see. Without Pacific corals and all the fish they bring, Costa Rica would have to buy a lot more seafood from other countries.
The Caribbean warming up like never before is thought by many people to be due to global warming. Global warming is thought to also cause more frequent warmings of the eastern tropical pacific, a phenomenon known as El Nino. Previous El Ninos have caused massive bleachings on all of Costa Rica’s pacific coral areas, from Guanacaste to Cocos Island, including some local species extinctions. This negatively affects diving, sport and commercial fishing, dolphin and whale watching and tourism in general.
But even if the sea does not heat up unchecked development and over fishing off the Caribe and the Pacific coasts will continue to damage the reefs. Already the reef sections off the south Caribbean’s Puerto Viejo are mostly dead and that was long before last years bleaching. Inside the waters of the Gandoca Manzanillo National Wildlife Refuge and Cahuita National Park the marine life clearly appears healthier than outside to divers, evidence that the earthquake damage and agricultural runoff are not the only big factors hurting the reef. But even in protected Manzanillo waters, where locals are allowed to hunt but there are no “no take zones,” most divers admit that overfishing has factored into local sons knowing they will never make catches as big as their fathers. Will the next generation even get to see coral reef?
The most important things we can do to save the tico reefs involve slowing water contamination. If tourists, travel agents, guidebooks and newspapers began checking the waste water treatment systems of the hotels and operators that they stay in, book, and write about, businesses would clean up their act fast. A certification, like divers must have, for sustainable Costa Rican fisheries, would help little Ticos have a chance to eat local seafood and dive the reef and as well as keep tourists coming back. The Marine Stewardship Council shows an example of such a certification. Leaving more bush around waterways filters more sediment, preventing it from reaching the reef. More no take zones that act as nurseries for countless species are crucial. Protected areas must include more reefs. We must boycott any establishment, like hotels or dining, that uses salt water aquaruims with live coral in them, as it must be constantly replenished. Divers, snorklers and beachgoers can take care to not touch, stand on, or fin the highly stressed corals.
Viva el coral!
All rights reserved Costa Cetacea shawn larkin 2010
