Tag Archives: coral reef

The Coral Reefs of Huatulco: Unnatural Changes

By Julie Etra

I have been scuba diving and snorkeling here since our first trip in 2007, but I am no expert and certainly don’t have the decades of history and knowledge possessed by the locals regarding pre-Huatulco-resort (1985) conditions. What I can contribute are my observations from repeated trips to several reefs over the years, as well as some review of reef studies and possible preservative actions.

Huatulco’s nine bays and 35 beaches host18 coral reefs. For snorkeling I typically go to Entrega, San Augustín, and more recently, Riscalillo. Tejoncito is a sweet little cove within Bahia Conejos, but it is pretty rocky, with some coral but typically not great visibility. Arrocito is another popular spot for some of our good friends, but it does not have the fabulous reefs that support aquatic diversity. Maguey has a great reef for scuba diving, accessible by boat. All lie within the Parque Nacional de Huatulco, and all are managed under its jurisdiction. (The Park was established in 1998 through a presidential decree.)

Entrega. Huatulco’s reefs and beaches are gems, and like so many beautiful natural resources everywhere, they are being loved to death. Entrega is a bay within the larger bay of Santa Cruz, both protected and at the same time somewhat contained due to its configuration; it is the most popular and accessible reef of the nine major bays of Huatulco. Entrega has its own sewage treatment plant behind the restaurants.

We always make it a point to go early to Entrega as even during the week this beach is frequently packed. There are just too many people, too many boats, and, despite the treatment plant, perhaps inadequate sanitation.

Entrega, which means ‘delivery’ or ‘surrender’ in Spanish, is named for the unfortunate fate of Vincente Guerrero, the Mexican Republic’s second President. The liberal Guerrero was deposed by his conservative vice president, Anastasio Bustamante; in the ensuing conflict, Guerrero was lured onto a French ship in Acapulco, carried to Huatulco, and surrendered on the beach at Entrega. Thence he was transported to Oaxaca City, tried and convicted, and executed by firing squad.

San Augustín has a large accessible reef, both by car and boat, and no engineered waste treatment systems. There are baños/sanitarios but their design and effectiveness appears questionable. Sweet Riscalillo, recently accessible by car, has a gorgeous reef but absolutely no sanitation facilities. I have only been there a few times so can’t comment on its change, if any, but it is on my radar.

Studying the Reefs – about a Decade Ago

From 1998-2012 the Federal Government of Mexico monitored the health of various reef ecosystems in the Mexican Pacific, including reefs in Bahías de Huatulco. It used the Coral Health Index (CHI) to look at fish populations and the bottom layers of the ocean (an “ichthyic” and “benthic” survey). According to a 2013 master’s thesis on the survey, prepared by Montserrat Molina Luna, the CHI values for Huatulco were at an “optimal health state” after the initiation of protection measures through the creation of the Parque Nacional in 1998. The fish populations of all the evaluated reef ecosystems were herbivorous, which promotes a balanced ecosystem by controlling the proliferation of algae.

So as of 2012, the reefs of Huatulco, according to this report, were in good shape. But were they? In 2011, the independent news and analysis agency Quadratin published an article on studies conducted by the Parque Nacional, which found that the reefs of Entrega had diminished by 80%, due to such factors as climate change, pollution and poor tourism practices. Natalia Parra del Ángel, at the time coordinator of CostaSalvaje, an international eco-organization focused on preserving coastal and marine ecosystems, warned that these factors could lead to the extinction of Huatulco’s coral reefs.

At that time, the Parque Nacional suggested to the local CostaSalvaje team some actions that swimmers, boaters, and tourist guides could take to help preserve Huatulco’s 12 types of coral reefs. Boats should not drive over the reefs, much less anchor on them or drop oil or gasoline. The most important was that divers and snorkelers should make sure they did not damage the coral – preferably, they should be accompanied by certified, trained guides. Swimmers should not wear sunscreen, because it creates a floating grease stain that prevents light from reaching the live microalgae inside the coral. Divers, snorkelers, and swimmers should not stand on the reefs.

Protective Practices a Decade Later

And did these practices take hold? Not really – and this is far from a comprehensive list of examples.

2013: Scientists like Carlos Candelaria Silva, a research professor at UNAM, began pointing out that the deterioration of the coral reefs at Entrega and San Augustín was very “worrying.” Sediments carried down in the rainy season, rubbish left behind by beach-goers and swimmers, added to boat traffic and large numbers of snorkelers, were damaging the reefs. By 2015, Candelaria was saying that measures to “protect and heal” the coral were urgent.

2016: Fisherman and oyster and octopus divers complained that the construction of Barlovento, a 15-condo development above a little beach next to Entrega, was dumping tons of construction debris – dirt, stone, and mud – right onto the coral reef. If the coral reef were to die, the divers and fishermen would lose their livelihood. While the divers and fishermen were not opposed to development per se, the fact that the Barlovento was taking no measures to protect the reef was unacceptable. Meanwhile, the presale materials for the Barlovento touted how ideal “the quiet bays of Huatulco” were for a “wide range of water sports. If you practice diving or snorkeling, you will be amazed at the purity of the waters. The rugged coast of Huatulco and its unrivaled coral reefs will surprise you with their extensive underwater biodiversity, waiting to be exploited.” While they might have meant “explored,” yes, they said “exploited.”

2018: This was a mostly bad news/some good news year. The Chiapas-based news service Noticias: Voz y Imagen reported that snorkelers and divers who rented equipment and set off to view the living coral reef were being allowed to snap off chunks of live coral as souvenirs. No one, “not the restaurant owner, not the waiter, much less the maritime business that rented the equipment and sent them off into the sea,” told them breaking off the coral would “significantly alter one of the most valuable ecosystems” for thousands of marine organisms and hundreds of species.

The problem was most out of control at San Agustín; the coordinator of Nature Tourism for the Municipio of Santa María Huatulco, Pedro Gasca, said that with 44 restaurants and 20 places that rented snorkel gear in the low-season, many more in the high season, it was difficult to counteract the business practice of “the customer can do whatever the customer wants.” He suggested that education was the key, and prepared a workshop for the snorkel outfits; the content focused on educating the customers how to view the reef without destroying it.

At this point, the three major threats to coral reefs were identified as climate change, ocean acidification, and the usual biggie, mismanaged tourism practices. Climate change and ocean acidification combine to make it very difficult for coral to create and deposit the calcium carbonate that extends the “skeleton” of the reef. This is most obvious as bleaching; when corals are stressed by changes in temperature, light, or nutrients, the symbiotic algae living in their tissues die, causing them to turn completely white.

Between 1998 and 2018, Pacific corals thinned out, i.e., they were 20% less dense and grew more slowly (they were only making a centimeter – just over ⅜ of an inch – of skeleton a year as it was!). Some corals (the slowest-growing ones) adapt, others bleach out and die.

Given that mismanaged tourism is a more immediate problem to address, CONAMP started supporting CostaSalvaje in projects to protect the reefs. CostaSalvaje used CONAMP resources to string buoys to keep tourist boats from driving over and dropping anchor on the reefs. CONAMP developed educational programming for tourism providers and guidelines for tourists, although it appears the latter must be accessed on their website,

2020: In January of this year, CostaSalvaje and CONAMP were among multiple government, educational, and organizational sponsors of the first annual Festival Coralinos de Huatulco: Tesoro del Pacifico Mexicano (The Coral Reef Festival of Huatulco: Treasure of the Mexican Pacific). With scientific poster sessions, workshops, and meetings on the marine environment, the goal of the Festival Coralinos was to inform the public about the importance of the reefs to the region and to promote better tourism and environmental practices. Informational installations were set up in the central park in La Crucecita, in Rufino Tamayo Park, and in the Sports Plaza.

What It Really Looks Like Right Now

When I first arrived in November 2019, Entrega beckoned. I went out there with my good buddy PauI Biernacki and was appalled to observe what appeared to be an obvious decline in reef health since my last visit in April 2019. Huge algal blooms floated over and coated the reef, especially close to shore, where the sea seemed unusually murky and almost oily.

Algal blooms are described by the United States Environmental Protection Agency (EPA) as “overgrowths of algae in the water, which can be caused when nutrient pollution (nitrogen and phosphorus) in the water fuels algal growth. Note the murkiness of the surface water due to overgrowth of algae.”

Local guides I have spoken with have also noted the decline in reef health at Entrega. Basically, the blooms suffocate the reefs. Guides continue to see other sources of reef damage that have been discussed over the last decade (bleaching, sedimentation, physical damage, and chemicals such as sunscreen). Although the sedimentation can be natural, it is undoubtedly exacerbated by the turbidity caused by boat propellers.

Where do the nitrogen and phosphorus that kick off the algae blooms come from? Obviously not agriculture. Sewage? Currents bringing in contaminants from other sources? During multiple trips to Entrega over the winter, I noticed the currents had pushed the algae and deposited it on the northern part of the reef. I am happy to report that on an early morning swim on March 16, most of the algae was gone and the huge schools of green jacks (jurel bonito) were back.

I have not noticed algal blooms at either Riscalillo or San Augustín, locations that don’t get the same constant traffic as Entrega; however, like Entrega, San Augustín appears to be suffering from bleaching. We have seen the algal bloom called “red tide” from time to time in Huatulco, but red tide occurs naturally. And that sargassum we hear about over on the Mayan Riviera? It’s a type of kelp that isn’t often found in this area of the Pacific.

Of course, reef deterioration can be cyclical and caused by multiple factors, including seasonality and temperature associated with prevailing and changing currents. But human impact – those poor tourism practices – cannot be underestimated. Unfortunately, restricted use or quotas imposed by the government are unlikely to occur in a beach destination like Huatulco, whose economy depends on that tourism. It would be nice to at least see a monitoring program designed and implemented, and good science conducted with data made available to the public. Certainly, the universities on the coast, especially those that participated in the Festival Coralinos, can help.