Symposium Held at CEA to Discuss the Destruction of Coral Reefs

To celebrate 10 years of research at Akumal, CEA hosted a symposium on May 19 and 20, which brought together more than 20 leading scientists and the local community. Reef biologists and groundwater specialists from México and the United States presented findings of their research to an audience of scientists, members of the press and government, and interested individuals. The scientists agreed that coral diseases are killing the reef coral along the Mexican coast and that the diseases are caused, in part, by contamination from human sewage. Over the last 20 years live coral cover on Mexican reefs has declined from approximately 60% to less than 10%. Corals have died from diseases and global warming, which drive coral bleaching. This is startling information and is made even more relevant in light of the government’s plans to convert Akumal into a city of 250,000 people by the year 2028. CEA will have quite a lot of work to do in its next 10 years in order to ensure that any urban growth does not kill the reef.

Mr. Curtis Sparks was keynote speaker at the meeting. A wastewater engineer and President of North American Wetland Engineering of Minnesota, Mr. Sparks warned that unregulated development can destroy the natural environment that draws people to vacation on the Rivera Maya. He underlined the need for a partnership between the business community and environmental groups to enable sustainable development of the region.

Mr. Sparks outlined the successes and failures of U.S. efforts to deal with waste water. He stressed that México need not repeat the mistakes of its neighbor, such as allowing the use of deep injection wells, and accepting the idea that some level of pollution is acceptable. "Zero contamination is possible and there is no reason to accept anything less," Mr. Sparks said.

CEA director Paul Sánchez-Navarro presented a summary of the current development plan for Akumal. The plan, promoted by the Municipal government, will establish a city of about 250,000 inhabitants over the next 20 years. The information presented helped set the context for a discussion of the current impact on the reef from human activities, and the potential impact tourism development may cause if it occurs in an unsustainable manner.

Longtime Akumal research scientist Drew Harvell, of Cornell University, described The World Bank Targeted Research Program on Coral Sustainability, which she chairs. The group has met twice in Akumal. The program has four goals: 1) a global coral disease assessment and baseline; 2) coral resistance to disease; 3) impact of disease on coral reefs; and 4) management solutions. The group will work at four locations around the world: the Yucatán Peninsula, the Philippines, Australia and East Africa. The work on the Yucatán Peninsula will be based at UNAM in Puerto Morelos and at CEA in Akumal.

Several technical papers presented at the meeting dealt with the problems caused by overloading the coastal waters with nutrients. Dr. John Bruno, of the University of North Carolina, described the effects of nutrient loading on coral disease. His experiments show that excess nutrients greatly accelerated coral death by making the pathogens stronger. A report by Shauna Slingsby, of NOAA, described the way nutrients foster the growth of reef-smothering macroalgae.

Dr. Charles Shaw, of CEA, presented data to suggest that at present high-contamination levels of the coastal groundwater, large amounts of nutrients are being delivered to the marine environment. Hotel developments using deep wells to dispose of both treated and untreated sewage waste were identified as probable sources.

Deep wells were long thought to be a safe method of disposal, but studies carried out over the past few years at CEA have conclusively shown that fresh water, which is lighter than the salt water into which it is injected, floats back to the water surface close to the point where it is injected, especially at sites close to the coast, he reported. Sewage that does not reach the surface moves inland with landward-moving deep salt water. Eventually, the contaminated salt water rises to the base of the near-surface fresh water body that exists everywhere on the Peninsula. The contaminated water would there become entrained with the fresh water and return to the ocean at a shallow depth.

Dr. Shaw urged that deep wells be made illegal for disposal of wastes—"any type of waste at all," he stressed. Nutrients entering the ocean with sewage are mainly phosphorus from soaps and nitrogen from urine, with smaller amounts of mineral nutrients, such as iron.

UAM biologist Sylvia Díaz Ruiz and her students Enrique Cano-Quiroga and Christian Alva-Basurto presented papers that demonstrate a statistical pattern of seasonal variation in the distribution of fish species in response to direct environmental factors, such as temperature, salinity, depth and coral types. These seasonal changes allow a number of species of fish to utilize various preferred "stations" sequentially through the year in accordance with the life stage of the particular species.

Doctoral candidate Jessica Ward showed that coral diseases alter the environment used by fish and other species through death of various host coral species. The reduction in host abundance cascades through the ecosystem, causing diminished resources. Sharing strategies by fish can reduce the impact of these losses.

Scientists studying coral diseases reported six different diseases on the Mexican Caribbean: black band disease, dark spot disease, white plague, yellow band, white pox and white band on hard corals, and Aspergillus sydowii disease on the common sea fan.

Possible methods to arrest the spread of diseases and nutrients through the use of integrated waste management systems that use constructed wetlands as drain fields for septic tanks, plus composting toilet technology, were presented by Dr. Rina Aguirre. Thanks to the work of Dr Aguirre and Kathryn Robinhawk, CEA is proposing to build models of these systems as part of an Eco-park using a quarry near Akumal. The idea is to convert the abandoned quarry into a recycling and education center, with gardens managed from waste materials. Meanwhile, numerous constructed-wetland drain fields and composting toilets have been built in Akumal through the efforts of CEA and the Planetary Coral Reef Foundation. These may be inspected through appointment with CEA.

In an effort to further develop the technology of constructed wetlands, Dr. Rebecca Ferrell reported research on a strain of microbes that can be added to drain fields to enhance effectiveness in removing the nutrient nitrogen from waste water.

Kate Riley, of CEA, rounded off the presentations with a wonderful discussion of the need to integrate solutions which deal with the needs of both the Mesoamerican Reef and the human population that depend on a healthy ecosystem.

The plenary discussion culminated in a draft Declaration to be delivered to the Municipal government and the public. The Declaration will present the conclusions of the Symposium and offer essential steps to be taken, if the coral reefs of Mexico—the foundation of the economy of Quintana Roo—are to be saved from destruction. CEA will deliver the Declaration to the Committee for Ecological Land Use Planning (Plan de Ordenamiento Ecológico Territorial, POET) at its next meeting in an effort to ecologically influence the development plans.

CEA would like to thank the many scientists who presented their research and the community who shared their concerns and interest. We hope to have more of these types of events as part of our efforts to complete our mission.

Please contact CEA if you would like further information on the research presented at the Symposium or the government’s Plan for the Development of Akumal.

Declaration of Concerned Scientists.