The problems with run-off

Friday, March 11th, 2011

With all the rain and the ensuing run-off these past few months, the RMP received many questions about the effects of sedimentation on the reef. The earliest coral reef researchers recognized that coral growth was strongly inhibited wherever muddy freshwater enters the sea. Negative impacts of rivers include the introduction of freshwater and sediments such as mud, silt, and clay. While freshwater can cause bleaching, excessive sediment smothers and kills coral. Corals differ greatly in their ability to resist sedimentation, however most species are highly intolerant of even small amounts.

Unfortunately for the coral of Roatan, increases in development often worsen sedimentation. One of the main culprits is coastal dredging, like that which has occurred in Mahogany Bay and French Cay. Dredging generates huge muddy plumes which smother reefs in areas that previously had clear water. These plumes continue to cause damage long after the dredging has ceased as the mud is re-stirred by every storm, causing clouds of sediment to slowly work their way down coastlines, damaging reefs many times more before they are washed away.

The other main cause of sedimentation is soil erosion caused by increased deforestation and development. Depending on rainfall, topography, soil types, and land management, deforestation and development can result in up to thousand-fold increases in sedimentation in near shore waters. As a result sedimentation is taking a severe toll on almost all coastal reefs worldwide. In healthy coastal watersheds, sediments are naturally removed from fresh water before it enters the sea. Plants such as grass, trees, and mangroves act as buffers between the land and the sea by trapping sediment. If the natural buffer zones are damaged, sediment runs straight out onto the reef.

Roatan’s soil is composed mainly of red clay, which is easily soluble. After a heavy rain, it’s easy to see the threat to the reef as huge muddy plumes of water fill our lagoons. Our island’s reefs are under great threat of sedimentation. Unregulated deforestation and development, illegal road building (especially during rainy season), and the rampant destruction of huge swathes of mangroves, the list of threats is endless. Only through more conscientious development will Roatan’s reefs have a fighting chance.

Ten Reasons to save the coral reefs

Tuesday, May 11th, 2010

  1. Coral reefs occupy less that 1% of the oceans but support 25% of all marine fish species. If coral reefs disappear, more than 1,000,000 aquatic species are threatened.
  2. One-sixth of the world’s people depend on coral reefs for food, coastal protection, livelihood, and tourism income.  More than $350 billion in annual global income is at stake if the reefs are destroyed.
  3. As breeding grounds for many fish and other species, coral reefs provide habitat for the world’s commercial and subsistence fishing industries, and are a major protein source for more than 1 billion people.
  4. Coral reefs are natural wave barriers protecting coastal settlements from loss of life, erosion, floods, and damage from storms and tsunamis.  As reefs degrade and climates change, our coastal populations become more vulnerable.
  5. More biologically diverse than rainforests, coral reefs are important sources of new medicines being developed to treat cancer, heart diseases, arthritis, human bacterial infections and viruses.
  6. Coral reefs are like living museums that reflect thousands of years of ocean history. Having lost more than 25% of the world’s reefs, if we don’t act now, we may lose 50% by 2030.
  7. Eco-tourism to tropical locations is one of the fastest growing sectors of the travel industry, involving millions of tourists every year, providing essential income to some of the world’s poorest nations.
  8. Corals play an important role in absorbing carbon dioxide in the oceans and transforming it to create limestone skeletons that build reefs. Without corals, the amount of carbon dioxide in the water would rise even more dramatically.
  9. Sustainable tourism initiatives supported by well-managed MPAs and healthy coral reefs create income to fund community development projects including tuition and scholarships for children, improved healthcare services, and recreational opportunities.
  10. Coral reefs are some of the oldest and most diverse ecosystems on the planet and are integral to our heritage, as well as to the cultural and spiritual traditions of many communities.


Friday, March 19th, 2010

To create the “turquoise water and white sand beach” image that is printed on every postcard and advertisement in the Caribbean, hotels and resorts continue to remove seagrass. In addition to extracting it from the water, hotels and businesses either bury washed up vegetation or place it in plastic bags bound for the dump. This is done to create a more aesthetically pleasing swimming environment with the belief that seagrasses harbor organisms harmful to swimmers. Seagrasses, however, are an economically and ecologically crucial marine habitat. The same seagrasses that are removed for being unsightly actually protect the white sand beaches and tropical waters that draw tourists to our island.

 People should know that waters lacking sediment and nutrients are better for coral reef health. Seagrasses reduce impacts of sewage and run-off on corals by absorbing much of the nutrients before they reach the reef zone. Seagrasses also reduce wave power, thereby consolidating sediments and minimising coastal erosion. A recent study in Mauritius found that beachside hotels that removed seagrass became the victims of their own innovation. In as little as a year, beaches had entirely disappeared due to coastal erosion. The fishing industry also benefits from the existence of seagrasses. They provide shelter for juvenile grouper, snapper, conch and lobster, and are an important food source for adult fish, helping to keep fishing sustainable.

 Coral reefs are designed to benefit from occasional natural disturbances such as hurricanes. But human degradation of Roatan’s reef and associated habitats (upon which tourism success depends) is reducing its ability to recover from such events. The potential result–ecological and economic collapse, perhaps as soon as the next major hurricane.

 While authorities fail to enforce environmental laws, developers need to take on more of a moral responsibility to ensure that their activities are not damaging the natural resources that bring people to the island.