Protecting coral health in the region

 Cayman owes much of what it is to its coral reefs. The sandy beaches, the calm coastal waters and the excellent diving all point back to the reefs.
   Yet over the last couple of years, many of the corals on the reefs have become ever more scarce as the health of the reefs have declined.
   In the United States, the decline has caused an environmental group, Center for Biological Diversity, to file a petition that calls for 82 coral species to be listed as threatened or endangered under the Endangered Species Act. At present, only two reef building coral species, the staghorn and elkhorn corals, are listed as threatened under the act.
   Of all the species listed, many do not occur in Cayman waters, as the listed corals include those present in the US state of Hawaii. In fact only seven of the species are Caribbean corals, according to Carrie Manfrino, president of the Central Caribbean Marine Institute. However, some of the species listed are extremely important.
   “Listing the Montastraea spp is significant for the Caribbean because it was dominant, greater than 50 per cent of the population in the Cayman Islands before the 1990s and now is in the 30 per cent range,” says Manfrino.
   Even though the Endangered Species Act only has power within the US and its territories, that does not mean protection under the act will not have an impact on the health of coral in Cayman.
   Coral is highly mobile in the larval stage as it is carried on the ocean currents to settle out far from its originating colony. This means that protecting coral in one country may benefit coral across the entire region, while the destruction of a habitat may have a similar negative impact on regional coral health.
   Although the US act does not extend to Cayman, there are numerous other organisations and treaties that are in effect in Cayman.
   “The Cayman Islands is party to several international environmental conventions, including the United Nations Convention on Biological Diversity (the Rio Convention or CBD), the Ramsar Convention, and the Specially Protected Areas and Wildlife protocol to the Cartagena Convention (the SPAW Protocol) will also shortly be extended to the Cayman Islands by joint agreement with the UK Government,” says Manfrino.
   Such international conventions place obligations on the signatories, in this case the Cayman Islands government, to honour these agreements.
   “Protected area system CBD, Ramsar and SPAW all call on parties to establish and maintain a system of protected areas, in order to safeguard the country’s natural biological diversity,” according to Manfrino.
   Coral is a complicated, living creature, with many individual polyps making up a coral head. Many corals also live in a symbiotic relationship with algae. These benefit from the protection the polyps provide, as well as from the waste produced by the coral, while in turn providing energy via photosynthesis. However, when the coral is under stress, these algae can be expelled. As the algae provide the colour to the corals, such expulsion leads to coral bleaching. Stress on the coral can be as simple as a slight rise in water temperature, with a rise of one degree Celsius above normal being enough to trigger a bleaching event.
   While corals can recover from bleaching, the effect can also be permanent and lead to the death of the coral.
   Cayman experienced some bleaching events over the summer months, with almost all corals on shallow reefs around 30 feet showing signs of moderate to severe bleaching, and some 80 per cent of corals on reefs down to 120 feet showing early signs of bleaching. As the water temperature starts dropping in the latter part of the year, bleaching is halted and usually reversed.
   The installation of an Integrated Coral Observation Network station in Little Cayman is helping the monitoring of local reeds as well. The station monitors elements such as water temperature, ultraviolet light levels under water as well as various other elements. This information can assist in forming a picture of environmental factors likely to impact on local coral reefs and can also trigger a ‘bleaching potential’ alert, which can serve as an indicator for researchers to investigate the state of local corals.