INTRODUCTION

THREE ISLANDS BORN IN THE CARIBBEAN SEA
The Cayman Islands are a series of three islands; Grand Cayman – the largest & most populated – and the smaller Sister Islands of Little Cayman and Cayman Brac. The bedrock of all three islands is a porous limestone. Although it is thousands of meters thick, it is built from the external skeletons of millions upon millions of tiny marine organisms – examples of which are still living on the diverse reefs of the Caribbean.

Long before Christopher Columbus navigated our three little islands on his last voyage, major tectonic unrest along the boundary of the Caribbean and North American plates created a ridge from Cuba southwestward to Nicaragua. This ridge created a series of mounds across the Caribbean Sea that were close enough to the sunlit surface for corals to begin to congregate, and settle. Slowly, over 40 million years, through several major shifts in the earth’s climate, and dramatic fluctuations in sea levels, the Cayman Islands were formed.

Even the ironshore rock formations that rim our shores are remnants of reefs that formed only in the last few thousand years as ice melted and the sea level rose. During times of lower sea level, large caves formed in the limestone as it dissolved – imagine that underneath us the rocks look like Swiss cheese!

Over time, corals built the modern fringing reef up to sea level, creating a powerful barrier to large waves, protecting our islands from erosion and allowing plants to grow.

Cayman has a rich diversity of habitats – reefs, lagoons, mangrove, beaches – and yet the total land mass of our three islands is only 100 square miles!

These three islands have no rivers which could carry sediment and nutrients into the sea, giving Cayman some of the clearest waters on earth. Our healthy marine environment provides us with food, shelter and the very land that we live on.

The reefs and their inhabitants produced sand for our beaches and provided a barrier for our shallow lagoons. These reefs also play a significant role in reducing coastal flooding as the sea level continues to rise. Connections are clear between our reefs, the sandy beaches and the mangroves that developed soon after.

Reef Geography illustrating the connection between the island and nearby reefs through porous limestone. Modified from NOAA.

Relative to the enormous Great Barrier Reef of Australia, Caribbean coral reefs have a low marine biodiversity. Scientists conclude that our region is highly vulnerable to disease and over exploitation as a direct result. While Australia’s Great Barrier Reef has some 350 species of reef-building corals and 1,500 species of fish, in the Caribbean there are 60 species of corals and only a few hundred species of fish.

For too long, mankind has seen the ocean as a dumping ground. We assumed that it would always feed us, that the tides would wash our shores, sea winds would clean our air and evaporation from the oceans would bring us rain. We now know that the ocean is moderated and affected by every living thing on Earth.

Every ecosystem and every organism relies on a complex symphony that occurs beneath the sea. Coral reefs are a key part of that complex process. They are extraordinary, but to most people, most of the time, they are unseen. Only recently, in scientific terms have we begun to understand their importance, and their fragility. From the beginning of geologic time the sea has given birth to life on earth.

HAZARD: The porous limestone substrate enables fluids to be transported from land to sea quickly. Chemicals, pesticides, sewage, waste, and water flows almost directly into the sea and can potentially kill otherwise healthy corals and reef organisms.