Observed change

  • There has been an increase in the frequency and magnitude of coral disease and bleaching events over the last three decades.
  • Data from the Bermuda Atlantic Time-series Study station show carbon dioxide levels at the ocean surface of the Sargasso Sea southeast of the Bermuda Triangle are rising at about the same rate as atmospheric carbon dioxide. The change is even greater at deeper levels:  in the waters between 250 and 450 m deep, carbon dioxide levels are rising at nearly twice the rate of the surface waters (Glick, 2004).


Implications and possible future impacts

  • Bermuda’s mangrove forests are threatened by salt water inundation due to rising sea levels. Climate change is contributing to the death of mangroves at the Hungry Bay Mangrove Swamp, a designated wetland of international importance under the Ramsar Convention.  This mangrove forest is considered to be “in retreat.”
  • Turtle nesting sites are subject to erosion from tropical storms and hurricanes that affect the island.
  • Bermuda’s coral system is distinctive for being the most northerly of its kind in the world and is among the more geographically isolated reefs. The fate of this reef system is linked to those of the Caribbean, which seed them. The decline in Caribbean coral (see section 3.2.3) will likely affect coral dispersal and gene flow to Bermuda, increasing the geographically isolation of the system there.  Limited genetic variation within isolated populations in marginal environments, like the North Atlantic, could lead to a weakening of the coral’s capacity to respond to or recover from environmental disturbances. Local coral deaths, whether caused by pollution, dredging, disease outbreaks, hurricane damage or thermally induced bleaching, will have lasting effects (Jones, 2004).