The Shallow Reefs of Bermuda

Image: Dr. Manuel Gonzalez-Rivero at work on the reefs of Bermuda


The shallow reef research team, lead by Dr. Manuel Gonzalez-Rivero from the University of Queensland, has now been in Bermuda for five days surveying the coral reefs of the area for the Catlin Seaview Survey. These are the most northern coral reefs (Bermuda lies at 32° N in the Atlantic ocean) that the team has ever surveyed, so we have been excited to see how a reef growing in temperate conditions compares to a reef found in tropical waters (such as the Mesoamerican Reef that we surveyed in July, 2013).


Happy to see hard corals

So far, the shallow reef team has been pleasantly surprised by the strong concentration of corals present in Bermuda, possibly 80% of corals present are hard corals including massive boulders of brain and star corals. Hard corals are important, as they are the building blocks of coral reefs; their carbonate skeletons provide the structure of the reef system, offering areas for new coral to settle and grow, and shelter for marine life. There is a low diversity of corals species with only 18 to 20 known species (compared to 70 or 80 species in the Caribbean region) however, the corals that are here, look to be thriving. The high abundance of coral in this area could be due to the island’s isolated location, weather conditions, ocean currents or temperature fluctuations.


Living on the edge 

During summer, the average sea temperature in Bermuda is 25-29° celcius, however, during winter, the water temperatures can drop to only 18°. Compared to the Caribbean region, (which has a smaller range between 21-29° celcius) corals that grow in Bermuda can withstand a greater change in temperature which interests the science team greatly. Bermudian corals live at the edge of their physiological temperature limits, which means that any effects from environmental stressors, such as an increase in sea temperature, ocean acidification or sea level rise, will effect the Bermudian reefs first.