Golf course fertilizer runoff causes nutrient enrichment leading to harmful algae blooms on a Bahamian coral reef

Bahamas National Natural History Conference: A Conference Highlighting the Importance of Research, Conservation, and Environmental Stewardship in The Bahamas

March 5-8 2013 Nassau

Golf courses overlooking the sea are popular tourist attractions. There are no studies on effects of golf course fertilizer runoff on coral reefs, although many environmental impact assessments deny deterioration would occur. We studied changes in coastal algae, algae nutrient contents, and health of adjacent coral reefs, before and after construction of Bakers Bay Golf Course on Guana Cay, Abaco. After construction new algae blooms appeared along shores nearest to golf course greens, smothering corals in adjacent reefs, along with sharply increased coral diseases. Bakers Bay claimed there was no link between algae blooms and fertilizer use, that blooms were natural, caused by hurricanes, or due to septic tank leakage from remote areas. We measured coastal algae nitrogen and phosphorus contents around Guana Cay in dry and rainy seasons. Guana Cay waters are phosphorus limited. The highest abundance of harmful algae is in waters next to the golf course, and they contain higher nitrogen than algae from any other part of the island. Algae nitrogen/phosphorus ratios were higher in the rainy season and phosphorus contents lower. The nutrient source triggering algae blooms appears to be nitrogen leaching from golf course fertilizer into the sea via groundwater seepage. We believe similar results could be found in any golf course overlooking tropical shores, however this study is the first to document such impacts. Much stronger water quality standards, monitoring, and enforcement, better fertilizer management, and planning controls on siting are needed to protect coral reef environments from golf course fertilizer-caused eutrophication.

Thomas J. Goreau – Global Coral Reef Alliance, Cambridge MA 0239, USA

James Cervino – Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA

Troy Albury – Guana Cay Reef, Guana Cay, Abaco, The Bahamas