Tom Goreau Explains Data on Bakers Bay Coral Decline at Bahamas National Natural History Conference
Acclaimed coral scientist Tom Goreau spoke in Nassau about coral reef decline at Baker's Bay Club as a result of excessive fertilizer run-off. The speech, given at the Bahamas National Natural History Conference on March 7, was well received by the audience and by the Bahamas National Trust, which hosted the event.
The speeach, billed as "Golf Course Fertilizer Runoff Causes Nutrient Enrichment Leading to Harmful Algae Blooms on a Bahamian Coral Reef", was co-written by Tom Goreau of the Global Coral Reef Alliance, James Cervino of the Woods Hole Oceanographic Institution, and Troy Albury, President of Save Guana Cay Reef, and presented by Goreau.
Goreau begins by describing Bahamian coral reefs of 50 years ago.
He describes how they were famous for huge corals and incredible coverage of living corals. Bahamian reefs were also known for large schools of fish. Today, Bahamian reefs are not nearly what they were fifty years ago, and the only way we can glimpse into the state of the reefs from that time is to view the historical photographs of the time.
Goreau explains the dilemma of shifting baselines; that each generation of diver can only compare the state of the reef to what he knows. But no divers from today have the same baseline as divers of fifty or sixty years ago. The relatively slow rate that the reefs have declined have made it difficult for anyone to accurately measure the decline.
Following is an annotated view of Goreau's presentation:
Goreau next asked the question, "Does development hurt coral reefs?"
• Dead reefs next to tourism developments all around the world
• Impacts of sewage and fertilizer nutrients cause massive growth of weedy algae
• Algae then smother and kill coral
• Higher incidence of coral diseases associated with sewage wastes
• NO before and after studies on either hotels or Golf Courses
Golf and Tourism: How Green Is It?
• Every major tropical tourist destination has golf courses. Most are near to the ocean.
• Huge amounts of fertilizers are used.
• Tiny amounts of fertilizer cause algae to overgrow and kill coral.
• Every golf course environmental impact assessment says no damage will result.
• No before and after studies have ever been completed.
Existing Bahamian Golf Courses:
• Baker's Bay Golf & Ocean Club, Great Guana Cay, Abaco
• Blue Shark Golf Club, Nassau, New Providence
• Fortune Hills Golf & Country Club, Freeport, Grand Bahama
• Lyford Cay Club, Nassau, New Providence
• Our Lucaya Resort - Lucayan Course, Freeport, Grand Bahama
• Our Lucaya Resort - Reef Course, Freeport, Grand Bahama
• Radisson Cable Beach & Golf Resort, Nassau, New Providence
• Sandals Emerald Reef Golf Club, Great Exuma
• South Ocean Golf & Beach Resort, Nassau, New Providence
• The Abaco Club on Winding Bay, Marsh Harbour, Abaco
• The Ocean Club, Paradise Island, New Providence
• Treasure Cay Golf Club, Treasure Cay, Abaco
Many more are planned.
• Guana Cay, Abaco, is a native Bahamian fishing community
• Outside developers given Crown Lands to build golf course, mega- yacht marina, hotel, mansions
• Locals opposed this because it would kill their coral reefs and fisheries, to no avail
Bakers Bay was pristine in 2003 before development, with lush mangroves and some of the finest coral reef in the Bahamas.
Prior to any development at Bakers Bay Bakers Bay
• Three groups of scientists independently studied health of reefs at North Guana Cay and other sites in the region.
• Dr. Michael Risk 2004
• Dr. James Cervino 2006 -2007-2012
• Dr. Thomas Goreau 2007 & 2012
• Found almost no coral diseases, low levels
of nuisance algae
Coral reef health monitoring sites marked with green X
2004 Bakers Bay Environmental Assessment and Management Plan Assessment and Management Plan
• Claimed that there would be NO adverse effects of Golf Course, sewage, construction, or erosion on water quality due to “advanced” waste water treatment, lining of golf courses to prevent leaching, and construction of buffer zones to prevent chemicals washing into sea. Promised “To maintain water quality parameters in coastal groundwater and near shore marine waters at pre-construction levels”.
Environmental Impacts of Bakers Bay
• Dredging and sedimentation
• Deforestation, landfilling, bulldozing, construction of greens, mega-yacht marina, houses, restaurants, hotels, services
• Few homes occupied, so little or no sewage input
• Golf course built, fertilized, & maintained
Before and After Photos
Silt curtains (yellow) failed to contain sediments that passed right under them. right under them.
After the Golf Course
• Large increase in all coral diseases at the North End especially White Plague. This
disease is the fastest spreading and kills most coral species
• Increase in this disease much less at other sites
• Increase in weedy algae overgrowth around coral bases
• Big increase in cyanobacteria
White Band Disease, the most dangerous of coral diseases, suddenly became common at Guana Cay Reef after the golf course was established, along with algae overgrowth.
Black Band Disease and many other coral diseases were very rare at Guana Cay before the golf course was established, but became commn right after the golf course was established.
Image of soft coral being overgrown and killed by toxic cyanobacteria on reef near golf course. The problem began only after the golf course was established.
Next to Golf Course
• Big increase in high-nutrient “end of sewer pipe” algae species
• Weedy algae cover beach rock areas near golf course, but not away from it
• Algae are bright green and red from high nutrient levels from golf course fertilizers
• Reef is in early stages of very rapid eutrophication: overgrowth by harmful algae blooms
The morning sun shines right through the “impermeable barrier” at the seaward edge
of the Bakers Bay golf course green. It retains soil but water and dissolved nutrients flow
right through it.
Water nutrient analysis problems
• measuring dissolved nutrients Is extremely expensive, prone
To sampling, storage, and analytical errors
• due to rapidly varying concentrations in time and space one needs a vast data base to be meaningful, which is almost never measured
• measuring dissolved nutrients is extremely expensive, prone to sampling, storage, and
Algae nutrient monitoring
• algae continually take up nutrients and integrate the variations over their lifetime
• one can map nutrient distributions more accurately and cheaply from analyzing
algae carbon, nitrogen, & phosphorus contents, & their c- 13/c-12 and n-15/n-14 ratios
Algae sampling locations around Guana Cay. Aerial image taken before golf course and marina construction.
Northwest Guana Cay from the air. The algae bloom off the golf course closest to the shore is the brown fringe right along the shore at A. The dark patch in the algae bloom area is due to algae growing directly on the sand in front of the beach where fertilizer runoff leaches into the water, with no beachrock present. Dark areas at bottom left are eroded limestone rock with relatively little algae, dark areas along the upper left beach (G) are beachrock, with some algae but much less than the bloom area, dark patches offshore at upper left are coral reefs undergoing coral disease outbreaks, and dark patches at lower right and right are seagrass beds. The letters show near shore algae sampling sites.
The golf course greens come right next to the sea, with little or no vegetated buffer zone. The algae are right in front of them.
In front of the golf course, the bottom is covered with brightly colored algae that had not been there before.
In contrast to algae at Bakers Bay, algae in Guana Cay Harbour, next to the main settlement, are pale, indicating lower nutrients.
Green algae have more pigment near the golf course (left) than away from it (right), indicating higher nutrients.
Red algae have more pigment near the golf course (left) than away from it (right), indicating high nitrogen.
Dry season nitrogen isotope data (shown) indicates highest sewage type nitrogen near the golf course, least is furthest away. In the rainy season, the ratios are lower. That is to say the natural nitrogen sources predominate.
Bakers Bay Claims
• No algae blooms
• algae blooms are
• algae blooms all
Over guana cay
Bakers Bay Reality
• algae blooms
• algae blooms caused by nutrients
• algae blooms near nutrient sources
• does not fit pattern
• biggest blooms, highest nitrogen by
Golf course greens, not near populated areas
• caused by hurricanes
• caused by sewage
• no fertilizer leaks Into groundwater
• golf course fertilizers cause harmful algae blooms
• appear to be related to coral disease
• densely populated areas are already eutrophic
• many others are on the verge of eutrophication
• golf courses should not be located near coastal coral reefs
• much better management of fertilizer and sewage nutrients is needed to prevent large scale eutrophication
• ecologically sound water quality standards are needed
• they must be rigorously enforced