Thomas J. F. Goreau
President, Global Coral Reef Alliance

Dolphins excrete about as much as cows!


Discovery Bay is the site of the world’s longest and most detailed scientific studies of coral reef change, going back about 65 years. I have personally been involved in research at Discovery Bay Marine Laboratory, founded by my parents, over this entire period. My earliest memories include swimming at Puerto Seco Beach and riding the water slide around 65 years ago, and I have studied the changes in Discovery Bay coral reefs since then. In the early 1980s Discovery Bay reefs were overwhelmed, and almost all corals killed, by weedy algae overgrowth caused by inadequately treated sewage. At that time my research team did detailed work measuring nutrients in the water in Discovery Bay, and their effects increasing harmful algae growth. In the last 10 years improved sewage treatment has been implemented in Discovery Bay, water quality has improved, the harmful algae have greatly diminished, and the reef is starting to recover. This is one of the few places in the world where this has happened, but nutrients in the water are still too high and need to be further reduced.

Discovery Bay is a highly protected bay, nearly enclosed by the coral reef, with generally weak circulation, except during storms and northers. Pollution introduced into southern Discovery Bay tends to remain and fester before it is diluted, often clearly visible when there are spills of bauxite at the pier. Discovery Bay has a general trade wind-driven counter-clockwise circulation, so wastes from the Puerto Seco dolphin pens will largely wash right towards the public beach and fishermen’s beach next door. I looked at the Puerto Seco dolphin pen site the week before the dolphins were introduced, and found that the water in the dolphin pens was clear, and the fences and nearby sea floor were free of weedy algae, showing that the water was clean before dolphins moved in, and there was no local source of nutrients at that time. You can see how it looked just before the captive dolphins were introduced here:



I have personally studied the environmental impacts of captive dolphin facilities in the Mexican Caribbean, and found them to be intense sources of pollution, but I have not personally studied any of the captive dolphin facilities in Jamaica, and have no information on how many dolphins they have imported into, or how many have died or been born in Jamaica. I work on the environmental impacts on the marine environment, not on the dolphin trade itself. Many people do work on those aspects and can provide such information. However, I am aware that most captive dolphins in Jamaica are imported, and may include dolphins from the Solomon Islands in the Pacific that were re-exported from Mexico.

I am the only scientist in the world to directly study the environmental impacts of captive dolphin facilities on water quality, algae abundance and chemistry, coral reef algae overgrowth, and coral diseases. I am extremely familiar with the environmental effects of captive dolphin facilities in Mexico, the largest in the Caribbean. I have personally swum along the shore both up-current and down-current of all the captive dolphin facilities in both Cozumel and Isla Mujeres, Mexico, and filmed and sampled the algae around these sites. I found that all the captive dolphin pens were intense sources of nutrient pollution to surrounding waters. The waters downstream from them was turbid with white particles of dolphin excrement and rotting food, overgrown by bacteria, viruses, and fungi, flowing out of the dolphin pens and being eaten by schools of excrement-feeding fish. The fencing around the dolphin cages was overgrown with long slimy reddish mats of cyanobacteria diagnostic of extremely high nutrients, an “end of the sewage pipe” indicator because that is where it is most certainly found. Corals kilometers down-current from captive dolphin pens were being overgrown and killed by harmful algae blooms, and coral diseases were unusually abundant in the survivors.

The same effects would be found around any captive dolphin pen anywhere. I found the same patterns around captive turtle pens in Grand Cayman. The Cayman Government Department of the Environment asked me to advise them on algae, coral reef health, and water quality at all proposed captive dolphin sites on Grand Cayman. I found all the proposed dolphin pen sites were already over-run by harmful algae before any captive dolphins were introduced, because of local nutrient sources from sewage, garbage, golf course fertilizer, and soak away toilets. Captive dolphin facilities should not be placed where they can harm coral reefs and fisheries in receiving waters, and especially in any marine protected area or fish sanctuary, such as Discovery Bay. You can see the direct impacts of dolphin wastes on coral reefs in my video Tourism, Water Quality, and Coral Reefs:



Nitrogen and phosphorus in dolphin faeces and urine act as fertilizers, causing massive overgrowth of cyanobacteria and harmful algae blooms that smother captive dolphin pen fences, and overgrow and kill corals on reefs nearby. I looked at all captive dolphin facilities in Cozumel and in Isla Mujeres, near Cancun, Mexico, the largest concentration of such facilities in the Caribbean. All had down-current plumes of dirty bacteria and nutrient-rich water and coral reefs down-current from them were being killed by harmful algae blooms up to kilometers away. I found the same pattern with captive turtle pen wastes in Grand Cayman.

I wrote the coastal zone management plans for both ends of Jamaica in the 1990s. Dead algae-overgrown coral reefs are found down-current from sewage inputs from all major tourist areas and towns, for example Kingston, Montego Bay, Ocho Rios, Runaway Bay, Negril, etc. Discovery Bay is not a tourist town, and the local human sewage is now being properly treated, so Discovery Bay water quality has actually improved, one of very few places this has happened! Wild dolphins swim tens of kilometers a day, so their wastes are dispersed over large areas, but captive caged dolphins are forced to foul their own nest. Dolphins are large animals, they produce an amount of wastes more like that of a cow than a human being. Introducing 4 dolphins is equivalent to dumping all the wastes of about 20 or more people into the water of the pen, and this foul water will become the major single pollutant within the bay, causing the water in the pens to turn greenish with microscopic algae, slimy cyanobacteria mats to grow over the fences, the water to turn turbid with particles of dolphin faeces, rotting food, bacteria, fungi, and viruses, the dissolved nutrients will cause increased harmful algae blooms that smother and kill corals, as well as increased coral diseases in receiving waters down-current. This will cause a visible decline in the quality of the habitat for fisheries, and especially as juvenile fish habitat. Increased weedy algae growth will smother seagrass and growth of coralline (sand-producing) algae, resulting in a loss of new sand production for the beaches, and accelerating the ongoing erosion of Puerto Seco Beach, which has lost about two thirds of its width over the last 50 years, based on comparison with our old photographs.

Human faeces are well known to contain pathogenic bacteria and viruses and must be treated to prevent spread of diseases. Over the last 20 years large numbers of new diseases have been killing corals, and other reef organisms. My team did much of the work identifying these new diseases, and have identified some of the bacteria pathogens that cause them. Many of these diseases are much more abundant in waters down-current from inputs of human or livestock sewage, including captive dolphins, captive turtles, fish farms, and shrimp farms. These diseases are currently ravaging coral reefs in Jamaica and all around the Caribbean, killing off most of the last large ancient corals that have luckily survived all of the pollution, bleaching, and hurricane damage until now. Introducing new sources of bacteria in dolphin wastes that may damage the coral reefs further will reverse the recovery of water quality in Discovery Bay. This should not be permitted in a Fish Sanctuary and Marine Protected Area: it is illegal by Jamaican law under the Natural Resources (Marine Park) Regulations Section 6(1) to discharge or deposit in water any polluting substances which injures plant/animal life into a Marine Park. Discovery Bay is a designated Marine Protected Area and a Fish Sanctuary and No Fishing Zone, so fisheries can recover.

The captive dolphin facility will inevitably cause green water, faecal and food particles, slimy bacteria, and harmful algae blooms that will degrade water quality first inside the pens, spreading to the public bathing beach, the Fishermen’s beach, the east side of the bay, and finally the west side and outer coral reefs. The quality of the entire bay as a juvenile fish nursery, the purpose of the Discovery Bay Fish Sanctuary, will deteriorate, reducing its capacity to regenerate local fisheries resources. The world’s most famous coral reef research site, the Discovery Bay Marine Laboratory, where decline of coral reefs due to mismanagement of wastes and reef recovery following waste reduction were understood and documented, will be impacted. The slow environmental recovery that has happened due to treatment of human sewage will become reversed by dolphin sewage. If Discovery Bay reefs are now damaged by dolphin wastes, Jamaica’s reputation as a world leader in coral reef research will turn into the case example of coral reef mismanagement.

The reputation of Puerto Seco for calm white sands with clear blue water will be seriously impacted, along with the livelihood of those who depend on it. Puerto Seco Beach has always been one of the most popular beaches for Jamaicans, and for generations people have come from all over the island to enjoy its calm, clear, protected waters. Dolphin wastes will make the beach unattractive to Jamaicans who have always traditionally used this beach, as well as to cruise ship passengers paying to go to the adjacent private beach next to the dolphin pens. Jamaica could come to be regarded as a “bottom-end” destination where water pollution for profit is condoned, a place environmentally aware and health-conscious guests will avoid. People seeking improved environmental quality are an increasingly valuable tourism market sector world-wide.

Prior to the introduction of the dolphins I predicted that the consequences in Discovery Bay, based on my personal observations at many other captive dolphin facilities in the Caribbean, will be, in approximate order of appearance:
1) increase in turbidity due to suspended particles of dolphin faeces and rotting food particles, being overgrown by fungi, bacteria, and viruses
2) change in water colour from blue to green due to blooms of microscopic phytoplankton algae caused by increased concentrations of nitrogen and phosphorus nutrients from dolphin urine, faeces, and rotting food. Before the dolphins went into the pen there was no difference in water clarity and color between the pens and surrounding waters.
3) massive growth of slimy cyanobacteria and harmful algae blooms of red and green algae on the captive dolphin cage fences
4) overgrowth of nearby seagrasses by harmful weedy algae blooms
5) overgrowth of down-current coral reefs by harmful weedy algae blooms
6) increase in coral diseases down-current
7) reduction in fish nursery quality
8) reduction in Puerto Seco public bathing beach and fishing beach water quality
9) increase in beach erosion

Six months after the dolphins were introduced local observers report that all of these effects are now underway in Discovery Bay, just as I had predicted, causing turbid water, bad smells, algae proliferation, slimy material accumulating on the beach, and skin infections in bathers.

The Puerto Seco dolphin permit was issued with no assessment of the environmental impacts of dolphin wastes. Polluting wastes should not be released into a Fish Sanctuary and Marine Protected Area, nor into areas where they negatively impact fisheries and coral reefs. The permit does not require monitoring of ammonium, nitrite, nitrate, phosphate, dissolved oxygen, chlorophyll, bacteria, fungi, virus, micro-algae abundance, macro-algae abundance and algae nutrient concentrations, and nutrient sources, coral overgrowth by algae, coral diseases, and fish populations, the minimal essential list of items that would be monitored in a scientifically-sound monitoring plan along with temperature, salinity, pH, changes in the beach, etc.

A highly competent independent environmental assessment of dolphin impacts in Discovery Bay is essential. The minimal essential list of items that would be monitored in a scientifically-sound monitoring plan includes temperature, salinity, pH, ammonium, nitrite, nitrate, phosphate, dissolved oxygen, chlorophyll, bacteria, fungi, virus, micro-algae abundance, macro-algae (seaweed) abundance and algae nutrient concentrations and identification of nutrient sources, coral overgrowth by algae, coral diseases, and fish populations. Algae in nearby areas should be analyzed for species abundance and carbon/nitrogen/phosphorus ratios. Their carbon and nitrogen stable isotope ratios should be analyzed to determine the source of their carbon and nitrogen. Coral reef health needs to be assessed with regard to algae overgrowth and coral diseases. Changes in the nearby beaches should be measured.

Climate change damage to corals is real, but caused by very different factors than local pollution. The Discovery Bay Marine Laboratory is where the HotSpot method of predicting coral bleaching from satellite data was invented and developed. As the result of global warming, on top of land-based sources of pollution, Discovery Bay reefs have steadily lost corals. There are now clear signs of coral recovery at Discovery Bay in the last 10 years due to better sewage treatment resulting in cleaner waters. Global warming is caused by pollution outside Jamaica, and in the long run action to reverse atmospheric pollution will be essential to the future survival of coral reefs. But global warming impacts from abroad are no justification for dumping more wastes in the water at home!