It seems some viable solutions are on the horizon for dealing the millions of gallons of untreated effluent the Cayman Islands Turtle Farm has been pumping into the ocean for the past 40 years.
It’s also anticipated the move will pave the way for the restoration coral reefs, which have been badly damaged by the waste through a proven reef-building technology that has been used to great success all over the world.
On 25 June, a few dozen invited guests heard from Thomas Goreau, president of the Global Coral Reef Alliance and Henning Gatz of Aquacare Environment, on their plans for the Turtle Farm.
Mr. Goreau’s research focuses on the effects of global warming and pollution on coral reefs and on coral reef restoration, taking him to coral reefs all across the Caribbean, Indian Ocean and Pacific.
Mr. Gatz is an expert on developing cost-effective solutions to aquaculture industry water treatment, and an authority on closed-system mariculture.
‘We hope that by developing this relationship we can play our part to establish a very strong tourist attraction, and work to undo the damage we have done over the last 40 years,’ said Turtle Farm Managing Director and COO Joseph Ebanks.
Mr. Goreau, who has a Harvard PhD. in Biochemistry as well as undergraduate and graduate degrees in planetary physics and astronomy from Caltech and MIT, has more than a passing interest in Cayman’s reef. He was raised in Jamaica, the son of the first diving coral reef scientist who pioneered modern coral reef science.
‘When it comes to the factors affecting reef health, we tend to focus on things we can see and smell, but we can’t see and smell the nutrients in the ocean,’ he said.
‘The issue is, when people take measurements of waters surrounding a reef they discount nutrient levels as too low to be significant.’
He observed that algae growth is a sign marine nutrient levels are too high. After witnessing the slow and steady death of Jamaica’s reefs over 40 years, he warned Cayman may be next if something is not done, and soon.
‘Cayman has less people and rainfall. The process is slower here, but at my last visit four years ago to the reef by the Turtle Farm it was clear there was too much algae in the water,’ he said.
He also noted that Cayman is not alone in its water issues. Mr. Goreau said only Turks and Caicos in the Caribbean requires every tourist development to have a wastewater plant and to recycle its wastewater.
‘What we need to do is deal with wastewater in Cayman before it is too late,’ he said.
While observing that the Turtle Farm is by no means Cayman’s only major source of blue-green algae, specifically pointing out the dump and the wastewater facility, he said if the will is there to trap nutrients and recycle water, it will be possible to reduce or eliminate algae problems.
He said there is no use casting blame on such typical targets as fishermen.
‘Some of my colleagues might say overfishing has killed all the algae-eating fish and that’s why there is so much of it, when in fact, algae growth just attracts even more algae-eating fish,’ he said.
‘If we don’t get to the real cause of algae growth we are wasting our time.’
He suggested that instead of dumping sewage directly into the ocean, facilities like the Turtle Farm can extract the waste, feed it to plants and reuse the cleaned water.
However, because regulations don’t address coral health, it is up to the private sector to act in the meantime.
‘We need water quality standards to protect coral reefs, which do not exist anywhere in the world,’ he said.
‘These are extremely low, for instance, 0.014 parts per million for nitrogen, which is 1,000 times lower than the standards we normally use, which are based on human, health, not ecosystem health.’
Systems used also use freshwater measurements, not saltwater.
‘We do not have a handle on the thousands of little sources, although we can go around Cayman and systematically measure nutrients in the water to determine where the major sources are,’ he said.
‘And at the same time, we have to be using better methods to scoop nutrients out. We can recycle them to the land and not kill the oceans, all at the same time.’
Mr. Gatz praised the Turtle Farm for taking the initiative in doing something about its waste to reverse the coral damage that has been done as a result of its operations.
‘What is happening here at the Turtle Farm is exciting in that it is turning back the damage of 40 years. By deciding to do something, by inviting people to come in and present their ideas we are on the way.
‘If we don’t start of making these kinds of changes we may lose the reefs for good.’
After viewing footage taken by Mr. Goreau’s researchers showing the dramatic impact small amounts of nutrients have had on coral reef systems adjacent to dolphin pens in Mexico, attendees got a better picture of what the growth of red and green algae results in.
Footage of the turtle farm reef showed all the rocks are overgrown with green algae, and all corals that are still alive are diseased.
‘Our goal is to bring this reef back to life, which means cleaning up the water and regeneration of the reef,’ said Mr. Goreau.
Mr. Gatz then took the reins, explaining that while the Turtle Farm’s effluent may now be a problem, it can be turned around with the right technology.
‘In ecology, we know that there is no such thing as waste, it is just a nutrient growing in the wrong place,’ he said.
We are here to devise a cost-effective means of dealing with aquatic waste, and the Turtle Farm as an awareness-building facility makes it an ideal place to do a project like this.’
Mr. Gatz outlined Aquacare’s advanced water management tools, which include options the Turtle Farm may be able to use.
For instance, a surface-level aerator and bio-filter, which also creates currents to move water around, inhibits algae growth, while a special super-fine screen filter can remove solids as small as 350 micron, which is then removed using a compressed screw for reuse as fertilizer.
The advantage of the fine filter is that is can significantly reduce the load on smaller and therefore less expensive wastewater plants, like a two-tank biological reactor.
Mr. Gatz also discussed use of a living machine, which is in fact a series of ponds or artificial wetlands that filter wastewater and can be seamlessly integrated into the built environment.
The next step for the Turtle Farm after devising a way to clean its effluent would be to regenerate the damaged reef out of Mr. Goreau’s Biorock technology.
These reefs have been successfully applied to fish and shellfish mariculture as well as to growing limestone breakwaters to protect islands and coastal areas from erosion and rising sea levels.
Coral reefs built with the Biorock process are now growing in Maldives, Seychelles, Thailand, Indonesia, Papua New Guinea, Mexico, Panama and in one of the most remote and unexplored reef areas of the world, Saya de Malha Banks in the Indian Ocean.
Their structures are formed using regular construction rebar, solar panels generate an electric current that causes the steel to lose its rust, then limestone begins to build up creating a natural structure.
Once the limestone begins forming, naturally broken coral fragments are tied on to the structure.
Over a few months, the entire structure cements itself to the rock it’s built on, and if care is taken to grow it slowly, it ends up being three times stronger than pre-stressed concrete.
Advantages of these reefs include the speed of growth of the coral, which is three to six times faster than normal coral, the coral can survive higher water temperatures and it has shown hundreds of times higher baby coral settlement, not to mention attracting incredible numbers of fish.
‘The reefs can be quickly restored, and fishermen can build habitat and become farmers and not hunters, by releasing baby fish and grow them on the reefs,’ said Mr. Goreau.
‘Furthermore, they make great breakwaters at a fraction of the cost of the price of stone or concrete. It is a pleasure to see the reef growing before your eyes, it’s like having a beautiful garden.’
‘The DoE is encouraged to see the Cayman Turtle Farm exploring a variety of options for dealing with the effluent discharge from their operation and we look forward to working alongside our colleagues at the Water Authority to bring this long-standing issue to conclusion,’ said Department of Environment Director Gina Ebanks-Petrie.
The report on Mr. Goreau and Mr. Gatz’ proposed plan of action is due within three weeks.
‘Once accepted by the regulator, they will issue a conditional license, we will commence instillation, post application testing and reporting to the regulator will then commence,’ said Mr. Ebanks.
‘We will also be making recommendations for the dolphinarium to select an application. They will pay for it, which we will monitor and regulate.’