Coral crash: can our reefs be saved?

I.CARE coral-reef restoration in action
I.CARE coral-reef restoration in action - but it helps when water-users do their bit to help

Florida’s live hard-coral cover has crashed from 20th-century highs to as low as 3% today: JOHN CHRISTOPHER FINE returns to the I.CARE coral-restoration team to find out how their work is going, and finds that it takes only one careless boat-owner to frustrate their efforts

“It’s not always with malice. It’s ignorance. There are some that just do not care,” said Mike Goldberg. He was standing in the office doorway of Key Dives, a business he started in Islamorada, Florida, 20 years ago. Previously Mike ran a dive operation in the British Virgin Islands. 

Also read: Help to pinpoint dive-sites of scientific interest

He had just returned from a coral-planting dive on which he had witnessed an anchor stuck in coral, its chain dragged over the reef, its cut line tangled and damaging newly replanted staghorn coral – but more about that below.

Two years ago, dismayed that live coral coverage on offshore reefs had dwindled almost to nothing as widespread stony coral deaths left swathes of rubble under water, Mike teamed up with Dr Kylie Smith, adjunct professor at Clemson University, to form I.CARE (Islamorada Conservation And Restoration Education).

I have written about I.CARE on Divernet before. Partnered with Mote Marine Laboratory, Reef Renewal, Clemson and Florida State University, it is located with Mote’s land-based coral nursery on land provided by the Stanczyk family, owners of Bud ’n’ Mary’s Marina at Mile Marker 79 on the Atlantic Ocean.

Mote scientists select healthy corals that have survived assaults from raised temperatures, changes in acidification of sea water and stony coral tissue-loss disease. Under special permits these corals are harvested, cultivated in lab tanks called runways and replanted in the ocean on dead coral substrate.

Mote Marine Coral Lab runway tanks, where selected corals are grown before planting
Mote Marine Coral Lab runway tanks, where selected corals are grown before planting

Re-planting coral in the ocean is not a new undertaking. Researchers have been trying to restore reefs in many of those parts of the world where areas have been left barren. 

Live brain and other stony corals once covered 90% of Keys reefs, and relatively recent estimates from the 1970s considered live coral coverage to be as high as 70%. But during my dives last year, what scientists had determined was only too evident: live coral coverage is now from 3-5% – astounding decline in stony coral on Florida’s offshore reefs. 

I.CARE interns monitoring coral that has been planted
I.CARE interns monitor coral that has been planted

What caused these coral deaths?

To the uninitiated diver, Florida’s reefs still appear vibrant enough, with their soft corals, colourful tropical fish and sponges, but these organisms are also way down in terms of live coverage. Mountains of dead coral abound. Where once huge brain coral boulders thrived, skeletons barren of anything but algae remain as memorials to a worldwide epidemic of coral demise.

The pressing question is this: what caused these coral deaths? 

Coral is an animal that begins life as a free-swimming planula larva, released from living coral into open ocean. It eventually settles on a substrate, attaches and grows.

Various forms of budding occur. Coral spreads in limestone colonies and in time reproduces. Zooxanthellae, plants living inside the coral, assist with coral synthesis of nutrients and help the coral to grow. Like all plants, this commensal organism requires sunlight and a precise range of ocean temperatures conducive to life.

There you have one, and only one, aspect of coral death. Turbidity in ocean water resulting from human activities as well as higher ocean temperatures kills these plants. As a result, coral bleaches white and usually dies within two weeks. 

A dead brain coral in the Florida Keys
A dead brain coral in the Florida Keys

The next threat is stony coral tissue-loss disease. A bacterium of unknown origin or species has infected corals throughout tropical environments, and hard corals die as the infection spreads. 

As Florida became the third most-populated state in the USA, over-development and waste streams from 22 million people with their agricultural pursuits and chemicals have destroyed reefs.

Florida Bay, for example, is a dead zone in many places because of agricultural run-off high in pesticides, insecticides, herbicides and nutrient-rich fertiliser containing nitrogen. Heavy metals contaminate fish, making them unhealthy to eat.

Doing something about it

Is there hope? Mike Goldberg realised that the only way forward in the Keys was to grow coral and replant it. The science is good. He, Kylie and all those researchers and volunteers make offshore sorties to carry out the work. 

The I.CARE project began with elkhorn and staghorn, spiky hard corals resembling the horns of deer or elk. Researchers successfully micro-harvest brain coral, growing small elements on ceramic plates called pucks and watching while the colony grows before planting pucks of living coral on dead coral-heads.

So what? Callous as that sounds, while any undertaking has to be grounded in the solid science evident with coral-planting, there must also be good reason to undertake projects such as coral reforestation. 

Vast regions of the Florida Keys are within sanctuary areas, protected from harvesting of corals and many other species. No-harvest zones and no-take zones are many and protected. So what? Coral reefs protect the land from storm-wave surges, reducing wave intensity significantly. Without reefs, land on shores would be wiped out.

Mote Marine Lab grown brain coral on pucks placed on a dead brain coral-head
Mote Marine Lab-grown brain coral on pucks placed on a dead brain coral-head

Coral reefs are nurseries for juveniles of many species. Life itself takes place on and inside the reefs. Living in the oceans means having a niche, a place to reproduce, to lay eggs and for animals to survive. Large predators live on smaller reef organisms in the food-cycle of life.

For those impressed by financial benefits, in the Florida Keys alone recreation and tourism account for 33,000 jobs and attract an income of $2.3 billion annually. This accounts for 58% of all income in the area. Commercial fishing accounts for 4,000 jobs and 5% of the Keys’ annual income.

Money talks, so economic benefit is directly tied to healthy reefs. Fishing stocks have decreased worldwide, and without a healthy habitat where fish species can reproduce and grow to maturity, there will be no food supply – indeed, no reason for recreation, no fishing and no diving.

Will replanting work?

Can re-planting corals in the ocean make a difference, and does it work long-term? The answer, while somewhat mixed in terms of observing replanted corals reproduce so far (because the I.CARE programmes are in their infancy), is yes. 

Replanted coral growing healthily after a year under water
Replanted coral growing healthily after a year under water

Corals replanted two years ago on two reef areas are thriving. A few coral stands didn’t make it, but others have grown significantly and are healthy.

I.CARE’s Mote Marine Lab-raised corals have survival rates in excess of 70% – an extraordinary record. I.CARE replanted corals are thriving in the open ocean, so people who care can make a difference. 

As a species, human beings have become sorcerers’ apprentices on a giant scale. Chemical compounds we invented have disrupted nature. The oceans can dissipate waste, replenish themselves and heal – but they have to be given the chance for that healing process to take place.

Turning anchor damage around

A careless boater dropped this anchor at a reef site being replanted
A careless boater dropped this anchor at a reef site being replanted

“It’s like someone going into a museum and slashing a valuable painting,” said Joe Gonzalez, founder and president of Mother Ocean Fund, echoing Mike Goldberg above. Joe was aboard Key Dives’ Giant Stride dive-boat, on an I.CARE mission with volunteers and interns at a site called Victory Reef.

The divers were bringing staghorn coral down, preparing the substrate and then planting the live, lab-grown coral at a depth of 12m. As I observed and photographed them at work under water, I swam along the reef to examine previously planted corals. 

I at first supposed what I saw to be one of the tapes I.CARE uses to delineate the reef. That notion quickly changed when I saw an anchor-line splayed over the reef, whipping back and forth.

I could see where a boater had cut the line, and began gathering it in. It led to anchor-chain and an anchor, wedged into coral at the edge of the reef. They had caused damage. The line was wrapped over newly planted brain-coral pucks.

Joe Gonzalez’s observation had been valid. The I.CARE team are putting their hearts into creating a valuable natural resource, so destroying it through careless, deliberate anchoring on a replanted reef is akin to slashing a painting or throwing paint over a statue.

Anchor-line wrapped around the pucks
Anchor-line wrapped around the pucks
Divers working to remove the damaging anchor, chain and line
Divers working to remove the damaging line

Boaters know not to anchor on coral reefs, if for no other reason other than that they will jam their anchor. That they will damage coral and marine life is also clear. Rules, regulations and laws abound to punish offenders. Goodwill and knowledge should be enough, without needing more to make commonsense boating take hold.

Mother Ocean Fund and other organisations of goodwill are seeking means to support I.CARE’s work financially, so the offending anchor, chain and line were brought up by Key Dives divemasters. They are being displayed, along with photographs I took of the damage, to serve as an educational tool.

There are always lessons to be learned from bad human conduct. When the History of Diving Museum in Islamorada organises a display as part of its educational outreach programme, this one anchor can serve as an illustration of many. It only takes one small voice to say: “Daddy, don’t anchor here.”

Also on Divernet: Deep Doodoo: Diver's-Eye View Of A Florida Problem, Sponges: Glue Of The ReefTen Ways Tech Is Rescuing CoralA Dive Pioneer Turns 80 On Bonaire


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Brian Daigle
Brian Daigle
9 months ago

Excellent Article. I gained a lot of knowledge reading this. I’ll definitely spread the word.

Kirk Callison
Kirk Callison
9 months ago

wonderful article

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