By Carrie Manfrino
Research aimed at improving the survival of corals has exploded in the last five years especially because it is widely accepted that corals are among the most threatened animals on Earth.
The United Nations Environment Programme estimates that one-fifth of reefs worldwide are dead, and that 90% may disappear completely within 30 years. Coral reefs in many locations are degraded and a wide variety of restoration approaches have emerged.
Research labs, including our own at the Central Caribbean Marine Institute, have made great progress in improving the ‘fitness’ of corals so they are more resilient. While there has been enormous progress, the scientific knowledge needed to regrow a coral reef is still is in its infancy.
The greatest challenge will be finding suitable habitats and environmental conditions for restoration to succeed. The survival of corals restored and relocated can vary from 80% success to 100% mortality.
Concern over port claims
We are especially concerned about the claims by Verdant Isle that David Vaughan can regrow new reefs in Cayman as a tradeoff to destroying the reefs in our harbour. The VIPP team report that the micro-fragmenting technique in the Florida Keys has had success in the labs growing 50% of Caribbean coral species.
They have successfully grown a total of only five large individual (metre-scale) mound corals. Scientists are not yet capable of regenerating a complex reef. No project anywhere in the world has been able to replicate, restore or transplant a coral reef system with the same biodiversity of a natural reef.
Coral reefs are rightly compared to tropical rain forests in terms of species numbers and biodiversity. Current science aimed at reef restoration could be compared to being able to grow a few plants taken from the forest – but it cannot replicate or even come close to establishing the complex, multi-species eco-system found in nature.
Key problems outlined
We believe the most significant problems are:
- Coral mortality after two to three years at many restoration sites can be 100%. Long-term monitoring of restoration sites is limited, so success is often unknown beyond a short timeframe post-project.
- We have found no large-scale long-term evidence of successfully recreating the biodiversity of a reef anywhere in the world.
- The George Town Harbour pier project will require the removal of approximately 22 acres where live coral reef, significant reef structure, limestone bedrock, and carbonate sand currently deposit. The immediate area has extraordinary marine life.
In a rapid assessment of five sites along the west side of Grand Cayman, CCMI found coral cover is highest in the harbour (up to 58%) and averages 23%. Dredging and cruise ship operations will also compromise reefs adjacent to the dredged area.
- Live reef structure reduces wave energy, surge and erosion. Reefs are at risk if water quality degrades and light penetration is reduced due to construction and operations. Whether reefs are degraded or removed to make way for the pier, they will have less potential for protecting the island from storms.
- Polaris Applied Sciences are proposing to relocate a large number of corals to two sites. Work on this scale is risky and success cannot be guaranteed. Two current Grand Cayman restoration projects to repair damage caused by a cruise ship at Eden Rock and a large yacht in West Bay are being cited as successful by the project engineers. Neither site has recovered. At the Eden Rock site, our team measured around 7% coral cover which is three times less than other nearby reefs.
The engineers are claiming that their restoration at West Bay resulted in 89% survival (after two years). However, they relocated less than a quarter of the coral at the site, so the overall impact has been a loss of more than 80% coral cover.
- Stakeholders are being asked to believe that the microfragmenting technique is the solution for coral restoration and they will be able to grow large corals, equivalent to hundreds of years of growth, within a few years. This has not been accomplished to any scale. The survival of the microfragments in the Florida Keys reefs is minimal due to disease outbreak and predation, as outlined in the project peer-reviewed paper.
- The restoration group is proposing to grow 10 corals for every one coral that is removed. By chopping up corals into micro-fragments, corals can indeed grow fast. Large numbers of tiny corals have been successfully grown in labs; however, the claims of growing large colonies are misleading. Vaughan acknowledged at a public meeting that he had successfully grown only five coral colonies (by fusing microfragments). The microfragmenting technique has been well known for 30 years and is yet to be scaled to the levels being promoted as part of the George Town dock project.
- It is risky to get into a contract to relocate and restore our reefs without having a detailed plan that is approved by ecologists, international restoration experts, and experts at the Department of Environment.
- Producing 1 million micro-fragments (from 400 corals) in 12 months, as was promised in radio interviews, is not realistic or practical. The engineers on the project estimated between 150,000 and 180,000 corals in the harbour.
They have said they will produce 10 new corals for every coral they remove. This means they are planning to grow up to 1.8 million microfragments. Not only would this be an unprecedented technical feat but considering it has taken two years to produce ‘only’ 25,000 micro-fragments, at that rate it would take them 20 years to produce 250,000 micro-fragments, and 120 years to produce 1.5 million micro-fragments.
We support innovative solutions that pioneer the protection or restoration of coral reefs, but feel the community should clearly understand that this has never been accomplished anywhere in the world. We know that the risk to the Cayman marine environment is enormous.
Restoration techniques are in a race against time to support ailing reefs – they should not be promoted as a like-for-like mitigation technique because they are not proven at this scale.
Read more: Microfragmenting research paper