Coral Reef Restoration and Remediation

Restoration and Remediation Working Group

Coral reefs are suffering degradation from a number of natural and man-induced causes. Tackling the root causes of this degradation through effective coastal management measures is likely to be the best way forward for reducing damage and allowing reefs to return to viable healthy states. In addition, there can also be opportunities for direct intervention to actively restore degraded coral reefs.

At present there is only a rudimentary understanding of the complex processes that contribute to natural recovery of coral reef systems from disturbance and it is difficult to assess what the most appropriate restoration actions might be. Criteria are needed which specify the degree to which an injured site might benefit from better management and/or active restoration.

Background

The CRTR Restoration and Remediation Working Group is seeking to address many of the knowledge gaps which hinder restoration and to advise the management community so that restoration projects can be undertaken in a more informed way and with a better chance of success.

What do we mean by restoration, rehabilitation and remediation?

Restoration: bringing a degraded ecosystem back, as nearly as possible, to its original condition.

Rehabilitation: partially, or occasionally fully, replacing structural or functional characteristics of an ecosystem that have been diminished or lost, or the substitution of alternative qualities or characteristics to those originally present with the proviso that they have more social, economic or ecological value than existed in the disturbed or degraded state.

Remediation: remedying or repairing damage to an ecosystem.

Some key messages underpin any approach to Restoration, Rehabilitation and Remediation:

We cannot create fully functional reefs. Although restoration can enhance conservation efforts, restoration is always a poor second to the preservation of original habitats.
Coral reefs that are relatively unstressed by anthropogenic impacts can often recover naturally from disturbances without human intervention.
Restoration includes passive or indirect management measures to remove impediments to natural recovery, as well as active or direct interventions such as transplantation.
Active restoration is not a magic bullet. Improved management of reef areas is the key.
The aims of reef restoration are likely to be dictated by economic, legal, social and political constraints as well as ecological realities. However, ignoring the latter means a high risk of failure.
The goals of restoration projects should be formulated at the outset as precisely as possible within a wider coastal management planning context.
Targets or measurable indicators should be set that allow both the progress towards restoration goals to be assessed over time and adaptive management of the restoration project.
Major physical restoration of reefs is for experts only. Seek expert civil engineering advice. Some physical restoration may be a prerequisite for any chance of successful biological restoration.
There are at least 300,000 km2 of coral reefs in the world. Lack of hard substrate is not a critical issue. Management of degradation of natural reefs is the critical issue.
Use of artificial reefs in restoration needs to be considered carefully and critically in terms of need, ecological impact, cost-effectiveness and aesthetics.
Consider restoration not as a one-off event but as an ongoing process over a time-scale of years which is likely to need adaptive management.
Major physical restoration of reefs costs in the order of US$100,000 –1,000,000 per hectare. Low-cost transplantation appears to cost about US$2000 –13,000 per hectare. With more ambitious goals this rises to about $40,000 per hectare. For comparison, a global ball-park estimate of the average total annual value of coral reef goods and services is US$6,075 per hectare.

Our Research

Research Activities

The Restoration & Remediation Working Group (RRWG) is examining the state of restoration and remediation techniques and is targeting investigations to test the efficacy of a range of potential applications. This research includes:

the scientific protocols necessary to design and implement restoration strategies
baseline data for developing effective criteria
the efficacy and feasibility of restoration and remediation techniques
prospects for enhancing natural recovery
opportunities to combine reef remediation with small and micro-enterprise at the local level working on three research programs for Phase One.

These programs involve studies of both natural recovery processes and restoration interventions:

Long-term efficacy and cost-effectiveness of restoration interventions
The effectiveness of restoration interventions should be judged in terms of what these interventions achieve in comparison to what occurs in natural recovery over at least a five to ten year timescale. Because of the variation of the natural reef and other confounding factors, it is difficult to perform adequately controlled comparisons using patches of natural reef.

To address this problem, the Restoration and Remediation Working Group is using standardized artificial structures of sufficient scale and replication to allow long-term statistically rigorous comparisons between outcomes of natural processes and a range of interventions.

The experiments are being set up in Mexico, Bolinao and Palau so that comparisons can take place at sites with very different recovery potentials.

Enhancing recovery by culture and transplantation of corals
In this program the Restoration and Remediation Working Group is focussing on asexual propagation of corals to assist restoration. The challenge of restoration using transplants is balancing the costs of nursery rearing and effective use of limited source material against the likelihood of survival of transplants.

This program is investigating the effect of the size and structure of coral fragments on subsequent growth and survival for a range of species. Low-cost approaches involving direct transplantation are being compared to more expensive approaches involving periods of in situ culture prior to transplantation to damaged reefs.

The research is taking place on a lagoon near the Bolinao Marine Laboratory in the Philippines which has suffered from both blast fishing and mass bleaching and subsequent mortality of coral since the 1998 El Nino warming. Recovery since then has been negligible and while blast fishing has ceased there is still heavy fishing pressure in the area.

Enhancing larval recruitment
In this program the Restoration and Remediation Working Group is looking at the sexual propagation of corals from the larval stage following spawning. This involves a higher level of technology and at present much higher costs but does offer the potential of rearing hundreds of thousands of sexual recruits for restoration.

Research is being carried out in Palau International Coral Reef Centre (PICRC) with additional work on coral reproduction at the Bolinao Marine Laboratory in the Philippines.

Research Update

Long-term efficacy and cost-effectiveness of restoration interventions
Two Working Group projects which are assessing the cost-effectiveness of restoration interventions over the longer term (5-10 years) are now both gathering data in Bolinao, Palau and Mexico with the final intervention (larval enhancement) taking place in Palau in April 2008. There should be sufficient monitoring data to assess initial results by the year end.

Enhancing recovery by culture and transplantation of corals
Interesting results are emerging on the effect of transplantation on colony fecundity and the effect of fragmentation on fecundity of donor colonies. Data on competency curves continue to be collected for a range of species in Palau and Bolinao and “coral plug-ins” (wall-plugs with 2 cm diameter concrete heads) are being trialled as settlement substrates to provide a cost-effective method of rearing coral larvae from spat. These trials are at an early stage. Larval enhancement of seven pallet balls was carried out at Palau at the April 2008 mass-spawning.

In Palau a disease outbreak in some of the mid-water culture cages in January 2008 resulted in disappointing survival of Acropora being co-cultured with snails, while transplanted juveniles suffered from fish grazing. However, similar work being conducted at Akajima, Japan shows 10-50 times better survival.

Enhancing larval recruitment
Despite a Crown-of-thorns outbreak and Drupella attacks as well as the bleaching in 2007, experiments continue and data on relative robustness of different species continues to mount as well as methods for more cost-effective culture and deployment of corals being refined. Overall, a key message emerging is that any restoration project without considerable maintenance and monitoring (and adaptive management) is more than likely doomed, and the risks to transplants need to be fully realized and where possible reduced by judicious selection of species.

Who we are

Working Group Members

Working Group members bring international experience to this targeted research.

Project Partners

Working Group partners bring capacity to this research endeavour.

Contact

Restoration and Remediation Working Group:

Chair: Dr Alasdair Edwards
University of Newcastle,
United Kingdom

Co-chair: Emeritus Professor Edgardo Gomez
The Marine Science Institute
University of the Philippines

Project Executing Agency:

Global Coral Reef Targeted Research and Capacity Building for Management Program
The University of Queensland
Brisbane QLD 4072
Australia
Tel: 61 7 3346 9942
Fax: 61 7 3365 4755
Email:

Information Resources

Poster: CRTR Program Restoration Working Group [download]
Brochure: CRTR Program Summary [download]
Reef Restoration Concepts and Guidelines: making sensible management choices in the face of uncertainty
- Order free hard copy Online [Click Here]
- Download Full Report (English) [PDF, 3Mb]
- Download Full Report (French) [PDF, 1.3Mb]