Study in Progress

Interventions to Increase the Resilience of Coral Reefs

Topics: Life Sciences

The Netflix Original Documentary, Chasing Coral, has helped created awareness of the plight of coral reefs around the world. On November 14, 2017, join this exclusive screening of the film followed by a discussion about making coral more resilient to warming seas. The event will help launch this new National Academies' study.

An ad hoc study committee will be assembled to review the science and assess potential risks and benefits of ecological and genetic interventions that have potential to enhance the recovery and persistence of coral reefs threatened by rapidly deteriorating environmental conditions that are warmer, less favorable for calcification, have impaired water quality, and pose continuing disease threats. Given these environmental conditions, the committee will consider near- future scenarios (5-20 years) and more severely degraded environmental scenarios as part of an overall risk assessment in an ecosystem context. The coral intervention strategies will be assessed with regard to the goal of increasing the long-term persistence and resilience of tropical coral reefs and their ecological functions.

Statement of Task

Specifically, this review shall:

1. Review and summarize scientific research on a range of intervention strategies, either designed specifically for coral or with the potential to be applied to coral, including evaluation of the state of readiness. Strategies of interest include, but are not limited to, stress-hardening, translocation of non-native coral stocks or species, manipulation of symbiotic partnerships within the coral holobiont, managed selection, genetic modification, and to the extent possible, proposed engineering solutions to promote reef persistence, such as shading/cooling during bleaching events.

2. Provide an environmental risk assessment framework for evaluating the likelihood of potential ecological benefits and harms of the novel interventions. The framework will include the following elements, as probabilistically as possible, to support decision making.
-- Assess the likelihood that implementation of particular intervention strategies will substantively improve the persistence and resilience of coral reefs and their ecological functions, including support of reef-associated ecosystems and fisheries, over and above conventional management regimes;
-- Describe the nature and likelihood of predicted risks (e.g., disease introduction; loss of reefs, ecological functions, or coral species) and potential unintended consequences (e.g., species invasions, loss of genetic diversity) and tradeoffs of specific intervention strategies;
-- Assess the relative harms and benefits of different interventions compared with one another and the status quo of conventional management techniques.

3. Develop a decision pathway (a conceptual sequence of events) spanning initial research, laboratory and field-based research, to implementation and monitoring of the potential interventions. The pathway will include identification of specific ecological criteria or thresholds (e.g., population or environmental tipping points such as onset of annual bleaching) that may justify implementation of a more risky intervention strategy depending on the magnitude and urgency of the degradation. Case studies may be used to illustrate how the decision pathway could guide selection of an intervention strategy under different scenarios of near-future conditions for tropical coral reef systems.

4. Identify the research needs to refine the intervention strategies and reduce uncertainties in the environmental risk assessments. The research should include activities that could increase confidence in predicted net benefits and minimize, avoid, or mitigate risks of implementation.

5. Assess interventions under near- future conditions (e.g., 5-20 years, as projected under the IPCC Representative Concentration Pathway 8.5) for Atlantic/Caribbean coral reef systems based on the risk assessment framework and available information. Intervention strategies should be assessed relative to the objectives and performance measures, identified by the committee, for sustaining coral reefs and their ecological functions. Interventions should be characterized, using designations such as "not appropriate," "needs further investigation," "feasible for field testing," "feasible for implementation." Atlantic/Caribbean coral reef systems are specified for this assessment due to their advanced state of coral reef degradation, less complex ecological conditions (e.g., smaller basin, lower diversity), and imperiled status of foundational reef building coral species, compared to the Indo-Pacific.

Two reports will be produced. The first interim report will address task 1 and second report will address the other elements of the task.

This study is focused on the state-of-the-science of novel intervention strategies to identify and compare potential ecological risks and benefits. Although these interventions also raise societal, policy, legal, and likely ethical implications for decision making, these considerations are beyond the scope of this review. Effectiveness of reef management and restoration activities currently underway will be considered only to the extent that they set a baseline for use in the risk assessment of the novel interventions.