Biocriteria Development for Coral Reefs

EPA is working with US Virgin Islands Department of Environmental Protection to develop biocriteria for coral reefs. EPA's Ocean Survey Vessel Bold will provide support for coral reef sampling beginning in 2006. The primary goal of this effort is to develop a data collection protocol that quantifies biologically meaningful aspects of coral reef condition. The sampling protocol will provide the foundation for long-term monitoring and assessment of coral reef condition in the USVI. Preliminary work in the Florida Keys provided pilot data and experience for the biocriteria project in the US Virgin Islands.

Coral reefs have experienced unprecedented levels of bleaching, disease, and mortality during the last three decades. Stressors such as elevated water temperature, increased exposure to solar radiation, and degraded water quality may be responsible either directly, or interactively, for this dramatic decline. Continued stress results in the loss of coral tissue and eventual disintegration of their calcified coral skeleton that many reef species depend on for food, shelter, and substrate. The Clean Water Act provides a regulatory framework to restore and protect coral reef systems. Biocriteria provide a regulatory tool for defining expectations for the biological condition of water resources. Biocriteria also provide the mechanism for regulating human activities that threaten coastal resources.

In the US Virgin Islands, the taxonomic identity, physical size, and % living tissue of each coral colony will be recorded by divers at each coral reef sampling station. From these measurements, attributes of coral reef condition will be quantified, such as the number of unique coral species, % living tissue averaged across coral colonies, and living surface area of coral. Coral attributes with consistent and predictable responses to human influence will be selected as bioindicators of reef condition. Coral reef metrics will be evaluated for their ability to detect change in reef condition over space and through time.

Key components for the development of biocriteria

Scientifically-defensible biocriteria for coral reefs rely on the successful completion of several steps. The key components described below relate to reef classification, defining data collection protocols, metric testing against human disturbance, sampling effort and survey design, validation of methods, definition of biocriteria, and implementation of long-term monitoring programs. Select one of the components described below for more description and examples from the US Virgin Islands and the Florida Keys. (Adapted from Jameson, Erdmann, Karr and Potts [2001].)

1-A Classify coral reef systems

Define number and types of unique reef environments
Describe or identify expected reference condition

1-B Develop testable hypotheses about response to human influence

Prepare list of attributes to be evaluated based on these hypotheses
Define directional expectations for those attributes (e.g., taxa richness declines with increasing human influence)
Define how attributes will be quantified (e.g., count of taxa, % living tissue, etc.)

1-C Define data collection protocols

Collect appropriate biological data
Document type and magnitude of human activity for each sample site

2 Biological sampling

Represent entire gradient from minimal human influence to severely altered
Collect data from the full set of habitat types
Collect enough data to evaluate sources of variability

3 Screen attributes to define metrics

Select metrics based on observed changes in value across human influence gradient (i.e., dose-response curves)
Develop scoring rules for metrics based on expectations for reference condition

4 Determine appropriate sampling effort for reliable assessment

Consider seasonal patterns and define index period
Consider level of replication needed and optimal sampling unit size

5 Define data handling and analysis protocols

Test repeatability of the protocol
Statistical power analysis of reef metrics
Define QA/QC procedures

6 Validate decision processes with additional data sets

Classification is at needed level (not too few or too many)
Selection of metrics matches regional human influences
Metrics respond predictably to known human influences for an independent data set

7 Define biocriteria

Define expectations for each designated use
E.g., numeric biocriteria would be higher for reserve areas than for urban bays

8 Implement monitoring programs

Probability-based status and trend monitoring
Targeted sampling for effectiveness monitoring

9 Diagnose causes of degradation for specific sites and implement management programs

Preserve or protect exceptional waters
Manage to reduce effects of human actions
Manage to restore degraded resource systems

10 Evaluate management effectiveness

Modify management decisions or actions to accomplish biological goals.

11 Communicate results of work to citizens and policy makers

Connect results to management policies
Present data as graphics that are understandable to a non-scientific audience

Return to Coral Reef Biocriteria

See the following pages:

Biological Indicators | Aquatic Biodiversity | Statistical Primer

Biocriteria Development for Coral Reefs

Key components for the development of biocriteria

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