![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Implement Monitoring Programs
- Classify coral reefs
- Develop testable hypotheses
- Define data collection protocols
- Biological sampling
- Screen attributes to define metrics
- Determine appropriate sampling effort
- Define data protocols
- Validate decision processes
- Define biocriteria
- Implement monitoring programs
- Diagnose causes of degradation
- Evaluate management effectiveness
- Communicate results
Consider both probability-based status and trend monitoring and targeted sampling for effectiveness monitoring.
Successful regional monitoring programs typically include three types of sampling approaches to 1) assess the current status of the resource, 2) detect trends over time, and 3) evaluate conditions at specific, targeted locations. Status, trend, and targeted sampling all differ in the manner in which sampling units (e.g., reef stations) are selected from among the total population of all possible sampling units.
To assess status of a resource, the best approach uses random (probability-based) selection of sampling sites from the regional area being evaluated. The best sampling designs for trend detection initially select sampling locations randomly, but then re-visit the same locations each year. For targeted sampling, locations are selected based on specific criteria, such as sites with best management practices in place or sites with known sources of disturbance.
For assessing status and trend, the primary advantage associated with random site selection is that any summary statistics derived from a random sample will be representative of the entire population, including all the sites that were not sampled.
Non-random sampling |
|
Random sampling |
|
|
|
Three reef types are shown with sampling points indicated by black circles. |
||
|
|
|
Results apply only to the small area surrounding the sampling sites (indicated by shaded area). |
Results apply to the entire reef area from which locations were selected (shaded area). Note that linear reef (red shading) was not included in the sampling and results do not apply to that area. |
Rotating panel monitoring design for US Virgin Islands
During the first year of sampling within east St. Croix Island, 50 sites would be randomly selected: 10 for trend and 40 for status. An additional 10 targeted sites could also be visited. During the next 3 years, similar sites would be selected in the remaining regions. During the 5th year, data would be compiled for status and trends and more sampling would be allocated to targeted sites with known problems or required 5th-year inspections. In the 6th year the cycle repeats, with the same 10 trend sites visited in each geographic panel, but by selecting new status sites in each panel.
Year |
1 |
2 |
3 |
4 |
5 |
East St. Croix |
10 trend |
||||
West St. Croix |
10 trend |
||||
St. Thomas |
10 trend |
||||
St. John |
10 trend |
||||
Targeted |
10 |
10 |
10 |
20 |
40 |
Total |
60 |
50 |
60 |
60 |
40 |
For the US Virgin Islands, status monitoring is designed to answer questions such as:
- What percentage of coral colonies are composed of living tissue in the near shore environment surrounding St. Croix?
- What is the total surface area of living coral surrounding St. Croix?
- What coral species contribute the greatest percentage to the overall coral surface area surrounding St. Croix?
Trend monitoring is designed to answer questions such as:
- Has the percentage of live coral increased (or decreased) during the sampling period?
- Is coral surface area increasing (or declining)?
- Has decline in live coral been greater in areas with high recreational use than in areas without?
Targeted sampling may be used to answer questions such as:
- Is the percentage of live coral lower near beaches with more frequent closures?
- Is the surface area of living coral lower in locations with higher recreational use than in less disturbed areas?
- Which coral species are most sensitive to effluent and boat traffic associated with industrial land uses?