Alexandra Kler Lago
Field Support and Partnerships Manager, MERMAID
How do we design coral reef monitoring that answers the right questions, produces reliable data, and supports better conservation decisions?
The new free online course, CRRI102x Coral Reefs: Data and Monitoring, introduces learners to the full monitoring cycle—from defining objectives and selecting appropriate methods to collecting, interpreting, and communicating data.
WCS and MERMAID contributed expertise to the course, particularly to the modules on coral bleaching and reef fish monitoring. The course is designed for NGO staff, government practitioners, natural resource managers, fishers, community members, and others working to understand and protect coral reefs.
From monitoring questions to conservation action
Effective monitoring begins before anyone enters the water. Programs first need to identify their objectives, decide what information will answer their questions, and select methods that are appropriate for their ecological, social, and management context.
CRRI102x helps learners develop this foundation. Through applied examples and realistic scenarios, the course explores how to:
Define clear monitoring goals
Select appropriate data types and methods
Collect robust and useful information
Interpret results in relation to monitoring objectives
Communicate findings to relevant audiences
Integrate scientific data with traditional and local knowledge
Apply gender and inclusion considerations when planning, interpreting, and communicating monitoring
This full-cycle perspective is essential. Data have their greatest value when they are collected for a clear purpose, managed consistently, and translated into information that communities, managers, and decision-makers can use.
Learning about coral bleaching and fish monitoring
WCS and MERMAID’s contributions focus particularly on coral bleaching and reef fish monitoring—two important components of understanding reef condition and change.
Monitoring coral bleaching helps teams document how corals respond to thermal stress and other pressures. Consistent observations can help reveal which taxa, sites, and reef areas are most affected and support assessments of bleaching severity and recovery.
Reef fish monitoring provides information about the abundance, size, biomass, and composition of fish communities. These data can help programs examine ecological condition, fishing pressure, management effectiveness, and changes in reef function over time.
The course introduces the principles behind these monitoring approaches and situates them within the broader process of planning, collecting, analyzing, and communicating reef data.
Continue the workflow with MERMAID
Learners who want to put these approaches into practice can use MERMAID, WCS’s open-source platform for collecting, managing, visualizing, and sharing coral reef monitoring data.
MERMAID supports standardized workflows for the fish belt transect and coral bleaching rapid assessment methods featured in the course. Users can enter data online or offline, work collaboratively within projects, validate records before submission, and view automatically calculated reef health metrics on MERMAID Collect.
For fish belt surveys, MERMAID calculates abundance and biomass, including summaries by fish family and trophic group. For bleaching surveys, it summarizes coral colony condition and the percentage of normal, pale, bleached, and recently dead colonies, along with key benthic cover measures.
Submitted results can be visualized on MERMAID Explore, exported for reporting, or accessed programmatically through the mermaidr R package for reproducible analysis.
More monitoring methods beyond the course
The course provides a strong foundation, but coral reef monitoring programs often collect additional information to understand the ecosystem more fully. MERMAID supports several methods that are not covered in CRRI102x.
Benthic monitoring
MERMAID supports three widely used benthic methods:
Point intercept transects
Line intercept transects
Benthic photo quadrat transects
These methods help teams estimate the cover and composition of corals, algae, and other benthic groups. MERMAID organizes observations using a standardized hierarchy and automatically calculates percentage cover, making it easier to compare results across transects, sites, and monitoring periods.
AI-assisted photo-quadrat annotation
MERMAID also offers AI Image Classification (Beta) for benthic photo quadrats.
The feature uses a single pre-trained model developed in collaboration with CoralNet. Monitoring teams can upload photo quadrat images and receive suggested classifications for 25 points on each image without first creating a label set or training their own model.
Because the model uses a standardized set of MERMAID benthic labels, results can be integrated directly with other data in a MERMAID project. A trained observer must review and confirm every classification, maintaining human oversight while reducing the effort required to begin image annotation.
This offers an accessible entry point for programs that do not have the imagery or technical capacity to build a custom classifier. Teams that require region-specific label sets or custom-trained models can continue working in platforms such as CoralNet and bring their results into MERMAID.
Macroinvertebrate monitoring
MERMAID now also supports macroinvertebrate belt surveys. Programs can record the abundance and optionally the size of sea cucumbers, sea urchins, giant clams, lobsters, crown-of-thorns starfish, and other macroinvertebrates along belt transects.
MERMAID uses the surveyed area to calculate total density and density by groups of interest. These observations can complement fish, coral bleaching, and benthic data to provide a more complete understanding of reef condition, fisheries, ecological function, and management outcomes.
Other supported approaches include visual assessments of habitat complexity. An overview is available in the MERMAID survey methods documentation.
Strengthening the reef monitoring community
Training and technology are most powerful when they work together. CRRI102x helps practitioners understand how to develop meaningful monitoring programs, while MERMAID provides practical infrastructure for carrying those programs forward from field data collection and validation to visualization, analysis, and sharing.
Together, these resources can help more teams produce consistent, accessible, and decision-relevant information about the reefs they monitor.
Learn more and enroll in CRRI102x Coral Reefs: Data and Monitoring. The course is free.
To learn more about using MERMAID for coral reef monitoring, visit datamermaid.org or contact contact@datamermaid.org.