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Indonesia

Reef Protection Goes High-Tech

Bunaken National Park’s management has gone hightech, with the introduction of satellite imagery to monitor changes in coral reef health.With the assistance of Candace Newman from the University of Waterloo in Canada, the project uses IKONOS imagery to detect if Bunaken’s zonal system (which divides the reef area into tourism, village use, and strict conservation areas) has resulted in more coral and seagrass coverage.

The IKONOS, a US-constructed satellite launched in 1999, takes photographs of the islands 600 km from earth, which facilitates identification of docks, jetties, boats, and ecological features of the reef flat. "It’s possible to distinguish between seagrass, sand, and coral reefs, and we can even make out areas where local boats have left drag marks in the soft sandy bottom," said Newman.

IKONOS imagery has a resolution of either 1x1m or 4x4m, which means any underwater feature larger than this scale is observable. "Sometimes there’s confusion between some features, so we spend a lot of time ground-truthing," said Newman. Ground-truthing involves confirming, on the ground, what’s seen in the satellite image. Once completed, underwater features in the image are classified into different categories with a relatively high level of accuracy.

This project first began in 2001 when IKONOS satellite imagery of Bunaken and Siladen Islands was captured and confirmed. In June 2004 a second image was taken, and Newman is now developing a technique to use the two images to estimate changes in coral health through time.

Satellite images will provide the Bunaken National Park management advisory board with scientific evidence of the successfulness of the existing zonal plan, and identify areas that need greater protection.

To learn more about this study visit    http://www.fes.uwaterloo.ca/u/cmnewman/

This article is from Asian Diver, page 20 of the December/January, 2005 issue.