Satellite imagery is being used to map coral reefs worldwide

How satellite imagery is being used yo map coral reefs to inform coral conservation. This is the first 3.7m-resolution coral conservation tool, mapping and monitoring the world’s coral in unprecedented detail.

Satellite imagery is being used to map coral reefs worldwide
Satellite imagery is being used to map coral reefs worldwide

Satellite imagery is being used to map coral reefs worldwide

Coral reefs are declining worldwide because of various factors. 

Coral reefs are characteristic topographical features of tropical and sub-tropical sea areas, and they play many roles, like protecting coastlines, diversifying the ecosystems of the reefs, fishing grounds, landscape elements, and tourist resources. It is considered that coral reefs are being affected by changes in the environment, and are declining worldwide due to various causes such as the rise in water temperature, the flow of soil sediment, and damage due to crown-of-thorns starfish.

Thus to overcome such situations, the scientists are practising an innovative approach that enables the use of high-resolution satellite imagery and advanced analytics for monitoring, capturing and thereby preserving the coral reefs all around the globe. This technique- being used for the first time by the Allen Coral Atlas. By December 2020, Allen Coral Atlas aims to have all the world’s coral reefs mapped at 3.7-meter resolution.

The initiative includes collaborative work from Carnegie Institution for Science, Planet, Arizona State University, University of Queensland, and National Geographic Society. 

Explaining the method behind Atlas 

The initial stage to create coral maps is to collect Planet’s satellite imagery data. Planet uses a number of processing techniques to Clean the raw data before passing it on to the Carnegie Institute. The team at Carnegie corrects the data for issues like waterbody detection, depth calculation, sun glint removal, atmospheric effects and bottom reflectance estimation. The researchers at the University of Queensland classify the different coral reef environments by using the models developed by the Center for Global Discovery and Conservation Science (GDCS) at Arizona State University.

Once the maps are created, field teams are sent to collect geo-referenced data in selected regions to help test, develop and implement the mapping algorithms by the National Geographic Society. However, on a larger scale, its focus is to build awareness and understanding about the Atlas so it can be leveraged globally by the users and help government coral monitoring and mapping programs.

Earlier this year, the Allen Coral Atlas integrated Coral Reef Watch data on sea temperature trends from NOAA, allowing Atlas users to add sea temperature visualizations on demand. This enhanced capability provides researchers with a new ability to track sea temperature trends to more closely approximate potential bleaching events - and activate proactive responses when possible. The Atlas will continue to add features and capabilities as the entire global mosaic is completed in the next two years.