Girls with drones

by Stephanie Duce, lecturer at James Cook University

A quick google search of “girls with drones” currently returns more pictures of bikinis and bottoms than propellers and controllers… but that is something that will hopefully change in the near future particularly with the work of organisations like She Flies.

Recently, I was fortunate to join She Flies co-founder and James Cook University researcher Dr Karen Joyce on a field expedition to the northern Great Barrier Reef (GBR). The aim of this trip, led by Dr Chris Roelfsema from the Remote Sensing Research Centre at the University of Queensland, was to collect data (photographs) from the different coral reef habitat zones to allow detailed habitat maps to be created from satellite imagery and ecological based modelling.

The fantastic (and well gender balanced) research team from the University of Queensland and James Cook University.

At each reef a team of snorkelers or divers swam long transects (sometimes more than 1 km!) across the shallow reef flat or deeper reef slopes, taking georeferenced photos every couple of meters to record the type of cover on the sea floor (e.g., sand, dead coral, live coral, algae…). Meanwhile Karen and I used “Casper” the friendly drone to take high-resolution photographs of the same areas from above. All these photographs will be used to “ground truth” (calibrate and validate) satellite images for the 200 reefs between Cairns and Cooktown. This will be coupled with ecological based modelling to create the habitat maps. Presently very few reefs on the GBR have been mapped in detail. Without detailed maps it is impossible to know what is there, what has changed and how to manage the reefs effectively.

Overall, we flew at seven of the nine reefs we visited (the wind was too strong for Casper at two reefs). I really enjoyed my first foray into the world of droning and was impressed by the large area that drones can cover with very high quality imagery. For a more detailed description of the trials and tribulations of coral reef droning check out Karen’s blog.

Casper in flight over Boulder Reef offshore from Cooktown

In terms of reef health, I had prepared myself for some depressing scenes as I knew the reefs of the northern GBR had been hit hard by the 2016 coral bleaching event. Indeed the reefs we visited north of Cairns had a lot of dead coral which had been over grown by algae. A very sad sight. Massive Porites were often the only hard corals still alive and soft corals provided the only splashes of colour. Pleasingly, some of the reefs we visited south of Cairns still had beautiful live coral cover.

A high-resolution mosaic of drone images over Farquharson Reef offshore from Mission Beach, south of Cairns

A characteristic scene of the reef scape at Chinaman Reef north of Cairns.

Stephanie is a Lecturer at the College of Science and Engineering at James Cook University. Her primary area of research interest is the application of geospatial technologies, including Geographic Information Systems (GIS) and remote sensing, to the study of Earth’s environment and natural processes. She is particularly interested in coral reef processes and geomorphology.

Posted on: 16/02/2017, by : Shari Gallop