Seagrass meadows and kelp forests are among the most productive ecosystems on Earth.

In Central Coast of British Columbia, Canada, this abundance of plants and algae buffers the coastline from winter storms, draws-down atmospheric carbon, and provides habitat for a diversity of other creatures.

These dynamic ecosystems can shift rapidly due to factors such as the changing ocean climate, and the recovery of certain top predators like sea otters. The main purpose of this project is to better understand the local and regional factors that drive change in these coastal ecosystems, and the consequences of these dynamics.

Institute	Hakai Institute
Country	Canada
Industry	Environmental Monitoring
Project Date	August 2015
Project Members	Will McInnes, Ray Brunsting
Project Size	4.5 Square Kilometers
Number of Images	415
GSD	12.5 cm

Mapping the ecosystem

The project was driven by The Hakai Institute is a scientific research institution that advances long-term ecological research at remote locations on the coastal margin of British Columbia, Canada.

Images were captured by manually flying a DJI drone – Phantom 3 Professional – from an 8-meter open boat at low tide. To map the seagrass meadows and kelp forests, we conducted two drone flights and captured 415 images at an altitude of 300 meters over an area of approximately 4.5 km².

A Topcon GRS (Geodetic Rover System) field surveying equipment system was used to provide accurate locations of the ground markers and better georeference the final orthomosaic.

Long term monitoring

From the images taken from the DJI consumer drone, Pix4Dmapper generated a 3D point cloud and 2D orthomosaic of the McMullin Islands in high resolution. The on-site flight and ground survey took one day, and processing this data required an additional two days.

Mapping of coastal regions requires very specific timing of acquisition to coincide with tidal events. By using UAVs and Pix4D technology, the team was able to reduce standby costs and could fly at a moment’s notice. Will McInnes from the Hakai Institute confirmed "We only require very short weather windows to fly, and therefore do not need to try to coordinate a helicopter or plane."

Seagrass meadows and kelp beds are clearly visible in the resulting orthomosaic, which allows researchers to easily delineate the extent of these vital coastal ecosystems. These images act as a baseline that can be compared to future images to monitor potential changes over time and will be of vital importance as the ocean's climate continues to change.