In 2021, we started mapping kelp beds using aerial drone surveys.
Our drone surveys help to establish a baseline for abundance and distribution of kelp in Alaska.
Gathering baseline population data will allow us, researchers, regulators, and other stakeholders to monitor changes from one year to the next and better understand potential effects from the emerging kelp farming industry, climate change, or other ecological relationships (like sea otters and sea urchins). We want to be proactive in conserving these vital habitats by documenting the health of kelp beds in Alaska.
Foundational Questions
1) How much kelp is there? 2) Where is it located?
There is a lot to be learned about kelp farming and wild kelp beds, so where do we begin? We think these two foundational questions are essential in order to understand and develop kelp farming and continue wild harvesting sustainably.
We spend our summer working around kelp beds and making observations. Since we're already on the water in remote coastal locations, we're excited to collect this information and be a part of helping to answer these questions.
Establishing a Baseline
In 2021, Barnacle Foods launched a kelp mapping program. The drone surveys generate precise, geo-referenced images that record the location and presence of kelp at a point in time.
Our Methods
We survey as many kelp beds as possible in our region each summer. In 2022, we flew 25 surveys. With this data, we can begin to establish baseline information about kelp on the coast and observe trends in real time.
From mid June through August, when kelp biomass is at its peak, we visit the kelp beds by boat. Our surveys occur at low tide to make the results as consistent as possible. In Southeast Alaska, the tide fluctuates up to 25 feet in a six hour tide change. We also need rain-free conditions to fly the drone, which are a little hard to come by in our soggy coastal rainforest.
Using a consumer level RGB drone (we use a DJI Phantom 4), we create a flight path that covers the extents of the beds. The drone is launched (from the boat!) and flies a grid while continuously taking overlapping photos.
The hundreds of images are stitched into one large orthomosaic image that is analyzed using computer software. The software determines kelp and non-kelp pixels and provides an estimation of canopy cover. By measuring and tracking canopy cover, we can quantify year-to-year and bed-to-bed differences.
Our team developed a computer program, KelPy, to automate the data analysis process. KelPy stitches all the aerial images together and identifies the presence of kelp. KelPy is an open-source computer program that employs Open Drone Maps and Kelp-o-Matic (developed by the Hakai Institute) with a user-friendly interface to easily process drone imagery.
Become a partner
Alaska’s coastline stretches over 30,000 miles, and much of this coastline is dotted with kelp beds. Partnerships and collaborations will be key to survey as many kelp beds as we can. In Alaska, we have a unique opportunity to map kelp beds in a healthy state, whereas many kelp beds around the globe have seen decline. This adds urgency to the kelp bed mapping project and to establish baseline information.
Expanding kelp bed mapping is a way to be proactive in caring for our coasts and to better understand what is happening in the oceans. There are many ways entities and individuals can get involved in this effort and we are actively looking for partners. Please reach out if interested.
The data currently lives on the Alaska Ocean Observing System website, see below.
Special Thanks
As we began delving into mapping, we were introduced to many researchers and institutions that are also mapping kelp beds throughout the world. We receive much advice, guidance, and assistance and we are grateful to those below (and more) who help:
Tom Bell, Luba Reshitnyk, Tyler Cowdrey, Kyle Cavanaugh, Mike Stekoll, Kaylah Duncan, Chet Russell, Toby Robinson, Tiff Stephens, Thomas Farrugia, Vienna Saccomano, Norah Eddy, Hakai Institute, Pacific State Marine Fisheries Commission, Alaska Ocean Observing System, Axiom Data Science