Counting Glacier Bay's Harbor Seals With Drones

Julian Dale, lead engineer, and Dave Johnston, professor of marine science, of Duke University, review seal imagery collected by drone in Johns Hopkins Inlet, Glacier Bay. NPS / Jamie Womble.

Seals worth watching

The Park Service has monitored harbor seals in Glacier Bay since the 1970s, from the ground and the air. Since the early 1990s, seals have declined in both glacial ice and land habitats there, making them a high priority for monitoring.

A new way to count

The Park Service's Southeast Alaska Network is working with Duke University's Marine Robotics and Remote Sensing Lab to develop survey methods using unoccupied aircraft systems (UAS) — drones — to photograph harbor seals in Glacier Bay National Park and estimate where they are and how many there are, for long-term population monitoring.

In 2023 and 2024, the team flew Blue UAS drones to collect high-resolution images of seals on glacial ice and on land. The photos will be used to estimate the seals' density, abundance and body condition.

Harbor seals on ice in Johns Hopkins Inlet, photographed by drone. Image from the NPS's page.

Why drones

• Better methods: they will help refine sustainable, long-term monitoring.
• Safety: fewer risks for biologists and pilots.
• Efficiency: more efficient data collection in future.
• A lighter touch: less noise, less fuel, and less impact on wilderness.

Harbor seals at Spider Island Reef, Glacier Bay, photographed by drone. Image from the NPS's page.

More on the network's marine predator monitoring.

Sources

Based on "Using New Tools and Technology to Monitor Harbor Seals," Southeast Alaska Inventory and Monitoring Network, National Park Service; a work of the United States government in the public domain. The source's text names the Duke professor "David Johnson"; its photo credit, "Dave Johnston," is followed here.