KelpExplorer Launches: A Living Atlas of British Columbia's Underwater Forests
Luba Reshitnyk remembers the moment she first saw it all come together on screen—hexagons lighting up along the BC coast, colour-coded from yellow to deep blue, each one a compressed summary of decades of kelp data stretching back to the 1980s. After years of building datasets that lived mostly on her own hard drives and in her own head, she was looking at something anyone could open in a browser.
"I just saw the implications of it," she says. "There'll be a time when the whole coast will be covered, and anyone will get to come here and see that."
That platform is KelpExplorer, and it launched this spring.
Floating kelp forests trace the coastline of British Columbia. KelpExplorer brings together decades of satellite, aerial, and drone observations, allowing users to explore how these ecosystems have changed through time.
Developed by the Hakai Institute and released as part of CoastConnect—a growing suite of open tools for coastal science and stewardship—KelpExplorer brings together kelp canopy data collected from satellites, aircraft, and drones into a single publicly accessible web platform. For the first time, anyone with a browser can explore how kelp forests along the BC coast have changed, year by year, going back nearly 40 years.
CoastConnect itself forms part of a broader movement toward open coastal data infrastructure, complementing initiatives like the Canadian Integrated Ocean Observing System, which helps standardize and share marine observations across the country.
Reshitnyk, a geospatial scientist who leads Hakai's marine habitat mapping program, has spent more than a decade building the foundation for this. The program started in 2014 with researchers hanging out the side of a helicopter, cameras in hand, photographing kelp beds around Calvert Island. Drones arrived shortly after. Machine learning tools like Habitat-Mapper—developed in partnership with Hakai's software team—eventually automated what used to take months of image processing into same-day results.
Research scientist Luba Reshitnyk reviews data collected during a kelp monitoring survey on British Columbia’s Central Coast. Field observations help validate and improve the remote sensing tools that power KelpExplorer.
Meanwhile, Reshitnyk and colleagues at Woods Hole Oceanographic Institute are working together to use Landsat satellite imagery—collected globally since 1984 at 30-metre resolution—to map kelp across the full complexity of the BC coastline, a distance which is Washington to California, 5 times over. Cloud cover, tides, coastal geometry—all of it had to be accounted for before those data are usable.
Members of Hakai’s geospatial mapping team recover a drone following a kelp survey on British Columbia’s Central Coast. Drone imagery provides fine-scale observations that help validate and interpret kelp patterns observed from aircraft and satellites.
"It's like a pantry," Reshitnyk says. "In some cases we [Hakai] provide the recipe where you can go and run a thing for yourself, like with Habitat-Mapper. But in some cases, we are providing the cake—the end products, the insights, that you can be using directly."
Before this existed, working with kelp data meant specialized GIS software, powerful computers, and the technical fluency to reconcile datasets that came in different formats, resolutions, and spatial scales. Will McInnes, who coordinated the development process between Hakai's scientific and technical teams, describes the challenge as trying to take an enormous, messy pile of information and make it "snappy in a browser."
"There are folks who don't have any GIS experience," McInnes says, "but are able to go in and get access to this rich kelp data that they would not normally be able to use."
The platform's hexagonal aggregation system—one of its key design decisions—reflects both a technical and a scientific choice. Individual pixels of kelp shift with every tide and current, making direct year-to-year comparison noisy. Grouping data into hexagonal cells at the scale of a bay or a stretch of coastline smooths that variability into something meaningful. Users can also draw their own area of interest directly on the map and pull trend charts for that specific location across all available datasets.
Hakai engaged with a range of partners—including First Nations and Indigenous-led organizations, federal and provincial agencies, and MPA network members—whose feedback shaped what the platform prioritizes and how data are presented. The result is a platform that pulls 3 distinct data sources together in one place: Landsat for the long view coast-wide, aerial surveys from Hakai's Airborne Coastal Observatory for regional detail and species-level mapping, and drone data for fine-scale monitoring at long-term study sites.
The development of KelpExplorer continues through ongoing dialogue with partners and communities. Full BC Landsat coverage coast-wide is coming soon, with new drone surveys and Planet satellite imagery to be fed into the system as they are collected. Each dataset has different strengths, different resolutions, and different limitations—and KelpExplorer is designed to communicate those distinctions, not hide them.
KelpExplorer combines satellite, aerial, and drone observations into a single web platform. Users can explore long-term trends in kelp forest extent, compare datasets, and examine changes across specific locations along the BC coast.
The platform sits within CoastConnect alongside tools for community-based drone surveying and other nearshore habitat monitoring—a growing infrastructure for making open science accessible to the people who need it most: coastal First Nations, stewardship offices, government agencies, marine park managers, and harvesters making decisions about what's in the water.
Sea urchins graze on young kelp and can transform productive kelp forests into urchin barrens when their populations grow unchecked. Researchers are using KelpExplorer to better understand how ecological relationships influence kelp recovery across the BC coast.
The data already tell stories. On the Central Coast near Calvert Island, where Hakai has monitored kelp continuously since 2014, the arrival of a raft of roughly 100 sea otters in 2023—and their subsequent spread into the Northwest Calvert region—has produced what Reshitnyk describes as a 900 percent increase in kelp forest cover between 2024 and 2025. She can see it in the drone footage. She can see it in the satellite imagery.
But the more quietly compelling story is the one emerging from the contrast between the Central and North Coasts. When the 2015–16 marine heat wave swept through the northeast Pacific, kelp forests across much of BC and California declined sharply. On the Central Coast around Calvert, the decline was modest or in some cases, not seen at all. On the North Coast near Porcher Island—home to some of the largest kelp forests in the province—the drop was severe, and unlike elsewhere, the beds have not rebounded.
The difference, Reshitnyk suspects, comes down to sea otters. The Central Coast has them. The North Coast, largely, does not. Otters eat urchins; urchins eat kelp. In a healthy otter-urchin-kelp system, a marine heat wave causes a setback. Without otters holding the urchin population in check, the same event can push a kelp forest into a decline it struggles to recover from.
"There may be landscape-level implications," she says, "that we can see from space."
That kind of observation—made possible only by having 4 decades of coast-wide data in one place—is exactly what KelpExplorer was built for.
Black rockfish shelter among giant kelp on British Columbia’s coast. Kelp forests provide habitat, food, and refuge for a remarkable diversity of marine life and support ecosystems that extend far beyond the kelp itself.
The data already exist for that kind of reckoning. Old bush pilots who flew the inside of Vancouver Island decades ago once recalled there was a lot more kelp back then. Coastal families remember beds that aren't there anymore. First Nations stewards carry knowledge of these shorelines across generations.
KelpExplorer doesn't replace any of that knowledge. But for the first time, it gives those observations somewhere to land—a way to compare memory, lived experience, and local understanding against four decades of satellite record stretching across the coast.
KelpExplorer was developed by the Hakai Institute and is part of CoastConnect. Visit kelpexplorer.hakai.org to explore the platform.
