Just What Lives on the Rocks of Calvert Island?
Scientists track changes to biodiversity on the shores of the BC Central Coast.
To see a predawn sky in late July you have to get up early. A gray glow is cast over a dozen damp, smiling faces. Water—coming down as part mist, part drizzle—is already working its way through well-worn Gore-Tex as we gather outside the main lodge at the Calvert Island Ecological Observatory. The coffee hasn’t kicked in yet, but there is an unspoken excitement in the air. The tide is dropping to low, and there’s biodiversity to study.
Biodiversity—the variety of living things in an area—may seem like a buzzword used by scientists when asked why an area is important. But recent research, published in the journal Nature, found that biodiversity is more than buzz.
“Biodiversity is not just a pretty face,” says Emmett Duffy, lead author of the paper and director of the Smithsonian Institution’s MarineGEO network, as well as a member of this day’s predawn survey team. “[Biodiversity] is really important for having ecosystems that work well—that are productive, that can recycle nutrients, absorb wastes, and protect shorelines.”
After an hour of walking across sand beaches, crawling around fallen trees, and whacking a few bushes, we arrive at our seaside destination. Our leaders, Laura Anderson and Nate Fletcher, visiting scientists from the University of California, Santa Cruz (UCSC), are clad head-to-toe in carrot-orange rain gear, conspicuous beacons against the gray sky.
Anderson picks out a perfect spot to establish a new biodiversity survey site—a tennis court-sized, algae-encrusted granite bench overlooking the open Pacific Ocean.
A little rain doesn’t stop researchers from surveying the biodiversity in the rocky intertidal during a low tide. Video by Josh Silberg
Life in the intertidal zone is like a layer cake. The top layers, which are only periodically splashed by sea spray, are sparsely populated, mostly barren rock with a few hardy periwinkle snails. Then comes a band of barnacles, followed by thick beds of jet-black mussels. Below the mussels are seaweeds of all shapes and sizes, resembling everything from mini tree branches to feather boas to spaghetti. And at the water’s edge are zones that are only revealed at the lowest of tides. Timing our arrival to coincide with a super-low tide gives us the chance to investigate every layer—if we move fast.
The first step is to lay out a checkerboard-like grid of measuring tapes over the rock. The morning’s calm is interrupted when Matt Whalen, a Hakai postdoctoral fellow, uses a rock drill to secure a metal pin at each corner of the survey grid. These pins allow scientists to resurvey the exact same spot on later visits to track how intertidal biodiversity shifts as our oceans change.
“Ideally, we’d resample our sites about every five years,” says Anderson. “Regardless of how much time passes between revisiting a site, we are still able to pick up interesting and important new data each time we return.”
In the time between surveys, invasive species may have established a presence, a disease may have altered the animal communities, or new species could have shifted their range north or south as the climate is altered. Without a comparable baseline, scientists would have difficulty measuring these changes.
Anderson and Fletcher are part of MARINe, the Multi-Agency Rocky Intertidal Network, a consortium of researchers from universities, government agencies, the US Navy, and nonprofits that use standardized methods to compare rocky intertidal habitats along the west coast of North America.
At UCSC and under the auspices of MARINe, they also work with the Partnership for the Interdisciplinary Studies of Coastal Oceans (PISCO), a group that has been studying long-term changes to coastal ecosystems by monitoring sites with many of the same standardized protocols. PISCO started with a five-year grant from the David and Lucile Packard Foundation—which also started the prestigious Monterey Bay Aquarium Research Institute. PISCO’s research still continues almost two decades later.
These biodiversity surveys don’t merely sit on a shelf. The data collected have been used to design and evaluate marine protected areas in California, assess damage after environmental disasters, and monitor disease events such as sea star wasting syndrome.
“Any opportunity to add another site is beneficial because it adds more data for comparison along the entire [Pacific] coast,” says Anderson. “It’s also unique that this site is on an island that is already being extensively studied and surveyed by the Hakai Institute.”
While survey sites are spread along a 4,000-kilometer stretch of Pacific coast between the Alaska panhandle and Baja California, their distribution is uneven. Three-quarters of the over 140 existing UCSC sites are in California and only five are in British Columbia. None of the BC sites had been revisited for over a decade. So in addition to setting up the new site on Calvert Island this summer, the team took the opportunity to return to nearby Duck Island with BC Parks rangers to resurvey a site that hadn’t been sampled since 2005.
“These surveys with UCSC are part of Hakai’s broader research in the intertidal,” says Hakai scientist Margot Hessing-Lewis. “Through these types of collaborations, Hakai is filling gaps in long-term research efforts across the region.”
While Anderson and Fletcher haven’t completed their analysis of the data yet, the biodiversity on the BC Central Coast left an impression.
“Just from being there and conducting research, it seemed like the site may have some of the highest species richness we’ve encountered,” says Anderson.
The incredible diversity was also evident for Duffy, who spends most of his time on the Atlantic coast.
“Out in the intertidal zone today, it seemed to me like a Hollywood movie of what the coastal seashore should look like—just chock-a-block with every kind of seaweed and invertebrate in bright colors that you could see,” says Duffy. “It’s like a coral reef, only colder.”