Center for Coastal Studies marine ecologist Dr. Agnes Mittermayr knows eelgrass. Or at least she thought she did. As director of SeagrassNet, she monitors seagrass beds at more than a hundred sites around the world. But then she went to the Izembek Lagoon, a remote wilderness in the Aleutian Islands.
“I was blown away,” she recalls.
Izembek Lagoon is in Izembek National Wildlife Refuge, a 65-square-mile preserve located near the tip of the Alaska Peninsula, bordered to the north by the Bering Sea, and to the south by the Gulf of Alaska. According to Mittermayr, the eelgrass beds there are thought to be the largest in the world.
“It’s so pristine, there is no pollution, and no people. That’s why the grass can grow as it does. Izembek is a relatively small area that’s well studied, but there have been hardly any attempts to map the rest of Alaska. So nobody knows the full extent of the grass there,” she explained.
Every summer, researchers survey the eelgrass to monitor its health and abundance. They evaluate the population of sponges, sea stars, gastropods, crustaceans and bivalves that live in the eelgrass beds, and study how the eelgrass is affected by environmental factors, like temperature and salinity.
“They do annual surveys because the seagrass beds are so important for the wildlife there. We wouldn’t know they were healthy if we didn’t survey them,” said Mittermayr.
Because of her reputation at SeagrassNet, Mittermayr was asked to participate in this summer’s research. She arrived on August 3, flying into Cold Bay, Alaska, a former World War Two military camp, chosen for its location because of the persistent cloud cover which obscured it from Japanese reconnaissance.
Joining Agnes were two scientists from the US Geologic Survey, one from the US Fish and Wildlife Service, and one from the National Estuarine Research Reserve for 12 days of field work.
Working 10 to 11 hour days, the five researchers divided into two teams and two Zodiacs. Wearing drysuits and snorkels, they surveyed 150 locations identified by GPS coordinates in both Izembek Lagoon, on the Bering Sea, and Kinzerof Lagoon, on the Gulf of Alaska.
They used quadrants to determine the percentage of grass coverage, and measured the lengths of the blades. The longest they found was 306 centimeters, or about nine feet.
“That’s outrageous!” said Mittermayr, noting that the seagrass she measures in Provincetown is closer to two feet in length.
Eelgrass (Zostera marina) is a type of seagrass. Called the “forgotten ecosystem,” seagrass is a vital natural resource that supports biodiversity, cycles and stores nutrients and pollution, protects coastal areas, and provides nurseries for larger fisheries. It also mitigates climate change through highly effective carbon sequestration.
One of the last untouched and pristine frontiers, the refuge is an important spawning ground for Pacific herring, a nursery for sea otters and harbor seals, and also home to brown bears, walruses and massive numbers of birds, including the entire Pacific migration of brant geese.
“It’s always been on my bucket list,” said Mittermayr.
Normally very cold, this past August, Mittermayr noted that it was unusually warm.
“Climate change is happening so we don’t know how that will affect eelgrass there,” she said.
Ironically, the eelgrass beds in the refuge are so abundant that the standard methods of measuring it, used by SeagrassNet researchers around the world, can’t be used. In short, there’s too much to count.
“I couldn’t swim through it without getting stuck. Before I went on this trip I was pretty content about the seagrass beds we have in Provincetown. But now that I’ve seen Izembek Lagoon, I’m not so happy because I see what they would have looked like hundreds of years ago,” she said.
Photos from top to bottom: The eelgrass beds were much thicker than Mittermayr had ever experienced; the survey team at Grant Point, Izembek Lagoon; Eelgrass can grow up to 9-feet in length; Cold water anemone with rhodoliths and eelgrass in the background; Mittermayr in a Zodiac with fellow scientist David Ward from the USGS; Izembek National Wildlife Refuge.