Snorkel Surveys Offer a Closer Look at KP’s Eelgrass Meadows

I barely have time to marvel at the psychedelic transformation that happens when my viewpoint goes underwater.”

After her first day snorkeling the undersea eelgrass meadow off Joemma Beach State Park, Jeff Gaeckle asked his niece Natalie Gaeckle what she thought. She launched into an enthusiastic description of the colorful crabs, sea stars, fish, and snails she had encountered.

The elder Gaeckle waited. Finally, hearing no mention of what had brought more than a dozen of us together for four days of snorkel surveys, he asked, “Did you not see all the seagrass I planted?”

Gaeckle has a right to take pride in the extensive eelgrass meadow here. Before 2015, when his team at the Department of Natural Resources made its first test plantings at a number of sites around South Puget Sound, neither eelgrass nor all the species that depend on it existed here.

Since then, Joemma has become the most successful eelgrass restoration project in Washington.

My mind is on critters, too, when I first hop into the water. Eelgrass meadows are highly productive, like coral reefs. They provide food and shelter to all kinds of life and serve as nurseries and hunting grounds for larger fish and crustaceans. Plus, they clarify water and capture carbon.

Gaeckle sends me marching off through waist-deep water with Bart Christiaen, also of DNR. When we reach a series of eelgrass patches that were planted a few years ago to test a new planting method, Christiaen dips his face into the water and gestures for me to do the same. He will teach me the survey method.

I barely have time to marvel at the psychedelic transformation that happens when my viewpoint goes underwater: from a murky, almost dirty-looking mess of green blades underfoot, the eelgrass extends and blooms into a brilliant light-catching geometry of emerald and lime. Snails and their eggs are everywhere. The blades dance.

But shoot density and canopy height are what we’re after. Christiaen tosses in a metal square and runs his fingers through the tangled mass of eelgrass to find and count each shoot inside the square. Eelgrass, unlike seaweed and kelp, and other marine algae, is a flowering plant. In Puget Sound, it mostly spreads through rhizomes, creating thick mats, though it also reproduces by setting seed. After counting shoots, Christiaen uses a metal ruler to measure the length of three blades. He records the data on the back of the ruler with a pencil, moves the square, and starts again.

I try to follow his lead. It’s slow going. To breathe and orient my body to the current and with my wetsuit-inflated buoyancy while preserving a mental image of the shoots I’ve counted takes all my attention. By the end of the day, I have discovered that my fingers are more effective than my eyes in counting, and I have a far more tactile sense of how these plants grow from the delicate white place where the rhizome meets a cluster of blades.

Eelgrass is sensitive to disturbance. Since 2000, DNR has been doing surveys throughout the state with an underwater video camera to better understand its expansions and contractions, a program Christiaen leads. Before 2000, data were minimal, making it hard to determine trends. The total eelgrass area has been roughly stable since then, though from site to site, there are fluctuations. This year, for reasons unknown, a restoration site at Anderson Island had significant dieback.

Lack of data makes it impossible to know eelgrass’s full extent before the land around Puget Sound was logged and developed. Gaeckle thinks two things historically have had a big impact on eelgrass. First is logging. When land is denuded, high sediment loads flow down creeks and settle in nearshore areas where eelgrass grows, burying its growing tips.

The Joemma restoration site got a dose of that treatment this summer when the tidal channel at Whiteman Cove was restored to benefit juvenile salmon. A load of pent-up sediment was released. Several stretches of the eelgrass meadow, including some outlying plantings, were heavily affected, with some patches vanishing. Gaeckle expects the meadow to recover since this was a one-time release of sediment. He said the sandy substrate already looks better now than when he visited last winter.

The second impact on eelgrass, which is ongoing, is fouling by algae. High levels of nutrient runoff from home fertilizers create blooms of underwater algae. These algae can smother eelgrass beds, starving them of light. There is a lot of sea lettuce around as we snorkel.

On the second day, clouds and wind come. There are hints of whitecaps. Surveying around the deeper edges of the meadow is rough work. Underwater visibility is poor enough that we cannot see the shoots while floating three feet above them.

Gaeckle, indefatigable, disappears again and again into the waves. He tries to stick his face right in the sand while counting. We do our best to imitate him.

Crabs wander into my square. A change of tide brings cold water and slightly better clarity. I take time to drift, though it is still hard to get a clean breath with the waves. For a while, I float with a school of shiner perch and watch their course corrections in the churning water, their thin bodies silver and ephemeral against the backdrop of eelgrass.

It’s more than a backdrop. My fingers know that after two days of surveys. Flowering underwater, the seagrass seems as rich as any coral.

Part one of a two-part series on local eelgrass restoration. Next month, the planting of eelgrass takes center stage, involving a remote underwater vehicle named Grasshopper 4.