Wading off into the dark

Winter beach projects

It’s time for the Beach Watchers Eelgrass Monitors to brave the winter chill for eelgrass sample collection. The work isn’t hard, but the night is dark and cold and there’s an awful lot of knee deep water to wade through, so project lead Jan Holmes has wisely rounded up a couple of helpers (her husband, Steve and me) to keep her company and carry stuff.

The testing protocol requires that samples come from the same section of the meadow each time.

What do you do when you want to find a particular section of an eelgrass meadow during the winter?

Image of wading in dark
  • You choose the night with the lowest tide since July and wait until the tide is almost all the way out.
  • You strap on headlamps and don boots with little reflectors on the back.
  • You start walking out across the mud flats, gazing at the ground, looking for the markers you planted in daylight six months ago.
  • You wander this way and that so that to the casual observer you look like you’re lost.
Image of eelgrass meadow at night

This section of the Holmes Harbor eelgrass meadow appears to be rebounding nicely after a die back a couple of years ago.

Jan and Steve locate the markers, which are hard to find in all that blackness.

Image of temperature sensor in eelgrass bed

The temperature sensor is still in place on one of the marker posts.

Eelgrass sample collection

Image of digging in eelgrass bed for eelgrass sample collection

Jan carefully digs out a few plants

Image of selecting a sample of eelgrass
Image of people wading in dark after eelgrass sample collection

Samples in hand, Jan and Steve head back through the wind and snow to their nice warm car.

What will the samples be used for?

The project’s science mentor, Dr. Sandy Wyllie-Echeverria, who runs the seagrass lab at the University of Washington’s Friday Harbor Lab on San Juan Island suggested Jan create an eelgrass id sheet.

Jan says: “I needed better photos of rhizomes, roots, etc. I also wanted to see what the quadrats looked like compared to summer, but the water was too high, so I just took some shots to get some kind of idea. The samples will not be used for any kind of data analysis. I also photographed a few invertebrates on the blades of the grass. Sandy suggested a project that involves making a pictorial guide that shows physical evidence of environmental and biological impacts on eelgrass such as grazing, epiphytes, freezing, desiccation, etc.”

Jan also noted that the water was higher than she expected given the tide chart. “There may have been a low pressure zone attributing to the higher water that night – the beds should have been exposed. Mary Jo (Adams, a fellow Beach Watcher biologist) was up at Rosario (Rosario Beach, near Deception Pass) and she said the tide levels were higher than she expected at that time of night also.”

More information about the Beach Watchers Eelgrass Monitoring project is available at Watching The Eelgrass Grow, a chronicle of the inaugural season.

  1. Wow! Thanks Brian, for the kind words. And thanks for letting me know about your blog. I'll add it to my links. I really like the in depth and thoughtful posts I see on your site. I'll be using it as a resource. Maybe we'll meet up some time – perhaps at Sound Waters(?)

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