Tuesday, June 21, 2011
The University of Washington's Friday Harbor Laboratory has been perched here on the point north of the town for most of the last century. The research focus was historically more on marine biology and rocky coastlines than on beaches, which makes sense given its location.
The lab, like other water-oriented developments, has grown somewhat organically along the edge of the water - with the interest clearly more in getting to the water or using the water (the labs thrive on a lifeblood of circulating salt water) than in the shoreline itself. I found the waterfront a little ragged with its crumbling stone walls, its collapsing piles of riprap, and its abundance of pipes.
It might be interesting to look at historical photos of the lab's shoreline. I wouldn't expect too much natural change, although I saw some evidence that the beaches (limited as they are) may be continuing to erode. They would have done so anyways, plus any material that would have originally eroded from the banks to resupply them is safely secured behind all the riprap!
But it's sure a neat place to have a meeting! It's not exactly convenient, but it's a far more pleasant venue that an interior conference room in an office building in Olympia.
If you take a rocky coastline and add a little sand and gravel, you'll get pocket beaches and there are no shortage of them here on the south end of San Juan Island. I knew this one existed, but didn't know you could actually get to it without owning it, until I found the little public access and parking area amidst the Sunset Magazine centerfolds.
The beach is only a few hundred feet long, it's sand and gravel isolated from every other beach in the world by rocky headlands and deep water. The gravel stays high, piled in steep berms and buried under drift logs. The sand forms a rippled terrace in the lower intertidal.
The south end of San Juan Island is why you can't categorize Puget Sound beaches in any simple way. It's the same ocean, and the same physics, both here and on the forested shores of Eld Inlet, but the beaches are cut from completely different cloth.
South Beach is a broad gravel berm that appears to have built seaward over time from the original base of the slope. It is covered with logs - apparently this is the last obstacle for logs trying to escape Puget Sound and many get no further than this. There are sand dunes - well-vegetated ones for the most part - climbing the slope to the north. The most obvious source of the beach gravel is the high eroding bluffs east toward Cattle Point, although I wonder if this beach also tells a story about the gradual erosion of Salmon Bank, which extends far offshore.
American Camp, of which this all part, is overrun with non-indigenous foxes. Cute little beggars - certainly cuter than those chickens all over the beaches on Kauai!
The north and south sides of the peninsula that ends in Cattle Point couldn't be much different. The south side is high grassy bluffs looking over the broad gravel strand of South Beach and twenty miles of water at the Olympic Mountains. The north side is forested and slopes down to Griffin Bay, where it is broken into a wonderful series of barrier lagoons. At the west end, down towards Fourth of July Beach, is Old Town Lagoon. At the east end, down towards Cape San Juan and it's exclusive nest of high end real estate, is Third Lagoon. And in the middle is Jakle's Lagoon, with it's gravel barrier, its lagoon, and its forest.
There is some evidence of an occasional tidal opening near the west end, but certainly not a persistent or regular connection. The wide gravel barrier gives rise to a broad marsh and eventually to a lagoon, its edges lined thickly with old drift logs. The pickle weed (Salicornia virginica) was doing its best to survive a colorful infestation of dodder (Cuscuta salina), a plant parasite that apparently takes many forms the world over.
I walked the cobbly beach to Third Lagoon, and then worked my way back via the mossy trail that follows the top edge of the bluff. On one shady section of beach, the upper intertidal gravel was covered with small snails (Littorina littorea, I assume). I've never seen them gathered so densely and have no explanation.
I've exceeded by usual quota of Latin, normally enforced by my ignorance of biology. Fortunately, the evening that followed this great day of beaches included dinner with people who actually understand this stuff.
Cattle Point is a rocky headland at the south east end of San Juan Island, jutting out into the eastern end of the Strait of Juan de Fuca. The lighthouse is perched on dunes, which are in turn perched on top of glacial sediments, which in turn mantle the underlying bedrock. There are a couple of wonderful pocket beaches just north around the corner and South Beach stretches out to the west.
Ship Harbor is a north-facing cove just east of the Anacortes Ferry Terminal. It's a swash-aligned barrier beach and marsh with a long and complicated human history. It's basically a pocket beach trapped between Shannon Point and the ferry terminal to the west and the old railroad grade on the east. There may be some sediment trickling in from adjacent shorelines, but certainly no way for it to get out, except by gradual attrition or perhaps some loss offshore.
The shape of the beach is altered a bit by the remains of the old cannery -- metal slag (old tin can cuttings?), concrete foundation piers, and a forest of piles - each with it's own gull. The sand and gravel segregate themselves, both across the profile and along the beach. There was a sandy berm encroaching on the vegetation at the east end, suggesting some accretion there recently.
I'm not sure how the wetland drains - through the berm or through a pipe somewhere out of sight? There is a small "stream" bubbling from a concrete vault on the east end, carrying storm water from the new subdivision on the hill. It forms a small low tide delta -which is probably the sink for any extra sediment that makes its way to this end of the bay.
Ship Harbor, February 2009