Monday, June 30, 2014

The Pisaster Disaster and other Tidepooling Discoveries in Oregon

One of the breaks from my working, cooking, and knitting routing while in Oregon earlier this month was visiting my friends Eve and Rob Gill in Toledo, Oregon, where I joined them for just a couple days in their wholesome routines of retirement, including eating healthy, fresh foods, qigong exercises, and walks on the beach.

Their current favorite is Schooner Beach, a southern extension of Moolack Beach north of Newport, immediately north of Yaquina Head.

On our first afternoon, it was high tide, and there wasn’t much invertebrate life to be noticed. But we did walk most of the way to Starfish Cove and spotted this immature Bald Eagle, a bird that Rob and Eve have come to know well.

We also saw these two Heermann’s Gulls and at least three Black Oystercatchers at the creek mouth.

Walking back close to the bluffs, looking for interesting fossils and stuff, I noticed this blooming Trailing Pearlwort (Sagina decumbens ssp. occidentalis), an inconspicuous member of the carnation family.

We returned the next morning at low tide, one of the lowest of the month, and what a difference.

The southern base of Yaquina Head is famous for its tidepooling, but there was a lot to see here on these isolated rocks on the beach. We probably saw five or six species of fish, including these Tidepool Sculpins (Oligocottus maculosus), the only ones that photographed halfway decent through the water surface.

The Ochre Sea Star (Pisaster ochraceus) is normally a very common animal here, and this apparently healthy one was on an isolated rock near the low tide line.

But in the deeper crevices and pools I found only two others, and they were both showing signs of the now year-old plague called the sea star wasting syndrome, the devastating the populations up and down the coast. Nicknamed the “Pisaster Disaster,” the cause is apparently still unknown, though a pathogen is suspected. There is lots of information and press released to be found on the web, but the central clearinghouse for information is this website run by the University of Santa Cruz.

While several species of sea stars are afflicted, other organisms are fine, such as this pretty, pink-tipped Aggregating Anemone (Anthopleura elegantissima).

The yellow plumes identify this sea slug (nudibranch) as the Monterey Sea Lemon (Archidoris montereyensis).

This is Purple Ribbon Worm (Paranemertes peregrina) is a vicious predator of other worms.

It was fun to discover this very concentrated aggregation of Pacific Mole Crabs (Emerita analoga). Apparently they colonize Oregon beaches as larvae from California, with no self-sustaining populations this far north. That may be changing.

I’m not sure whether this tiny crustacean, apparently scavenging on a remnant of a jellyfish, is an amphipod or isopod; it’s not like any of the species in Bugguide.

This Black Oystercatcher was one of a pair on the rocks near Starfish Cove, whistling excitedly at the other beachcombers and tidepoolers; I suspect they had a nest nearby.

On the way back, we picked along the wrack line, finding some nice clam fossils and living invertebrates. This click beetle is in the genus Athous.

I had no idea what family this odd looking, tiny (3 mm) beetle belonged to, but thanks to Vassily Belov on Bugguide, I found that it’s merely a carabid (ground beetle), Akephorus obesus. Given that it’s apparently restricted to beaches in the Pacific NW, I declare its English name the Obese Beach Beetle.

This much larger beetle is in the same family, but a different subfamily, and is the Greater Night-stalking Tiger Beetle (Omus dejeanii). It’s largely nocturnal and is unusual in being a flightless tiger beetle.

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