DUXBURY REEF

Jess, Jessie, Mike, and I went tidepooling today at Duxbury Reef, which is this large shale reef up in Bolinas, and a perfect example of rocky intertidal habitat: hence, many tide pools and amazing tide pool organisms. The tide was pretty low and in the afternoon today (see last week), the former due both to the full moon and the Earth’s proximity to the sun at this time of year, making for excellent conditions. The reef was extensive, with tons of pools. The zonation was not quite what I had expected, with only a very thin region of mussel and barnacle beds, but with sea stars spanning both sides of that line (usually they stick to the mussel beds and below, since they feed on the mussels). This was my first time with truly exemplary tide pools out here, so I was hoping to see a nudibranch. And we did! Jessie and mike found an opalescent nudibranch (Hermissenda crassicornis), about one inch long. Beautiful little thing, almost amazing as that picture at eNature. They found it on a piece of kelp. We also found a flat porcelain crab (Petrolisthes cinctipes), which has these excellent long antennae and strange, angular claws. We saw plenty of ochre sea stars (Pisaster ochraceus), little shrimp I’m not sure we identified, aggregating and great anemones, what I think were purple sea urchins (Strongylocentrotus purpuratus), and other cool things. We were freezing by the end of it, and more than a little wet, but we saw lots of cool things and I didn’t fall in like the last time I was down by the shore.