Ten Mile State Marine Reserve

Intertidal and offshore pinnacle at Ten Mile State
Marine Reserve, Mendocino County, CA, Jan 2015.

Friday was a bright sunny winter day on the northern California coast. I went tidepooling at Ten Mile State Marine Reserve a few miles north of Fort Bragg in Mendocino County. I discovered this site years ago and named it site 71.70 from the mile marker for nearby state highway 1. In 2012, this area was incorporated into a state marine reserve. Access to the intertidal is down a hundred foot coastal bluff which is impossible in most places except for a steep thin trail that leads down loose soil and rocks. It isn’t the easiest trail, but it isn’t particularly harrowing either if one is careful.

There are abundant intertidal gardens and tide pools here among dark boulders of various sizes. Numerous pinnacles and rocks off shore provide some protection to the immediate coastline, which is a fairly narrow beach consisting of coarse sand, cobbles and bedrock. The swells were relatively calm. January is about the least optimal time to observe the glory of marine algae in the northeast Pacific, but there were perennial kelps, rockweeds and red seaweeds present on the rocks. Photos from my last visit during summer 2008 indicated that patches of the sea palm Postelsia palmaeformis were present on intertidal rocks at this site, but there was no sign of that species today. Perhaps new sporophytes (adult plants) of this species will appear this coming spring.

Left: Intertidal Postelsia population in summer 2008. Right: Jewel top snail, 2015.

One of the most striking plants I observed today was Codium setchellii, a dark green (almost black), seaweed of velvet texture that spreads over rocks in the lower to mid-intertidal zone. It is sister to another green seaweed, Codium fragile, that has the popular name of “dead-man’s fingers” because of its cylindrical dark green branches. Instead of morbid appendages hanging pendant on the rocks, however, C. setchellii grasps the substrate with crenulations that aren’t too dissimilar to a human brain. I think therefore, in honor of its relative, an appropriate common name for this plant is “dead man’s brains”.

Codium setchellii, aka "dead man's brains"!

This tidepooling trip was also the maiden voyage for a new “action” video camera I purchased. I’ll need to practice the underwater techniques in the future, but I’ve included a short video of some tidepool footage. 

Looking north at Ten Mile State Marine Reserve from the coastal bluffs, Jan 2015.