Today I made what is likely my last trip to Franklin Point for several months. Tonight’s blue moon brings us the last of the good low tide series until the end of October. For me, a “good” tide series is one in which the low lows occur during daylight hours and are below the zero mean low low water (MLLW) height. Now that we’re more than a month beyond the summer solstice we are losing daylight at an almost-noticeable rate; and for reasons I’ve never been able to understand, at this time of year the spring tides (when we have the highest highs and lowest lows) get dampened out so the magnitude of the tidal exchange is less.
My plan is to take full advantage of this last tide series. This morning I was up well before dawn to catch the low at 05:19. For the past day or so the swell has been coming from the southwest, which is unusual, with unpredictable waves and surges. Plus, the sand has been piling up on the beach for the last month, and only the tops of many of the rocks were visible. This is a typical pattern: Sand accumulates on beaches during the calm summer/autumn months, then gets washed away during the winter storms. If the predicted El Niño that everyone is talking about brings the storms that California desperately needs, we could end up with a dramatically different coastline next summer.
But in the meantime, I wanted to continue testing my new camera. Today was the first day I’ve had it in the field and I was particularly interested in seeing how well the ‘microscope’ setting, which is a super-macro setting, would do underwater. The verdict: Pretty dang well!
Case in point. This is a shot of a swarm(?) of the sand crab Emerita analoga, in a shallow pool. I saw many thousands of them when I was here two weeks ago, and this morning they were still there. Anyway, as expected the ‘microscope’ setting on the camera has a very narrow depth of field, but I still think this photo is cool. That long feathery object in the lower right hand corner is the second antenna of one of the crabs that’s not actually in the photo.
To give you a sense of scale, these crabs are about 1 cm long. And that second antenna is about as long as the rest of the body. The crabs swivel their second antennae around and catch food particles on those fine side branches.
The camera did a great job with this close-up shot of the nudibranch Dirona picta. I saw four of these slugs in one area.
What makes this nudibranch unusual is the warts on the cerata (the inflated dorsal projections). This species feeds on bryozoans. I didn’t see any egg cases, but where there are slugs there are always eggs (and vice versa, I suppose) so I must have overlooked them.
Today was the second trip in a row out to Franklin Point that I’ve seen brittle stars. This morning I saw three, two of which were pretty mangled. This is the most intact one, and it is beautiful:
Armtip-to-armtip, this little guy measured about 1.5 cm. Although brittle stars share a star shape with their kin the sea stars, they locomote in an entirely different way. Whereas sea stars walk on hundreds or thousands of suckered tube feet, brittle stars use their arms to push and pull themselves along. They move much more quickly than sea stars. See here:
And, my favorite photographic model of the intertidal, the sea anemone Anthopleura sola. Here’s the entire animal:
And here’s a close-up of the mouth. I took this shot from a distance of about 8 cm. I suppose I could have just cropped and zoomed in on the above photo, but where’s the fun in that when you can do this?
On the hike back over the dunes I stopped to listen and look around and was rewarded with this sighting of a doe in the grass. She may or may not have had fawns with her, but I didn’t see them. Of the several photos I took of her, this is my favorite because even though it’s a little washed out you can see the Pigeon Point lighthouse very faintly in the background.
So that’s it for now. The next time I visit Franklin Point the low tide will be in the afternoon and I will be fighting both darkness and wind. It will still be entirely worth it, though.
Tomorrow I’m going up the coast a bit more, to just north of Pigeon Point. It will probably be my last trip to this particular site, also. I hope to come back with some snails (for my upcoming class) and pictures (to share).