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Leavings on the beach

A week ago today, on Valentine's Day, I accompanied two students from the Natural History Club to Seacliff State Beach. Catie and Ryan, on behalf of the NHC, want to take charge of a now-empty glass display case at the visitor center and turn it into an exhibit of some sort. I became an official faculty sponsor of the NHC this semester. During the meeting as we were filling out the paperwork, I had to undergo an initiation rite: the club officers told me I had to present my 5 best bird calls. This is easy enough to do when I'm relaxed at home watching birds, but having to do it on the spot with no warning effectively drove everything I knew about birds right out of my head. Fortunately I was able to pull myself together and give them a California quail, a golden-crowned sparrow, a flicker, a chickadee, and an Anna's hummingbird. The easiest one, the acorn woodpecker ('waka-waka-waka') never even occurred to me.

A few months ago, Joseph, the head interpretive ranger at Seacliff, showed me the display case and asked if I knew of a group of students who would like to do something with it. I told him I'd ask the NHC if they'd be interested in taking on a project like this. It would be good outreach for the club and get their name and branding out into the greater community. Fortunately they jumped at the chance, and Catie and Ryan volunteered to come to Seacliff with me to meet Joseph and discuss his and their plans for the case.

Shortly after our arrival at the visitor center, a woman burst through the door and said, "We can't get out! A tree fell across the road!" And sure enough, a tree had indeed fallen across the road:

Fallen tree at Seacliff State Beach
2019-02-14
© Allison J. Gong

Catie, Ryan, and I figured it would be a while before the road was cleared and we could leave, so we might as well take a walk on the beach. It had been a very stormy week, with wind, heavy rain, and even snow in the area. Down at sea level we were fortunate to escape much of the really bad stuff, but the pounding rain and big swell had done some erosion damage to the shoreline and moved tons of sand down the coast, resulting in steep beaches. This is a normal phenomenon that happens during winter storms, but the extent of the sand removal was unusual even for winter.

For one thing, this structure was partially exposed:

Exposed structure on Seacliff State Beach
2019-02-14
© Allison J. Gong

We didn't know what this thing was. There were other parts of it poking out of the sand, too. When we got back to the visitor center Joseph told us that this object is part of the original seawall, dating to the 1920s. It was allowed to crumble into disrepair and be reclaimed by the beach, and only rarely ever sees the light of day.

We saw other interesting things on the beach, too. Dead birds are interesting, right? Of course they are!

Ryan examines the foot of a dead common murre (Uria aalge)
2019-02-14
© Allison J. Gong

The removal of so much sand from the beach bared a lot of rocks that had been buried underneath. Many of them were fossil rocks! Catie was pretty excited about them. And she certainly was right, because aren't these super cool?

Rock containing fossilized clams and snails, at Seacliff State Beach
2019-02-14
© Allison J. Gong

In addition to things long dead (fossils) and recently dead (murre), we found the results of recent spawning. The Pacific herring (Clupea pallasii) is a small schooling fish with a wide geographic distribution in the North Pacific. It had been an important fishery species but in the 1990s the fishery collapsed. Since then, with managed fishing, the species has been making a slow recovery.

Herring may spawn throughout the year, but the major spawning events occur at the beginning of the calendar year, when adults venture to shallow water in protected bays and estuaries. Females prefer to lay their eggs on eelgrass and other vegetation near the shore. According to The Lost Anchovy, the herring had been spawning in various locations in San Francisco Bay throughout January 2019.

Herring eggs
2019-02-14
© Allison J. Gong

We saw several clusters of what I think are herring eggs washed up on the beach at Seacliff. Some of the clusters were still wet, but without access to my dissecting scope I couldn't determine whether they were alive. Probably not. Herring eggs are heavily preyed on by birds, so in retrospect it was surprisingly to see so many that hadn't been eaten.

All in all it was a great afternoon for Catie, Ryan, and me. We hadn't planned on getting stuck behind a fallen tree, but if you're going to get stuck behind a fallen tree there are many worse places than a state park in California. None of us had to get back to campus at any particular time so we were free to meander as the fancy struck us. While we were at it we also did a mini beach clean-up, picking up as much trash as we could. That is always a depressing endeavor, but every piece picked up is one piece removed from the environment, and that can't be a bad thing. Some leavings were never meant to wind up on the beach.


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