WordCraft.NatureFocus

Bay-to-Beach Life Blog

Dungeness crabs

During the summer of 2013 I got to know Dungeness crabs very well. (Also see my 2013 post.) For three months, small crabs (about an inch or two across) and crab molts (old shells discarded so the crab can grow) littered the beach I walk regularly. Some days there were a few and some days they were everywhere.

 

 

I started tossing them back into the water, but given the numbers, gave up. I found that when I rolled them off their backs and dug a little trench behind them, they would back into a hiding spot in the sand.


This was fun for me and probably better for them than being hurled into surf (I hoped).

I haven’t seen young Dungeness crabs along this stretch of beach since that summer. Populations of crab larvae naturally fluctuate with sea surface temperature, correlated to the Pacific Decadal Oscillation. Dungeness crabs prefer cooler waters and the lack of beached crabs recently could be related to a warm-water El Niño and the blob off our coast. Another explanation for the excess crabs on this particular beach that year could have been beach nourishment. [During the winter of 2012 – 2013, approximately 7,500 m³ of Monterey Harbor dredge material was used to nourish this critical south Monterey Bay erosion area, according to a Currents 2013 poster by A. Snyder et al.] Who knows for sure?

Why talk about 2013 now? Dungeness crab seasons open this month, and it takes the crabs about 3 years to grow enough to be part of the fishery. The crabs I saw in 2013 are now being harvested.

Last week (November 5), the recreational Dungeness crab season opened along the California coast. It was accompanied by a health warning to fishers catching crabs north of Point Reyes (Marin County) to not eat the viscera (guts) due to elevated levels of domoic acid (a natural toxin produced by single-celled algae). Domoic acid is a powerful neurotoxin and poisoning effects range from nausea to death in birds and mammals, including humans and possibly dogs eating sand crabs at the beach.

This week (November 15), the commercial season will open from Point Reyes (Marin County) south. However, according to California Department of Fish & Wildlife (CDFW), the CDFW Director is moving on state health agencies’ advice to close the commercial fishery between Point Reyes and the Sonoma/Mendocino county line (see CDFW website for related rock crab info). This is also due to domoic acid. (Most of last season was closed for the same reason.)

Update (as of Nov. 24) on open and closed areas from CDFW: https://wordpress.com/read/feeds/357812/posts/1234769465 

 

 

The good news is that the Dungeness crab fishery is considered sustainable according to CDFW’s 2011 status report. So as coastal waters cool this year during a La Niña, I hope little “dungies” will return this summer to my beach.

 

Warblers on the move

During my Half Moon Bay birding walk last week, we saw several warblers on the move (always): some fall visitors, some spring visitors, and a few elusive residents. My thanks to local guides Slow Adventure and Alvaro’s Adventures for a great week.

Townsend’s Warblers winter along our coast and then fly north for summer breeding.
townsendswarbler

Yellow Warblers are here during the summer and then migrate to the south for winter.
yellowwarbler

Orange-crowned Warblers are here year-round. They move south during the winter and then north and inland for the summer.orange-crowned-warbler

 

 

 

 

 

 

Common Yellowthroats are supposedly here year-round, but during the spring walk I saw my first one (below). We mostly heard them during the fall walk and I didn’t get a photo.
commonyellowthroat

Wilson’s Warblers migrate through between northern breeding and southern wintering. (This photo is from the spring walk, but we saw them briefly on this fall’s walk.)

wilsonswarbler

 

Half Moon Bay surprise

One of the surprises on my birding walk around Half Moon Bay was this little cutie.


This long-tailed weasel popped out of a hole (squirrel? or gopher?) in the Coastside Trail along a shoreline cliff. We were looking across the ocean for seabirds and whales, and our birding guide, Alvaro Jaramillo, spotted the weasel at our feet. Adorable (except if you’re prey).

Half Moon Bay Coastside 4: How many?

Which of these birds doesn’t belong?
This photo was taken during day 3 of walking the Half Moon Bay Coastside Trail in Pillar Point Harbor (not far from the breakwater in an earlier post). It’s a good example of what you can find if you look closely.

shorebirds

And, here’s the list of birds along the breakwater in the photo I posted with Coastside 2, starting with the easiest to identify (see photo below). The dark bird at the top of the breakwater about 2/3rds of the way across is a Heermann’s Gull (there are more scattered throughout the rocks). At the base of the breakwater, about 1/3rd of the way across, the two large brown birds are Brown Pelicans. All the way across the top and scattered throughout, the black-capped birds with orange bill are Elegant Terns. At the top between the terns on the left and the Heermann’s Gull, if you look closely, there’s a sleeping Western Gull (white head with bill tucked under gray back).

Now it starts getting tricky, in part because the photo isn’t as clear as I’d like (more practice needed). But here goes. Follow along the water line at the base of the breakwater (starting with the pelicans and move left). To the left of an Elegant Tern almost to the end of the photo, is a round bird with a black back and white belly. I think that’s a Black Turnstone (but don’t quote me on that one).

Back to the pelicans, if you look straight up from them, you’ll see an all-white bird (head hidden) and another farther up to the left (preening so you can see its head with a black bill and a little yellow near the eye). Those are Snowy Egrets.

img_3681

Now let’s tackle the birds on the right side of the image. Start at the Heermann’s Gull on the top and move down past the Elegant Terns. Below those about half way down are two birds with a long bill. The upper one is preening and the lower one is turned so you can see a white strip over its eye — those are Whimbrels. Just to the right of the preening Whimbrel, it looks like there’s a Black-bellied Plover (just the front half showing a short black bill, dark eye, and dark leg, non-breeding plumage). To the right of the plover are several Willets preening and sleeping (grayish-brown head and back, white belly, no distinguishing marks).

I think that’s it — nine species!
If anyone spots anything else, let me know. And, if I misidentified anything (which happens), let me know, too.

Answer: The answer to the riddle in the top photo — look at the fourth bird counting from the left along the water’s edge. It’s a Marbled Godwit hiding among the Willets.

 

Half Moon Bay Coastside 3

Yesterday was another long day (7+ miles) and so I’m a bit behind on sorting through my photos. We had sunny skies and very little wind in Pillar Harbor (Princeton-by-the-Sea), and so the shorebird sightings were varied. These first three were on the same rock paying no mind to one another.

black-oystercatchers

Black Oystercatchers

dunlin

Willet

spotted-sandpiper

Spotted Sandpiper

Across from the bayside rock was a breakwater (with a view of Maverick’s when it’s breaking – but not today). The breakwater was dotted with Black Turnstones (named for their habit of overturning stones for food). I counted about a dozen (but I could have double counted). This one was dodging a small wave.

black-turnstone

Black Turnstone

Another good day… and more on the way.