Just in time for Easter -- lots of eggs!

  

We went out to the rocky shore early this morning to start some surveys.  Right away Eric noticed that the tidepools looked unusual.  All of them appeared cloudy or milky.  We were aware recent ocean conditions might trigger spawning in some marine invertebrates, and sure enough, this was a massive spawning event of California Mussels (Mytilus californianus), probably the largest we've encountered.

In the photo above, the orange coloration is eggs released by female mussels.  Here's another example, with clusters of eggs concentrated along the edge of a pool:

 

 

In other pools, the color was white or gray, clouded by vast quantities of sperm released by male mussels:

 

 

Nearly every tidepool we observed on Bodega Head appeared to have mussels spawning, so the extent of this synchronous mass spawning event was truly remarkable.  Even the largest pools were visibly cloudy:

 

 

 

The ocean temperature went up from 11°C (52°F) to 13°C (55°F) yesterday, and there was a phytoplankton bloom nearshore — both environmental cues that are thought to trigger spawning in some invertebrates.

Amazing!  Let us know (and send photos) if you notice local marine invertebrates spawning, too!

Nearshore bloom

If you've been near the ocean recently, you might have noticed that the water looks very brown.  To document this algal bloom, I took a few photos tonight (28 August 2018):

 

 

 

I haven't heard which species of phytoplankton are dominating this event, but if I learn more details I'll add some information to this post.  

If you're interested in learning about algal blooms in general, this document "A Primer On California Marine Harmful Algal Blooms" from the Kudela Lab at UC Santa Cruz is a good place to start.

 

Cloud shadows

23 March 2012

Wind from the east/southeast, 10-15 mph (cold front approaching)

5 ft. swell (calm before the storm)

 

Note the brownish band close to shore — an accumulation of phytoplankton that's been visible since Monday, 19 March 2012.