Fish in the Bay – November 2022 – Sturgeon Alert!

The disastrous San Francisco Bay Red Tide of August 2022 is now fading into memory.  The most crushing long-lasting effect may be on our Bay-Delta Sturgeon.  Between 400 to 600 adult White Sturgeon carcasses were counted on shores around San Francisco Bay and in the Lower Delta.  Many more likely died and quickly sank into bay and creek bottoms unseen.

  • The H. akashiwo red tide bloom killed many big reproductive Sturgeon. Extreme heat just after the bloom probably added to the death toll.  Meanwhile, ongoing drought continues to stunt growth and survival of young Sturgeon.
  • Unfortunately, the government process for assessing fish populations and recreational take limits takes many months to adjudicate. For all we know, the Bay-Delta Sturgeon population may have already lost too much of its aged brooding stock.
  • California Water Blog from November 6th:


Good News! (sort of)  We counted seven Sturgeon in Coyote Creek on sonar in early November!  Some young ones have returned to feed and grow big on Coyote Creek abundance.  But, it was only seven.  For all we know, Coyote Creek may be one of the few last corners of the Bay with enough food to support them!

Bad News!  The fates of both White and Green Sturgeon may now depend on good corporate citizenry.  Please don’t fish the big ones.  It may be best not to fish them at all for a couple of years.  Today’s teenagers (White Sturgeon between 15 to 20 years old) are still within the approved slot limit, but the red tide may have broken the slot limit.  The population was already stressed.  Sturgeon are in trouble! 


Fish and bug counts in Lower South Bay seem to be unaffected by the Red Tide bloom. 

Fish counts dropped considerably over the last few months, but this is normal.  November is usually the transition month when warm season fishes, like Anchovies and Gobies, leave and cool season fishes, like Longfin Smelt and English Sole, start to show up.   


Filter Feeders:  A big explosion of jumbo-sized Tunicates and a lesser surge of Musculista mussels continued.  In both cases, the November numbers were the highest we have seen in at least 3 years.   

The San Francisco Bay Red Tide of 2022 was our biggest biological disaster of the new century.  The event killed tens of thousands of small fishes in Lake Merritt and around Oakland and Alameda, but in Lower South SF Bay we found only one dead Sturgeon, and that fish did not appear to be a Red Tide casualty.

  • This southern-most corner of the Bay is generally warmer, hosts denser populations of phytoplankton, and has the highest nitrogen concentrations by far.
  • According to all the rules we understand, the H. akashiwo red tide should have hit here first and hardest. We must unravel this mystery!

I shared many thoughts about Red Tides and small fishes for a “Lakeside Chat” hosted by Katie Noonan and the Lake Merritt Rotary Nature Center on November 4th: 

  • My talk starts at about the 14-minute mark in the video.
  • At around the 25-minute mark, I mention that “some anonymous internet guy” first identified the H. akashiwo bloom on July 16th. I have since discovered that the guy is “Luis.”  Luis is a phyto expert.  He has observed small H. akashiwo blooms for years and has documented the flora and fauna at Seaplane Lagoon in Alameda.  He also maintains his own photography website:
  • I also learned that Katie Noonan and Damon Tighe, who work and volunteer with the Lake Merritt Rotary Nature Center, have their own microscopes and monitor the biological health of Lake Merritt in Oakland.
  • Damon’s presentation of his observations of the Red Tide bloom in and near Lake Merritt is posted here.   
  • These volunteer experts provided the first microscopes on the scene when H. akashiwo struck in July and August.


1. The Lower South Bay November fish catch continues to look normal/good.

Male Longfin at Alv2 on 5 Nov 2022.

Longfins have begun to arrive!  79 Longfins were caught in November.  The winter spawning population is returning.  (We caught two Longfins in October, but November brought the first surge.) 

  • This is the highest number of Longfins we have ever seen in a November! (2018 came close with 75.)  Many more Longfins should arrive in December and January!


More Longfin Smelt in restored Pond A19 on November 6th.


Anchovies!  The November Anchovy tally was 28.  That represents a sharp decline from summer, but the decline is typical when the temperature drops in November.

Recruitment Success! The 28 Anchovies included many very young fish.  Some were post-larval, no more than one or two months old.  The Anchovy summer 2022 spawning season was a success!  


American Shad, Coy4, 5 Nov 2022


Oddball Fishes. 

  • One very young Plainfin Midshipman was caught at Art3. This is an unusual place and time of year for Midshipmen.
  • Four Bay Pipefish were caught at upstream stations. The Pipefish caught at Art2, shown above, was a pregnant male full of eggs!


Leopard Sharks.  Only 3 leopards were caught in November.  These have grown from 6 to 8 inches at birth to their current size of around 15 inches.  Most of their siblings have already left for deeper parts of SF Bay.  Winter rains can make Lower South Bay too fresh for sharks, so they must leave soon.  The Leopards usually start returning here around March.

Caroline Newell is shown holding one of our sharks.  She joined us for our Sunday trawls.  Caroline is a UC Davis graduate and staff researcher at the UC Davis Center for Watershed Sciences. 


Shovelnose Guitarfish, LSB1, 5 Nov.

Shovelnose Guitarfish.  Two more babies were caught: one each at stations LSB1 and LSB2.  That brings the 2022 Guitarfish total to eight!  We had never seen more than one in any given year before. Most likely drought and high salinity is drawing them in, but hopefully, this could become the new normal.   


2. More Green Water.

Green water at Art1.  The phytos were happy.  The water was various shades of green at all stations.  It had rained just days before, and that most likely helped. 


A bunch of Mysids at Art3.

Mysids.  We always hope to see a good Mysid bloom as the weather cools.  They are very small shrimp-like crustaceans.  Some people call them Opossum Shrimp.  Like Brine Shrimp (Sea Monkeys), Mysids are excellent fish food.  They enhance finfish production in these marshes. 

The Mysid catch has been very weak the last two years. The lack of good rainwater flushing probably limited their blooms.  The November 2022 catch looked fairly good.   


3. November invertebrate catch was unusual.

Some jumbo-sized Tunicates at Alv3 on 5 Nov.

Tunicate Explosion Continues (aka sea squirt, aka Mogula manhattanesis).  The Tunicate count jumped from 193 in September to 1623 in October, and now to 2376 in November.  These are the biggest numbers we have seen since at least mid-2018.  And, we have never counted so many Tunicates at upstream stations in Coyote Creek and Alviso Slough. 

These filter-feeders are like Tribbles from the old Star Trek episode.  When they are well-fed they grow big and then multiply.  They clone themselves by budding. 

  • The Tunicate count usually increases after about September, but not as much and not as far upstream as we have seen this year.
  • Since September 2022, we are finding big, fat, juicy Tunicates well upstream in Alviso Slough and Coyote Creek. Relatively few were collected at deep LSB stations. 


Invertebrate collage.

Top panel: Musculista, aka Arcuatula senhousia, aka “Asian Date Mussel.”
The November Musculista count was 170. That is a very high number for us. We usually see zero to a few dozen at most.  This again suggests that there was a lot of food for filter-feeders in the system.

  • These filter-feeders also rapidly bloom into dense colonies across the mud bottom. They anchor themselves to the mud, each other, and to anything around them with a dense network of byssal threads.
  • Musculista mussels are invaders from northeast Asia:
  • Musculista mats can smother native clams and inhibit seagrass beds. On the other hand, they also provide habitat for amphipods and other invertebrates.  As non-natives, they are undesirable here, but here to stay whether we like them or not.

Bottom Panel: Invertebrate diversity at LSB1.  We caught a little bit of everything in November: Tunicates, Scale Worms, Comb Jellies, Orange-striped Anemones, Philine sea slugs, and more. Two highlights …

  • Philine snail, aka New Zealand Sea Slug, aka Tortellini Snail, aka Bubble Snail aka Philine auriformis. These nasty non-native ‘snot-balls’ have returned.  Their monthly numbers jumped from near zero to 90 in October then 126 in November.  They eat small bivalves, using gizzard plates to crush their shells.  The only good news here is that Philine probably help keep non-native Corbula clams in check.
  • Decorator Crab, aka Tuberculate Pear Crab, aka Pyromaia tuberculata, aka Aka Fire Crab. Only three were caught this time, but we rarely catch more than a few.  For years, I identified this small crab only as “Decorator Crab,” then this month Katie Noonan, and the folks at Lake Merritt, taught me its true species name.  Another mystery has been solved!
    • Decorator crabs/Pear Crabs are members of the spider crab family “majoidea.” They become reproductive after about three months.  They reproduce throughout the year, so if conditions are good, up to three generations are produced per year.


Nudibranch collage.

Top Panel: Screenshot from “Lakeside Chat” by Katie Noonan with Lake Merritt Rotary Nature Center Friends on 4 Nov 2022.  The Lake Merritt Rotary Nature Center members documented an unusual increase in various species of Nudibranchs caught this year.  

Bottom Panel: a Nudibranch in LSB.  Four more Enosima Aeloids (Sakuraeolis enosimensis) were counted on Saturday.  Lower South Bay also experienced the biggest Nudibranch year by far.   

  • Why did Nudibranch populations increase in both Lake Merritt and LSB?


4. An Intelligent Worm!

Nereid Polychaete (Alitta succinea). We often catch a few polychaete “Pile Worms”.  I have long surmised that Pile Worms are very intelligent.  Every time I put a Pile worm in a clear plastic box, it immediately senses its surroundings and develops an escape plan.  Fish, nudibranchs, and every other creature tested have never figured out how to escape from the box.  Only these polychaetes know how to escape.

  • This Polychaete was caught at Station Alv1 in Alviso Slough. As we motored to our next trawling station, I photographed it escaping the box THREE TIMES!  At the end of trials 1 and 2, I plucked it up and put it back in the box.  The worm did not like being plucked.  It squirmed in highly agitated defensive manner.  (This was negative reinforcement.)  Nonetheless, the worm was undeterred.
  • After the third escape attempt, I released the worm back to the slough. He/She earned it. 
  • This worm demonstrated cephalopod/octopus level of intelligence with no brain! It has only a ganglion of nerves!


5. Red Seals.

Red Seals at Calaveras Point – 5 Nov 2022

Red Seals (Pacific Harbor Seals) at Coy4.  Luca and I took telephotos and attempted to count seals as we trawled station Coy4.  Luca’s tally was 33.  Those were the ones that just happened to be resting at that moment.  Others were likely foraging.

  • These seals are most likely all females. As far as we know, alpha male harbor seals have jealously guarded their harems here during each winter breeding season at least since the mid-1800s. 
  • With luck, we will see at least a dozen or more pups by March or April.

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