Fish in the Bay – June 2024, Part 2. Gobies, Pipefish, & Bugs.

This is part 2 of the June report.  – These are additional observations that couldn’t be squeezed into the initial June report. 

Small brown fishes (Gobies, Sculpins, and Pipefish) provide many clues.  Invertebrates on the bethic bottom yield even more information. 

1. Gobies & Sculpins.

Gobies & sculpins are charming little fishes.  

Some of the same Gobies & Sculpins as shown above – a second view.

Staghorn Sculpin count = 22.  Once again, the Staghorn count is low.  The cumulative total for 2024 is 172.  We should have seen between a few hundred to thousands by this time of year.   –  Staghorn numbers decline during El Ninos. This is a verified fact!

Shokihaze Goby count = 5.  Shokihaze Gobies are nicknamed “bearded gobies” owing to fleshy papilla that line their faces. – The alternating light and dark brown bands along their bodies make them easy to identify. 

Monthly Shokihaze counts dropped off sharply after May 2021.  Two months later, Shimofuri Goby catches skyrocketed and have remained higher ever since.  – Shimos are outcompeting Shokihazes throughout the mid-salinity reaches of our trawling range.    

More Gobies at Alv2.

Yellowfin Goby count = 83.  Yellowfins are once again our number one goby.  Shimofuris took first place in the later months of 2021 and 2023, but Yellowfins keep flooding back in spring months. 

Shimofuri Goby count = 29.  Shimo numbers are still fairly low.  Puffy-cheeked males indicate that we are still early in the Shimofuri spawning season.  Shimo populations tend to explode in late summer. 

Chameleons like salty water.  It is unusual to find them upstream of LSB stations.  

• One Chameleon each was caught at stations Alv2 (salinity 5.8 ppt) and Art3 (salinity 9.8 ppt) in June.

Chameleon Goby count = 6.  Chameleons like fairly salty water.  Hence, it was surprising that we caught one Chameleon each at stations Alv2 (salinity 5.8 ppt) and Art3 (salinity 9.8 ppt).

• Salinity at even the saltiest LSB stations hovered just over 20 ppt on the June weekend. That is the lowest tolerance range for Chameleon Gobies. 
• We only ever see Chameleons at the extreme low-salinity edge of their preferred salinity range. Chameleons here appear to be consistently youngish: post larval to young-of-year. They overwhelmingly display “watermelon” longitudinal stripes.
• Identification Tip:  The Chameleon Goby anal fin has red and black bands and a white margin.  When the fin is unfolded, the red band is usually conspicuous on adults.  For juvenile Chameleons the contrasting black band against the white margin is sometimes more visible.  (Anal fins of Shimofuris are brownish with only an orange margin.)    

2. Bay Pipefish.

Bay Pipefish count = 8.  As of June, the year-to-date Pipefish count is 70.  This a very good year for Pipefish already.

• 2022 was our record year with 162.
• 2015 and 2016 were our second and third best Pipefish years with 89 and 85 respectively.
• We catch Pipefish thoughout the year, so we may still set a new second or third place record.    

Same two Pipefish as shown above.

3. Bugs on the Bottom.

Young Crangon at station Coy2, 1 June 2024.

Shrimp Report.  – Shrimp counts are low.  Is this an El Nino effect, or just random variability?  Lower than normal salinity should favor young Crangon and non-native Exopalaemon recruitment, but that does not seem to be happening.    

• Crangon count = 4905.
• Palaemon count = 671.
• Exopalaemon count = 7.

Musculista Mussel count = 85.  Musculista mussels have roughly the size and feel of kidney beans tightly wrapped in a muddy byssal thread cocoon. Byssal threads tie up adjacent shells and plant stems into a tight spongy mass that covers the benthic bottom.

• Non-native Musculista were rare here from 2010 to 2021. Then, their numbers exploded in August 2022 … then again in August 2023.
• We are waiting for the next late-summer Musculista explosion.

Corbula Clam count = 1,418.  Unfortunately, 2024 is already a good year for invasive Corbula.  Corbula counts were relatively low from 2021 through 2023 following drought & La Nina years.  Monthly numbers increased after October 2023.

• Ten years of data show some correlation between LSB Corbula increases and El Nino-related warm Pacific Sea Surface Temperatures (SSTs). However, the cause and effect relationship is indirect.
• Bottom Up.  Like many estuarine creatures, Corbula clams reproduce and recruit in response to robust rainwater flushing that distributes detrital food and disperses larval planktonic clams.  El Ninos and warmer SSTs near California result in more local rainfall on average.  More rainfall = More Corbula.   
• Top Down. Conversely, La Nina-associated colder SSTs and upwelling off the California coast encourage potential predators of Corbula, like Crangon shrimp, Dungeness crabs, and English Sole – See Cloern et al (2007):  “A cold phase of the East Pacific triggers new phytoplankton blooms in San Francisco Bay.”  https://www.pnas.org/doi/full/10.1073/pnas.0706151104 
• Good News??? The top-panel photo above shows many live Corbula clams (and many dead shells) entwined in the iron embrace of Musculista byssal threads. Non-native Musculista mussels exert additional natural control over this Corbula invasion.

Harris Mud Crab count = 7.  All crabs were at upstream stations. 

Harris Crabs were the second most numerous invertebrates (after shrimp) in similar trawls performed under South Bay Dischargers Authority (SBDA) from 1981 to 1986.  But, nowadays, we rarely see non-native Harris Mud Crabs.  – They remain well established and healthy, just not numerous like they were in the 1980s.

Crabs can be useful indicators of death and decomposition. They like to feast on decaying stuff.  

• Secondary treated sewage was discharged in this marsh until 1979.
• Massive levee building and land subsidence occurred from the 1930s to 1960s.
• Harris Mud Crab decline over recent decades may reflect a vast improvement in marsh health IMO.

Isopods.

Sowbugs – Synidotea laticauda (or perhaps Synidotea laevidorsalis)  These are “sowbugs” that inhabit salty water.  (They cannot fold into a pill, hence they are sowbugs.)  They are sometimes so numerous that they blanket the bottom at many stations in LSB.  https://invasions.si.edu/nemesis/species_summary/546963

Pillbugs – Sphaeromatid types (two species, at least) inhabit slightly fresher water.  They burrow into levee banks and pilings.  They are analogous to terrestrial “Pillbugs.”  They roll (fold) into a ball when threatened.  https://en.wikipedia.org/wiki/Sphaeromatidae 

• This folding behavior makes photography a challenge: If the pillbug is not comfortable, he or she immediately rolls up into a ball. The pillbug shown here was unusually calm and relaxed on Saturday.

Isopods:  A second view of the same bugs at Alv3.

Sowbugs & Pillbugs  https://entomology.ca.uky.edu/ef439 

4. Bonus Seaweed.

Ulva.  A tasty green algae.  We occasionally see this green lettuce-like algae draped across mudflats at low tide.  More often, we catch pieces in the net.  Abundant literature identifies Ulva as a very edible seaweed.  It does taste surprisingly good.

Gutweed (Ulva Intestinalis)  “Ulva intestinalis is a conspicuous bright grass-green seaweed, consisting of inflated irregularly constricted, tubular fronds that grow from a small discoid base. Like other members of the genus, Ulva intestinalis is a summer annual, decaying and forming masses of bleached white fronds towards the end of the season. … More or less world-wide in its distribution.”  https://www.marlin.ac.uk/species/detail/1469 

• “Gutweed is not so good to eat raw, but has great flavour once dried or deep fried, whereby it tastes like its close cousin in the Ulvagenus sea lettuce , or the crispy seaweed often used in Japanese cuisine. Sprinkle it on salads, sushi or finished dishes like seasoning.” https://gallowaywildfoods.com/gutweed-identification-edibility-distribution/#:~:text=Edible%20Uses%3A%20Gutweed%20is%20not,or%20finished%20dishes%20like%20seasoning.
• A crisp and delicate green algae that can be harvested in many places along the coastlines of Denmark, it is readily available throughout the spring and summer.   https://vildmad.dk/en/ingredients/gutweed#:~:text=Gutweed%20tastes%20like%20the%20shell,toothsome%2C%20without%20being%20too%20fibrous. 
  • Seaweed Vinegar recipe. https://vildmad.dk/en/recipes/tangeddike 
  • Sea Lettuce Salad récipe: https://vildmad.dk/en/recipes/sosalat-med-agurk-og-fennikel

Sea Lettuce (regular Ulva) “Commonly called Sea Lettuce or Green Laver, it can also be used as a substitute for nori (see Porphyra) a seaweed used in sushi. Ulva should be washed well then use or as an option soak it in water for two hours before using to moderate the flavor.

Besides soups and salads it can even be toasted over charcoal. When toasted it add yet another flavor to soups and salads. Ulva can be stored for two or three days in the refrigerator or frozen for six months without loss of flavor.”   https://www.eattheweeds.com/ulva-sea-soup-salad-2/

As always – HEED THIS WARNINING!  Eating local seaweeds and marsh plants can be hazardous to your health. Legacy contamination from Mercury, PCBs, and chlorinated pesticides, and even modern herbicide application are always present in LSB.  Tiny crustacean or protozoan parasites may also pose a risk.  Don’t take unnecessary chances. Don’t eat seaweeds from Lower South San Francisco Bay.