JANUARY HIGHLIGHTS

*note: for the full suite of HAB taxa sampled weekly, see the SCCOOS and CeNCOOS HABMAP database and the Imaging FlowCytobot Dashboard.

Pseudo-nitzschia -

* Important update to C-HARM in this bulletin. C-HARM version 3 is now operational at NOAA CoastWatch. Major changes include: new operational circulation model (WCOFS) for currents, salinity, and temperature and VIIRS ocean color products in place of MODIS Aqua. WCOFS is a 4DVAR data assimilative model run at NOAA Coast Survey Development Lab (CSDL). NOTE: There are serious issues with WCOFS salinity accuracy that have notable consequences for the Particulate Domoic Acid predictions; we will address the impact this has on pDA accuracy in these bulletins.   

• • C-HARM tells us where conditions are suitable for species of the diatom Pseudo-nitzschia spp. (all size classes) to grow well and where they might be more likely to produce the deadly neurotoxin, domoic acid (DA). Three independent models are run daily to produce nowcasts and three-day forecasts of the probability of a bloom, the probability of a DA event for particulate DA only, and the probability of a DA event for the cellular portion of DA only. Here, in the bulletin, we summarize nowcasts for the month.
  • C-HARM predictions for Pseudo-nitzschia spp. blooms in January contain some pixelation from VIIRS. Bloom potential is very high throughout the month, covering the entire coastline, sometimes extending very far offshore. This suggests a high rate of false positives given that we know blooms were not so pervasive in January, but this also corroborates something we've seen for a while in the California Current, which is that conditions are fairly regularly conducive to supporting Pseudo-nitzschia populations in most coastal zones.  
  • HABMAP weekly pier sampling indicated moderate to low Pseudo-nitzschia spp. activity in the nearshore environment, in keeping with recent trends at the piers. However, bloom levels were reached at two locations in January: Stearns Wharf at the end of January and Scripps Pier, also in late January, the latter being the more toxigenic size class, P. "seriata."
  • Pseudo-nitzschia activity from CDPH coastal sampling in January detected the more toxigenic size class, Pseudo-nitzschia 'seriata,' as 'Common' at Scripps Pier in early January but "Rare" at most other sites sampled.
  • A selection of CA Imaging FlowCytobot (IFCB) Network images from the Bodega Marine Laboratory in northern California and from an offshore buoy at Del Mar (San Diego) in January illustrates some interesting latitudinal gradients from north to south. Large centric diatoms, the large dinoflagellate genus, Prorocentrum, and small particles dominate the Bodega samples, while Tripos (formerly Ceratium) and Lingulodinium polyedra are most abundant at the Del Mar site in southern California.  
  • C-HARM probabilities for particulate domoic acid (pDA) and cellular domoic acid (cDA) in January suggest highest potential for toxic events in central California as well as a large part of the Southern California Bight. The intensity is much higher for pDA, which we think is biased by the overestimated salinity fields produced by WCOFS. If we look more exclusively at cDA, which does not rely on the salinity prediction, we see similar overall patterns to pDA, albeit with lower probabilities throughout the Bight for much of the month and lower probabilities along the coastline in central CA. Another stark difference between the cDA and pDA is the high pDA risk hugging the coastline in northern California for much of the month. 
  • Only one animal was reported stranded from potential DA toxicosis in January (La Jolla, by SeaWorld). This stranding directly aligns with the CDPH observation of "Common" levels of the more toxigenic Pseudo-nitzschia 'seriata' size class on January 3 in La Jolla. It more generally aligns with the predicted cDA and pDA risk for the region but is less consistent with the Scripps Pier HABMAP results, which captured bloom levels of Pseudo-nitzschia 'seriata' at the end of January. Interestingly, DA was not detected at any of the HABMAP sites in January, including at Scripps Pier in La Jolla. This is an expected result for the time of year, however, this is not consistent with the stranding record in La Jolla.
  • CDPH lifted an advisory on January 9 for mussels, scallops, and most types of clams in Humboldt County due to PSP and ASP. However, the advisory related to sport-harvested razor clams from Humboldt and Del Norte counties remains in effect due to ASP risk. Given the low depuration (detox) rates of razor clams, DA levels in razor clams are usually more a reflection of long-term exposure to DA rather than real-time or recent bloom conditions. However, since this same advisory was lifted in June and then reinstated in November of this year, there has likely been persistent, if low-level, production of DA in the North Coast region. Note that the annual quarantine on consuming recreational mussels was lifted at the end of October, except for Humboldt, San Mateo, Monterey, and San Luis Obispo.
    

    Alexandrium -

    • CDPH detected 'Rare' levels of Alexandrium spp. in January at Goleta Pier, consistent with the HABMAP record of Alexandrium at Stearns Wharf. In line with that, the Paralytic Shellfish Poisoning (PSP) advisory was lifted on January 9 for mussels, scallops, and most types of clams in Humboldt County. 

    Summary written by Clarissa Anderson on 4 April 2023

Pseudo-nitzschia "seriata" was detected at "Common" density levels once:

• 2023-01-03 10% La Jolla, Scripps Pier

Pseudo-nitzschia "seriata" was not detected at "Present" density levels.

Pseudo-nitzschia "seriata" was detected at "Rare" density levels on 11 occasions:

• 2023-01-03 0.5% Tomales Bay, Lease #M430-15
• 2023-01-04 0.5% Goleta Pier
• 2023-01-08 0.5% San Francisco, Presidio Pier
• 2023-01-09 0.5% Tomales Bay, Lease #M430-15
• 2023-01-13 0.5% Bolsa Chica
• 2023-01-12 0.5% San Clemente Pier
• 2023-01-23 0.5% Humboldt Bay, Indian Is. Ch.
• 2023-01-30 0.5% Drakes Bay, Chimney Rock LBS
• 2023-01-31 0.5% San Clemente Pier
• 2023-01-29 0.5% Pacific Beach Pier
• 2023-01-28 0.5% Monterey Bay, Commercial Wharf

Alexandrium spp. were detected in 1 of the 67 samples: 

Alexandrium spp. were not detected at "Common" density levels. 

Alexandrium spp. were not detected at "Present" density levels.

Alexandrium spp. were detected at "Rare" density levels once: 

• 2023-01-04 0.5% Goleta Pier