- 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 October intensified from September, indicating even more extensive, statewide potential for large blooms, sometimes extending very far offshore north of Pt. Conception.
- HABMAP pier sampling was again inconsistent with C-HARM given the low Pseudo-nitzschia spp. activity in the nearshore environment, in keeping with recent trends at the piers. Pseudo-nitzschia spp. were rarely detected and only crossed the bloom threshold at three sites for the less 'toxigenic' group P. 'delicatissima': Cal Poly Pier, Stearns Wharf (Santa Barbara), and Scripps Pier (San Diego).
- Pseudo-nitzschia activity from CDPH coastal sampling, however, detected the more toxigenic size class, Pseudo-nitzschia 'seriata,' as 'Abundant' at northern California sites in Del Norte and Humboldt Counties and "Common" at mostly northern California sites as well as Diablo Cove (San Luis Obispo).
- The CA Imaging FlowCytobot Network images from the piers in October did not detect a Pseudo-nitzschia bloom, consistent with the weekly HABMAP sampling. As reported last month, most sites captured a "red tide" of the bioluminescent dinoflagellate, Lingulodinium polyedra (Santa Barbara to San Diego). Interestingly, and illustrating the power of having real-time plankton community records from IFCBs, the rarely viewed encystement of L. poly cells was also captured over the month of October. This signaled the end of the bloom, although new growth in L. poly did re-appear later in the month as the bloom showed a resurgence. There is significant debate as to whether the observed "planozygotes" are actually cysts or if they are Fragilidinium cf. mexicanum, a heterotrophic dinoflagellate that is known to prey on Lingulodinium polyedra populations (Jeong et al., 1999, Harmful Algae).
- C-HARM probabilities for particulate domoic acid (pDA) at the beginning of October were similar to those at the end of September, with a large eddy of high probabilities off the coast of San Diego suggesting high DA in that region, while areas surrounding Monterey Bay were also very high in risk potential. The central coast in general was predicted to have high pDA risk until mid-October, with some of that focus shifting briefly to areas of the North Coast.
- The pattern for C-HARM predictions of cellular domoic acid (cDA) probability diverged from that of pDA, with high risk areas located in central and northern California rather than the Santa Barbara Channel or further south into the Bight. Cellular toxicity was more likely to be elevated along the Central Coast or the North Coast in a fairly narrow coastal band, with implications for the November Dungeness crab season opener in northern California.
- While results for DA from HABMAP sampling are still pending for September and October at many sites, the year-long trend of no DA at all nearshore stations appears to persist. As noted in the previous bulletin, the strong decoupling with offshore DA was quite apparent during the recent marine mammal mortality event. We now know that that event was driven by high offshore and subsurface DA levels and resulted in incredibly high (possibly record-breaking) DA levels in animal tissue collected from stranded animals.
- Consistent with the high DA risk predicted by C-HARM for the central coast, there were four stranding cases from DA toxicosis reported in the month of October by TMMC from Santa Cruz, Monterey, and San Luis Obispo Counties. This is in contrast to lack of Pseudo-nitzschia spp. activity at the piers in those regions.
- CDPH issued a sport-harvested razor clam health advisory for domoic acid in Del Norte County on November 3rd. 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 still in effect until October 31st.
- CDPH detected Alexandrium spp. at background "Present" relative abundance levels at sampling sites throughout central and northern California in October. Meanwhile, a Paralytic Shellfish Poisoning (PSP) advisory initially issued for San Mateo County in early September was extended to Humboldt, Monterey, and San Luis Obispo Counties in October, consistent with observed Alexandrium spp. from CDPH sampling and from HABMAP sampling at Santa Cruz Wharf. However, note that none of the other central CA sites detected Alexandrium spp. in October.
Summary written by Clarissa Anderson on 21 November 2022
Note that data for some stations are not shown because they are not yet recorded in the public HABMAP archive.
Differentiating Pseudo-nitzschia species by light microscopy is difficult. For this reason, Pseudo-nitzschia "seriata" does not refer to an actual species but rather the larger size class of Pseudo-nitzschia, which is generally a more toxigenic group of species. Alternatively, Pseudo-nitzschia "delicatissima" refers to the smaller size class that is generally non-toxigenic. The dashed line on the plots demarcates the 10,000 cells/L "bloom" threshold designated here for Pseudo-nitzschia populations only.
Three water samples were collected at Bodega Marine Lab in October. Pseudo-nitzschia "delicatissima" and Pseudo-nitzschia "seriata" were detected twice (October 3, 10), below the bloom threshold. Alexandrium spp. were detected twice (October 10, 17). Domoic acid results are pending.
The Bodega Marine Lab shore station is supported by CeNCOOS PI John Largier.
Four water samples were collected at Santa Cruz Wharf in October. Molecular probes for toxigenic Pseudo-nitzschia in the "seriata" class are conducted for this site, and was not detected. Alexandrium spp. were detected each time (October 5, 12, 19 ,26). Domoic acid results are pending analysis.
The Santa Cruz Wharf shore station is supported by CeNCOOS PI Raphael Kudela at UCSC
Four water samples were collected at Cal Poly Pier in October. Pseudo-nitzschia "delicatissima" was detected once on October 4, then again on November 1 above the threshold. Pseudo-nitzschia "seriata" was detected once on October 25. Alexandrium spp. were not detected and domoic acid results are pending.
Cal Poly Pier shore station is supported by SCCOOS and PI Ally Pasulka at Cal Poly.
Three water samples were collected at Stearns Wharf in October. Pseudo-nitzschia "delicatissima" was detected on each occasion (October 5, 11, 21), with the middle sample above the bloom threshold. Pseudo-nitzschia "seriata" and Alexandrium spp. were not detected. Domoic acid results are pending.
Stearns Wharf is supported by SCCOOS and PIs Mark Brzezinski and Libe Washburn at UCSB.
Three water samples were collected at Newport Beach Pier in October. Pseudo-nitzschia "delicatissima" and Pseudo-nitzschia "seriata" were not detected in the first sample (October 3), with the last two (October 11, 17) pending analysis. Alexandrium spp. and domoic acid were not detected.
Newport Beach Pier is supported by SCCOOS and PI David Caron at USC.
Five water samples were collected at Scripps Pier in October. Pseudo-nitzschia "delicatissima" was detected on each occasion (October 3, 10, 17, 24, 31), with the second sample above the bloom threshold. Pseudo-nitzschia "seriata" was detected once on October 24, below the threshold. Alexandrium spp. were detected three times (October 3, 10, 17). Domoic acid results are pending.
Scripps Pier is supported by SCCOOS and PIs Melissa Carter and Clarissa Anderson at UCSD.
View the interactive map and data table of California Department of Public Health (CDPH) data from January 2019 to present, developed by SCCOOS, below. Or, view CDPH Toxic Phytoplankton Observations Map with layers of Pseudo-nitzschia and Alexandrium spp. as well as other phytoplankton species observations (in the pop-up windows).
Data are provided by the Environmental Management Branch of the CDPH. Please note, starting in July 2019, CDPH moved to only reporting Pseudo-nitzschia of the seriata complex and not all Pseudo-nitzschia spp. as previously provided.
Please email CDPH at Susan.Paulukonis@cdph.ca.gov for any potential marine HAB-related illness in humans.
From October 1-31 2022, water samples were collected by volunteers and sent to the California Department of Public Health (CDPH) for analysis.
Pseudo-nitzchia "seriata" group was detected in 34 of the 88 samples:
Pseudo-nitzschia "seriata" was detected at "Abundant" density levels on 2 occasions:
- 2022-10-24 70% Hunter Rock, north
- 2022-10-31 70% Humboldt Bay, Indian Is. Ch.
Pseudo-nitzschia "seriata" was detected at "Common" density levels on 5 occasions:
- 2022-10-03 15% Port San Luis, Diablo Cove
- 2022-10-09 25% Trinidad Pier
- 2022-10-10 11% Humboldt Bay, Indian Is. Ch.
- 2022-10-24 10% Humboldt Bay, Indian Is. Ch.
- 2022-10-29 35% Trinidad Pier
Pseudo-nitzschia "seriata" was detected at "Present" density levels on 15 occasions:
- 2022-10-03 1% Tomales Bay, Lease #M430-15
- 2022-10-03 8% Humboldt Bay, Indian Is. Ch.
- 2022-10-12 3% Goleta Pier
- 2022-10-14 1% Point Dume
- 2022-10-15 3% Pacifica Pier
- 2022-10-17 1% Humboldt Bay, Indian Is. Ch.
- 2022-10-17 9% Morro Bay, Boat Launch
- 2022-10-18 2% Cayucos Pier
- 2022-10-19 1% Goleta Pier
- 2022-10-21 2% San Simeon Pier
- 2022-10-21 4% Port San Luis, Diablo Cove
- 2022-10-24 1% La Jolla, Scripps Pier
- 2022-10-28 5% Port San Luis, Diablo Cove
- 2022-10-28 8% Palos Verdes Rocky Pt Offshore
- 2022-10-31 1% Tomales Bay, Lease #M430-15
Pseudo-nitzschia "seriata" was detected at "Rare" density levels on 12 occasions:
- 2022-10-03 0.5% Morro Bay, Boat Launch
- 2022-10-04 0.5% Mendocino, Noyo Harbor
- 2022-10-05 0.5% Santa Cruz Is., Scorpion Anch.
- 2022-10-10 0.5% Tomales Bay, Lease #M430-15
- 2022-10-15 0.5% San Simeon Pier
- 2022-10-17 0.5% Tomales Bay, Lease #M430-15
- 2022-10-18 0.5% Pismo Pier
- 2022-10-24 0.5% Tomales Bay, Lease #M430-15
- 2022-10-24 0.5% Santa Barbara Ch., Naples Pt
- 2022-10-25 0.5% Santa Cruz Is., Prisoners Hrbr
- 2022-10-26 0.5% Goleta Pier
- 2022-10-31 0.5% San Diego Bay, U.S. Navy Pier
Alexandrium spp. were detected in 20 of the 88 samples:
Alexandrium spp. were not detected at "Common" density levels.
Alexandrium spp. were detected at "Present" density levels on 6 occasions:
- 2022-10-03 1% Port San Luis, Diablo Cove
- 2022-10-03 5% Morro Bay, Boat Launch
- 2022-10-10 5% Tomales Bay, Lease #M430-15
- 2022-10-17 3% Tomales Bay, Lease #M430-15
- 2022-10-19 1% Bodega Harbor, USCG Dock
- 2022-10-21 2% Port San Luis, Diablo Cove
Alexandrium spp. were detected at "Rare" density levels on 14 occasions:
- 2022-10-03 0.5% Bodega Harbor, USCG Dock
- 2022-10-03 0.5% Tomales Bay, Lease #M430-15
- 2022-10-10 0.3% La Jolla, Scripps Pier
- 2022-10-12 0.5% San Francisco, Presidio Pier
- 2022-10-12 0.5% Santa Cruz Wharf
- 2022-10-17 0.5% Humboldt Bay, Indian Is. Ch.
- 2022-10-18 0.5% Mendocino, Noyo Harbor
- 2022-10-18 0.5% Pismo Pier
- 2022-10-18 0.5% Cayucos Pier
- 2022-10-20 0.5% Imperial Beach Pier
- 2022-10-21 0.5% San Simeon Pier
- 2022-10-24 0.5% Drakes Bay, Chimney Rock LBS
- 2022-10-24 0.5% Tomales Bay, Lease #M430-15
- 2022-10-24 0.5% Humboldt Bay, Indian Is. Ch.
CDPH and OEHHA Health Advisories
November 3. The California Department of Public Health (CDPH) is advising consumers not to eat sport-harvested razor clams from Del Norte County.
October 31. The California Department of Public Health (CDPH) announced the statewide annual quarantine on mussels taken by sport harvesters from California’s ocean waters ends at midnight on Monday, October 31, 2022, for all coastal counties except Humboldt, San Mateo, Monterey, and San Luis Obispo.
October 27. Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from Humboldt and San Luis Obispo counties.
September 2. The California Department of Public Health (CDPH) is advising consumers not to eat sport-harvested mussels, clams, or whole scallops from San Mateo County.
For the latest closures and updates, please visit the CDPH Health Advisories page as a central location of information related to CDPH health advisories. Also available is a map showing the current CDPH Recreational Bivalve Shellfish Advisories (see below).
The HAB-related illness workgroup has developed a new webpage for marine HAB-related illness tracking work (https://oehha.ca.gov/fish/general-info/marine-harmful-algal-bloom-hab-related-illness-tracking).
A network of Imaging FlowCytobots (IFCBs) continuously photographs particles, such as plankton, in the water. Using machine learning, plankton species can be automatically identified. This will help improve the ability to detect and respond to Harmful Algal Blooms, including the ability to assess conditions that may lead to toxin production or blooms of toxin-producing algae.
Additional images and data are available on the IFCB dashboard.
A Lingulodinium polyedra bloom occurred at Newport Beach Pier and Scripps Pier in late September, followed by encystment (or possibly predation by Fragilidinium) in October. A) IFCB image of L. polyedra bloom at Newport Beach Pier on Sep 27. B) Photo from Newport Beach Pier on Oct 11 and C) IFCB image of cysts on Oct 11. D) Close up cyst.
Domoic acid (DA) is a potent neurotoxin produced by some diatom species of the genus Pseudo-nitzschia. Species exposed to DA can result in seizures, epilepsy, cardiomyopathy, and death depending upon the ingested dose. DA toxicosis commonly occurs in California Sea Lions (Zalophus californianus), presumably due to a combination of foraging behavior and seasonal movements. The Marine Mammal Center (TMMC), Channel Islands Marine Wildlife Institute (CIMWI), California Wildlife Center (CWC), Marine Mammal Care Center Los Angeles (MMCC-LA), Marine Animal Rescue (MAR), the Pacific Marine Mammal Center (PMMC), SeaWorld, and Southwest Fisheries Science Center (SWFSC) act like an emergency room by working to rescue and rehabilitate sick and injured marine mammals, seabirds, and sea turtles.
CWC, CIMWI, MMCCLA, SeaWorld, MAR, and PMMC did not record any strandings due to suspected domoic acid in October 2022. Results from SWFSC are pending.
October strandings due to suspected DA toxicosis occurred in the following counties:
- Santa Cruz (TMMC)
- October 11 - Adult, female, California Sea Lion
- October 22 - Subadult, male, California Sea Lion
- Monterey (TMMC)
- October 4 - Juvenile, male, California Sea Lion
- San Luis Obispo (TMMC)
- October 7 - Yearling, female, California Sea Lion