Pseudo-nitzschia - 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). In a break from the trend of previous C-HARM predictions which generally showed good habitat suitability for Pseudo-nitzschia spp. throughout the state, predictions in July suggest patchy suitable habitat for Pseudo-nitzschia spp. Northern California is a persistent hot spot throughout the first half of the month, followed by localized hot spots around San Francisco Bay/Half Moon Bay/Monterey Bay and the Pt. Conception area. As the month progresses, the entire coastline, particularly in central and north CA, is increasingly impacted by bloom predictions, although more confined to the nearshore zones of the Southern California Bight where bloom probabilities southeast of the Santa Barbara Channel region were generally low throughout the month. Given ongoing COVID-19 sampling restrictions and delays that continue to hamper our ability to acquire timely HABMAP observations from piers, most but not all piers are currently making data available. While Pseudo-nitzschia was observed at all the pier sites where data were reported in July, bloom levels were only recorded at Newport Beach Pier (P. 'delicatissima' size class) and Cal Poly Pier (both size classes). The Relative Abundance Index (RAI) for the Pseudo-nitzschia "seriata" size class recorded by the California Department of Public Health (CDPH) reached "Abundant" levels (>50%) at two sites in northern CA near the OR border, "Common" levels (10-49%) at Morro Bay and Diablo Cove (San Luis Obispo region, near Cal Poly Pier), and "Present" at various sites near the San Francisco Bay (e.g. Tomales Bay, Greater Farallones National Marine Sanctuary), Seacliff Pier in Monterey Bay, and sites within the Santa Barbara Channel, Santa Monica/Bolsa Chica in LA County, and at Scripps Pier in San Diego County. 

Moderate to very high C-HARM probabilities (50-100%) for particulate domoic acid (pDA) were predicted for large sections of the California coastline in July, with notable "hotspots" in offshore parts of central CA and parts of the coast north of the San Francisco Bay, central coast surrounding Monterey Bay, as well as in and around the Santa Barbara Channel and into the Southern CA Bight. Similar patterns were predicted for cellular domoic acid (cDA) risk as those for pDA, although with much lower probabilities in the Santa Barbara Channel and the Bight. Those cDA probabilities intensified to near 100% from Marin/Sonoma County to Monterey Bay by the end of the month and along most of the north Coast (Humboldt and Del Norte Counties). Mammal stranding data corroborate much of these patterns with a total of seven sea lions stranding from potential DA toxicosis along the central coast (San Luis Obispo to Marin Counties) and one additional stranding in Orange County in southern California. HABMAP pDA data are only so far available at Santa Cruz Wharf for July where no DA was detected. No new shellfish warnings or closures associated with DA occurred in July outside of the annual seasonal quarantine for harvesting recreational shellfish and ongoing razor clam advisories in parts of northern California (lifted in Aug 2021).

Alexandrium - CDPH noted that Alexandrium spp. were "Common" in Morro Bay in July and "Present" at many other sites throughout central CA. This is somewhat consistent with HABMAP sampling, which caught some striking spikes in Alexandrium abundance at Santa Cruz Wharf and Cal Poly Pier throughout July. No recreational shellfish advisories related to PSP were issued in July (however, note the PSP advisory for Marin Co. issued on Aug 27th). 

*Please note that HABMAP sampling, CDPH sampling, and marine mammal rescues have been greatly reduced in response to COVID-19 safety measures.

Santa Cruz Wharf

Four water samples were collected at Santa Cruz Wharf in July. Molecular probes for toxigenic Pseudo-nitzschia in the "seriata" class are conducted for this site, and was detected on July 7 below threshold. Alexandrium spp. were detected three times (July 7, 21, 28). Domoic acid was not detected.

The Santa Cruz Wharf shore station is supported by CeNCOOS PI Raphael Kudela at UCSC.

Cal Poly Pier

Four water samples were collected at Cal Poly Pier in July. Pseudo-nitzschia "delicatissima" was detected once (July 5), above the threshold. Pseudo-nitzschia "seriata" was detected twice (July 5, 12) with the first above the threshold value. Alexandrium spp. were detected twice (July 5, 19). Domoic acid results are not yet available. 

Cal Poly Pier shore station is supported by SCCOOS and PIs Ryan Walter and Ally Pasulka at Cal Poly. 

Stearns Wharf

Two water samples were collected at Stearns Wharf in July. Pseudo-nitzschia "delicatissima" and Pseudo-nitzschia "seriata" were detected July 5 and 12, both below the bloom threshold. Alexandrium spp. were not detected. Domoic acid results are not yet available.

Stearns Wharf is supported by SCCOOS and PIs Mark Brzezinski and Libe Washburn at UCSB. 

Santa Monica Pier

Four water samples were collected at Santa Monica Pier in July. Pseudo-nitzschia "delicatissima" and Pseudo-nitzschia "seriata" were detected three times (July 5, 12, 19), all below the threshold. Alexandrium spp. were detected once on July 26. Domoic acid results are not yet available. 

The Santa Monica Pier shore station is supported by SCCOOS and PI Rebecca Shipe at UCLA.

Scripps Pier

Scripps Pier water samples are not available for April 2020 through July 2021.

Scripps Pier is supported by SCCOOS and PIs Melissa Carter and Clarissa Anderson at UCSD.