Santa Cruz Wharf
Wednesday, December 17, 2025

* Quick HAB Observations *
– Pseudo-nitzschia: Common
– Alexandrium: None
– Dinophysis: None
– Margalefidinium: Abundant
* Impressions *
Another sunny and cool morning at the wharf. Water temperature increased 1C and it was calm and clear (visibility >10ft). The net tow assemblage shifted to mostly dinoflagellates this week and Margalefidinium was the most abundant genus. Pseudo-nitzschia were seriata size. There were no P. multiseries this week and P. australis were counted at similar concentrations to Pmu last week.
Dinoflagellates:
A: Margalefidinium
R: Ceratium
R: Akashiwo
R: Protoperidinium
R: Lingulodinium
R: LRB
Diatoms:
C: Chaetoceros
C: Pseudo-nitzschia
P: Pleurosigma
R: Thalassiosira
R: Detonula
R: Skeletonema
R: Thalassionema
R: Lithodesmium
R: Coscinodiscus
R: Rhizosolenia
R: Proboscia
* Environmental Information *
Time: 8:30 am
Collector: M Conci
Water Conditions (SCW)
Water Temperature: 14.3 C
Water Conditions: Calm
Water Color/Code: Green, 10G 3/6 (#32)
Water Visibility: +10 ft
Tide: Falling, High – 7:47, 5.6 ft
Surf Report: WNW swell, 3-5 ft
NDBC buoy 46236
– Significant wave height: 2.0 m
– Swell height/direction: 1.6 m, W
– Wind wave height/direction: 1.2 m, W
Weather Conditions (KudelaHawk)
Sky: Sunny
Air Temperature: 55.8 F (13.2 C)
Wind: 2 mph, WNW
Solar radiation: 68 watts/m^2
Monterey Wharf II
Wednesday, December 17, 2025

* Quick HAB Observations *
– Pseudo-nitzschia: Present
– Alexandrium: Rare
– Dinophysis: Rare
– Margalefidinium: Present
* Impressions *
This morning, conditions were mostly cloudy. The water surface was calm, and visibility was over 5m. Phytoplankton density was low today, and diatoms and dinoflagellates were about equally present in the assemblage. Chaetoceros, Ceratium, and Gyrodinium were common (10 – 49%). Thalassiosira, Pseudo-nitzschia, Pleurosigma, Navicula, Proboscia, and Cochlodinium were present (1 – 9%). The HAB species that were observed in the water this morning included Pseudo-nitzschia, Alexandrium, Dinophysis, and Cochlodinium.
Dinoflagellates:
R: Prorocentrum spp.
R: Dinophysis spp.
C: Ceratium spp.
R: Gonyaulax spinifera
R: Protoperidinium spp.
R: Alexandrium spp.
C: Gyrodinium spp.
P: Cochlodinium spp.
R: Oxytoxum spp.
R: Amylax
Diatoms:
C: Chaetoceros spp.
P: Thalassiosira spp.
P: Pseudo-nitzschia spp.
R: Ditylum spp.
P: Pleurosigma spp.
R: Hemiaulus spp.
R: Lauderia spp.
P: Navicula spp.
R: Leptocylindrus spp.
P: Proboscia spp.
Others:
R: Dictyocha spp.
R: Acantharians
Zooplankton:
R: fecal pellets, nauplii, tintinnids, calanoids, fish larvae, eggs
* Environmental Information *
TIME: 0803 PT
COLLECTOR: Elise Tysdal
Water Temperature: 15°C
Water Conditions: calm
Water Color: 5GY 2/2
Visibility: 5+ m
Tide: Falling, 1.75 m, low at 1530 h
Sky: cloudy, 90% cloud
Air Temperature: 15.56°C
Wind: offline, 1.56m/S
Rare (R): <1% ~~~ Present (P): 1 – 9% ~~~ Common (C): 10 – 49% ~~~ Abundant (A): >= 50%