CALIFORNIA DEPT.OF PUBLIC HEALTH ENVIRONMENTAL MANAGEMENT BRANCH

Marine Biotoxin Monitoring Report June 2017 Technical Report No. 17-19

INTRODUCTION: The aptly named Mussel Shoals sampling location, with Rincon Island in the

This report provides a summary of biotoxin activity

for the month of June, 2017. Toxin concentration

ranges are provided for the paralytic shellfish poi-

soning (PSP) toxins and for domoic acid (DA). Esti-

mates are also provided for the distribution and

relative abundance of Alexandrium, the dinoflagel-

late that produces PSP toxins, and Pseudo-

nitzschia, the diatom that produces domoic acid.

Summary information is also provided for any

quarantine or health advisory in effect during the

reporting period.

Please note the following conventions for the phy-

toplankton and shellfish biotoxin distribution

maps: (I) All estimates for phytoplankton relative

abundance are qualitative, based on sampling

effort and percent composition; (ii) All toxin data

are for mussel samples, unless otherwise noted;

A chain of the PSP toxin-producing dinoflagellate Alexandrium.

(iii) All samples are assayed for PSP toxins; DA anal-

yses are performed as needed (e.g., on the basis of

detected blooms of the diatoms that produce DA);

(iv) Please refer to the appropriate figure key for

an explanation of the symbols used on the maps.

background (Photo courtesy of the Ventura County Environmental Health

Department).

Northern California Summary:

Paralytic Shellfish Poisoning

Alexandrium was observed at numerous locations

between Del Norte and Monterey counties (Figure

1). The relative abundance of this dinoflagellate was

highest in a sample collected offshore of Pt. Pinos in

Monterey County and, to a lesser extent, in samples

from outer Tomales Bay and near the Golden Gate in

San Francisco Bay. Cell numbers were low at all oth-

er sites.

PSP toxicity was detected in shellfish from sites in

Del Norte, Humboldt, Marin, and Monterey counties

(Figure 2). The highest concentration of toxin detect-

ed was in sentinel mussels from Drakes Bay (Marin

County), which contained 322 ug/100 g (June 26).

Low levels of this toxin were detected in sentinel

mussels near the mouth of Humboldt Bay during the

second and third weeks of the month. Low concen-

trations of the PSP toxins continued to be detected

throughout the month in samples of rock scallop vis-

cera from the Monterey Commercial Wharf.

(Continued on page 2)

(Continued from page 1)

Page 2 June 2017 Technical Report No. 17-19

Domoic Acid

Pseudo-nitzschia was observed at sites in each

northern California coastal County in June (Figure

1). The relative abundance of this diatom increased

at sites in Del Norte, Humboldt, Santa Cruz, and

Monterey counties compared to observations in

May. The highest relative abundance of this diatom

was observed in a sample collected offshore of Pt.

Pinos (Monterey County), the same sample with

significant numbers of Alexandrium as noted

above. Elevated relative abundances of Pseudo-

nitzschia were also observed in samples from Wil-

son Creek (Del Norte County) on June 26 and at In-

dian Island inside Humboldt Bay on June 27.

High concentrations of domoic acid were detected

in mussel samples from Hunter’s Rock in northern

Del Norte County (25 ppm on June 30) and from

the Commercial Wharf in Monterey

County (55 ppm on June 6). Low con-

centrations of this toxin were also de-

tected in mussels from Wilson Creek,

outer Humboldt Bay, and the Santa

Cruz Pier.

Very high concentrations of domoic

acid continued to be detected in razor

clams from Humboldt County in June

(Figure 2). Toxin concentrations ex-

ceeded the alert level in 10 of 11 clam

samples from Clam Beach, with the

highest concentration being 120 ppm. (Continued on page 4)

Figure 1. Toxic phytoplankton distribution in northern California.

Page 3 June 2017 Technical Report No. 17-19

Figure 2. Distribution of shellfish biotoxins in northern California.

Page 4 June 2017 Technical Report No. 17-19

(Continued from page 2) Figure 3. Toxic phytoplankton distribution in southern California.

Six of 11 clam samples

from Little River State

Beach exceeded the alert

level for domoic acid, with

the highest concentration

being 85 ppm.

The CDPH Food and Drug

Branch collected samples

of rock crab fished from

offshore of Shelter Cove in

southern Humboldt Coun-

ty. The crab viscera con-

tained varying concentra-

tions of domoic acid, rang-

ing from nondetectable to 73 ppm.

Non-Toxic Species

Diatoms continued to dominate the northern

California phytoplankton assemblage, with Chaetoceros and Skeletonema ubiquitous along most of

the coast.

Southern California Summary:

Paralytic Shellfish Poisoning:

Alexandrium was observed at several sites between San

(Continued on page 5)

The Marine Biotoxin Monitoring and Control Program, managed by the California Department of Public

Health, is a state-wide effort involving a consortium of volunteer participants. The shellfish sampling and

analysis element of this program is intended to provide an early warning of shellfish toxicity by routinely as-

sessing coastal resources for the presence of paralytic shellfish poisoning (PSP) toxins and domoic acid.

The Phytoplankton Monitoring Program is a state-wide effort designed to detect toxin producing species of

phytoplankton in ocean water before they impact the public. The phytoplankton monitoring and observation

effort can provide an advanced warning of a potential toxic bloom, allowing us to focus sampling efforts in

the affected area before California's valuable shellfish resources or the public’s health is threatened.

For Information on Volunteering: For Recorded Biotoxin Information Call:

Email redtide@cdph.ca.gov or call 510-412-4635 (800) 553 - 4133

Luis Obispo and Santa Barbara counties (Figure 3). Multiple sampling locations along the San Luis Obispo

coast contained low numbers of Alexandrium and one site offshore of the Santa Barbara coast also contained

Page 5 June 2017 Technical Report No. 17-19

Figure 4. Distribution of shellfish biotoxins in southern California.

(Continued from page 4) pared to observations in May, but

remained abundant offshore of

Tajiguas Beach in Santa Barbara

and near Santa Rosa and Santa low numbers of this dinoflagellate.

PSP toxins were not detected in

any shellfish samples

collected in June.

Domoic Acid

Pseudo-nitzschia contin-

ued to be observed at

almost all sampling sites

between San Luis

Obispo and San Diego

counties (Figure 3). This

diatom decreased in rel-

ative abundance at

Cruz islands. The highest cell

masses were observed in a

June 28 sample collected off-

shore of Palos Verdes (Los An-

geles County).

Domoic acid was detected in

only one sample in June

(Figure 4). A low concentra-

tion of this toxin was detected

in mussels from an aquacul-

ture lease offshore of Santa

Barbara during the first week

of the month, declining below

the detection limit in subse-

quent weeks. This site had ex-

perienced alert levels of do-

moic acid throughout May.

Non-Toxic Species

A mix of diatoms and dinoflag-

ellates were observed along

the southern California coast

in June. The diatom Chaetocer-

os was observed at sites in all

coastal counties except San

Diego. Thalassiosira was com-

mon to abundant along the San

Luis Obispo coast. The dinoflagel-

late Ceratium furca became domi-

nant the latter part of the month

at sites in Santa Barbara and

Ventura counties. In addi-

tion to C. furca, the dino-

flagellate Lingulodinium pol-

yedrum was common to

abundant at sites between

Los Angeles and San Diego

counties. Of note is the ob-

servation of the harmful red

tide dinoflagellate Cochlod-

An example of the ‘stair-step’ overlapping pattern of Pseudo-nitzschia cells. (Continued on page 6) most locations, com-

Page 6 June 2017 Technical Report No. 17-19

(Continued from page 5) Table 1. Program participants collecting phytoplankton samples.

inium, which was common in a sam-

ple from Imperial Beach in southern

San Diego County.

QUARANTINES: The annual mussel quarantine began

as scheduled on May 1 and will con-

tinue through at least October 31.

Due to the persistent presence of

dangerous levels of domoic acid in

razor clams from beaches in Hum-

boldt and Del Norte counties, the Cal-

ifornia Department of Fish and Wild-

life’s (CDFW) closure of the razor

clam fishery remains in effect.

On June 2 CDPH issued a press re-

lease rescinding the health advisory

for rock scallops and clams, with the

exception of razor clams, in Del Norte

County and all clams and rock scal-

lops in Marin County.

On June 6 CDPH announced a Health

Advisory warning consumers not to

eat recreationally harvested bivalve

shellfish, including mussels, clams,

and rock scallops, from Los Angeles

County.

A Health Advisory issued on May 5

warned consumers not to eat recrea-

tionally harvested bivalve shellfish,

including mussels, clams, and rock

scallops, from Santa Barbara County.

The health advisory included rock

crab caught in state waters around

Santa Rosa Island and the northern

Channel Islands.

An April 28 Health Advisory warned

consumers to avoid eating recrea-

tionally harvested bivalve shellfish

AGENCY # AGENCY #

DEL NORTE COUNTY

Yurok Tribe Environmental Program 3 CDPH Voilunteer (Jim Hooper) 2

HUMBOLDT COUNTY

Coast Seafood Company 4 Humboldt State University Marine Lab 2

Bureau of Land Management 1 CHPH Volunteer (Olivia Giovannetti) 3

MENDOCINO COUNTY CDPH Volunteer (Marie DeSantis) 3

SONOMA COUNTY

CDPH Marine Biotoxin Program 1 Sonoma Coast Watch 1

MARIN COUNTY CDPH Volunteers 5

CDPH Marine Biotoxin Program 4 (Brent Anderson,George Clyde)

Hog Island Oyster Company 4

SAN FRANCISCO COUNTY

Exploratorium 4 CDPH Volunteer (Eugenia McNaughton) 2

SAN MATEO COUNTY

Friends of the Sea Otter 2 The Marine Mammal Center 4

San Mateo County Environmental Health Dept. 3 U.C. Santa Cruz 1

SANTA CRUZ COUNTY

CDPH Volunteer (Jeff Palsgaard) 4 U.C. Santa Cruz 5

MONTEREY COUNTY

Monterey Abalone Company 2 The Otter Project 4

Nomad Charters 1 Marine Pollution Studies Laboratory 1

SAN LUIS OBISPO COUNTY

CDPH Volunteer (Dan Hoskins) 1 Friends of the Sea Otter 3

Grassy Bay Oyster Company 3 Monterey Bay National Estuary Program 2

Monterey Bay National Marine Sanctuary 4 Tenera Environmental 2

SANTA BARBARA COUNTY NPS 1

Santa Barbara Channel Keeper 3 U.C. Santa Barbara 4

VENTURA COUNTY

CDPH Volunteer (Fred Burgess) 4 Channel Island High School 1

National Park Service 2 Ventura County Environmental Health Dept. 1

LOS ANGELES COUNTY City of L.A. Environmental Monitoring Division 1

CDPH Volunteer (Shounak Roy, Likai Wei) 2 Los Angeles County Health Department 2

Los Angeles County Sanitation District 4 Los Angeles Water Keeper 2

ORANGE COUNTY Amigos de Bolsa Chica 5

Back Bay Science Center 3 CDPH Volunteer (Truong Nguyen) 2

SAN DIEGO COUNTY Carlsbad Aquafarms, Inc. 3

Sea Camp/HABNet 2 Scripps Institute of Oceanography 4

Tijuana River National Estuary Research 5 U.S. Navy Marine Mammal Program 3

from Ventura County due to dangerous levels of domoic acid.

A Health Advisory was issued on April 13 warning consumers not to

eat recreationally harvested bivalve shellfish from Santa Barbara

(Continued on page 7)

Page 7 June 2017 Technical Report No. 17-19

(Continued from page 6) Table 2. Program participants collecting shellfish samples.

County, including the northern Channel Is-

lands. Dangerous levels of domoic acid were

detected in this region.

Consumers of Washington clams, also known

as butter clams (Saxidomus nuttalli), are cau-

tioned to eat only the white meat. Washington

clams can concentrate the PSP toxins in the

viscera and in the dark parts of the siphon and

can remain toxic for a long period of time. Per-

sons taking scallops or clams, with the excep-

tion of razor clams, are advised to remove and

discard the dark parts (i.e., the digestive or-

gans or viscera). Razor clams (Siliqua patula)

are an exception to this general guidance due

to their ability to concentrate and retain do-

moic acid in the edible white meat as well as in

the viscera.

PSP toxins can produce a tingling around the

mouth and fingertips within a few minutes to a

few hours after eating toxic shellfish. These

symptoms can be followed by disturbed bal-

ance, lack of muscular coordination, slurred

speech and difficulty swallowing. In severe poi-

COUNTY AGENCY #

Del Norte Tolowa Dee-ni’ Nation 1

Yurok Tribe Environmental Group 1

Humboldt Coast Seafood Company 9

California Department of Fish and Wildlife 22

CDPH Volunteer (Steve Fox) 1

Humboldt County Environmental Health Department 1

Mendocino Mendocino County Environmental Health Department 1

Sonoma CDPH Marine Biotoxin Program 1

Marin Cove Mussel Company 4

Hog Island Oyster Company 4

Marin Oyster Company 4

CDPH Marine Biotoxin Program 2

San Francisco None Submitted

San Mateo San Mateo County Environmental Health Department 2

Santa Cruz U.C. Santa Cruz 3

Monterey Monterey Abalone Company 6

San Luis Obispo Grassy Bar Oyster Company 8

Morro Bay Oyster Company 6

California Polytechnic State University 1

Santa Barbara Santa Barbara Mariculture Company 4

U.C. Santa Barbara 4

Ventura Ventura County Environmental Health Department 1

Los Angeles Los Angeles County Health Department 1

Orange None Submitted

San Diego Carlsbad Aquafarm, Inc. 4

U.S. Navy Marine Mammal Program 3

sonings, complete muscular paralysis and

death from asphyxiation can occur. toms should seek immediate medical care. Consumers are

Symptoms of domoic acid poisoning can occur also advised that neither cooking or freezing eliminates do-

within 30 minutes to 24 hours after eating tox-

ic seafood. In mild cases, symptoms of expo-

sure to this nerve toxin may include vomiting,

diarrhea, abdominal cramps, headache and

dizziness.

These symptoms disappear completely within

moic acid or the PSP toxins from the shellfish tissue. These

toxins may also accumulate in seafood species such as crab,

lobster, and small finfish like sardines and anchovies.

Contact the “Biotoxin Information Line” at 1-800-553-4133

for a current update on marine biotoxin activity prior to

gathering and consuming shellfish.

If you are having difficulty accessing this document, please contact CDPH at 1-800-553-4133 to request this information in an alternate format.

several days. In severe cases, the victim may

experience excessive bronchial secretions,

difficulty breathing, confusion, disorientation,

cardiovascular instability, seizures, permanent

loss of short-term memory, coma and death.

Any person experiencing any of these symp-

Page 8 June 2017 Technical Report No. 17-19

The single-celled diatom Isthmia.

Chains of the diatom Skeletonema.

The dinoflagellates Lingulodinium polyedrum (round cells) and Ceratium furca.