The Oregon Seal Oregon Department of Fish and Wildlife  
 »ODFW Home    » Fish Division   » Marine Resources   » Harmul Algae
About Us Fishing Hunting Viewing License/Regs Conservation Living With Wildlife Education
Commercial and recreational marine fisheries

Razor clams

Harmful Algae - Recreational and Commercial Shellfish

red tide
Red tide

Monitoring Oregon's coastal harmful algae

Oregon’s Harmful Algal Bloom monitoring (MOCHA) project existed from 2005 to 2012. After a 2005 coast wide shellfish harvesting closure due to Domoic Acid (DA), ODFW requested rapid response funding from the NOAA Center for Sponsored Coastal Ocean Research (CSCOR) that enabled Oregon to initiate a monitoring program similar to Washington State’s ORHAB (Olympic Region Harmful Algal Bloom) project.

In 2006, ODFW in collaboration with Oregon State university, University of Oregon and the NOAA Northwest Fisheries Science Center were awarded a 5 year nearly $2.3 million competitive grant from the NOAA CSCOR Monitoring and Event Response for Harmful Algal Bloom (MERHAB) research program to develop an integrated harmful algal bloom (HAB) monitoring and event response program. This program, MOCHA, begun collecting data in 2007. ODFW staff, in conjunction with Oregon Department of Agriculture monitored 10 sites along the coast of Oregon for any potential signs of the phytoplankton that cause Domoic Acid (Pseudo-nitzschia sp.) and Paralytic Shellfish Poisoning (Alexandrium sp.).

Harmful Algae Blooms (HAB’S)

  • Over 300 species of phytoplankton have been implicated in causing “red tides”
  • While most “red tides” are harmless over 80 phytoplankton species may produce toxins that are harmful to humans and marine life
Domoic Acid explanation

ODFW and ODA biologists discuss Oregon’s biotoxins and HAB’s


  • Phytoplankton
    The Latin roots of phytoplankton translate to “phyto” meaning plant and “plankton” meaning drifter
  • Phytoplankton is a primary producer responsible for approximately 90% of earth’s oxygen production.
  • There are an estimated 5,000 marine species
  • Phytoplankton are the base of the oceans food web and help sustain all marine life
  • Usually single celled organisms, though they commonly form colonies
  • Cells range in size from 2 microns to 2 millimeters
  • Phytoplankton reproduce by sexual or asexual reproduction
  • Use photosynthesis to convert light, carbon, and nutrients into energy
  • Capable of living in a wide variety of marine environments

Phytoplankton Species commonly found in Oregon and their associated toxins
Click on images to see larger

Amnesic Shellfish Poisoning (ASP) caused by the production of Domoic Acid
Diarrhetic Shellfish Poisoning (DSP) 
Paralytic Shellfish Poisoning (PSP)


ODFW scientist grabs water sample from surf 
ODFW scientist grabs water sample from surf 

Phytoplankton samples are collected weekly at the following sites. Clatsop Beach (3), Cannon Beach (1), Agate Beach (1), Tillicum Beach (1), North Spit (1), Bastendorff Beach (1), Whiskey Run (1), Gold Beach (1). Sampling for phytoplankton consists of testing sea surf water by the two following methods:

1) Whole Water Sample- This sample is taken from the surf using a five gallon bucket to first collect the water. After the sand settles a small 8 oz sample jar is filled. A temperature and salinity reading is taken, the jar is labeled and prepared to be sent back to the lab for analysis.

2) Net Tow Sample- This sample is taken using a phytoplankton net to concentrate what plankton are in the water. The net is made of a selective material allowing the sea water to escape while trapping the phytoplankton. The net can either be towed through the surf for a short amount of time or the sampler may pour a bucket or two of water through the top end to collect the sample. The sample is then placed in a container, labeled and sent to the lab.


Back at the lab, internationally trained staff receives and prepares the samples for analysis. Using a light microscope, concentrated samples are viewed to determine the presence of Pseudo-nitzschia sp. and Alexandrium sp. This gives staff a quick idea of what phytoplankton is abundant along the coast. Staff then tests the whole water samples using a 0.1 ml nano-plankton chamber. Any Pseudo-nitzschia sp., Alexandrium sp. or other variety of phytoplankton are recorded and quantified. The results are then checked against acceptable levels that were developed by the ORHAB project and action is taken if necessary.

Program goals

  • Mitigate impacts of HAB's events to local economies
  • Reduce human health impacts caused by HAB’s
  • Provide an early warning system for HAB events
  • Further our knowledge of ocean health
  • Fill a data gap in Oregon’s key transition zone in west coast oceanography and the Ocean Observing System
  • Combine data from oceanographic research with data from ongoing plankton and shellfish monitoring programs

Groups of interest

Northwest Fisheries Science Center - NWFSC Harmful Algal Blooms Program
NOAA’s Harmful Algae Bloom Page - Harmful Algae: Red Tide
Oregon Department of Agriculture (ODA) - ODA Food Safety Division Shellfish safety closures


About Us | Fishing | Crabbing & Clamming | Big Game Hunting | Game Bird Hunting | Wildlife Viewing | License / Regs | Conservation | Living with Wildlife | Education | Workday Login

ODFW Home | Driving Directions | Employee Directory | Social Media | | File Formats | Employee Webmail | ODFW License Agents

4034 Fairview Industrial Drive SE   ::   Salem, OR 97302   ::    Main Phone (503) 947-6000 or (800) 720-ODFW [6339]

Do you have a question or comment for ODFW? Contact ODFW's Public Service Representative at:
Share your opinion or comments on a Fish and Wildlife Commission issue at

   © ODFW. All rights reserved. This page was last updated: 08/11/2022 4:27 PM