Monitoring Oregon Coastal Harmful Algae: Observations and implications of a harmful algal bloom-monitoring project

•Saxitoxin events most likely in late upwelling season, at north and south coast regions.•A 2009–2010 warming event coincided with elevated HAB activity in the region.•Alexandrium spp. cell counts correspond to saxitoxin events in well-sampled zones.•Mussels & razor clams are better indicators of saxitoxin & domoic acid events, respectively.•Particulate and dissolved domoic acid above 103ngL−1 preceded shellfish toxicity.