The west coast of the North America is experiencing a very strong toxic algal bloom that reaches from Mexico to Alaska. It is unusual to this early in the season...usually we see these in July and August but not at this level. Shellfish harvesting and Dungeness Crab harvest have been cancelled for the time being. These algal blooms usually are strongest when the water warms, upwelling brings up nutrients from deep water, and there is abundant sunshine. All three of these factors are currently present. So to some degree it is not surprising that we see these blooms now. How long they will last in anybody's guess...perhaps throughout the summer. Check the link for more information:
Commercially harvested shellfish for sale in stores and restaurants are closely monitored for toxins and are considered safe to eat.....but do not eat shellfish that are sport harvested...or that you harvest...you may be very sorry....but not remember why.