Southern Washington and Norther Oregon coasts are experiencing diatom blooms. These blooms are great for razor clams. Diatoms are single-celled plants (phytoplankton) found in both fresh and salt water. They are one of the most important food sources in the ocean.
In the winter, spring, and early summer, diatoms rapidly multiply in the surf zone. Diatoms absorb large amounts of nitrates and phosphates that are delivered to the ocean by coastal rivers, contributing to their population explosion. Everything in the ocean feeds on diatoms and other plankton, either directly or indirectly. Even great baleen whales, like the gray whale, filter plankton and diatoms as part of their diet.
When the surf zone becomes too saturated with diatoms, they wash ashore. When they do wash ashore, it is in such great quantities that they resemble an oil spill.