After a winter and early spring with exceptionally clear ocean waters, the inlets and bays are beginning to grow cloudy with plankton again. Tide- and shorelines are thick with a creamy white scum these days - and some of you might be concerned with what kind of pollution this could be. It is the natural kind : in this case millions and millions of barnacle exuviae are concentrated by wind and current and, in some places, are forming extensive floating blankets, trapping other flotsam, such as kelp and wood debris.
The micrograph inset is completely filled with the shed skins of the feather-like thoracopods (a.k.a. cirri) of barnacles (a.k.a. cirripedia). Like all crustaceans (yes, barnacles and crabs are kissin’ cousins !), they grow in stages, shedding their skin (or shell) at each growth-spurt.
So this is what creates the tidal scum on our waters these days : unsightly perhaps and not nice for swimming, but 100% organic.
P.S. the dark grains suspended among the barnacle skins are conifer pollen.