Researchers have identified an invasive blood-sucking parasite on mud shrimp in the waters of British Columbia's Calvert Island. The discovery represents the northern-most record of the parasite on the West Coast and is likely an indication of its ability to spread without human transport.

A parasitic isopod that scientists identified five years ago has all but decimated mud shrimp populations in coastal estuaries ranging from British Columbia to northern California - with the exception of a handful of locations in Oregon from Waldport to Tillamook.