Mattawoman Creek is famous as a spawning ground and nursery for River Herring. While it retains a strong River Herring run, upstream usage by spawning adults has dropped precipitously in the last decade. The numbers of young in the estuary have dropped as well. This alarming situation correlates with the watershed passing the 10% threshold for being covered by hard surfaces such as roads, roofs and parking lots, which funnel polluted runoff in erosive flows into our streams and rivers. This is one reason why "land conservation is fish conservation," and why MWS is so concerned with land use planning.
River Herring are an important forage fish in the Atlantic ocean, but must migrate each spring to freshwater to spawn. They once were a cultural icon when our rivers boiled with the massive spawning runs. Populations along the Atlantic seaboard crashed in the mid-1970's, and have continued to decline ever since. As a result, in 2012 the Atlantic States Marine Fisheries Commission gave states a choice to improve conservation: either place a moratorium on possession, or else produce a sustainable fishery plan. Numbers have become so depleted that Maryland opted for a moratorium of this fish popular with anglers and watermen seeking bait. River Herring now join their shad cousins in a moratorium.