Fish consumption advisories are public health notices that warn people about possible health risks from eating fish and shellfish from certain waterways.

Fish passageways allow shad and other anadromous fish to pass over dams and reach their upstream spawning grounds. There are five major fish passageway designs used in the Chesapeake Bay watershed: denil, steeppass, vertical slot, pool and weir, and fish lifts.

Dams block shad and other anadromous fish from reaching their upstream spawning grounds. Historically, most shad and river herring spawned in freshwater areas that are now upstream of dams, road culverts and other blockages.

Fish passage is the ability of fish to migrate up rivers, streams and other waterways, often to access spawning or rearing areas. Barriers to fish passage (which can include road culverts, dams, dikes and other obstructions) can reduce the distribution and habitat available to anadromous fish and, in some cases, eliminate fish populations altogether.

American shad are not listed as an endangered species. However, populations along the East Coast are very low.

Shad are anadromous, which means they migrate from the ocean to spawn in freshwater rivers and streams.

Shad spend most of their lives in the ocean. They migrate to freshwater rivers and streams to spawn. After hatching, young shad slowly migrate downstream, eventually leaving the Chesapeake Bay for the ocean.

Some fish and crabs may be able to swim away from areas without enough oxygen. But other animals – such as oysters, clams and worms – are not able to swim away, and can die if there is not enough oxygen around them.

Bay grass beds form communities that provide food and shelter for many species. Fish, crabs and other animals visit bay grass beds to seek out food and find shelter from larger predators. Bay grasses are also an important source of food for waterfowl such as ducks and geese.