American Shad
Alosa sapidissima
Fish Illustrations by: Roz Davis Designs, Damariscotta, ME (207) 563-2286
With permission, the use of these pictures must state the following: Drawings provided courtesy of the Maine Department of Marine Resources Recreational Fisheries program and the Maine Outdoor Heritage Fund.
Common name: American shad, Atlantic shad, common shad, white shad, poor man’s tarpon
Scientific name: Alosa sapidissima
Classification: Shad are members of the herring family, which also includes alewives and blueback herring.
Range: American shad are highly migratory, and can be found along the Atlantic coast of North America from Newfoundland to Florida. They were also introduced along the Pacific coast of North America, and are now found from Cook Inlet in Alaska southward to Baja California in Mexico.
Identification: American shad are the largest members of the herring family, and are native to the eastern seaboard of North America. Adult females can reach greater than 24 inches and adult males almost 20 inches in length, and can weigh between 2 – 13 lbs. American shad are dark blue to green above with paler sides and a silver underbelly. Behind the upper edge of their gill cover is a large dark spot that is usually followed by several small, less distinct, dark spots along the upper side of the body.
Life history: American shad are anadromous, meaning they spend most of their lives in the Atlantic Ocean and return to the freshwater rivers where they were hatched to spawn. Adults return as in May or June in Maine, and can travel inland up to 90 miles.
American shad are broadcast spawners and spawn multiple times when they enter rivers. Spawning normally occurs at sundown and until midnight in shallow waters with moderate flow; the ideal temperature for shad spawning is approximately 65℉. In the southern part of their range, American shad are semelparous; they spawn once and die, like salmon in the Pacific Northwest. In the northern part of their range, including Maine, American shad are iteroparous; they can make spawning migrations several times in their lives. Adults leave shortly after spawning and head back to the estuary and then the Gulf of Maine. No matter their origin, all the adult shad that survive spawning convene in the Gulf of Maine to feed for the summer before spreading out along the mid-Atlantic for the winter.
American shad eggs are fairly small, which enables a single female adult to brood and lay up to 600,000 eggs in a spawning season. Once laid, the eggs sink to the bottom of the river. After hatching, juvenile American shad spend the summer months growing and feeding on microscopic plants and zooplankton in freshwater before migrating out to sea in the fall. Juvenile American shad spend between two and five years at sea growing to adulthood, schooling in large numbers with shad from other regions and feeding on plankton and other small fish or crustaceans. Upon reaching maturity, they will return to the streams where they were born to spawn.
Fun Fact: Shad “hear” better than other fish. They have fine sensory hairs in their otoliths, a network of water filled channels in their heads, and a swim bladder that extends up into their brain. Together, these unique features allow the shad to be extremely sensitive to movement in the water, and sensitive to noise such as the clicks and echolocation communication used by dolphins which prey on shad.
Cultural importance: American shad provided a valuable food resource to the Native American tribes and colonial settlers of Maine. The fishery in the Gulf of Maine annually produced over 2.5 million pounds of shad in the late 1800s, with over half of that total being landed in Maine. By 1931, these historic amounts had declined to just 157,000 pounds in Maine. Although shad once supported major commercial fisheries and were more abundant than salmon, stripers, or sturgeon, shad were also among the first migratory species to disappear from our rivers.
Threats: American shad were historically abundant in Maine prior to the 1830s. The primary causes for low shad populations today are dams, habitat loss and overfishing. Dams are particularly troublesome because many traditional fish ladders do not pass American shad effectively; they are too sensitive to changes in temperature, light, and water flow, making them skittish about fishways. Before long, shad runs had been reduced to the point where some feared the population had disappeared entirely.
The 2020 American shad benchmark stock assessment is the most recent assessment for the American shad stock. Similar to the results of the 2007 assessment, the 2020 assessment found coastwide populations to be depleted. Additionally, the assessment found that shad recovery is limited by restricted access to spawning habitat, with 40% of historic habitat in the U.S. and Canada currently blocked by dams and other barriers.
Restoration efforts: There is some history of shad stocking in Maine, but wasn’t a popular enough effort to gain much traction. The Waldoboro Hatchery produced American shad fry for stocking in the Androscoggin, Kennebec, and Sebasticook Rivers from 1992 to 2008, but the program ended in 2009 due to lack of funding. Dam removals on Maine’s rivers, such as the Veazie and Great Works dams on the Penobscot and the Edwards dam on the Kennebec, have improved the numbers of shad that are able to make it to upstream spawning grounds. Finding effective American shad passage, however, is challenging. The Maine Department of Marine Resources currently monitors American shad usage of fish passage facilities on all major rivers in the state, including video monitoring at the Brunswick fishway. New fishways have recently been constructed on the Saco River (2012) and the Penobscot River (2014) with the goal of increasing American shad passage.
Fishery: As with most other species of sea-run fish, shad populations are severely depleted compared to historic levels. There is no commercial shad fishery in Maine, but the fish is caught by recreational and subsistence anglers.
Shad are increasingly being recognized as an exciting sport fish, with some going so far as to call American shad “the poor man's tarpon” because of their ability to leap and fight. The most popular time of year to go shad fishing is in the spring when these fish are returning to their coastal streams and rivers to spawn. In Maine, the catch limit is two fish per day. There is no minimum size, but you can only use a hook and line to catch them. They prefer moving water that is not too deep, and although shad are primarily plankton feeders, they will take a variety of baits, lures and flies.
Sources:
https://www.fws.gov/species/american-shad-alosa-sapidissima
https://www.nrcm.org/nrcm-creature-feature/american-shad/