They have been called poor man's salmon and white shad. The exquisite taste of their meat is reflected in their Latin species name, sapidissima, meaning savory. They are American shad, the largest member of the herring family.
Native Americans harvested shad during the annual spring spawning runs and taught colonists how to catch shad to feed their families. Dried shad has been credited with saving George Washington's troops from starvation as they camped along the Schuylkill River at Valley Forge.
By the 1800s, fishermen caught shad by the ton. Even farmers took advantage of this seemingly endless supply of fish, using shad as fertilizer for their fields. People prized shad for their succulent meat and tasty roe (eggs). Everyone eagerly awaited the spring migration of shad.
Found along the Atlantic seaboard from Labrador to Florida, shad are also an important source of food for such species as the bluefish and striped bass.
As the human population increased so did the demand for shad. The Chesapeake Bay shad fishery was an important seasonal industry by the 1800s. Shad became one of the most commercially valuable fish in the District of Columbia, Maryland, Pennsylvania and Virginia.
By the late 1800s, though, excessive harvesting was taking its toll on shad. This exploitation, coupled with pollution and the loss of spawning grounds, began a downward spiral of shad populations. From an annual harvest of 17.5 million pounds at the turn of the century, Chesapeake shad harvests dwindled to less than 2 million pounds by the 1970s.
American shad are anadromous fish, meaning they spend most of their lives in salt water but spawn in fresh water. Rising spring temperatures prompt shad to leave the ocean and return to the waters in which they were born. Biologists believe the fish find their natal streams through their sense of smell.
Males arrive on the spawning grounds first, followed by egg-laden females. A female releases 100,000 to 600,000 eggs into the water to be fertilized by several males. Adult shad return to the ocean soon after spawning. The transparent, fertilized eggs are carried by the current.
The larvae hatch in 4 to 12 days. Juvenile shad spend their first summer in fresh water. By autumn, the young shad gather in schools and swim to the ocean. They will live in the ocean for 3 to 6 years, until they are sexually mature, then return to fresh water to complete their life cycle. This sustained a thriving shad population for centuries, but that changed as America prospered.
The Susquehanna was once the Bay's most important river for spawning shad. But the Pennsylvania canal system, built in the 1830s, required feeder dams that restricted migration in the lower 45 miles of the river. Later, four hydroelectric dams eliminated all shad runs in Pennsylvania. Meanwhile, damming continued on other rivers throughout the watershed.
Early attempts at creating fish passages, or fishways, around dams failed. Resource managers attempted to restore shad stocks by releasing hatchery-reared shad into rivers. This attempt proved futile as overfishing continued and spawning grounds remained blocked. Populations continued to decline and restocking efforts ceased by the 1930s.
In 1980, Maryland shad harvests fell to a record low of 25,000 pounds and the state placed a moratorium on shad harvests in the Chesapeake Bay. Shad was one of the most abundant fish in Virginia. In the 1980s, shad harvests ranged from 2 million to 3 million pounds. By 1992, fishermen harvested less than 500,000 pounds and Virginia banned shad fishing in rivers and the Chesapeake Bay after the 1993 spring harvest.
Shad restoration is under way in 15 river basins from Maine to Virginia. Its success will depend on improving water quality, preventing overfishing and reopening spawning grounds. The goal is to achieve self-sustaining runs of shad and to reopen hundreds of miles of spawning habitat. To do this, fishways around dams and other barriers must be constructed.
One successful fish passage facility is an elevator system at Conowingo Dam near the mouth of the Susquehanna River. Two elevators, or fish lifts, move migrating fish to the top of the dam. The shad are sorted out and transported, by truck, 60 miles upstream, past 3 dams to their spawning grounds.
Other efforts are focusing on the Patapsco and Potomac rivers in Maryland, the James River in Virginia and Rock Creek in the District of Columbia. More than 170 miles of spawning habitat are now open to anadromous fish.
Throughout the watershed, barriers are being removed or modified, opening spawning areas to shad and other migratory fish. Road culverts and gauging stations are being redesigned to provide the gradient and flow of water that the fish need. Dams no longer in use can be breached. Breaching removes all or part of a dam to allow fish to swim upstream.
Dams still in use may require a fish ladder. A fish ladder is an inclined water channel structure with a series of baffles or weirs. The baffles interrupt and slow the flow of water, simulating pools and rapids. Fish swim up the ladder just as they would swim up natural rapids. Larger dams require fish lifts.
But fishways alone will not restore shad populations. After a stream blockage is removed, biologists must reintroduce shad into newly opened spawning grounds. One technique releases fertilized eggs and juvenile shad in upriver areas. Adults that are ready to spawn can also be captured and released in newly accessible spawning areas.
Fishways and stocking must be reinforced by protecting important fish habitat. Larval fish are more susceptible to pollutants and require good water quality to survive.
Establishing sustainable harvests is also critical to restoration. Atlantic Coast states have agreed on coastwide harvest limits but not all states enforce these through legislation. Coastal harvesting still intercepts many shad before they can reach protected waters to spawn.
Cooperation between federal and state agencies and government, businesses and private citizens is the key to the successful restoration of shad and other anadromous species. The steps taken today will sustain fisheries now and for future generations.