American Shad Alosa
sapidissima and Hickory Shad Alosa mediocris were two of the most important commercial and
recreational fish species in the Chesapeake Bay. In response to severe
population declines from 1900 to the 1970s, Maryland closed its fishery in
1980. The fishing moratorium, habitat improvements, pollution mitigation and
fish passage construction did not result in recovery, primarily due to lack of
adult spawners. In 1994, Maryland Department of Natural Resources (MDNR) and
several partners began a program to reintroduce shad spawning
runs to selected tributaries through restorative hatchery stocking.
Traditional strip spawn culture methods require access to large numbers of ripe
adults. We developed methods to induce spawning in broodfish collected from the
Susquehanna River using synthetic reproductive hormone implants and tank
spawning systems (Mylonas et al. 1995). Fertilized eggs can be produced from
any migratory pre-spawned female using this method. Traditional strip spawning
is also performed. Larvae and juveniles are marked and stocked into target
tributaries. Surveys are conducted to sample larval, juvenile and adult shad.
From 1994 to 2015 the program stocked 44.5 million American Shad and 111.6
million Hickory Shad in the Choptank River, Patuxent River, Patapsco River and
Hatchery contributions are intended to provide
adult spawners that will produce self-sustaining populations in the target
tributary. These fish have tremendous value for stock assessment purposes at
the larval, juvenile and adult life stages since all shad are marked prior to
The department began a pilot project
in 1993 to assess the response of American Shad adult broodstock during
collection, handling and captive holding. In 1994, experimental spawning was
conducted using timed-release hormone implants. The success of these trials
encouraged development of a long-term spawning, culture, stocking and
assessment program. In 1995, a non-funded, full-scale hatchery production
effort was conducted with positive results. The project continued over the next
three years through various short-term funding sources. In 1998, it was determined
that a long term funding source would be required, since it would take years of
additional stocking and assessment to successfully support restoration. Federal
Aid in Sport Fish Restoration funds support this long-term effort. Federally
funded Choptank River and Patuxent River restoration work began in 1999.
Marshyhope Creek, a tributary to the Nanticoke River, was added in 2001.
In 2001, the decision was made to collect ripe
fish on the spawning grounds and manually strip eggs and milt from mature brood
fish. The Potomac River was chosen as the source population due to its strong
American Shad spawning population. The department previously documented
some encouraging progress with restoration of these species in Maryland.
Beginning in 2006 however, most Atlantic coast states began to observe
decreased numbers in migratory shad stocks. It is hypothesized that
undocumented mortality is occurring to out-migrating young-of-year shad or
sub-adults in coastal waters. After careful consideration of recent shad population
trends, project biologists determined that a change in approach was warranted
for this restoration project. In 2010, the grant proposal was amended to
suspend stocking the Patuxent River and Marshyhope Creek and to focus all
project resources towards stocking and monitoring in the Choptank River.
Limited monitoring of adults will continue every three years in the Patuxent
River in order to maintain trend data.
American Shad restoration efforts continue to occur in the
Choptank River. In 2016, the project’s efforts to sample Adult American Shad in
the Choptank River were rewarded with the capture of 45 individuals. Of the 45
fish sampled, 11 were larval stocked (25%), 19 were early juvenile stocked
(43%) and 14 were wild origin (32%). This is encouraging compared to a
recovered Patuxent River population. One year of sampling does not indicate
restoration efficacy, but it is encouraging to discover that 32% of the sampled
adults were wild origin, and there is a robust juvenile population. Project staff
will continue to sample different areas of the Choptank River using gill nets
to determine where American Shad are staging and spawning in the river. Project
staff can now assess the adult composition in conjunction with wild caught
juvenile American Shad component to estimate Choptank River restoration
progress. The data collected from increased adult recaptures will further aid
in Choptank River progress analysis. As hatchery-produced adult spawning stocks
increase, the wild component of the juvenile population should exhibit
corresponding growth. Restoration goals will be met when natural reproduction
overwhelms the contribution of hatchery-produced fish in the juvenile
The department incorporated Hickory Shad into the project in 1996. The Choptank and Patuxent rivers were designated as the restoration target tributaries.
Hickory Shad populations in the Patuxent River were determined to be self sustaining in 2007, after years of stocking effort. In 2014, Hickory Shad populations were also designated as restored in the Choptank River. Data analysis from an adult recapture survey indicates that wild contributions steadily increased each year, from a low of 26% in 2001 to a high of 75% in 2014. Wild contribution exceeded 75% since 2011. Trend data will be maintained in these rivers by sampling on a three year rotation.
Currently the program is shifting focus to
determine additional restoration need in Maryland's Chesapeake Bay. In 2015 and
2016, preliminary surveys were conducted on the Pocomoke River, Marshyhope
Creek, Chester River, Sassafras River, Elk River, Northeast River, and the
Patapsco River for baseline Hickory Shad abundance data. The map indicates potential survey locations, along with
the program's historic survey locations. Future target tributaries will be
chosen based on historical data, angling opportunities, and potential for
Hickory Shad spawning and nursery habitat.
To offset habitat impacts associated with
dredging, the Maryland Port Administration (MPA) was required to develop a
compensatory mitigation package. The Patapsco River shad and herring
restoration project is part of this plan and receives MPA funding to conduct
fish production, stocking, and assessment activities.
In 2013, the department began stocking
larval and juvenile American Shad, Hickory Shad, Alewife, and Blueback Herring
into the Patapsco River. After determining there were abundant stocks of
spawning Blueback Herring and Alewife, stocking of these species ceased in
2014. In 2016, the department stocked 290,000 American Shad, and 615,000
Hickory Shad in the Patapsco River.
Since the inception of this project 1.98 million American Shad and 2.99
million Hickory Shad have been stocked across all life stages into the Patapsco
The Patapsco River restoration project will
hopefully add fishing opportunities for the local community by re-establishing anadromous species such as American and Hickory Shad to the Patapsco River.
For more information concerning shad restoration in Maryland, contact. Chuck Stence at 410-643-6788 ext. 2114
580 Taylor Ave, Annapolis MD 21401