The blueback herring, blueback shad, or summer shad (''Alosa aestivalis'') is an anadromous species of

herring Herring are various species of forage fish, belonging to the Order (biology), order Clupeiformes. Herring often move in large Shoaling and schooling, schools around fishing banks and near the coast, found particularly in shallow, temperate wate ...

from the east coast of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, with a range from

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. Blueback herring form

schools A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...

and are believed to migrate offshore to overwinter near the bottom. These fish are silvery in color, have a series of

scute A scute () or scutum (Latin: ''scutum''; plural: ''scuta'' "Scutum (shield), shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of Bird anatomy#Scales, birds. The ter ...

s (modified, spiny and keeled scales) along their bellies, and are characterized by deep bluish-green backs. They reach a maximum size of approximately and are believed to live up to 8 years. The most distinguishing characteristic of this species is the black to dusky color of its peritoneum (the lining of the abdominal cavity). It is one of the "typical" North American

shad The Alosidae, or the shads, are a family (biology), family of clupeiform fishes. The family currently comprises four genera worldwide, and about 32 species. The shads are Pelagic fish, pelagic (open water) schooling fish, of which many are anadr ...

s. They are often confused with alewifes because blueback shad and alewives are difficult to distinguish from one another, and together these two species are often regarded collectively as "river herring". Alewives have larger eyes, greater body depth, and pearly to white peritoneal linings. This fish has, in the past, been used as a baitfish for the

lobster Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on th ...

fishing industry. It is also used for human consumption, usually smoked. It is caught (during its migration up stream) using large dip nets to scoop the fish out of shallow, constricted areas on its migratory streams and rivers.

Range

The native range of this fish is found along the Atlantic Coast from

Cape Breton Cape Breton Island (, formerly '; or '; ) is a rugged and irregularly shaped island on the Atlantic coast of North America and part of the province of Nova Scotia, Canada. The island accounts for 18.7% of Nova Scotia's total area. Although ...

, Nova Scotia, to the

St. Johns River The St. Johns River () is the longest river in the U.S. state of Florida and is the most significant one for commercial and recreational use. At long, it flows north and winds through or borders 12 counties. The drop in elevation from River s ...

, Florida. During spawning season, it migrates into coastal rivers.

Non-indigenous occurrences

Blueback shad were first collected in

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York (state), New York. The Canada–United Sta ...

in 1995, and have been collected from the

Tennessee River The Tennessee River is a long river located in the Southern United States, southeastern United States in the Tennessee Valley. Flowing through the states of Tennessee, Alabama, Mississippi, and Kentucky, it begins at the confluence of Fren ...

in Georgia and Tennessee; Oneida Lake, the Oswego River, and

Lake Champlain Lake Champlain ( ; , ) is a natural freshwater lake in North America. It mostly lies between the U.S. states of New York (state), New York and Vermont, but also extends north into the Canadian province of Quebec. The cities of Burlington, Ve ...

in New York. In North Carolina, blueback shad were introduced into the Savannah, Broad, and Yadkin River basins, and into non-native areas of the Cape Fear and Roanoke River basins. It has been introduced to an unspecified location in the Chesapeake Bay basin in Pennsylvania. They have been collected in Lake Jocassee, Lake Keowee, Picalet River, Broad River, and Lake Murray in South Carolina. Stock obtained from the Cooper River, South Carolina, was released in Texas by the Texas Parks and Wildlife Department in Lake Theo, Briscoe County, and at an unidentified research site in North Texas in 1982 (and in the upper Red River drainage). Bluebacks have been collected from Lake Champlain, Vermont, and have been stocked in several inland reservoirs in Virginia, including Smith Mountain Lake, Occoquan Reservoir, Kerr Reservoir, and Lakes Anna, Brittle, and Chesdin. It is established as a species in Texas, New York, North Carolina, Vermont, and Virginia.

Ecology

This fish is anadromous, living in marine systems and spawning in deep, swift freshwater rivers with hard substrates. It migrates to spawning grounds in the spring. In Connecticut, blueback shad spawn in water, usually later in the spring than the alewife. During spawning, many eggs are deposited over the stream bottom, where they stick to gravel, stones, logs, or other objects. Juveniles spend three to seven months in fresh water, then migrate to the ocean. The blueback shad is a planktivorous forage species.

Reproduction

Blueback herring spawn from late March through mid-May, depending on latitude. Females usually mature by age five and produce between 60,000 and 103,000 eggs. Males generally mature earlier at between 3 and 4 years of age and at a smaller size than the females. For both species, adults migrate quickly downstream after spawning and little is known about their life history while in the marine environment; however, they are believed to be capable of migrating long distances (over ).

Conservation

Blueback populations have exhibited drastic declines throughout much of their range. There are several threats that have most likely contributed to their decline. These threats include: loss of habitat due to decreased access to spawning areas from the construction of dams and other impediments to migration; habitat degradation; fishing; and increased predation due to recovering striped bass populations. In response to the declining trend for river herring, the states of

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

Massachusetts Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...

Rhode Island Rhode Island ( ) is a state in the New England region of the Northeastern United States. It borders Connecticut to its west; Massachusetts to its north and east; and the Atlantic Ocean to its south via Rhode Island Sound and Block Is ...

Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...

and

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

have instituted moratoriums on taking and possession. The blueback herring is a U.S. National Marine Fisheries Servic
Species of Concern
Species of Concern are those species about which the U.S. Government's

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, ...

, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA).

References

* (2006): A molecular phylogenetic perspective on the evolutionary history of ''Alosa'' spp. (Clupeidae). ''Molecular Phylogenetics and Evolution'' 40(1): 298–304. (HTML abstract) *http://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=488 * *Good, S. - Vermont Department of Fish and Wildlife, Pittsford, VT. *Guest, W. C. 1983. Blueback herring evaluation. Federal Aid Project F-31-R-9. *Hauser, M. 1998. Champlain Canal fish barrier study. Aquatic Nuisance Species Digest 2(3):26–27. *Howells, R. G. 1992a. Annotated list of introduced non-native fishes, mollusks, crustaceans and aquatic plants in Texas waters. Texas Parks and Wildlife Department, Management Data Series 78, Austin, TX. 19 pp. *Hurst, T. P., K. A. McKown, and D. O. Conover. 2004. Interannual and long-term variation in the nearshore fish community of the mesohaline Hudson River Estuary. Estuaries, 27(4):659-669. *Jenkins, R. E., and N. M. Burkhead. 1994. Freshwater fishes of Virginia. American Fisheries Society, Bethesda, MD. *MacNeill, D. - New York Sea Grant, State University of New York at Brockport, Brockport, NY. *Menhinick, E. F. 1991. The freshwater fishes of North Carolina. North Carolina Wildlife Resources Commission. 227 pp. *Owens, R. - U.S. Geological Survey, Oswego, NY. *Owens, R. W., R. O'gorman, E. L. Mills, L. G. Rudstam, J. J. Hasse, B. H. Kulik, and D. R. MacNeill. 1998. Blueback herring (Alosa aestivalis) in Lake Ontario: First record, entry route, and colonization potential. Journal of Great Lakes Research, 24(3):723-730. *Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA. *Rasmussen, J.L. 1998. Aquatic nuisance species of the Mississippi River basin. 60th Midwest Fish and Wildlife Conference, Aquatic Nuisance Symposium, Cincinnati, OH. 7 December 1998. *Rohde, F.C., R.G. Arndt, J.W. Foltz, and J.M. Quattro. 2009. Freshwater Fishes of South Carolina. University of South Carolina Press, Columbia, SC, 430 pp. *Winkelman, D. L. and M. J. Van Der Avyle. 2002. A comparison of diets of blueback herring (Alosa aestivalis) and threadfin shad (Dorosoma petenense) in a large southeastern reservoir. Journal of Freshwater Ecology, 17(2): 209–221. *Yako, L. A., M. E. Mather, and F. Juanes. 2002. Mechanisms for migration of anadromous herring: An ecological basis for effective conservation. Ecological Applications, 12(2): 521–534. {{Authority control Alosa Fish of the Great Lakes Smoked fish Fish described in 1814