The blueback herring (Alosa aestivalis) ranges from Prince Edward Island in the northwest Atlantic south to the mouth of the St. John's River in Florida.

There are landlocked populations, but the furthest inland the bluback herring exists is Lake Champlain and the Mohawk river, New York.

Biogeographic Regions: atlantic ocean (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Atlantic coast from Nova Scotia to St. Johns River, Florida. Landlocked populations occur in coastal plain lakes and several reservoirs in Virginia and the southeastern U.S. (Bozeman and Van Den Avyle 1989, Page and Burr 1991).

The blueback herring is slender like the alewife (Alosa pseudoharengus) and several papers that exist only for identification purposes between these two species (MacLellan et.al. 1981). The blueback herring has a smaller eye, its otolith has more hooked shape than the alewife's L-shaped otolith, and the lining of the viscera is black instead of silver (this is the most distinguishing characteristic). However, if you do not want to sacrifice the fish just to identify it: the dorsal surface of blueback herrings have a blue color, and they have 41 to 51 gill rakers. Also characteristic of bluebacks are one dark spot on the shoulder. The American shad (Alosa sapidissima) often has 4-5 spots in the same location.

Blueback herrings grow to a maximum of 15 inches, but are more commonly around one foot long. Smith (1985) notes that most adults are 10 to 12 inches long in the Hudson River, NY.

In general Clupeids, or the herring, shad, and menhaden (among others) family, are silvery with a sharp ventral keel. This keel has given them the common name of "sawbellies," which is an adaption for optimal schooling movement and organization. They have forked caudal fins and the anal fin is usually longer than the dorsal fin. Their body shape is teardrop, but more elongate than faster moving fishes such as the tunas. The maximum depth of the fishes' body is just anterior to the dorsal fin.

Range mass: 400 (high) g.

Length: 38 cm

Often confused with A. PSEUDOHARANGUS.

The blueback is anadromous and develops in freshwater, then migrates to marine, and then migrates back to freshwater to spawn.

Habitat Type: Freshwater

Comments: Riverine, estuarine, and Atlantic coastal waters; also in certain lakes and reservoirs in the southeastern U.S. Adults in saltwater except during breeding season; occurs as far offshore as 200 km. Juveniles move to sea when about 1 month old. Spawns in freshwater or brackish, tidally influenced portions of coastal rivers (Bozeman and Van Den Avyle 1989). According to Lee et al. 1980, spawns in deep swift water over hard substrate. According to Bozeman and Van Den Avyle 1989, spawns in shallow areas covered with vegetation, old ricefields, and river swamps and small tributaries above tidal influence. Rarely uses standing or brackish water. Eggs sink and adhere to objects on bottom (Scott and Crossman 1973); after a few hours eggs unstick and drift downstream (Dadswell 1980). Larvae occur in or slightly downstream from spawning areas; juveniles may exhibit net upstream movement until emigration from freshwater in summer or fall (or, in some areas, the next spring) (Fay et al. 1983). Nursery areas in Neuse River, North Carolina, were characterized by deep, black water draining hardwood swamps, with little salinity or current and with a mud or detritus bottom (Bozeman and Van Den Avyle 1989).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Migrates between coastal river spawning habitat and marine nonspawning habitat. Probably undertakes similar winter- summer, offshore-onshore migrations as do shad (Dadswell 1980).

Blueback herring are planktivores and eat anything the size of larval fish to zooplankters. Blueback herring also consume small fishes and shrimps. (Froese and Pauly, 2001)

Comments: Eats primarily zooplankton, though fish eggs, crustacean eggs, insects and insect eggs, and small fishes may be important in some areas or for larger individuals (Fay et al. 1983).

Important link in estuarine and marine food webs, between zooplankton and top piscivores; may be highly utilized by gulls and terns (Fay et al. 1983).

Comments: Feeds most extensively during daylight (Fay et al. 1983).

Average lifespan

Status: captivity: 8 years.

Blueback herring, like many other clupeids are anadromous fish, meaning they spawn and spend larval development in freshwater, and then they migrate out to spend most of their lives in marine waters. Landlocked populations will make spawning runs up rivers and streams, but spend most of their life in the pelagic zone of lakes. Many fish can make extensive spawning runs. In New York, the species can reach the Mohawk river, more than 150 kilometers from the Atlantic Ocean. Ian Blackburn and Karin Limburg, researchers at the SUNY college of environmental science and forestry, are trying to determine whether some of these individuals found here are migratory or residents of the Mohawk River.

Spawing runs can get large and begin in mid to late April (as soon as the water is 4-9 degrees Celcius) and last until mid-August. The blueback herring is also known as the summer herring since most of the large spawning runs occur from mid-may to mid-july. (This is another environmentally friendly way to separate alewives and bluebacks: the spawning runs are spatially and temporally separated from each other). Spawning occurs in separate runs in groups through the season, but the fish can be inhibited by high temperatures (27 deg C). Bluebacks prefer spawning habitat with swift water and a hard bottom, and fish from ages 3-7 normally spawn.

During courtship, the female is often pursued by several males--all of which will swim as a group in circles. Males nudge the vent region of the female with their snouts, most likely to stimulate the female to release her gametes. All together, they make a dive towards the bottom, stop short, face the current and release their gametes. The eggs need 50 hours of incubation at 72 deg F to develop.

Average age at sexual or reproductive maturity (male)

Sex: male: 1277 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 1460 days.

Spawns in spring, or in early summer in far north. Eggs hatch in about 2-3 days at 22-24 C. Most spawn by 4th year. Few live beyond 7 years. See Fay et al. (1983) for additional details.

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Global rank is out of date and in need of review.

Comments: Dams have reduced freshwater range and abundance (Page and Burr 1991).

The blueback herring is has been the subject of fisheries. It is more commonly known with come other clupeids as river herring, which includes the alewife. Very general "river herring" labels may include other bait fish such as the American shad and menhaden (Brevoortia tyrannus), or bunker.

Comments: In the last two decades, has gained in recognition and interest as source of fish meal, fish oil, and fish protein, especially for the animal food industries (Fay et al. 1983). However, has declined in commercial importance in South Atlantic region in recent decades (Bozeman and Van Den Avyle 1989).

Comments: Formerly placed in genus Pomolobus (Lee et al. 1980).