Thank you for visiting the New Hampshire Fish and Game Department website. www.wildlife.state.nh.us NH Fish and Game

 

 

Blueback Herring

Blueback herring

 

herring

 

herring

 

herring

 

Blueback herring

The inner lining of the abdominal cavity of the blueback herring is dark gray in color.

 

NH Conservation Status: Special Concern

 

State Rank: Apparently secure (in need of review)

 

Scientific Name: Alosa aestivalis

 

Distribution: Blueback herring migrate from the ocean into Atlantic coastal rivers from Nova Scotia to Florida. In New Hampshire, blueback herring historically spawned in the rivers and streams that drain into Great Bay, coastal drainages, the Merrimack River, and the Connecticut River.

 

Description: The blueback herring may grow up to 15 inches, but is generally smaller than the alewife. It has a bluish-green dorsal color, large silvery scales, and a deeply forked tail. The blueback herring may be distinguished from the alewife by its smaller eye. The width of its eye is the same length as the distance from the tip of the snout to the front edge of the eye. The inner lining of the blue back herring's body cavity, called the peritoneum, is black, as opposed to the white lining of the alewife. The lower jaw of the alewife has an indented, or shovel shaped appearance, while the American shad has a straight lower jaw.

 

Species commonly confused with: Alewife, juvenile American shad

 

Habitat: Blueback herring inhabit coastal waters for most of their lives, but they migrate into freshwater rivers and streams to spawn. Unlike alewives, which spawn in the calm water of lakes, ponds, and backwaters of rivers, blueback herring prefer to spawn in flowing water.


Life History: The life history of the blueback herring is similar to that of the closely related alewife. Both species are anadromous, which means that they live in the ocean, but migrate into freshwater habitats to spawn. The blueback herring has a more southern distribution than the alewife and prefers to spawn in slightly warmer water. In New Hampshire, the spawning run of blueback herring usually begins in late May and peaks in June. Eggs are deposited in areas of moderate current in rivers and streams. Juvenile blueback herring grow rapidly in freshwater until late summer and fall, when they migrate downstream to the ocean. Maturity is reached after 3 to 4 years in males and 4 to 5 years in females. Blueback herring may live up to 8 years and can spawn multiple times. Juveniles feed on zooplankton, while the diet of adults consists of small fish and plankton. Adults do not feed during their spawning run. Little is known about the habits of blueback herring in salt water.

 

Blueback herring

Blueback herring (below) have a smaller eye than that of the alewife (above).

Origin: Native

 

Conservation/Management: Blueback herring numbers have declined throughout their range. Commercial landings of river herring, a collective term for alewives and blueback herring, have declined by 95% since 1950. These declines have been observed in local rivers, such as the Oyster River in Durham and the Taylor River in Hampton. Twenty years ago, these rivers supported productive blueback herring runs with counts exceeding 100,000. Currently, only a few thousand blueback herring are counted at the Oyster River each spring and the Taylor River blueback herring run has been reduced to less than 100 fish.

 

The NHFGD is working to restore river herring to coastal rivers and the Merrimack River watershed. Fish ladders are monitored by the NHFGD on the major tributaries of Great Bay, including the Cocheco, Oyster, Lamprey, and Exeter Rivers. However, much of the former spawning habitat of river herring remains inaccessible in New Hampshire. Dam removals and fish passage construction are the best option for restoring river herring runs. However, blueback herring may be reluctant to use certain fishways compared to alewives. Blueback herring are rarely observed using the fish lift at the Essex Dam on the Merrimack River.

 

herringThe river herring population in the Merrimack River watershed has been severely depleted. Historic spawning runs, which likely numbered in the millions, have been reduced to the low thousands each year. The NHFGD is working with partners like the U. S. Fish and Wildlife Service and the Massachusetts Fish and Wildlife Division to restore river herring numbers in the Merrimack River. Strategies include stocking adult river herring from other rivers including the Kennebec, Androscoggin, Lamprey, and Cocheco Rivers, into suitable habitat within the Merrimack River watershed. The largest of these stocking sites is Lake Winnisquam, which has the potential to produce herring returns in the hundreds of thousands by the year 2017.

 

The ultimate success of the restoration program will depend on improvements in fish passage, which will allow river herring to reach as much suitable spawning habitat as possible. Fish passage is currently available at the first three dams on the mainstem of the Merrimack River (the Essex Dam in Lawrence, MA, the Pawtucket Dam in Lowell, MA, and the Amoskeag Dam in Manchester, NH) and at the first two dams on the Nashua River. The long term goal of a self-sustaining river herring population in New Hampshire will depend largely on the efficiency of these existing fishways and on the construction of new fishways at dams throughout the Merrimack River watershed.

 

Recommendations:

 

  • Monitor existing fish passage facilities.
  • Improve fish passage with new fishway construction and dam removals to provide access to suitable spawning habitat.
  • Work with partners to monitor commercial bycatch and make recommendations that will increase stocks of river herring in the ocean.
  • Continue to implement the Merrimack River River Herring Restoration Plan (link)

 

Distribution Map: Wildlife Action Plan Profile PDF Document