Blueback herring
| Blueback herring | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Clupeiformes |
| Family: | Clupeidae |
| Subfamily: | Alosinae |
| Genus: | Alosa |
| Species: | A. aestivalis |
| Binomial name | |
| Alosa aestivalis | |
The blueback herring (Alosa aestivalis) is an anadromous species of herring from the east coast of North America from Cape Breton, Nova Scotia to the St. John’s River in Florida. Blueback herring form schools and are believed to migrate offshore to overwinter near the bottom.
This fish has, in the past, been used as a baitfish for the lobster 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. It is one of the "typical" North American shads. They are often confused with alewifes and together these two species are often called "river herring". They reach a maximum size of approximately 16 inches (40 cm) and are believed to live up to 8 years.
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 1200 miles).
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 Massachusetts, Rhode Island, Connecticut, Virginia and North Carolina have instituted moratoriums on taking and possession.
The blueback herring is a U.S. National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the U.S. Government’s National Oceanic and Atmospheric Administration, 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
- Faria, R.; Weiss, S. & Alexandrino, P. (2006): A molecular phylogenetic perspective on the evolutionary history of Alosa spp. (Clupeidae). Molecular Phylogenetics and Evolution 40(1): 298–304. doi:10.1016/j.ympev.2006.02.008 (HTML abstract)