Blueback herring 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). Blueback herring The blueback herring or blueback shad ("Alosa aestivalis") is an anadromous species of herring from the east coast of North America, with a range from Nova Scotia to Florida. Blueback herring form schools and are believed to migrate offshore to overwinter near the bottom. These fish are silvery in color, have a series of scutes (modified, spiny and keeled
Coastal fish but ascend rivers to spawn; eels are catadromous, living in rivers and streams, but returning to the sea to breed. Besides the species that migrate through estuaries, there are many other fish that use them as "nursery grounds" for spawning or as places young fish can feed and grow before moving elsewhere. For example, herring and plaice are two commercially important species that use the Thames Estuary for this purpose. Mangrove swamps are associated brackish water habitats. Many, though not all, mangrove swamps fringe estuaries and lagoons where the salinity changes with each tide. Among the most specialised residents of