A 6-year study (released in 2012) of rainbow smelt populations in the Northeast offers a gloomy picture of the species’ current status and future as an important recreational fish and food source for larger predators. The same problems continue to plague the species in 2014.
“A Regional Conservation Plan for Anadromous Rainbow Smelt in the U.S. Gulf of Maine” is a collaborative document produced by members of the Maine Department of Marine Resources, the Massachusetts Division of Marine Fisheries, the New Hampshire Fish and Game Department and the University of Maine.
Its overview of the smelt situation reads:
The rainbow smelt (Osmerus mordax) is a small anadromous fish that over-winters in estuaries and bays prior to spawning each spring in coastal streams and rivers. Smelt have supported culturally important commercial and recreational fisheries throughout New England since at least the 1800s. However, in recent years, concerns have risen about the population status of rainbow smelt. The species has disappeared from the southern end of its geographic range, which once extended to the Chesapeake Bay and now may extend only as far south as Buzzards Bay, Massachusetts. High numbers of rainbow smelt that once supported commercial fisheries in New England have declined precipitously since the late 1800s to mid-1900s. While recreational fisheries for rainbow smelt continue, declining catches have also been noted by anglers, particularly since the 1980s.”
In 2004, the National Oceanic and Atmospheric Administration (NOAA) listed rainbow smelt as a federal “Species of Concern.” New Hampshire also lists smelt as a “Species of Special Concern.”
According to the study, smelt face numerous challenges. Water quality plays a major role in the hatching and survival of smelt eggs in fresh water. In many rivers, pH levels, high temperatures, turbidity and an increase in nutrients have led to declines. Heavy metals can also lead to egg mortality and impair development of young smelt. High algae growth resulting from an overabundance of nitrogen is another factor that can negatively impact the development of smelt embryos. In addition, dams and other impediments to upstream and downstream migrations of smelt can cause further harm.