Ecological Risk Screening Summary - Blueback Herring (Alosa aestivalis) - High Risk

Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.

Alosa aestivalis, Blueback Herring, is a fish that is native to the Atlantic coast from Nova Scotia to Florida. These fish are an anadromous species that live in both freshwater and saltwater ecosystems. Adults occur at least 200 km off the coast, while juveniles spend 3-7 months in freshwater before migrating to sea. During breeding season, adults will migrate up coastal rivers
to spawn. A. aestivalis primarily feed on plankton, as well as crustaceans, insects, insect eggs, and smaller fish. A. aestivalis are considered “voracious planktivores”. Blueback herring are valuable to the commercial and recreational fishing industry. Historically, these fish were heavily used as a food source and bait to capture larger fish and lobsters and were even used as a fertilizer. Today, blueback herring is used in fish oil, fish meal, pet food, domestic animal feed, fishing bait, and a small remainder for human consumption. The importation, possession, or trade of A. aestivalis is regulated by nine States (see section 1). In Lake Theo, Texas, these fish were responsible for the elimination of several larger zooplankton species, causing a shift in the zooplankton community from cladocerans to copepods. The History of Invasiveness for A. aestivalis is classified as High due to the impact on native zooplankton. The climate match analysis for the contiguous United States indicates establishment concern outside the species’ native range. The highest climate match was centered on the native range along the Atlantic coast, but expanded beyond the native range into the Midwest, the Gulf of America coastal areas, and the Great Lakes. The Certainty of Assessment for this ERSS is classified as Medium because the known impact information comes from a population that may not be extant. There is sufficient biological, ecological, and distribution information for this species. The Overall Risk Assessment Category for A. aestivalis in the contiguous United States is High.