It’s not spring on Cape Cod until the herring are running. From late February to early April, two species of herring —alewife and blueback herring—return from the ocean and swarm the ponds and streams of New England, seeking the waters in which they were born.
“[Alewife] come back every year to find areas to reproduce, much like salmon [do] in freshwater ponds,” says Ivan Valiela, Distinguished Scientist at the Ecosystems Center at the Marine Biological Laboratory (MBL). The species are “canaries in the coal mines” indicating shifts in the health of the Northeastern coastal environment, he said.
Populations of coastal alewife have been in decline since the 1960s, with a sharp drop in the 2000s, according to a new research paper by Valiela and colleagues. Commercial landings of river herring in 2005 were only about 1 percent of 1958’s catch. MORE
Header image: Alewife (Alosa pseudoharengus) during their seasonal migration. Credit: Rita Monteiro Pierce.