“The alewife and blueback herring are two of the eight principal species taken by the river fisheries in Maine and the most extensively distributed of the anadromous fish species in the state (Atkins 1887).  The early fisheries for alewives were weir, dip net, seine, drift net, and set net. The bulk of the harvest during the 1800s was for human consumption, because they kept exceptionally well in salt or when smoked.  The demand for alewives for human consumption declined with the widespread use of refrigeration in the 20th century that made many other fish species available to the market. Refrigeration also permitted the export of lobsters in bulk and increased the demand for these species as lobster bait. No commercial distinction is made between blueback and the more abundant alewife; the species are equally useful for bait, for food, and are harvested and marketed in a similar fashion.”

http://www.maine.gov/dmr/searunfish/alewife/