What is the alewifes life cycle?
Strong scientific evidence to-date makes it clear that alewives do not significantly alter water quality in Maine’s lakes and ponds. It is well-substantiated that the major factor causing algae blooms in our lakes is the introduction of phosphorus. When adult alewives migrate into a freshwater pond or lake, there is an influx of phosphorus to the lake. However, the majority of the spawning alewives return to the ocean, taking phosphorus with them. Additionally, young alewives that grow in freshwater ponds and lakes incorporate phosphorus into their bodies. That phosphorus is removed when the young migrate to the ocean. Consider the general life cycle of alewives – Alewives enter the lake, eat plankton, and then leave the lake — thus exporting lake nutrients. Without alewives in the system, plankton will bloom, die and settle to the bottom to provide nutrients for the lake’s algae bloom the following year. Comprehensive studies coordinated by Maine DEP in the 1970s on Round Pond and on
