Factors affecting production of juvenile alewives in freshwater lakes
Adrian Jordaan; Allison Roy
Anadromous alewives (Alosa pseudoharengus) are an important forage for a variety of predatory fish species, are responsible for transporting nutrients across freshwater and marine ecosystems, and have a rich cultural and economic significance. Alewife populations, and thus their role in aquatic ecosystems, have declined throughout their range due to a combination of overfishing, predation, and habitat degradation. Current monitoring employs adult run counts at river fishways and fisheries surveys at sea and in large rivers and estuaries, but does not quantify juvenile recruitment in freshwater nursery habitats, and thus provides only a snapshot into population dynamics. My research aims to 1) optimize sampling methods and effort for accurately estimating juvenile densities in freshwater, and 2) quantify freshwater production across sites and determine factors influencing growth and survival. The results of this work will help determine sources of mortality, help prioritize restoration sites, and inform population modeling. Ultimately, this information will provide guidance for sampling methodology to inform stock assessment models, harvest regulations, and monitoring strategies.
National Fish and Wildlife Foundation
Massachusetts Division of Marine Fisheries