TABLE 3 Summary of identified paucities regarding the marine ecology of anadromous alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), and American shad (Alosa sapidissima). Knowledge gapDescriptionReferenceMarine movementLittle is understood about marine distribution, habitat preferences, thermal boundaries, and precise migration routes (seasonal patterns)ASMFC, 2012; Neves, 1981Extent of alewife overwintering is unknownThe cues that influence movement (lunar, environmental, or physical) are understudiedEffects of climate changeBehaviorUnknown response to changes in food distribution and prey availabilityBi et al., 2021; Bindoff et al., 2022; Behrenfeld &Falkowski, 1997; Jessop, 1975; Jones et al., 1978; Loesch & Lund, 1977; Richardson & Schoeman, 2004; Tsitrin et al., 2022Changing ocean currents and rising water temperatures have unknown consequences on habitat useFew assessments on resilience to warming oceans and population-specific eurythermalityMigrationUnknown effects of sea surface temperature changes on spatial distribution and migration patternsJessop, 1975; Loesch & Lund, 1977; Jones et al., 1978; Ogburn et al., 2024; Bi et al., 2021; Tsitrin et al., 2022Outdated research on temperature-driven movementPopulation dynamicsGenetic diversityGenetic integrity and diversity within individual stocks are unknownDadswell et al., 1987; Bethoney et al., 2013; Hasselman & Limburg, 2012; Rulifson & Dadswell, 2020; Bozeman Jr & Van Den Ayvle, 1989Are populations from different rivers genetically distinct?Stock mixingDegree of straying from natal rivers is unknown for blueback(Bethoney et al., 2013; Dadswell et al., 1987; Rulifson & Dadswell, 2020).Stock mixing into heterogeneous populations or single-species aggregations during marine migrations is unclearDistinguishing alewife from blueback and hybridizationAlewife and blueback are managed as one species due to morphological similarities and spatiotemporal overlapBigelow & Schroeder, 1953; Messieh, 1977; Collette & KleinMacphee, 2002; Lynch et al., 2015; Hare et al., 2021Inaccurate stock assessments and misinterpretation of population trends due to misidentification

Published as part of Brown, Caliyena R., Sergio, Ava J. A., Bate, Caitlin S., Koopman, Natalie, Roland, Joshua B., Notman-Grobler, Oscar D. P., Mastrodimitropoulos, Paris M. B., Piczak, Morgan L. & Lennox, Robert J., 2025, A review of migratory Alosidae marine ecology in the northwest Atlantic, pp. 688 in Journal of Fish Biology 106 (3) on page 688, DOI: 10.1111/jfb.15977, http://zenodo.org/record/17003533