A review of migratory Alosidae marine ecology in the northwest Atlantic

REVIEW ARTICLE A review of migratory Alosidae marine ecology in the northwest Atlantic Caliyena R. Brown 1 | Ava J. A. Sergio 1 | Caitlin S. Bate 1,2 | Natalie Koopman 1 | Joshua B. Roland 1 | Oscar D. P. Notman-Grobler 1 | Paris M. B. Mastrodimitropoulos 1 | Morgan L. Piczak 1 | Robert J. Lennox 1,2 1 Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada 2 Ocean Tracking Network, Dalhousie University, Halifax, Nova Scotia, Canada Correspondence Caliyena R. Brown, Department of Biology, Dalhousie University, 1355 Oxford St., Halifax, NS B3H 4R2, Canada. Email: [email protected];caliyena. [email protected] Funding information Natural Sciences and Engineering Research Council of Canada; Liber Ero Foundation; Fisheries and Oceans Canada; Canada Foundation for Innovation Abstract Migratory animals play a crucial role in connecting distinct habitats by transferring matter and energy across ecosystem boundaries. In the North Atlantic, anadromous species exemplify this through their movement between freshwater and marine environments. Alosids, including species such as alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), and American shad (Alosa sapidissima), exhibit this migratory behavior to maximize growth and fecundity and are, therefore, vital components of Atlantic coastal ecosystems. Despite their ecological importance, these species have experienced considerable population declines. Due to a research focus on dams and the freshwater phase of their ecology, the marine ecology of Alosids remains much less understood, potentially hindering effective management. This paper synthesizes current knowledge on the marine ecology of anadromous alewife, blueback herring, and American shad in the northwest Atlantic, focusing on life-history aspects, migratory patterns, and foraging behavior at sea. The paper also outlines current fisheries management and the anthropogenic threats these species face during their marine phase. We identified knowledge gaps regarding marine distribution, migration routes, impacts of climate change on movement and behavior, population dynamics, and the identification of gaspereau. By identifying gaps in the literature, we highlight research needs, emphasizing the role of telemetry studies in tracking marine movements and the impact of climate change on habitat use. Addressing these gaps through targeted research on marine ecology and movement patterns is essential for developing informed management strategies aimed at increasing Alosid populations. KEYWORDS anadromous, conservation, fisheries management, forage fish, migration, movement ecology 1|INTRODUCTION Migration moves matter rapidly across relatively impenetrable boundaries (Cooke et al., 2024). Migratory animals are, therefore, important conduits of matter and energy at a landscape scale and connect distinct ecosystems and habitats (Bauer & Hoye, 2014; Post & Walters, 2011). In coastal ecosystems, movement between fresh water and the ocean allows fish species to maximize growth and fecundity, Received: 6 August 2024 Revised: 9 October 2024 Accepted: 13 October 2024 DOI: 10.1111/jfb.15977 FISH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2024 The Author(s). Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles. J Fish Biol. 2025;106:677–695. wileyonlinelibrary.com/journal/jfb 677 thereby, enhancing their lifetime fitness (e.g., Atlantic salmon, Salmo salar; Thorstad et al., 2011). In the temperate North Atlantic, several species exhibit anadromy, spawning in the relative safety of the oligotrophic fresh waters while exploiting the seasonal productivity of the marine environment (Samways et al., 2018). The ecology of freshwater spawning migrations of the fishes within the North Atlantic has received extensive research attention, although much less is known about oceanic movements, which could be hindering the effective management of these species. Further, salmonids are represented in the literature far more relative to other diadromous species, including Alosids, which have many paucities regarding their marine ecology. Among the most productive and abundant migratory diadromous species are the Alosids, which are an anadromous group of fishes that include six species in North America, including alewife (Alosa pseudoharengus) and blueback herring (Figure 1a;Alosa aestivalis; collectively referred to as “gaspereau”or “river herring”because they are virtually indistinguishable to the eye, herein gaspereau), skipjack shad (Alosa chrysochloris), hickory shad (Alosa mediocris), Alabama shad (Alosa alabamae), and American shad (Alosa sapidissima; Figure 1b;Bi et al., 2021). Considered to be forage species, Alosids provide a critical link between the lower food web and higher trophic predators across diverse taxa of fish, marine mammals, and birds (Schmitt et al., 2017), highlighting their ecological importance in the marine food web. Additionally, Alosids are highly productive across the Atlantic coast and have supported substantial commercial and recreational fisheries in Canada and the United States (McPhee, 2003). However, Alosids have experienced considerable population declines attributable to several anthropogenic stressors such as dams (Hasselman & Limburg, 2012; Mather et al., 2012). For instance, yearly landings of American shad from several rivers in Maine were estimated to reach 2 million fish prior to damming in the 1930s (Saunders et al., 2006). More recently, annual returns of American shad were estimated at ≤2000 fish (Saunders et al., 2006). Likewise, landings of gaspereau off the Mid-Atlantic coast exceeded 25,000 t until the 1970s, but since 1993, they have declined to less than 1000 t (Kocik, Haas-castro, et al., 2009). Alosids play a critical role in coastal ecosystems, and although fresh water is relied on for spawning and rearing, most of the life of the anadromous Alosids is at sea (Turner & Limburg, 2016), where they are relatively challenging to study. In the ocean, Alosids are difficult to observe, and current landing records are limited; therefore, many questions about their marine ecology remain unanswered. It is necessary to fill these knowledge gaps to enable more effective management of these species and to manage marine ecosystems for resilience. The objective of this paper is to synthesize the current knowledge about the marine ecology of the anadromous Alosids native to Canadian waters: the alewife, blueback herring, and American shad. For each of these three Alosids, we examine several aspects of their life history, including diet, growth, spawning, and death. Next, we form a comprehensive summary of their movement ecology, including both spawning migrations and foraging behavior at sea. From there, we identify threats and current fisheries management. Lastly, we highlight key knowledge gaps and directions for future studies that could help address these paucities and aid in supporting population recovery of the forage fishes that form the base of the food web. 2|ALEWIFE 2.1 |Life history 2.1.1 | Diet Alewife begin their lives in freshwater, feeding on small, planktonic crustacean nauplii before they grow and move toward the sea (Bozeman Jr & Van Den Ayvle, 1989). Although the pelagic diet of invasive alewife in the Laurentian Great Lakes is well understood (e. g., Pothoven & Vanderploeg, 2004; Stewart et al., 2009; Strus & Hurley, 1992), thorough descriptions of the diet of anadromous alewife in the Atlantic are still limited. Some insights into their diet in the marine environment were, however, gathered from stomach content analyses from alewife caught along the continental shelf from New England to Cape Hatteras, North Carolina (Bowman et al., 2000). In that study, non-decapod crustaceans represented the majority of the alewife's prey by weight, and adults were found to primarily filter-feed on FIGURE 1 (a) Alewife and blueback herring (photo credit: Christopher Bartlett) and (b) American shad (photo credit: Mikey Lennox). 678 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License copepods and krill. However, the stomach contents of larger individuals (>20 cm) included mollusks, cnidarians, and juvenile fish, suggesting an ontogenic shift in alewife from primarily filter feeding to a mixed strategy that includes predation on a higher diversity of taxa (Table 1; Bowman et al., 2000). 2.1.2 | Growth In the Chesapeake Bay estuary, juveniles were found to grow to about 114–127 mm long in their first year (Table 1; Hildebrand & Schroeder, 1927); however, once alewife enter the sea, there is a distinct lack of information regarding their rate of growth from the time they enter the ocean to when they return inshore. Several studies have shown that alewife are sexually dimorphic where females spend a longer time at sea and reach a larger average adult length of 284.3 mm (standard deviation =15.77), whereas males reach an average length of 271.6 mm (standard deviation =13.09; Table 1; Fay et al., 1983; Marjadi et al., 2019). The observed sexual dimorphism is also exhibited in the model parameters from the von Bertalanffy growth function (VBGF; Bertalannfy, von L., 1938) where L∞is the mean asymptotic length of fish, K is the Brody growth coefficient and represents how quickly fish approach L∞, and t 0 is the hypothetical age at which fish length is equal to zero (x-intercept; Gilligan-Lunda et al., 2021). For alewife, L∞ranged from 291.67- (males) to 310.48 mm (females), K ranged from 0.4 (females) to 0.441 (males), and t 0 ranged from 0.103 (females) to 0.142 (males; Messieh, 1977). Alewife take 3–6 years to mature at sea before returning to rivers to spawn (Table 1; Loesch, 1987). Individuals at lower latitudes are typically shorter lived and quick to mature, which is consistent with the latitudinal relationship across ectotherms (Table 1; Munch & Salinas, 2009). 2.1.3 | Spawning Alewife preferentially return to their natal stream or pond, relying on olfactory mechanisms to detect the odor of the water from which they hatched (Table 1; Thunberg, 1971). The frequency of iteroparity in alewife populations is latitudinally influenced, with northern latitudes having a higher percentage of repeat spawners annually (Table 1; Fay et al., 1983). Iteroparity also varies at smaller spatial scales between sites, suggesting that river-specific drivers, like anthropogenic impacts (habitat degradation, overfishing, dams, and loss of river connectivity), are primary determinants of the survival and fidelity of anadromous alewife populations (Hare et al., 2021; Spares et al., 2023). In the Gaspereau River in Nova Scotia, the alewife stock is heavily impacted by overfishing; of the previously spawned adults, only 11.1% of males and 7.4% of females returned the following years, compared to an estimated 50% return rate in rivers with minimal anthropogenic stressors (Gibson, 2000). Unlike salmonids, for which males expend more energy spawning and females have higher rates of repeat spawning (Jonsson et al., 1991), interannual returns are higher among male alewife than females (Table 1). However, this may be attributed to artificial selection, with the longer mean length of females at spawning age increasing their likelihood of being caught in gillnets, decreasing their survival during spawning season (Spares et al., 2023). 2.1.4 | Mortality Southerly alewife live only 3–4 years, compared to their northern counterparts, which can live up to 9–10 years (Table 1; Fay et al., 1983). Predation is a primary cause of natural mortality, and alewife contribute to the diet of piscivorous fishes, birds, and mammals (Hare et al., 2021). Freshwater predation is a major bottleneck, and some predators may feed exclusively on alewife during their spawning migration (Hare et al., 2021), whereas predation at sea is more diffuse. Anadromous alewife store substantial energy from the ocean in their fatty tissues, contributing to the nutrient input of freshwater systems following their annual spawning events. Similar subsidies to the marine environment must be relevant, although they are less commonly considered than the subsidies provided to freshwater systems for anadromous species (Table 1; Dias et al., 2019). Although there is ample research on marine isotopes carried by anadromous fishes into fresh water (Durbin et al., 1979), there is little comparable work to find freshwater isotopic signatures in the marine environment that might suggest how alewife provide a reciprocal subsidy to the ocean via their anadromy. Nevertheless, alewife have shown to be significant to the diets of demersal groundfish, indicating a high degree of predation mortality at sea (Link & Garrison, 2002). Young of year (YOY) alewife immigrating from estuaries to the northeastern coastal shelf have even been suggested to influence the movement behavior of predator species (i.e., co-migration; Hare et al., 2021). Historically, the pursuit of alewife by Atlantic cod (Gadus morhua and other gadids) may have been a key driver of gadid movement into estuaries and river mouths where alewife aggregate to spawn (Ames & Lichter, 2013). In estuaries where alewife were extirpated, inshore gadid populations also disappeared and did not return, suggesting a high predator–prey linkage between gadids and alewife in the northeastern Atlantic and a role of freshwater–marine nutrient subsidies (Table 1; Ames & Lichter, 2013). Further, modeling suggests that if alewife populations increase, their migrations to and from the marine environment could positively impact species of economic importance and conservation concern by acting as a stable food source during unpredictable changes in climate for key marine species (Dias et al., 2019). 2.2 |Behavior 2.2.1 | Migration and foraging Anadromous alewife range from North Carolina to Newfoundland (Table 1; Collette & Klein-Macphee, 2002; ASMFC, 2009). YOY alewife typically migrate to marine environments in June and July (Schmidt et al., 1988). Once at sea, juveniles join large intraspecific BROWN ET AL.679 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License TABLE 1 Summary of life-history aspects and behavior in the marine environment for each alewife (Alosa pseudoharengus), blueback (Alosa aestivalis), and American shad (Alosa sapidissima). Aspect Alewife Blueback herring American shad Life history Diet •Mainly prey on non-decapod crustaceans •Adults also feed on copepods and krill •Larger individuals (>20 cm) feed on mollusks, cnidarians, and bony fish •Consume both pelagic and benthic prey, but more selective than alewife •Juveniles primarily feed on zooplankton •Adults also consume zooplankton, as well as small fishes, fish eggs, and small crustaceans •Adults cannibalize juveniles in nearshore areas on their migration back to sea •At sea, adults feed on copepods, mysids, and small fish Growth •Evidence of 114–127 mm of growth in their first year in the Chesapeake Bay estuary •Adults are sexually dimorphic; females spend longer at sea and reach a larger average length of 284.3 mm, whereas males average 271.6 mm •Maturation at sea takes 3–6 years •Lower latitude populations are shorter lived and quicker to mature •VBGF growth parameters: L∞=291.67 mm (males) –310.48 mm (females) K=0.4 (females) –0.441 (males) t 0 =0.103 (females) –0.142 (males) •Adults grow up to 197–322 mm in fork length •Females are larger than males; 289 mm and 277 mm, respectively •Growth rates plateau after spawning, and there is little growth between spawning events •Energetic trade-off between frequent spawning and at-sea growth (multiple spawners are smaller) •Maturation at sea takes 4–5 years for females and 3–4 years for males •VBGF growth parameters: L∞=231.33 mm (males) –259.85 mm (females) K=0.469 (females) –0.590 (males) t 0 =0.283 (females) –0.338 (0.338) •Juveniles migrate to sea when they reach 38–114 mm •Shad are larger than alewife and blueback and reach up to 760 mm •Females are larger than males •Northern populations are larger than southern contingents •Maturation at sea takes 2–6 years; males typically mature in 2 years, females mature in 3–4 years •Average VBGF growth parameters: L∞=481 mm K=0.44 t 0 =0.32 Spawning •Adults exhibit spawning site fidelity and return to their natal stream or pond using olfactory cues •Higher-latitude populations demonstrate more frequent iteroparity •Interannual returns are higher among males •Precede blueblack in spawning migrations of shared rivers •Adults return to their natal river to spawn •Exhibit iteroparity and will spawn up to four times •Gravimetric fecundity positively correlates with age and decreases with increasing latitude •Spawning season lengthens with increasing latitude •Spawning can take place in brackish water •Return to spawn later in the spring than alewife •Adults exhibit spawning site fidelity and return to their natal river to spawn; low levels (3%) of straying have been observed •Northern populations are iteroparous and can spawn up to five to seven times, whereas the southern populations are semelparous •Semelparity is observed only in St. Johns River, Florida, and Ogeechee River, Georgia Mortality •Lower-latitude populations live 3–4 years; northern counterparts live up to 9–10 years •Predation is a primary cause of mortality •Energy movement and nutrient input in the marine environment are understudied but likely comparable to the contributions in fresh water •Key driver of predator movement (i.e., Atlantic cod and other gadids) •Maximum age of an individual observed in sampling studies were 8 and 12 years old •Females live longer than males •Males are more abundant in younger age classes •Predation by fish, sea birds, and marine mammals is a leading cause of mortality in the marine environment •Can live up to 13 years •Natural mortality rates differ based on latitude due to reproductive styles; northern populations live longer •Predation by sharks, several fish species, and marine mammals significantly contribute to adult mortality •Adults commonly die during spawning migrations Behavior Migration •Range from Carolina to Newfoundland •Juveniles join large schools of similar-sized individuals after they leave their spawning river •Schooling with menhaden or blueback is common •Marine range from Florida to Nova Scotia •Some migratory contingents remain resident in estuaries near spawning rivers; some undertake offshore migrations •Migrate from Florida to Newfoundland •Intraspecific schools of juveniles and postspawning adults overwinter in deep waters offshore Florida, the Mid-Atlantic Bight, and along the Scotian Shelf 680 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License TABLE 1 (Continued) Aspect Alewife Blueback herring American shad •Move northward and inshore in the spring and offshore and southward in the fall •Found along the Mid-Atlantic coastline in the winter and spring •Movement is regulated by zooplankton productivity and by abiotic factors, such as temperature, tidal currents, salinity, and depth •Marine temperatures > 14C are avoided •Water temperatures 5–10C cue spawning migrations •Spawning begins late March in the south and progressively later into July further north •Summer aggregations consist of a mixed stock of contingents from multiple rivers •Move southward in the fall to aggregate offshore in deeper waters in overwintering sites in Mid-Atlantic Bight and along Scotian Shelf •Migration follows temperature contours in northern limit of range and zooplankton availability •Move to mid-depth, coastal waters in the spring •Migration to spawning rivers when water temperatures range 14–22C •Spawning begins later than blueback herring, in late April •Overwintering aggregations are heterogenous mixtures of populations from many rivers •Spawning migrations occur when water temperatures are between 8 and 26C •Southern populations begin northward spawning migrations in January, and northern populations begin spawning migrations progressively later into the spring as latitude increases Foraging •Use a mixture of inshore and offshore foraging areas •Feeding schools are mixed stock of several populations •Have diel vertical migrations following zooplankton •Use both particulate (during day) and filter-feeding (during night) strategies •Zooplankton productivity and foraging partially regulate movement at sea •Forage in nearshore habitat until water is too warm (>14C) •School as single-species aggregations or with alewife to optimize feeding •Undertake diel vertical migrations following zooplankton throughout water column •Demonstrate active foraging and filter-feeding •Feeding migrations from North Carolina to Nova Scotia have been recorded •Some populations utilize inshore embayments for feeding in the summer •Juveniles join large intraspecific feeding schools along the coast •Demonstrate diel feeding patterns following zooplankton •Primarily feed in the evening •Summer foraging grounds include surface waters in the inner Bay of Fundy, the inner Gulf of St. Lawrence, and off Newfoundland and Labrador •Majority of foraging occurs in the marine environment •Adults demonstrate passive filter feeding and active foraging Abbreviation: VBGF, von Bertalanffy growth function. BROWN ET AL.681 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License feeding schools of similar-sized individuals, with smaller alewives preferring shallower regions compared to larger adults (Table 1; Stone and Jessop, 1981). These feeding schools are mixed-stock, meaning that several different alewife populations are moving and feeding together (DFO, 1986; Rulifson & Dadswell, 2020). Alewife are also known to form mixed-species schools with other herrings like menhaden (Brevoortia spp.) or blueback herring (A. aestivalis; Bigelow & Schroeder, 1953; Rulifson & Dadswell, 2020). Despite sustaining a critical fishery, there are limited investigations of the marine migratory movement of alewife (Gibson et al., 2017; Huveneers et al., 2016; Neves, 1981; Stone & Jessop, 1992; Tsitrin et al., 2020; Tsitrin et al., 2022; Ogburn et al., 2024). However, a recent acoustic telemetry study demonstrated that alewife from Choptank River, Maryland, migrated northward into Georges Bank and the Gulf of Maine in the summer and moved southward in the fall and winter (Ogburn et al., 2024). These findings validate the yearly migratory patterns inferred from catch and by-catch data, which suggest that alewife move northward and inshore in the spring, as many prepare to return to fresh water for spawning, and finally offshore and southward in the fall (Table 1; Neves, 1981; Stone & Jessop, 1992). This migration pattern was observed in populations from the Mid-Atlantic Bight, where summer and fall catches were concentrated in Nantucket Shoals, Georges Bank, and coastal Gulf of Maine regions, suggesting they moved northward from their natal stream (Neves, 1981). Furthermore, winter catches indicated they return to the Mid-Atlantic coastline in the winter and spring (Table 1; Neves, 1981; Tsitrin et al., 2022). These migratory patterns were further validated by alewife catch data along the coast of Nova Scotia that indicated alewife distribution shifted inshore and northward in spring along the Scotian Shelf and offshore and southward in fall toward the Gulf of Maine and Bay of Fundy (Stone & Jessop, 1992). The extent of offshore overwintering for alewife is still unknown; however, the theorized seasonal distribution of alewife closely resembles American shad migratory movements, which suggests that alewife may use a mixture of inshore and offshore foraging areas annually (Table 1; Neves, 1981). Alewife movement at sea is presently thought to be regulated by biological factors as they follow zooplankton productivity (DFO, 1986; Neves, 1981; Tsitrin et al., 2022). When alewife feed on plankton, they undertake diel vertical migrations following the vertical movement of zooplankton throughout the water column (Table 1; Neves, 1981; Stone & Daborn, 1987). Stomach content analyses suggest alewife particulate feed on macrozooplankton when water visibility is high during the day and filter feed on microzooplankton during low visibility at night (Table 1; Gilmurray, 1980; Stone & Jessop, 1992). Recent studies have demonstrated that alewife marine movement is also influenced by water temperature, tidal currents, salinity, and depth (Tsitrin et al., 2022; Turner et al., 2016), suggesting their distributions are constrained by suitable oceanographic conditions. For instance, seasonal spawning migrations are thought to be triggered by water temperatures around 5–10C (Jessop & Parker, 1988; Tsitrin et al., 2022). Therefore, mature alewife begin spawning migrations toward rivers in late March in the south and progressively later into July further north (Table 1; Cole et al., 1980; Mullen et al., 1986). A recent tagging study also suggests that alewife strongly avoid marine temperatures above 14C (Tsitrin et al., 2022). In this study, postspawned alewife emigrating from Gaspereau River, Nova Scotia, remained in the Minas basin and foraged in nearshore habitat for 20 days before water temperatures warmed, cueing offshore migration (Table 1; Tsitrin et al., 2022). Similar behavior was observed in American shad, which use cold tidal currents as migration corridors throughout at-sea movement (Neves & Depres, 1979; Tsitrin et al., 2022). 3|BLUEBACK HERRING 3.1 |Life history 3.1.1 | Diet Blueback herring consume a variety of prey, including pelagic and benthic species; however, their diet is more selective compared to alewife and primarily feed on zooplankton (Mullen et al., 1986; Stone & Daborn, 1987). As juveniles grow and move from their natal rivers into estuaries, larger zooplankton, such as adult copepods (e. g., Eurytemora affinis and Cyclops vernalis), become the primary diet (Table 1; Mullen et al., 1986). Adults in the marine environment are predominantly planktivorous and continue to consume zooplankton, although they also consume small fishes, eggs of other fish, and crustaceans such as pelagic shrimp (Table 1; Bigelow & Schroeder, 1953; Munroe, 2002). 3.1.2 | Growth Adult blueback herring can reach lengths of 197–322 mm in fork length and weigh 93–468 g for ages 3–12 (Jessop, 1993). Like alewife, adults are sexually dimorphic, where females are slightly larger and have an average total length of 289 mm, whereas males average 277 mm in length (Table 1; Bowlby & Gibson, 2016; Loesch & Lund, 1977). However, it is unclear whether there are further size similarities between alewife and blueback herring. Contradictory reports on size differences in Nova Scotia stated that blueback herring were substantially smaller than alewife on average (Bowlby & Gibson, 2016), whereas a different study found blueback herring to be only marginally smaller (Jessop, 1993). Parameters from the VBGF for blueback herring demonstrate the observed sexual dimorphism and the argument that blueback herring are smaller in size than alewife, with L∞ ranging from 231.33- (males) to 259.85 mm (females), K ranging from 0.469 (females) to 0.590 (males), and t 0 ranging from 0.283 (females) to 0.338 (males; Messieh, 1977). Most of the growth in blueback herring occurs during the first couple of years at sea and plateaus after they reach sexual maturity. Adults exhibit very little growth between spawning events, such that individuals ranging from 3 to 5 years old only grow an average of 13 mm between annual spawning (Table 1; Mullen et al., 1986; 682 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Bowlby & Gibson, 2016). Therefore, blueback herring that have spawned multiple times are smaller for their given age, particularly in weight, suggesting an energetic trade-off between frequent spawning and at-sea growth (Table 1; Bowlby & Gibson, 2016). Sex-specific variation exists within age at first reproduction, where maturation takes 4–5 years for females and 3–4 years for males. For instance, the highest proportion of first-time male spawners is at ages 3 and 4, accounting for 46.9% and 49.8% of the individuals in each age class, respectively (Marcy, 1969), whereas most first-time female spawners are older, ages 4 and 5, and account for 74.6% and 16.4% of individuals observed at each age class during spawning events (Marcy, 1969). The causes for this variation remain unclear (Bowlby & Gibson, 2016). 3.1.3 | Spawning Blueback herring are iteroparous and will spawn up to four times before death (Table 1; McBride et al., 2014; Bowlby & Gibson, 2016). They exhibit a degree of spawning site fidelity and will typically return to the same river to spawn (Table 1; Bozeman Jr & Van Den Ayvle, 1989); however, the frequency of return and the proportion that stray to novel spawning sites are unclear. It is speculated that blueback herring rely on olfactory mechanisms, similar to alewife; however, their migratory cues back to natal rivers are not well understood. Additionally, it is unknown whether ovary weight and fork length are related, but research suggests fecundity positively correlates with age and decreases with increasing latitude when measured gravimetrically (Table 1; Jessop, 1993). The length of the spawning season prolongs with increasing latitude and may be a function of cooler northern temperatures (Loesch & Lund, 1977; Lynch et al., 2015), likely compensating for the decreased fecundity at these latitudes. Although spawning typically occurs in freshwater (Bigelow & Schroeder, 1953), blueback herring will also fertilize eggs in slightly brackish (Kuntz & Radcliffe, 1918) and fully brackish waters (Breder, 1948). Regardless of salinity, studies suggest that spawning occurs beyond the influence of the tide (Bigelow & Schroeder, 1953; Hildebrand, 1963; Hildebrand & Schroeder, 1927). Despite the overwhelming similarities between alewife and blueback herring, there can be some spatial and temporal isolation between the two species during spawning events (Loesch & Lund, 1977). Both species can differ spatially by spawning in different systems or within the same river system but in different areas depending on spawning habitat preferences (Loesch & Lund, 1977). Temporal isolation occurred during the spawning migration to the Tusket River, Nova Scotia; alewife returned to spawn more than 4 weeks earlier than blueback herring (Table 1; Bowlby & Gibson, 2016). 3.1.4 | Mortality In situ observations during field studies in Nova Scotia suggest that the maximum age of blueback herring is variable. In the Tusket River, the oldest individual observed was 8 years old (Bowlby & Gibson, 2016); however, during sampling across the Tusket, Mactaquac, Gaspereau, and Margaree rivers, the maximum age observed was 12 (Table 1; Jessop, 1993). Females tend to live longer than males, and males are more abundant in younger age classes (3–5 years), whereas the abundance of older female blueback herring (7+years) tends to be far greater (Loesch & Lund, 1977). As forage fish, blueback herring provide an important connection between marine and estuarine food webs, transferring nutrients from their oceanic zooplankton food source to coastal piscivore predators (Ames & Lichter, 2013). Death in the marine environment is largely due to predation by a variety of predators, including spiny dogfish (Squalus acanthias), Atlantic cod (Gadus morhua), silver hake (Merluccius bilinearis), white hake (Urophycis tenuis), Atlantic halibut (Hippoglossus hippoglossus), bluefish (Pomatomus saltatrix), weakfish (Cynoscion regalis), striped bass (Morone saxatillis), seals, gulls, and terns (Munroe, 2002). 3.2 |Behavior 3.2.1 | Migration and foraging Blueback herring have a marine range from Florida (Hildebrand & Schroeder, 1927) to Nova Scotia (Table 1; Bigelow & Schroeder, 1953; Rulifson & Dadswell, 2020), where prespawned individuals spend 2– 5 years growing and feeding after leaving their natal rivers (Loesch, 1987). Despite the extensive proportion of their lives spent at sea, relatively little is known about blueback herring marine ecology in comparison to their freshwater, riverine migrations (Bethoney, Stokesbury, & Cadrin, 2014; Neves, 1981; Rulifson & Dadswell, 2020; Stone & Jessop, 1992). However, recordings of long-distance feeding migrations show migratory routes from North Carolina to Nova Scotia, which align with the routes of American shad (Rulifson & Dadswell, 2020). There is also evidence of the separation into migratory contingents, where a proportion of blueback herring are semi-resident in estuarine regions near their natal rivers and use inshore embayments for feeding instead of undertaking large offshore migrations (Table 1; Stone & Jessop, 1992; Rulifson & Dadswell, 2020). Due to the complex movement dynamics in each population, summer foraging aggregations consist of mixed stocks and therefore include multiple contingents from different spawning rivers (Table 1; Rulifson & Dadswell, 2020). When foraging in the marine environment, blueback herring benefit from schooling behavior (i.e., optimizing feeding and avoiding predators, etc.) and group into single-species aggregations at sea or school with alewife (Table 1; Bethoney et al., 2013; Rulifson & Dadswell, 2020). During summer feeding migrations, blueback herring follow zooplankton throughout the marine environment. There is evidence that blueback herring undertake diel vertical migrations (Jessop, 1990), which mimic the diel movements of zooplankton (Table 1; Neves, 1981). However, the availability of suitable water BROWN ET AL.683 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License temperatures may limit their vertical feeding migrations (Stone & Jessop, 1992). Similar to their vertical movements, the horizontal migrations of blueback herring are likely tied to zooplankton concentrations at different latitudes throughout the year, outside of the spawning migration (Neves, 1981; Stone & Jessop, 1992). Researchers in the Minas basin in Nova Scotia have found evidence of filter-feeding among anadromous blueback herring, although they may also undertake active foraging in the marine environment (Table 1; Stone & Daborn, 1987). After foraging at sea during summer, blueback herring move southward in the fall and aggregate in offshore overwintering sites in the Middle Atlantic Bight (Neves, 1981) and along the Scotian Shelf from the Gulf of Maine to the Bay of Fundy (Stone & Jessop, 1992). Neves (1981) speculated that temperature and availability of zooplankton drive the selection of specific overwintering sites. Although blueback herring are typically associated with inshore habitats and remain in shallower waters than alewife (Bethoney, Stokesbury, Schondelmeier, et al., 2014; Neves, 1981), during winter, they are found comparatively deeper, likely seeking warmer bottom water, preferring water >5C offshore (Stone & Jessop, 1992). This temperature preference suggests that blueblack migration strongly follows temperature contours in the northern limit of their range (Canada; Table 1; Stone & Jessop, 1992). In early spring, blueback herring start to occupy mid-depth, nearshore waters along the Atlantic coast as they move northward to reach spawning rivers in late spring (Neves, 1981; Stone & Jessop, 1992). The timing of arrival for the spring spawning migration is, again, thought to be temperature-driven, timing their movements to coincide with an optimal water temperature range of 14–22C for spawning (Table 1; Bi et al., 2021, Loesch & Lund, 1977, Ogburn et al., 2024). Blueback herring prefer warmer spawning temperatures than alewife, and so, they generally arrive later than alewife in their shared rivers (Bigelow & Schroeder, 1953). For blueback herring, this leads to a late-April arrival in spawning rivers (although this varies), and they can remain at these sites for several months into the summer before they return to sea (Jones et al., 1978). 4|AMERICAN SHAD 4.1 |Life history 4.1.1 | Diet On their migration back to sea, adult American shad prey on smaller freshwater fish, including shield darters (Percina peltata) and, at times, cannibalize juvenile American shad (Table 1; Chittenden Jr., 1976b). Beyond these nearshore data, there are only a few studies to rely on for characterizing American shad diet in the marine environment; however, adults are known to return to their planktonic diet at sea and primarily feed on copepods and mysids (Walburg & Nichols, 1967). Stomach content analyses have also shown that adults prey on small fish (Table 1; Facey & Van Den Avyle, 1986; Walburg & Nichols, 1967). More information is needed to better understand American shad diet at sea during juvenile and adult life stages. 4.1.2 | Growth In addition to freshwater environments, YOY American shad also use estuarine areas as nursery grounds (Crecco et al., 1983; McCormick et al., 1996), typically in low-velocity waters where food availability is higher (Limburg, 1996). Juveniles grow to 38–114 mm long before they emigrate into the marine environment in autumn (Bigelow & Schroeder, 1953; Mitchell, 1925), suggesting that growth and factors associated with size influence the timing of seaward emigration (Chittenden Jr., 1969; Miller et al., 1973). Most growth occurs at sea, where prespawned fish spend 2–6 years until they reach sexual maturity (Table 1; Bigelow & Schroeder, 1953; Walburg & Nichols, 1967). Males reach maturity younger than females, at around 2 years or when they reach 290 mm (on average), whereas females mature in their third or fourth year when they are closer to 400 mm (Walburg & Nichols, 1967). As such, American shad are sexually dimorphic; females are typically larger than males within their age class (Du et al., 2023). Compared to alewife and blueback herring, American shad are the largest among these Alosidae, and adults can grow up to 760 mm and weigh up to 5500 g (Bigelow & Schroeder, 1953). Their maximum size depends on latitude, and northern populations reach larger sizes than their southern contingents (Table 1; Gilligan-Lunda et al., 2021; Poulet et al., 2023; Robins et al., 1986). The VBGF parameters for American shad reinforce their size difference when compared to the parameters for alewife and blueback herring, with an average of 481 mm for L∞, 0.44 for K, and 0.32 for t 0 (GilliganLunda et al., 2021). 4.1.3 | Spawning American shad exhibit spawning site fidelity to their natal rivers (Table 1; Carscadden & Leggett, 1975; Hill, 1959; Nichols, 1966; Talbot, 1954), with low levels of straying (3%; Melvin et al., 1986)in some populations (Mansueti & Kolb, 1953; Williams & Daborn, 1984). Spawning strategies also differ latitudinally where northern populations are iteroparous and can spawn five (Grote et al., 2014; McBride et al., 2016) to seven times (Provost, 1987), whereas southern populations are semelparous (reproduce once then die; Table 1; Leggett & Carscadden, 1978; Poulet et al., 2023). Semelparous populations include those that spawn in the St. Johns River, Florida (Limburg et al., 2003) and the Ogeechee River, Georgia (Sykes, 1956). This semelparity observed in southern populations appears to be an adaptation to the consistent weather in the south, resulting in a higher probability of successful recruitment and consequently higher fecundity, when defined as the rate of successful recruitment (Carscadden & Leggett, 1975; Roff, 1992). 684 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 4.1.4 | Mortality American shad have been reported to live up to 13 years, and there is no recorded evidence of sexual dimorphism regarding maximum age, like in blueback herring populations (Altman & Dittmer, 1962). However, the natural mortality rate does differ based on latitude, where northern populations reach an older maximum age due to alternate reproductive styles, much like alewife (Gilligan-Lunda et al., 2021; Poulet et al., 2023). Other barriers that limit survival include predation, target fisheries, and by-catch (Table 1; Bailey et al., 2004; Bethoney et al., 2013). At sea, American shad are preyed on by sharks, bluefin tuna (Thunnus thynnus), kingfish (Scomberomorus cavalla), and porpoises in the southern United States (Walburg & Nichols, 1967). Passive tagging studies on American shad have also revealed that dogfish (S. acanthias) and Atlantic cod (G. morhua) also prey on American shad (Dadswell, 1990). Additionally, there are records of seals preying on American shad as they begin their spawning runs into river mouths (Dadswell, 1990). Although northern American shad are iteroparous, like gaspereau, it is not uncommon for adults to die on their spawning migration. For instance, in northern New Jersey, dead, egg-bound females were found during their migration upstream to spawning grounds, likely attributable to starvation (Chittenden Jr., 1976a). Therefore, attrition of American shad when they enter freshwater forms a key part of the species' marine demography. 4.2 |Behavior 4.2.1 | Migration and foraging American shad exhibit a complex marine migration pattern influenced by both environmental cues and intrinsic factors. They undertake extensive seasonal migrations in surface waters (Neves & Depres, 1979) along the northwest Atlantic, spanning from Newfoundland and Labrador (Dempson et al., 1983; Limburg et al., 2003) to Florida (Table 1; Williams & Bruger, 1972). YOY juveniles either spend the first year in the lower estuary of their natal river (Hoffman et al., 2008; Leggett & Whitney, 1972) or exhibit short residency, staying within fresh water for the summer, then migrating to sea in the fall (Greene et al., 2009; Neves & Depres, 1979). Upon entering the marine environment, juveniles join large intraspecific schools of immature and postspawning adults for feeding and growth (Bigelow & Schroeder, 1953; Dadswell et al., 1987). As water temperatures cool later into the fall, schools migrate in surface waters (Bigelow & Schroeder, 1953) southward to overwintering sites, which include deeper waters, 40–175 km offshore Florida, the Mid-Atlantic Bight, and along the Scotian Shelf (Collette & Klein-Macphee, 2002; Dadswell et al., 1987). The aggregations in these overwintering sites are heterogeneous mixtures of American shad populations from many rivers (Dadswell et al., 1987). Spawning can occur when water temperatures cool to 8–26C (Walburg & Nichols, 1967); however, peak spawning begins when water temperatures fall between 12 and 21C (Jessop, 1975; Jones et al., 1978). Therefore, spawning migrations are temporally influenced, and southern populations begin migrating toward natal rivers in January, with some reaching the southern limit of their range in the St. Johns River, Florida (Table 1; Limburg et al., 2003). Northern populations begin migrations to spawning rivers progressively later into the spring as latitude increases (Limburg et al., 2003). During the summer, spawning continues upstream from the Delaware River to the St. Lawrence River, and northern American shad populations concentrate in the surface waters of foraging grounds (Leim, 1924; Themelis, 1986) in the inner Bay of Fundy, the inner Gulf of St. Lawrence, and off of Newfoundland and Labrador (Table 1; Dadswell et al., 1987). Foraging behavior varies based on life stage and habitat. Walter III and Olney (2003) demonstrated that adult stomach fullness index was highest in the marine environment (Table 1), followed by estuarine habitats, then freshwater, indicating the majority of feeding takes place at sea. There is little information about juvenile stomach fullness; however, juveniles are known to form feeding schools along the coast (Greene et al., 2009; Neves & Depres, 1979) and demonstrate diel feeding patterns primarily foraging in the evening (Johnson & Dropkin, 1996; Massmann, 1963). Additionally, planktivorous adults feed both passively by filtering prey as they swim and by actively ambushing (Harris & McBride, 2009), suggesting that American shad mainly consume what they encounter and feed if suitable prey is available (Atkinson, 1951; Leim, 1924; Walter III & Olney, 2003). 5|THREATS AND FISHERIES MANAGEMENT 5.1 |Threats The IUCN most recently assessed alewife and American shad as “least concern,”whereas blueback herring were classified as “vulnerable” (Table 2). Despite mounting concern surrounding population declines, federal protection under the Species at Risk Act (SARA) in Canada and the Endangered Species Act in the United States have not yet occurred for these species due to data deficiencies (Table 2). Overfishing was historically the primary contributor to population declines of alewife, blueback herring, and American shad (Figure 2a; Bailey et al., 2004). Specifically, the commercial freshwater fisheries of gaspereau in Canada and the United States heavily contributed to population declines in recent history (DFO, 2021). Further, the estimated exploitation rates for Canadian alewife and blueback herring in the late 1990s were as high as 89% based on catch, escapement, and run size estimates for each year (DFO, 2021). Additional information regarding the effects and management of Alosid fisheries can be found in the comprehensive review by Hare et al. (2021). The decimation caused by freshwater fisheries should be viewed as a cautionary tale for marine fisheries to avoid similar population declines. Despite the continued exploitation of Alosids at the commercial scale, more recently, the most predominant threats to these species include habitat degradation (Figure 2b), by-catch in commercial fisheries BROWN ET AL.685 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Dadswell, M. J. (1990). The American Shad. Department of Fisheries and Oceans Canada. https://waves-vagues.dfo-mpo.gc.ca/librarybibliotheque/40627913.pdf Davies, K. T., & Brillant, S. W. (2019). Mass human-caused mortality spurs federal action to protect endangered North Atlantic right whales in Canada. Marine Policy,104, 157–162. Dempson, J. B., LeDrew, L. J., & Furey, G. (1983). Occurrence of American shad (Alosa sapidissima) in northern Labrador waters. Le Naturaliste Canadien,110, 217–221. DFO. (1986). Alewife. Underwater World. https://waves-vagues.dfo-mpo. gc.ca/library-bibliotheque/40724372.pdf DFO. (2021). 2021 Gaspereau –Integrated fishery management plan: Maritimes Region. https://www.dfo-mpo.gc.ca/fisheries-peches/ifmpgmp/gaspereau-gaspareau/index-eng.html#toc12 DFO. (2022). Stock status of alwife and blueback herring (gaspereau) in the DFO gulf region. DFO Canadian Science Advisory Secretariat Report, Science Advisory Report, 2022/014. Dias, B. S., Frisk, M. G., & Jordaan, A. (2019). Opening the tap: Increased riverine connectivity strengthens marine food web pathways. PLoS One,14(5), e0217008. Du, J., Liu, Q., & Zheng, Y. (2023). Screening and characterization of sexspecific sequences through 2b-RAD sequencing in American shad (Alosa sapidissima). PLoS One,18(3), 1–12. Durbin, A. G., Nixon, S. W., & Oviatt, C. A. (1979). Effects of the spawning migration of the alewife, Alosa Pseudoharengus, on freshwater ecosystems. Ecology,60(1), 8–17. Espinoza, M., Lédée, E. J. I., Simpfendorfer, C. A., Tobin, A. J., & Heupel, M. R. (2015). Contrasting movements and connectivity of reef-associated sharks using acoustic telemetry: Implications for management. Ecological Applications,25(8), 2101–2118. Facey, D. E., & Van Den Avyle, M. J. (1986). Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (South Atlantic) –American shad. U.S. Fish and Wildlife Service Biological Report No. 82 (11.45), and U.S. Army Corps of Engineers Report No. TR EL-82-4, Washington D.C. Fay, C. W., Neves, R. J., & Pardue, G. B. (1983). Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (mid-Atlantic): Alewife/blueback. Biological Report, United States Fish and Wildlife Service. Frankensteen, E. D. (Ed.). (1976). Genus Alosa in a channelized and an unchannelized creek of theTar river basin, North Carolina. Masters Thesis. East Carolina University. http://cybrary.fomb.org/pages/hms9_ diadro_habitat_2009_6.pdf Furey, N. B., Vincent, S. P., Hinch, S. G., & Welch, D. W. (2015). Variability in migration routes influences early marine survival of juvenile Salmon Smolts. PLoS One,10(10), e0139269. Gahagan, B. I., & Bailey, M. M. (2020). Surgical implantation of acoustic tags in American shad to resolve riverine and marine restoration challenges. Marine and Coastal Fisheries,12(5), 272–289. German, B., Watson, J., & Best, M. (2023). River herring habitat conservation plan. In Greater Atlantic region policy series [23–04]. Fisheries. https://www.greateratlantic.fisheries.noaa.gov/policyseries/347p Gibson, A. J. F., Bowlby, H. D., & Keyser, F. M. (2017). A framework for the assessment of the status of river herring populations and fisheries in DFO's Maritimes region. Canadian Science Advisory Secretariat Research Document,105,vi+69p. Gibson, J. A. (2000). Characteristics of the Gaspereau River alewife Stock and fishery –1999. Final Report to Nova Scotia Power Inc. ACER Publication No. 56. https://acer.acadiau.ca/tl_files/sites/acer/resources/ PDF%20Files/56%20ACER%20Publication.pdf Gilligan-Lunda, E. K., Stich, D. S., Mills, K. E., Bailey, M. M., & Zydlewski, J. D. (2021). Climate change may cause shifts in growth and instantaneous natural mortality of American Shad throughout their native range. Transactions of the American Fisheries Society,150 (3), 407–421. Gilmurray, M. C. (1980). Occurence and feeding habits of some juvenile fish in the southern bight of Minas Basin, Nova Scotia, 1979. Doctoral dissertation. Acadia University. https://scholar.acadiau.ca/islandora/object/ thesis:3848 Greene, K. E., Zimmerman, J. L., Laney, R. W., & Thomas-Blate, J. C. (2009). Atlantic coast diadromous fish habitat: A review of utilization, threats, recommendations for conservation, and research needs. Atlantic States Marine Fisheries Commission,464, 276. Grote, A. B., Bailey, M. M., & Zydlewski, J. D. (2014). Movements and demography of spawning American Shad in the Penobscot River, Maine, prior to dam removal. Transactions of the American Fisheries Society,143(2), 552–563. Hare, J. A., Borggaard, D. L., Alexander, M. A., Bailey, M. M., Bowden, A. A., Damon-Randall, K., Didden, J. T., Hasselman, D. J., Kerns, T., & McCrary, R. (2021). A review of the river herring science in support of species conservation and ecosystem restoration. Marine and Coastal Fisheries,13(6), 627–664. Hare, J. A., Morrison, W. E., Nelson, M. W., Stachura, M. M., Teeters, E. J., Griffis, R. B., Alexander, M. A., Scott, J. D., Alade, L., Bell, R. J., Chute, A. S., Curti, K. L., Curtis, T. H., Kircheis, D., Kocik, J. F., Lucey, S. M., McCandless, C. T., Milke, L. M., Richardson, D. E., … Griswold, C. A. (2016). A vulnerability assessment of fish and invertebrates to climate change on the northeast US continental shelf. PLoS One,11(2), e0146756. Harris, J. E., & McBride, R. S. (2009). American Shad feeding on spawning grounds in the St. Johns River, Florida. Transactions of the American Fisheries Society,138(4), 888–898. Hasselman, D. J., Anderson, E. C., Argo, E. E., Bethoney, D., Gephard, S. R., Post, D. M., Schondlemeier, B. P., Schultz, T. F., Willis, T. V., & Palkovacs, E. P. (2015). Genetic stock composition of marine bycatch reveals disproportional impacts on depleted river herring genetic stocks. Canadian Journal of Fisheries and Aquatic Sciences,73(6), 951–963. Hasselman, D. J., Argo, E. E., McBride, M. C., Bentzen, P., Schultz, T. F., Perez-Umphrey, A. A., & Palkovacs, E. P. (2014). Human disturbance causes the formation of a hybrid swarm between two naturally sympatric fish species. Molecular Ecology,23(5), 1137–1152. Hasselman, D. J., & Limburg, K. E. (2012). Alosine restoration in the 21st century: Challenging the status quo. Marine and Coastal Fisheries,4(1), 174–187. Hildebrand, S. F. (1963). Family Clupeidae, in fishes of the western North Atlantic. Part Three. Memorial Sears Foundation. Marine Research,1(3), 257–451. Hildebrand, S. F., & Schroeder, W. C. (1927). Fishes of Chesapeake Bay. U. S. Bureau of Fishery Bulletin,43,1–366. Hill, D. R. (1959). Some uses of statistical analysis in classifying races of American Shad (Alosa sapidissima). Fishery Bulletin of the Fish and Wildlife Service,59(147), 269–286. Hinson, K. E., Friedrichs, M. A., St-Laurent, P., Da, F., & Najjar, R. G. (2022). Extent and causes of Chesapeake Bay warming. JAWRA Journal of the American Water Resources Association,58(6), 805–825. Hoffman, J. C., Limburg, K. E., Bronk, D. A., & Olney, J. E. (2008). Overwintering habitats of migratory juvenile American Shad in Chesapeake Bay. Environmental Biology of Fishes,81(3), 329–345. Huveneers, C., Simpfendorfer, C. A., Kim, S., Semmens, J. M., Hobday, A. J., Pederson, H., …Harcourt, R. G. (2016). The influence of environmental parameters on the performance and detection range of acoustic receivers. Methods in Ecology and Evolution,7(7), 825–835. IPCC. (2021). Climate change 2021: The physical science basis. Contribution of working group I to the sixth assessment report of the intergovernmental panel on climate change. https://www.ipcc.ch/report/ ar6/wg1/ Jessop, B. M. (1975). A review of the American shad (Alosa sapidissima) stocks of the Saint John River, New Brunswick, with particular reference to the adverse effects of hydroelectric developments. 692 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Department of the Environment Report No.: MAR/T-75-6. https:// waves-vagues.dfo-mpo.gc.ca/library-bibliotheque/15250.pdf Jessop, B. M. (1990). Diel variation in density, length composition, and feeding activity of juvenile alewife, Alosa pseudoharengus Wilson, and blueback, A. aestivalis Mitchill, at near-surface depths in a hydroelectric dam impoundment. Journal of Fish Biology,37(5), 813–822. Jessop, B. M. (1993). Fecundity of anadromous alewives and blueback herring in New Brunswick and Nova Scotia. Transactions of the American Fisheries Society,122(1), 85–98. Jessop, B. M., & Parker, H. A. (1988). The alewife in the Gaspereau River, kings county, Nova Scotia, 1982-1984. Canadian Journal of Fisheries and Aquatic Sciences,1992, 29. Johnson, G. J., Buckworth, R. C., Lee, H., Morgan, J. A. T., Ovenden, J. R., & McMahon, C. R. (2017). A novel field method to distinguish between cryptic carcharhinid sharks, Australian blacktip shark Carcharhinus tilstoni and common blacktip shark C. limbatus, despite the presence of hybrids. Journal of Fish Biology,90(1), 39–60. Johnson, J. H., & Dropkin, D. S. (1996). Feeding ecology of larval and juvenile American shad (Alosa sapidissima) in a small pond. Journal of Applied Ichthyology,12(1), 9–13. Jones, P. W., Martin, F. D., & Hardy, J. D., Jr. (1978). Development of fishes of the Mid-Atlantic Bight. An atlas of eggs, larval and juvenile stages, volume 1. Acipenseridae through Ictaluridae. U.S. Fish and Wildlife Service, Biological Services Program, FWS/OBS78/12. Jonsson, N., Jonsson, B., & Hansen, L. P. (1991). Energetic cost of spawning in male and female Atlantic salmon (Salmo salar L.). Journal of Fish Biology,39(5), 739–744. Kan, C., Lichter, J., & Douhovnikoff, V. (2017). Genetic population structure and accuracy of morphological assessment in Alosa aestivalis (Blueback Herring) and A. pseudoharengus (Alewife). Northeastern Naturalist,24(4), 483–498. https://doi.org/10.1656/045.024.0407 Kessel, S. T., Hondorp, D. W., Holbrook, C. M., Boase, J. C., Chiotti, J. A., Thomas, M. V., Wills, T. C., Roseman, E. F., Drouin, R., & Krueger, C. C. (2017). Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor. Journal of Animal Ecology,87(1), 259–273. Kocik, J., Haas-castro, R. U. T. H., Shepherd, g., & Lipsky, C. (2009). Atlantic anadromous fisheries (p. 117). The Annual Report on the Status of US Living Marine Resources. Kocik, J. F., Hawkes, J. P., Sheehan, T., Music, P. A., & Beland, K. F. (2009). Assessing estuarine and coastal migration and survival of wild Atlantic Salmon Smolts from the Narraguagus River, Maine using ultrasonic telemetry. American Fisheries Society Symposium,69, 293–310. Kuntz, A., & Radcliffe, L. (1918). Notes on the embryology and larval development of twelve teleostean fishes. Bulletin of U.S (Vol. 35, pp. 87–134). Bureau of Fishes. Lara-Lizardi, F., Hoyos-Padilla, M., Hearn, A., Klimley, A. P., GalvánMagaña, F., Arauz, R., Bessudo, S., Castro, E., Clua, E., Espinoza, E., & Fischer, C. (2020). Shark movements in the Revillagigedo archipelago and connectivity with the eastern tropical Pacific. bioRxiv, 2020–03. Leach, S. D., & Houde, E. D. (2005). Effects of environmental factors on survival, growth, and production of American shad larvae. Journal of Fish Biology,54(4), 767–786. Leggett, W. C., & Carscadden, J. E. (1978). Latitudinal variation inreproductive characteristics of American Shad (Alosa sapidissima): Evidence for population specific life history strategies in fish. Journal of the Fisheries Research Board of Canada,35(11), 1469–1478. Leggett, W. C., & Whitney, R. R. (1972). Water temperature and migrations of American shad. U.S. National Marine Fisheries Service. Fishery Bulletin,70(3), 659–670. Leim, A. H. (1924). The life-history of the shad (Alosa sapidissima [Wilson]) with special reference to the factors limiting its abundance. Contributions to Canadian Biology,2, 161–284. Limburg, K. E. (1996). Growth and migration of 0-year American shad (Alosa sapidissima) in the Hudson River estuary: Otolith microstructural analysis. Canadian Journal of Fisheries and Aquatic Sciences,53(1), 220–238. Limburg, K. E., Hattala, K. A., & Kahnle, A. (2003). American Shad in its native range. American Fisheries Society,35(1), 125–140. Limburg, K. E., & Waldman, J. R. (2009). Dramatic declines in North Atlantic diadromous fishes. Bioscience,59(11), 955–965. Link, J. S., & Garrison, L. P. (2002). Trophic ecology of Atlantic cod Gadus morhua on the northeast US continental shelf. Marine Ecology Progress Series,227, 109–123. Loesch, J. G. (1987). Overview of life history aspects of anadromous alewife and blueback herring in freshwater habitats. Common strategies of anadromous and catadromous fishes. American Fisheries Society,S1, 89–103. Loesch, J. G., & Lund, J. R. (1977). A contribution to the life history of the blueback, Alosa aestivalis.Transactions of the American Fisheries Society, 106(6), 583–589. Lutcavage, M. E., Brill, R. W., Skomal, G. B., Chase, B. C., Goldstein, J. L., & Tutein, J. (2000). Tracking adult North Atlantic bluefin tuna (Thunnus thynnus) in the northwestern Atlantic using ultrasonic telemetry. Marine Biology,137, 347–358. Lynch, P. D., Nye, J. A., Hare, J. A., Stock, C. A., Alexander, M. A., Scott, J. D., Curti, K. L., & Drew, K. (2015). Projected ocean warming creates a conservation challenge for river herring populations. ICES Journal of Marine Science,72(2), 374–387. Mack, K., White, H., & Rohde, F. C. (2020). Use of acoustic telemetry to identify spawning river and spawning migration patterns of American shad in the Albemarle sound, North Carolina. North American Journal of Fisheries Management,41(1), 242–251. Mansueti, R., & Kolb, H. (1953). A historical review of the Shad fisheries of North America (Vol. 97, p. 293). Chesapeake Biological Laboratory. Marcy, B. C. (1969). Age determinations from scales of Alosa pseudoharengus (Wilson), and Alosa aestivalis (Mitchill), in Connecticut waters. Transactions of the American Fisheries Society,98(4), 622–630. Marjadi, M. N., Roy, A. H., Jordaan, A., Gahagan, B. I., Armstrong, M. P., & Whiteley, A. R. (2019). Larger body size and earlier run timing increase alewife reproductive success in a whole lake experiment. Canadian Journal of Fisheries and Aquatic Sciences,76(7), 1134–1146. Marrable, D., Barker, K., Tippaya, S., Wyatt, M., Bainbridge, S., Stowar, M., & Larke, J. (2022). Accelerating species recognition and labelling of fish from underwater video with machine-assisted deep learning. Frontiers in Marine Science,9, 944582. Maryland, D. N. R. (2024). Maryland fish facts: Alewife and blueback herring. https://dnr.maryland.gov/fisheries/Pages/fish-facts.aspx? fishname=Alewife+and+Bluebak+Herring Massmann, W. H. (1963). Summer food of juvenile American shad in Virginia waters. Chesapeake Science,4(4), 167–171. Mather, M. E., Frank, H. J., Smith, J. M., Cormier, R. D., Muth, R. M., & Finn, J. T. (2012). Assessing freshwater habitat of adult anadromous alewives using multiple approaches. Marine and Coastal Fisheries,4(1), 188–200. McBride, M. C., Willis, T. V., Bradford, R. G., & Bentzen, P. (2014). Genetic diversity and structure of two hybridizing anadromous fishes (Alosa pseudoharengus, Alosa aestivalis) across the northern portion of their ranges. Conservation Genetics,15, 1281–1298. McBride, R. S., Ferreri, R., Towle, E. K., Boucher, J. M., & Basilone, G. (2016). Yolked oocyte DynamicsSupport agreement between determinateandIndeterminate-method estimates of annual fecundity for a northeastern United States population of American Shad. PLoS One, 11(10), e0164203. https://doi.org/10.1371/journal.pone.0164203 McCartin, K., Jordaan, A., Sclafani, M., Cerrato, R., & Frisk, M. G. (2019). A new paradigm in alewife migration: Oscillations between spawning grounds and estuarine habitats. Transactions of the American Fisheries Society,148(3), 605–619. McCormick, S. D., Shrimpton, J. M., & Zydlewski, J. D. (1996). Temperature effects on osmoregulatory physiology of juvenile anadromous fish. Global Warming: Implications for Freshwater and Marine Fish,61, 279. BROWN ET AL.693 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License McHenry, J., Welch, H., Lester, S. E., & Saba, V. (2019). Projecting marine species range shifts from only temperature can mask climate vulnerability. Global Change Biology,25(12), 4208–4221. McPhee, J. (2003). The founding fish. Farrar, Straus and Giroux. Melvin, G. D., Dadswell, M. J., & Martin, J. D. (1986). Fidelity of American shad, Alosa sapidissima (Clupeidae), to its river of previous spawning. Canadian Journal of Fisheries and Aquatic Sciences,43(3), 640–646. Messieh, N. S. (1977). Population structure and biology of alewives (Alosa Pseudoharengus) and blueback herring (a. aestivalis) in the Saint John River. New Brunswick. Environmental Biology of Fishes,2(3), 195–210. Miller, J. P., Friedersdorff, J. W., Mears, H. C., & Billingsley, C. W. (1973). Annual progress report Delaware River basin anadromous fish project, AFS-2-6: July 1972 –December 1972. U.S. Fish and Wildlife Service. Mitchell, P. H. (1925). A report of investigations concerning shad in the rivers of Connecticut. Connecticut State Board of Fisheries and Game. https://hdl.handle.net/2027/uc1.$b33808 Mullen, D. M., Fay, C. W., & Moring, J. R. (1986). Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates. alewife/blueback. Munch, S. B., & Salinas, S. (2009). Latitudinal variation in lifespan within species is explained by the metabolic theory of ecology. Proceedings of the National Academy of Sciences,106(33), 13860–13864. Munroe, T. (2002). Herring and herring-like fishes: Order Clupeiformes. In B. B. Collette & G. Klein-MacPhee (Eds.), Fishes of the Gulf of Maine (3rd ed., pp. 104–158). Smithsonian Institution. Nack, C. C., Swaney, D. P., & Limburg, K. E. (2019). Historical and projected changes in spawning phenologies of American shad and striped bass in the Hudson River estuary. Marine and Coastal Fisheries,11(3), 271–284. NCDMF. (2022). Fishery management plan update river herring august 2022. 2021 fishery management plan review (pp. 173–197). NC Department of Marine Fisheries. Neves, R. (1981). Offshore distribution of alewife, Alosa pseudoharengus, and blueback, Alosa aestivalis, along the Atlantic coast. Fisheries Bullitin of Seattle,79(3), 473–485. Neves, R. J., & Depres, L. (1979). The oceanic migration of American shad, Alosa sapidissima, along the Atlantic coast. Fishery Bulletin,77(1), 199–212. Nichols, P. R. (1966). Comparative study of juvenile American Shad populations by Finray and Scute counts (No. 525). US Department of the Interior. NMFS [National Marine Fisheries Service]. (2019). Endangered and threatened wildlife and plants; endangered species act listing determination for alewife and blueback herring. Federal Register,84(118), 28630– 28666. https://www.federalregister.gov/documents/2019/06/19/ 2019-12908/endangered-and-threatened-wildlife-and-plantsendangered-species-act-listing-determination-for#::text=Based% 20on%20the%20best%20scientific,not%20warranted%20at%20this% 20time NOAA. (2023). River Herring: Management. https://www.fisheries.noaa. gov/species/river-herring/management Ogburn, M. B., Legett, H. D., Aguilar, R., Furey, N. B., Heggie, K., Livernois, M. C., & Richie, K. D. (2024). Acoustic telemetry captures the full annual migration of alewife between Chesapeake Bay and the Gulf of Maine. Marine Ecology Progress Series,745, 115–124. Palkovacs, E. P., Hasselman, D. J., Argo, E. E., Gephard, S. R., Limburg, K. E., Post, D. M., Schultz, T. F., & Willis, T. V. (2014). Combining genetic and demographic information to prioritize conservation efforts for anadromous alewife and blueback. Evolutionary Applications, 7(2), 212–226. Pershing, A. J., Alexander, M. A., Hernandez, C. M., Kerr, L. A., le Bris, A., Mills, K. E., Nye, J. A., Record, N. R., Scannell, H. A., Scott, J. D., Sherwood, G. D., & Thomas, A. C. (2015). Slow adaptation in the face of rapid warming leads to collapse of the Gulf of Maine cod fishery. Science,350(6262), 809–812. Poloczanska, E. S., Brown, C. J., Sydeman, W. J., Kiessling, W., Schoeman, D. S., Moore, P. J., Brander, K., Bruno, J. F., Buckley, L. B., & Burrows, M. T. (2013). Global imprint of climate change on marine life. Nature Climate Change,3(10), 919–925. Portner, H. O., & Peck, M. A. (2010). Climate change effects on fishes and fisheries: Towards a cause-and-effect understanding. Journal of Fish Biology,77(8), 1745–1779. Post, D. M., & Walters, A. W. (2011). Nutrient excretion rates of anadromous alewives during their spawning migration. Transactions of the American Fisheries Society,138(2), 264–268. Pothoven, S. A., & Vanderploeg, H. A. (2004). Diet and prey selection of alewives in Lake Michigan: Seasonal, depth, and interannual patterns. Transactions of the American Fisheries Society,133(5), 1068–1077. Poulet, C., Lassalle, G., Jordaan, A., Limburg, K. E., Nack, C. C., Nye, J. A., O'Malley, A., O'Malley-Barber, B., Stich, D. S., Waldman, J. R., Zydlewski, J., & Lambert, P. (2023). Effect of straying, reproductive strategies, and ocean distribution on the structure of American shad populations. Ecosphere,14(12), 1–21. Provost, J. (1987). L'alose savoureuse (Alosa sapidissima, Wilson) du Fleuve Saint-Laurent: etude comparative des phenotypes morphologiques et de certains aspects de la biologie de quelques populations. Master's thesis. University of Quebec. https://waves-vagues.dfo-mpo.gc.ca/librarybibliotheque/16560.pdf Reid, K., Hoey, J. A., Gahagan, B. I., Schondelmeier, B. P., Hasselman, D. J., Bowden, A. A., Armstrong, M. P., Garza, J. C., & Palkovacs, E. P. (2023). Spatial and temporal genetics stock composition of river herring bycatch in southern New England Atlantic herring and mackerel fisheries. Canadian Journal of Fisheries and Aquatic Sciences,80(2), 360–374. Richardson, A. J., & Schoeman, D. S. (2004). Climate impact on plankton ecosystems in the Northeast Atlantic. Science,305, 1609–1612. Righton, D., Westerberg, H., Feunteun, E., Økland, F., Gargan, P., Amilhat, E., …Aarestrup, K. (2016). Empirical observations of the spawning migration of European eels: The long and dangerous road to the Sargasso Sea. Science Advances,2(10), e1501694. Rikardsen, A. H., Righton, D., Strøm, J. F., Thorstad, E. B., Gargan, P., Sheehan, T., …Aarestrup, K. (2021). Redefining the oceanic distribution of Atlantic salmon. Scientific Reports,11(1), 12266. Robins, R. C., Ray, C. G., & Douglass, J. (1986). A field guide to Atlantic Coast fishes of North America. Houghton Mifflin Company. Roff, D. A. (1992). The evolution of life history strategies: Theory and analyses. Chapman and Hall. Rothermel, E. R., Balazik, M. T., Best, J. E., Breece, M. W., Fox, D. A., Gahagan, B. I., Haulsee, D. E., Higgs, A. L., O'Brien, M. H. P., Oliver, M. J., Park, I. A., & Secor, D. H. (2020). Comparative migration ecology of striped bass and Atlantic sturgeon in the US southern midAtlantic bight flyway. PLoS One,15(6), e0234442. Rulifson, R. A., & Dadswell, M. J. (2020). Alewife and blueback captured by intertidal weirs of the Inner Bay of Fundy, Canada, display seasonal demographics that suggest multiple migrating stocks. Marine and Coastal Fisheries,12(6), 441–456. Samways, K. M., Soto, D. X., & Cunjak, R. A. (2018). Aquatic food-web dynamics following incorporation of nutrients derived from Atlantic anadromous fishes. Journal of Fish Biology,92(2), 399–419. Saunders, R., Hachey, M. A., & Fay, C. W. (2006). Maine's diadromous fish community: Past, present, and implications for Atlantic salmon recovery. Fisheries,31(11), 537–547. Schmidt, R. E., Klauda, R. J., & Bartels, J. M. (1988). Distributions and movements of the early life stages of three species of Alosa in the Hudson River, with comments on mechanisms to reduce interspecific competition. In Fisheries Research in the Hudson River (pp. 193–215). State University of New York. Schmitt, J. D., Hallerman, E. M., Bunch, A., Moran, Z., Emmel, J. A., & Orth, D. J. (2017). Predation and prey selectivity by nonnative catfish on migrating alosines in an Atlantic slope estuary. Marine and Coastal Fisheries,9(1), 108–125. 694 BROWN ET AL. FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Spares, A., Robertson, G., Dadswell, M., Calvert, A., Gutowsky, S., Fifield, D., …Stokesbury, M. (2023). River-and sex-specific annual survival rates of mature anadromous alewife (Alosa pseudoharengus). Journal of Applied Ichthyology,2023(1), 6376322. Staveley, T. A., Jacoby, D. M., Perry, D., van der Meijs, F., Lagenfelt, I., Cremle, M., & Gullström, M. (2019). Sea surface temperature dictates movement and habitat connectivity of Atlantic cod in a coastal fjord system. Ecology and Evolution,9(16), 9076–9086. Stewart, T. J., Sprules, W. G., & O'Gorman, R. (2009). Shifts in the diet of Lake Ontario alewife in response to ecosystem change. Journal of Great Lakes Research,35(2), 241–249. Stone, H. H., & Daborn, G. R. (1987). Diet of alewives, Alosa pseudoharengus and blueback, A. aestivalis (Pisces: Clupeidae) in Minas Basin, Nova Scotia, a turbid, macrotidal estuary. Environmental Biology of Fishes,19, 55–67. Stone, H. H., & Jessop, B. M. (1992). Seasonal distribution of river herring (Alosa pseudaharengus) and A. aestivalis off the Atlantic coast of Nova Scotia. Fishery Bulletin,90(2), 376–389. Strus, R. H., & Hurley, D. A. (1992). Interactions between alewife (Alosa pseudoharengus), their food, and phytoplankton biomass in the bay of Quinte, Lake Ontario. Journal of Great Lakes Research,18(4), 709–723. Sykes, J. E. (1956). Shad fishery of the Ogeechee River, Georgia, in 1954 (No. 191). U.S. Department of the Interior Fish and Wildlife Service. https://fisherybulletin.nmfs.noaa.gov/sites/default/files/legacy-pdfs/ SSRF191.pdf Talbot, G. B. (1954). Factors associated with fluctuations in abundance of Hudson River shad. U.S. Fish and Wildlife Service Fishery Bulletin,56, 373–413. Themelis, D. E. (1986). Feeding ecology of American shad (Alosa sapidissima) in the lower bay of Fundy and Minas Basin. Master's thesis. Acadia University. Thorstad, E. B., Whoriskey, F., Rikardsen, A. H., & Aarestrup, K. (2011). Aquatic nomads: The life and migrations of the Atlantic salmon. Atlantic Salmon Ecology,1(6), 1–32. Thunberg, B. E. (1971). Olfaction in parent stream selection by the alewife (Alosa pseudoharengus). Animal Behaviour,19(2), 217–225. Tsitrin, E., McLean, M. F., Gibson, A. J. F., Hardie, D. C., & Stokesbury, M. J. (2020). Feasibility of using surgical implantation methods for acoustically tagging alewife (Alosa pseudoharengus) with V5 acoustic transmitters. PLoS One,15(11), e0241118. Tsitrin, E., Sanderson, B. G., McLean, M. F., Gibson, A. J. F., Hardie, D. C., & Stokesbury, M. J. (2022). Migration and apparent survival of post-spawning alewife (Alosa pseudoharengus) in Minas Basin, Bay of Fundy. Animal Biotelemetry,10(1), 11. Turner, S. M., & Limburg, K. E. (2016). Juvenile river herring habitat use and marine emigration trends: Comparing populations. Oecologia,180, 77–89. Turner, S. M., Manderson, J. P., Richardson, D. E., Hoey, J. J., & Hare, J. A. (2016). Using habitat association models to predict alewife and blueback marine distributions and overlap with Atlantic herring and Atlantic mackerel: Can incidental catches be reduced? ICES Journal of Marine Science,73(7), 1912–1924. Walburg, C. H., & Nichols, P. R. (1967). Biology and management of the American Shad and status of the fisheries, Atlantic coast of the United States, 1960. United States Department of the Interior. Walter, J. F., III, & Olney, J. E. (2003). Feeding behavior of American shad during spawning migration in the York River, Virginia. Biodiversity, status, and conservation of the world's shads. American Fisheries Society Symposium,35, 201–209. Weng, K. C., Boustany, A. M., Pyle, P., Anderson, S. D., Brown, A., & Block, B. A. (2007). Migration and habitat of white sharks (Carcharodon carcharias) in the eastern Pacific Ocean. Marine Biology,152, 877–894. Williams, R. O., & Bruger, G. E. (1972). Investigations on American shad in the St. John's River. Florida Department of Natural Resources Marine Research Laboratory Technical Series,66,1 –49. Williams, R. R., & Daborn, G. R. (1984). Spawning of the American shad (Alosa sapidissima) in the Annapolis River, Nova Scotia. Proceedings of the Nova Scotian Institute of Science,34,9–14. How to cite this article: Brown, C. R., Sergio, A. J. A., Bate, C. S., Koopman, N., Roland, J. B., Notman-Grobler, O. D. P., Mastrodimitropoulos, P. M. B., Piczak, M. L., & Lennox, R. J. (2025). A review of migratory Alosidae marine ecology in the northwest Atlantic. Journal of Fish Biology,106(3), 677–695. https://doi.org/10.1111/jfb.15977 BROWN ET AL.695 FISH 10958649, 2025, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jfb.15977 by Capes, Wiley Online Library on [29/08/2025]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License