Diversity in destinations, routes and timing of small adult and sub‐adult striped bass Morone saxatilis on their southward autumn migration

Abstract

Almost three-quarters of the 46 young adult and sub-adult striped bass Morone saxatilis that were acoustically tagged in Plum Island Estuary, Massachusetts, U.S.A., in the summer of 2006 were detected in one or more southern coastal arrays during their autumn migration. On the basis of the trajectories along which these M. saxatilis moved from feeding to overwintering areas, three migratory groups emerged. After leaving Plum Island Estuary, about half of the fish were detected only in a mid-latitude array, Long Island Sound. The other half of the tagged fish were detected during autumn and winter in a more southern array, the Delaware Estuary. This latter group of fish may have used two routes. Some travelled to the Delaware Estuary through Long Island Sound while other fish may have taken a second, more direct, coastal route that did not include Long Island Sound. Consequently, a seemingly homogeneous group of fish tagged at the same time in the same non-natal feeding location exhibited a diversity of southward movement patterns that could affect population-level processes. These three groups that differed in overwintering location and migration route could be movement contingents with migratory connectivity.

Movement Patterns and Stock Composition of Adult Striped Bass Tagged in Massachusetts Coastal Waters

“…Acoustic detection data obtained through the ACT Network enabled a relatively robust characterization of the seasonal migration patterns of adult Striped Bass that were tagged in MA coastal waters. In general, the movement patterns were consistent with those previously described for the species along the U.S. East Coast (Merriman 1941;Clark 1968;Boreman and Lewis 1987;Waldman et al 1990;Dorazio et al 1994;Mather et al 2010), with latitudinal migration between summer foraging habitat and overwintering or spawning habitat clearly evident. During the spring and fall migratory periods, tagged individuals appeared to make latitudinal movements along the coast (Collette and Klein-MacPhee 2002), often being detected or recaptured within 5 km of the shoreline, particularly between Delaware Bay and Cape Cod.…”

“…In the event that any user obtains detection data from a transmitter that is not their own, a query of the ACT database enables the detector to determine the identity of the transmitter (i.e., tagged species and initial tagging location) and to obtain contact information for the tagger. Accordingly, detection data obtained from this network can be used to examine large-scale movement patterns of individuals (or groups of individuals) over extended periods (i.e., months to years; e.g., Mather et al 2010;Kneebone et al 2014).…”

“…In several studies, Striped Bass that were tagged in major spawning areas of the mid-Atlantic were later recaptured off the MA coast during the summer (e.g., Chapoton and Sykes 1961;Clark 1968;Waldman et al 1990;Dorazio et al 1994); however, these observations provide little information on the seasonal residency of fish in MA coastal waters or potential migratory routes between spawning and foraging habitats. Recently, Mather et al (2010) and Pautzke et al (2010) described movements of subadult and young adult Striped Bass tagged within the Plum Island Sound estuary, and those authors provided some evidence of the existence of migratory contingents that return to the estuary annually to forage. Collectively, these tagging studies suggest that the seasonal mixed stock of Striped Bass encountered off the MA coast potentially consists of individuals from multiple spawning stocks that exhibit unique movement patterns into and out of the region.…”

The Roles of Large Top Predators in Coastal Ecosystems: New Insights from Long Term Ecological Research

“…Although ecologists have long recognized that individuals within a population vary in their behavior because of sexual, morphological, and ontogenetic differences, only recently has individual variation, separate from these factors, been considered in ecological and evolutionary studies (Bolnick et al, 2003;Araujo et al, 2011;Dall et al, 2012). This type of intrapopulation variation in behavioral patterns has been variously termed contingents (Secor et al, 2001;Mather et al, 2010;Pautzke et al, 2010), behavioral syndromes (Sih et al, 2012), personalities (Ogden, 2012), and individual specializations (Bolnick et al, 2003;Araujo et al, 2011). Common individual behavioral differences include boldness-shyness, avoidanceexploration, aggressiveness-passivity, and sociability-asociability (Conrad et al, 2011), and individual specialization can lead to differences in foraging/movement tactics and prey selection (Bolnick et al, 2003;Araujo et al, 2007).…”

Population Structure of a Neotropical Migratory Fish: Contrasting Perspectives from Genetics and Otolith Microchemistry

“…Previous studies spanning a wide range of North American taxa have identified many species with high levels of site fidelity and genetic population structure, including such diverse groups as salmonids (McDowall 2001), Swordfish Xiphias gladius (Alvarado Bremer et al 2005), and Atlantic Herring Clupea harengus (Ruzzante et al 2006). Other species disperse and interbreed widely and have little population structure, including Striped Bass Morone saxatilis (Mather et al 2010) and Sea Lamprey Petromyzon marinus (Waldman et al 2008). Population structure can also vary within species; for example, Palkovacs et al (2008) found high levels of genetic structure for landlocked populations of Alewife Alosa pseudoharengus, but low levels in anadromous populations.…”