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25Migratory species link spatially separated ecosystems, and understanding their migrations is 26 critical for conservation and management. The cownose ray Rhinoptera bonasus is a large-27 bodied batoid ray implicated in shellfish declines along the US Atlantic coast, but its migrations 28 and habitat use remain poorly understood. We used passive acoustic telemetry to track tagged 29 adult female (N = 30) and male (N = 12) rays released during summer and fall 2014-2016 in 30 Maryland, Virginia, and Georgia. Twenty-three tags provided data for more than one year. 31Individuals from all tagging locations overwintered in the same region offshore of Cape 32 Canaveral, Florida, then returned in summer to the estuaries where tagging took place. Hidden 33 Markov modeling identified three behavioral states (Resident, Ranging, Migratory), with ray 34 movements generally classified as non-migratory (Resident and Ranging behavioral states) in 35 summer and winter, and migratory (Migratory behavioral state) in spring and fall. Linear 36 discriminate analysis suggested strong philopatry to tagging locations. This study provides the 37 first full annual migration tracks for cownose rays along the US Atlantic coast, indicating that 38 they migrate between summer pupping and mating habitats in estuaries south of Long Island, 39 New York and shared overwintering habitats off the east coast of Florida near Cape Canaveral. 40 Our results highlight the value of national-scale networks of acoustic telemetry arrays for 41 identifying migratory patterns of highly mobile marine species.42 43 Cownose ray migration 3 66 Cownose ray migration 4 6-7 years with a maximum observed age of 18 years at a DW of 98 cm (Fisher et al. 2013).

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ABSTRACT. We evaluated the effect of tethering 2 species of juvenile fishes on their behaviour and susceptibility to predation under laboratory conditions in order to determine whether these fishes can be effectively used in field studies designed to assess predation rates. More specifically, this laboratory study investigated: (1) the effect of tethering, which required puncturing the body, on 2 mobile fish prey: the winter flounder Pseudopleuronectes arnericanus (42 to 85 mm total length, TL), and the tautog Tautoga onitis (47 to 91 mm TL); and (2) whether the predators, the summer flounder Paralichthys dentatus and the blue crab Callinectes sapidus, preferentially preyed upon tethered individuals. The behaviour of tethered individuals varied between species. Tethered P. americanus buried more extensively (i.e. greater percentage of body covered by sand) than untethered individuals. Therefore, tethering this species may reduce predation by visual predators because individuals are less visible. Tethered T. onitis were more likely than untethered individuals to occupy open areas of the experimental pool rather than to be found near shelter. In this case, tethering may increase potential predatory attacks because tethered fish are more accessible. Despite differences in behaviour caused by tethering P. americanus, there was no significant difference between the rates of predation by P. dentatus on tethered versus untethered individuals. However, as predicted by the change in T. onitis behaviour, P. dentatus preyed more frequently on tethered individuals than untethered ones. C. sapidus, a predator that uses olfactory cues, preferentially selected tethered P. americanus. The preference for tethered individuals may depend in part upon the release of prey body fluids and subsequent detection by predators that use olfactory cues. Furthermore, tethered individuals may change their shelter-seeking behaviour, and thusconfoundpotential habitat-specificdifferencesin relative predation rates. As a result, tethering as a tool to determine predation rates should be used cautiously for fishes. At a minimum, laboratory observations to detect tethering artifacts should be conducted before field experiments.