A general northward shift in marine species distributions has been observed in the western North Atlantic Ocean, which may have significant ecological consequences. Large coastal sharks can have wide migratory distributions but show fidelity to specific nursery habitats. Here we show evidence for nursery range expansion into Pamlico Sound, North Carolina by a marine apex predator, the Bull Shark (Carcharhinus leucas). Previous assessments have shown little to no use of estuarine North Carolina waters as nursery habitat by Bull Sharks from 1965–2011. Juvenile sharks were rarely captured in a fishery-independent gillnet survey conducted by the North Carolina Division of Marine Fisheries (NCDMF) from 2003–2011, but were present every year from 2011–2016. Juvenile Bull Shark presence in the Sound was strongly related to early summer temperatures and late summer salinities, which have increased in the estuary over the 13 survey years, and further evidence for increasing water temperatures in Pamlico Sound was found in a 45-year data set for the NCDMF estuarine trawl survey. These results suggest that increasing water temperature and salinity have allowed Bull Sharks to expand their nursery habitat. This shift will have unknown, but potentially strong, impacts on both the local ecosystem and interactions with humans.

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).

Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007–2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species.

Acoustic telemetry, in which transmitters projecting ultrasonic signals carrying unique identification codes are deployed on marine and aquatic animals and detected and logged by acoustic receivers, is becoming a common tool in fisheries science. Collaboration among researchers using this technology has led to the development of telemetry networks that are capable of detecting transmitters at coastwide and even continental scales through the combined coverage of all members' receivers. Two grassroots telemetry networks in the northwest Atlantic and Caribbean, the Atlantic Cooperative Telemetry (ACT) Network and the FACT Network, began as small-scale efforts among neighboring researchers and have expanded to include shared databases of tagged animals along entire coastlines. A third telemetry network, the Ocean Tracking Network (OTN), has brought additional capacity to the ACT and FACT networks and has provided a focus for telemetry activities in Canadian waters. It has also improved the power and efficiency of telemetry research globally through collaborative, standardized methods for storing, sharing, and processing data. When used in combination with other data collected by traditional fishery research methods and emerging technologies, such as remote sensing and autonomous vehicles, data collected through acoustic telemetry networks can address fundamental but previously unanswered questions about key habitat areas and data-poor species and can yield new insights into the ecology of species that are thought to be well known. Here, we provide an overview of acoustic telemetry networks, including a history of the ACT Network, FACT Network, and OTN and a review of recent and current research that has been made possible through the connections enabled by these networks.