Cod Population Structure and New England Fisheries Symposium: Furthering our understanding by integrating knowledge gained through science and fishing Movement Patterns of Cod off New England

Steve Cadrin University of , Dartmouth School for Marine Science & Technology Acknowledgments • Tagging • Collaborating fishermen • Historical Tagging – Jon Loehrke & Doug Zemeckis • Recent Tagging – Shelly Tallack & Northeast Regional Cod Tagging Program, … • Massachusetts Marine Fisheries Institute – Dave Martins, Bill Hoffman, Mike Armstrong, … • Larval Dispersal • Jim Churchill, Micah Dean, … 2007-2008 Groundfish Assessment Review Meeting

• Review of Tagging Information for Stock Identification of Cod off New England (Loehrke & Cadrin 2007, GARM WP3B) • Four region-wide cod tagging investigations • 1923-1932 (Rich 1925, Schroeder 1930, Higgins 1934) • 1955-1959 (Wise 1963) • 1984-1997 (Hunt et al. 1998) • 2003-2005 (Tallack 2006, 2011, 2012, Loehrke 2012) • … recent tagging (Zemeckis et al. 2014, 2017) • General results are consistent among studies • Similar major pathways of movement • Frequency of residency and movement vary Tagging on Nantucket Shoals in the Early 1900s • The earliest tagging studies of New England cod were in association with hatchery experiments (Tarr 1884) • Smith (1902) tagged of 4,000 cod at and found connectivity with Nantucket Shoals and the Mid Atlantic Bight. • Rich (1925) tagged on Nantucket Shoals • Tagging continued annually until 1932, primarily on Nantucket Shoals but also in other areas (Higgins 1934) Early 1900s • The group of cod on Nantucket shoals is mostly distinct from those to the north and east (Schroeder 1930) • “a very small percentage of the Nantucket cod stray to the north and east annually, and, conversely, only a few cod tagged to the north and east stray to Nantucket Shoals” • “A large part of the Nantucket Shoals cod population make a fall migration into the Rhode Island-North Carolina region, where most of them remain until the spring.” Tagging in Gulf of Maine in the Early 1900s • Higgins (1929) perception of cod groups • Sedentary groups of cod from northern Massachusetts to eastern Maine and on Gulf of Maine banks. • Cod in tend to migrate to the south • Tagging off the Maine had mostly local recaptures, and some moved east (Higgins 1933), but the cod off the Maine coast were not considered to be connected to those on the offshore banks (Higgins 1934). Tagging on Offshore Banks in the Early 1900s • Higgins (1931) • Tagging on Browns Bank suggested that most movement was north and northeast with a little to the south and west. • Tagging on Georges Bank suggested that most fish stayed on the Bank with movement to Browns Bank and less to Nantucket Shoals and southward. Tagging in Southern New England in the Mid-1900s • Wise (1958) tagged cod off New Jersey and confirmed the seasonal pattern described by Schroeder (1930) and Higgins (1929-1934).

RECAPTURES Tagging off Chatham in the Mid-1900s

• Wise (1963) <6 months 6 months-1 year • Tagging off Chatham in February-March 1957 • Most recaptured in the Great South (74%) • Some movement of cod to • the Gulf of Maine (15%), 1-1.5 years >1.5 years • southern New England-Mid Atlantic (6%), • Georges Bank (3%) and • the Scotian Shelf (1%) Tagging on Eastern Georges Bank in the Mid-1900s • Wise (1963) <6 months 6 months-1 year • Tagging on Georges Bank in March-April 1957 • Most recaptured on eastern Georges Bank (64%) • Movement of cod to the Scotian Shelf (36%)

• No recaptures on western 1-1.5 years >1.5 years Georges Bank, the Great South Channel, Nantucket Shoals, southern New England-Mid Atlantic or the Gulf of Maine Tagging on Browns Bank in the Mid-1900s • Wise (1963) <6 months 6 months-1 year • Tagging on Browns Bank in March 1957 • Most recaptured on Browns Bank (86%) • Some movement of cod to Eastern Georges Bank (14%) 1-1.5 years >1.5 years Tagging in the Late-1900s • Hunt et al. (1999) • Tagged >22,000 cod from 1984 to 1997, primarily on Georges Bank and Browns Bank. • 2400 tag recoveries were adjusted for fishing patterns and reporting rates. Tagging on Eastern Georges Bank in the Late-1900s • Hunt et al. (1999) • Most recaptured on eastern Georges Bank (54%) • Movement to • the Scotian Shelf (34%), • western Georges Bank (10%), • the Great South Channel (1%), and • the Gulf of Maine (1%) • No recaptures on Nantucket Shoals or southern New England-Mid Atlantic Tagging on Browns Bank in the Late-1900s • Hunt et al. (1999) • Most recaptured on the Scotian Shelf (62%) • Movement to • eastern Georges Bank(6%), • western Georges Bank (6%), • the Gulf of Maine (6%) • the Great South Channel (1%), and • Nantucket Shoals (1%) • No recaptures in southern New England-Mid Atlantic Tallack (2011, 2012) tag releases from Bay of Fundy to southern New England, 2003- 2005 Recent Tagging • Accounted for tag loss and tagging-induced mortality • Weighted releases and recaptures for resource, fishing and reporting patterns • Residence within management areas, with considerable movement among areas. Recent Tagging • Extensive movement between the Great South Channel & western Gulf of Maine • Movement between Georges Bank and the Scotian Shelf, but little movement from Georges to inshore New England. • Some mixing between the Bay of Fundy and offshore banks. • Inshore Gulf of Maine cod are more resident.

Tallack (2006, 2011, 2012) Recent Tagging • 2,572 spawning Ipswich Spring | Ipswich Winter | Mass. Bay Spring | Mass. Bay Winter cod tagged from major spawning grounds & seasons • Movement

patterns ranged S. New England | Great South Channel | Eastern Georges Bank from sedentary (southern New England) to dispersive (Eastern

Georges Bank) Loehrke (2012) Recent Tagging

• Acoustic tags and receiver arrays quantified spawning seasons, multi-year site fidelity and some straying among spawning sites within the spawning season. • Siceloff & Howell (2011) found an average of 30 days residence time of spring spawners in on the spawning ground Ipswich Bay. • Zemeckis et al. (2014) found and average of 38 days residence and 47-95% spawning site fidelity of spring spawners in Massachusetts Bay. Recent Tagging

• Geolocation from time, depth, and temperature data from electronic tags • Groeger et al. (2007) found connectivity between Stellwagen Bank and the Great South Channel • Liu et al. (2016) improved the method with validation from acoustic tags and found some connectivity between western Gulf of Maine and the Great South Channel. • Zemeckis et al. (2017) presented broad seasonal movement patterns for Groeger et al. 2007 western Gulf of Maine spring spawners. Liu et al. 2016 Zemeckis et al. 2017 Egg & Larval Dispersal • Retention on Georges Bank by recirculation and the clockwise gyre around Georges Bank (Lough et al. 2006) • Transport of from coastal spawning in the western Gulf of Maine • Downwelling in spring retains eggs and larvae west of the coastal current (Huret et al. 2007) • Upwelling conditions in winter transports eggs and larvae offshore and entrained in the coastal current (Churchill and Runge 2009, Churchill et al. 2011, 2016). Information on Movement and Mixing • Conventional tags definitively document movement patterns, but estimating movement rates from tags is difficult. • Electronic tags can provide precise information within acoustic arrays and lower-resolution information on movement between release and recapture positions. • Egg and larval dispersal modeling can suggest dispersal patterns and possibly rates, but larval dynamics and results are less certain. Major Pathways of Movement • Cod off coastal Maine are relatively sedentary (Higgins 1929, 1933; Tallack 2011). • Cod from Massachusetts Bay are largely residential in the western Gulf of Maine, but movement out of this area most commonly occurred southward (Higgins 1929-1934, Tallack 2011, Groeger et al. 2007, Liu et al. 2016). • There is extensive movement from the Great South Channel to the Gulf of Maine, with some movement to southern New England, Georges Bank and the Scotian Shelf (Wise 1963, Tallack 2011, Loehrke 2012). • There is extensive movement between Eastern Georges Bank and the Scotian Shelf, with little movement to the west (Higgins 1931, Wise 1963, Hunt et al. 1999, Tallack 2011, Loehrke 2012). • There is a group of cod moving between Nantucket Shoals and the Mid Atlantic Bight (Smith 1902, Schroeder 1930, Wise 1958, Wise 1963, Loehrke 2012). Are these patterns consistent with your observations?

Tallack 2009