Stock Assessment Report No. 07-01 (Supplement) of the Atlantic States Marine Fisheries Commission American Shad Stock Assessment Report for Peer Review Volume II August 2007 Working towards healthy, self-sustaining populations for all Atlantic coast fish species or successful restoration well in progress by the year 2015 Stock Assessment Report No. 07-01 (Supplement) of the Atlantic States Marine Fisheries Commission American Shad Stock Assessment Report for Peer Review Volume II Conducted on July 16 – 20, 2007 And Accepted by The Shad and River Herring Management Board August 16, 2007 A publication of the Atlantic States Marine Fisheries Commission pursuant to National Oceanic and Atmospheric Administration Award No. NA05NMF4741025. PREFACE The American Shad Stock Assessment Report analyzes the status of 31 stocks of American shad along the Atlantic coast. Due to the large volume of material contained within the report (1200+ pages), it is organized into three volumes. Volume I contains a comprehensive look at all of the stocks, including an introduction to the science and management of the species, summaries of coastwide indices, summaries of the state or river system assessments, conclusions and recommendations, and a look at hypothesized causes of decline. Volumes II and III provide an in-depth exploration of American shad stock status by state or river system. These volumes provide stand-alone assessments of stocks and serve as a reference for material contained in Volume I. The contents of the three volumes follow: • Volume I: Introduction Coastwide Summaries State and River Stock Assessment Summaries Conclusions and Recommendations Causes of Decline • Volume II: Maine New Hampshire Merrimack River Rhode Island Connecticut River Hudson River Delaware Bay and River Minority Report for Connecticut River • Volume III: Maryland Susquehanna River Potomac River Virginia North Carolina South Carolina Georgia Florida ii ACKNOWLEDGEMENTS The Atlantic States Marine Fisheries Commission thanks all of the individuals who contributed to the development of the American shad stock assessment and its terms of reference. The Commission also thanks the ASMFC Shad and River Herring Technical Committee (TC) and American Shad Stock Assessment Subcommittee (SASC) members who developed the consensus stock assessment report, especially Andrew Kahnle (NY State Department of Environmental Conservation) for his exceptional work as the Chair of the SASC. Members of the SASC include: Andrew Kahnle (Chair), Russ Allen (NJ Division of Fish and Wildlife), Christine Burgess (NC Division of Marine Fisheries), Kathryn Hattala (NY State Department of Environmental Conservation), Mike Hendricks (PA Fish and Boat Commission), Joe Hightower (U.S. Geological Survey/North Carolina State University), Laura Lee (ASMFC/RI Department of Environmental Management), John Olney (Virginia Institute of Marine Science), and Bob Sadzinski (MD Department of Natural Resources). Members of the Shad and River Herring TC include: Mike Hendricks, Chair (PA Fish and Boat Commission), Russ Allen (NJ Division of Fish and Wildlife), Phillips Brady (MA Division of Marine Fisheries), Michael Brown (Department of Marine Resources), Ellen Cosby (Potomac River Fisheries Commission), Phillip Edwards (RI Department of Environmental Management), Ruth Haas-Castro (NMFS), Don Harrison (GA Department of Natural Resources), Kathryn Hattala (NY State Department of Environmental Conservation), Reid Hyle (FL Fish and Wildlife Conservation Commission), Wilson Laney (USFWS), Rich McBride (FL Fish and Wildlife Conservation Commission), Larry Miller (USFWS), John Olney (Virginia Institute of Marine Science), Cheri Patterson (NH Fish and Game Department), Bill Post (SC Department of Natural Resources), Bob Sadzinski (MD Department of Natural Resources), Tom Savoy (CT Department of Environmental Protection), Jon Siemien (D.C. Fisheries and Wildlife), Michael Stangl (DE Department of Natural Resources and Environmental Control), and Sara Winslow (NC Division of Marine Fisheries). The Commission would also like to thank everyone individuals from outside of the SASC and TC who contributed to the American shad stock assessment, including Kristen Delano, A.C. Carpenter, and many other federal employees, state employees, and academics. The Commission appreciates the efforts of the Commission staff that assisted in the development and review of the American shad stock assessment. A very special thanks goes to Erika Robbins and Patrick Kilduff for their outstanding efforts in coordinating the stock assessment process, writing and editing substantial parts of the assessment, and ensuring the delivery of a complete and thorough assessment for peer review. iii TERMS OF REFERENCE 1. Compile and determine adequacy of available life history data for each stock. 2. Compile and determine adequacy of available fishery-dependent and/or independent data as indices of relative abundance for each stock. 3. Determine most appropriate method of estimating natural mortality. 4. Determine which assessment analyses are most appropriate to available data for each stock. 5. Assessment methods will range from simple trend analysis to more complex models. 6. Estimate biological reference points for each stock where possible. 7. Determine current status of each stock where possible. 8. Develop recommendations for needed monitoring data and future research. 9. Describe the locations and amounts of shad and river herring bycatch in commercial fisheries for mackerel, sea herring, and other pelagic species and estimate the contribution of that bycatch to fishing mortality. iv TABLE OF CONTENTS Preface ..........................................................................................................................................................ii Acknowledgements......................................................................................................................................iii Terms of Reference...................................................................................................................................... iv List of Tables ............................................................................................................................................... vi List of Figures.............................................................................................................................................. xi List of Terms.............................................................................................................................................. xvi 2.0 Maine .................................................................................................................................................. 1 3.0 New Hampshire................................................................................................................................. 47 4.0 Merrimack River, Massachusetts ...................................................................................................... 80 5.0 Pawcatuck River, Rhode Island ...................................................................................................... 117 6.0 Connecticut River, Connecticut ...................................................................................................... 173 7.0 Hudson River, New York................................................................................................................ 209 8.0 Delaware Bay and River ................................................................................................................. 302 Appendix A: Minority Report................................................................................................................... 347 v LIST OF TABLES Table 2.1 Maine rivers containing populations of American shad .................................................. 20 Table 2.2 Tag and recapture dates and recapture locations for American shad tagged in the Narraguagus River, Maine................................................................................................ 21 Table 2.3 Number of American shad larvae raised at the Waldoboro Hatchery and stocked in Maine rivers, 1992-2005................................................................................................... 21 Table 2.4 Number of adult American shad transferred to Maine rivers for restoration, 1984-2005 ......................................................................................................................... 22 Table 2.5 Percent of hatchery fish in samples of age-0 American shad from the Kennebec and Androscoggin rivers and Merrymeeting Bay, Maine................................................. 23 Table 2.6 American shad number-at-age and length data for the Saco River and the Androscoggin River in Maine........................................................................................... 24 Table 2.7 Reported commercial landings of American shad from Maine state and federal waters ............................................................................................................. 25 Table 2.8 Reported commercial landings (kg) of American shad in Maine by gear ........................ 26 Table 2.9 Estimated recreational catch of American shad in Maine water based on the MRFSS................................................................................................................... 26 Table 2.10 Characteristics of American shad passage up the east and west channel fishways