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Northeast Fisheries Science Center reference document ; 20-04

Additional file 1. Location source for tagged turtles and previously observed proportions of tagged turtles in the Mid-Atlantic Bight by month.

NOAA Technical Memorandum NMFS-NE ; 252

NOAA technical memorandum NMFS-NE ; 245

NOAA technical memorandum NMFS-NE ; 258

Under the 1994 amendments of the Marine Mammal Protection Act (MMPA), the National Marine Fisheries Service (NMFS) and the United States Fish and Wildlife Service (USFWS) were required to generate stock assessment reports (SARs) for all marine mammal stocks in waters within the U.S. Exclusive Economic Zone (EEZ). The first reports for the Atlantic (includes the Gulf of Mexico) were published in July 1995 (Blaylock et al. 1995). The MMPA requires NMFS and USFWS to review these reports annually for strategic stocks of marine mammals and at least every 3 years for stocks determined to be non-strategic. Included in this report as appendices are: 1) a summary of serious injury/mortality estimates of marine mammals in observed U.S. fisheries (Appendix I), 2) a summary of NMFS records of large whale human-caused serious injury and mortality (Appendix II), 3) detailed fisheries information (Appendix III), 4) summary tables of abundance estimates generated over recent years and the surveys from which they are derived (Appendix IV), a summary of observed fisheries bycatch (Appendix V), and a list of reports not updated in the current year (Appendix VI). Table 1 contains a summary, by species, of the information included in the stock assessments, and also indicates those that have been revised since the 2014 publication. Most of the changes incorporate new information into sections on population size and/or mortality estimates. A total of 43 of the Atlantic and Gulf of Mexico stock assessment reports were revised for 2015. The revised SARs include 27 strategic and 16 non-strategic stocks. This report was prepared by staff of the Northeast Fisheries Science Center (NEFSC) and Southeast Fisheries Science Center (SEFSC). NMFS staff presented the reports at the February 2014 meeting of the Atlantic Scientific Review Group (ASRG), and subsequent revisions were based on their contributions and constructive criticism. This is a working document and individual stock assessment reports will be updated as new information becomes available and as changes to marine mammal stocks and fisheries occur. The authors solicit any new information or comments which would improve future stock assessment reports.

This report provides estimated bycatch of 6 species of small cetaceans and pinnipeds bycaught in the New England sink (NESG) and mid-Atlantic (MAG) gillnet fisheries. The 2014 serious injuries and total mortalities in the NESG fishery were 128 (coefficient of variation [CV] = 0.27) harbor porpoises (Phocoena phocoena), 111 (CV = 0.47) short-beaked common dolphins (Delphinus delphis), 10 (CV = 0.66) Atlantic white-sided dolphins (Lagenorhynchus acutus), 917 (CV = 0.14) gray seals (Halichoerus grypus), 390 (CV = 0.39) harbor seals (Phoca vitulina concolor), and 57 (CV = 0.42) harp seals (Pagophilus groenlandicus). The NESG estimates are based on observed bycatch consisting of 28 harbor porpoises, 11 short-beaked common dolphins, 2 Atlantic white-sided dolphins, 159 gray seals, 59 harbor seals, and 9 harp seals. The 2014 serious injuries and total mortalities in the MAG fishery were 22 (CV = 1.03) harbor porpoises, 17 (CV = 0.86) short-beaked common dolphins, 19 (CV = 1.06) harbor seals, and 22 (CV = 1.09) gray seals. The MAG estimates are based on observed bycatch consisting of 1 harbor porpoise, short-beaked common dolphin, harbor seal, and gray seal.

Under the 1994 amendments of the Marine Mammal Protection Act (MMPA), the National Marine Fisheries Service (NMFS) and the United States Fish and Wildlife Service (USFWS) were required to generate stock assessment reports (SARs) for all marine mammal stocks in waters within the U.S. Exclusive Economic Zone (EEZ). The first reports for the Atlantic (includes the Gulf of Mexico) were published in July 1995 (Blaylock et al. 1995). The MMPA requires NMFS and USFWS to review these reports annually for strategic stocks of marine mammals and at least every 3 years for stocks determined to be non-strategic. Included in this report as appendices are: 1) a summary of serious injury/mortality estimates of marine mammals in observed U.S. fisheries (Appendix I), 2) a summary of NMFS records of large whale human-caused serious injury and mortality (Appendix II), 3) detailed fisheries information (Appendix III), 4) summary tables of abundance estimates generated over recent years and the surveys from which they are derived (Appendix IV), and a list of reports not updated in the current year (Appendix V). Table 1 contains a summary, by species, of the information included in the stock assessments, and also indicates those that have been revised since the 2013 publication. Most of the changes incorporate new information into sections on population size and/or mortality estimates. A total of 30 of the Atlantic and Gulf of Mexico stock assessment reports were revised for 2014. The revised SARs include 12 strategic and 18 non-strategic stocks.

This report provides estimated takes of 6 species of small cetaceans and pinnipeds bycaught in the New England sink (NESG) and mid-Atlantic (MAG) gillnet fisheries. The 2012 serious injuries and total mortalities in the NESG fishery were 277 (CV = 0.59) North Atlantic harbor porpoises (Phocoena phocoena phocoena), 95 (CV = 0.40) short-beaked common dolphins Delphinus delphis delphis), 9 (CV = 0.92) Atlantic white-sided dolphins (Lagenorhynchus acutus), 542 (CV = 0.19) gray seals (Halichoerus grypus grypus), 252 (CV = 0.26) harbor seals (Phoca vitulina concolor), and 6 (CV = 0.87) Risso's dolphins (Grampus griseus). NESG estimates are based on observed takes consisting of 34 harbor porpoises, 6 short-beaked common dolphins, 1 Atlantic white-sided dolphin, 91 gray seals, 37 harbor seals, and 1 Risso's dolphin. The 2012 serious injuries and total mortalities in the MAG fishery were 63 (CV = 0.83) harbor porpoises, 15 (CV = 0.93) short-beaked common dolphins, and 14 (CV = 0.98) gray seals. MAG estimates are based on observed takes consisting of 2 harbor porpoises, 1 short-beaked common dolphin, and 1 gray seal. Relative to 2011, total annual bycatch of all marine mammal species, save short-beaked com-mondolphin, hasdeclined. However, high uncertainty around estimated takes confounds definitive trends in marine mammal bycatch within the NESG and MAG fisheries.

Inherent uncertainties in the stock assessment for weakfish have precluded accurate and consistent advice concerning the management of commercial and recreational fisheries. Error within ageing techniques, used to assess relative age frequencies within commercial and recreational harvest, has been cited as a potential source for uncertainty during assessments of the weakfish fishery. The implications for age-reading error on weakfish stock assessment were explored using measurement-error growth models (i.e. Chapter 1), ageing error matrices within a statistical catch-at-age framework (i.e. Chapter 2), and Monte Carlo simulations to gauge robustness of ignoring this type of uncertainty during fisheries stock assessment (i.e. Chapter 3). Measurement-error growth models typically resulted in weakfish that grew to reach larger sizes, but at slower rates, with median length-at-age being overestimated by traditional von Bertalanffy growth curves, at least for the observed age range. Measurement-error growth models allow for incorporation of ageing uncertainty during nonlinear growth curve estimation, as well as the ability to estimate the ageing error variance. Age-reading error was further considered during statistical catch-at-age analysis of the weakfish fishery, mainly through permutations of true catch-at-age via ageing error matrices constructed from estimates of the ageing error variance, thus reflecting changes in relative age compositions as a consequence of ageing uncertainty. As a result, absolute levels of key population parameters were influenced, but general trends in those parameters tended to be similar, with strong congruency across models as to weakfish stock dynamics in most recent years. Finally, Monte Carlo simulations showed that implications for age-reading error on weakfish stock assessment are varied, depending upon the direction and magnitude of the ageing uncertainty. However, relative trends of parameter estimates over time tended to be similar, resulting in proper allocation of weakfish stock status, regardless of the type of ageing error considered. Furthermore, assuming negligible ageing uncertainty within fishery-independent surveys appears reasonable, as simulations incorporating ageing error within indices of relative abundance showed similar patterns to situations that only considered observation noise. Master of Science