Final Technical Report: - Southwest Fisheries Science Center - NOAA

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overwhelming majority of “Bryde’s or sei whale” sightings in the ETP region are Bryde’s whales. Include sightings of “Kogia spp.” in the Kogia sima model because the majority of Kogia sightings unidentified to species in the ETP are believed to be K. sima. Do not include Beaufort sea state as a predictor variable in the spotted dolphin models because the primary visual cue for Stenella attenuata sightings is flocks of birds flying overhead. Incorporate latitude and longitude, or a latitude/longitude/SST interaction term in the eastern spinner model to differentiate eastern spinner from whitebelly spinner habitat. Include islands in the distance-to-shore computation to improve the prediction accuracy of the bottlenose dolphin encounter rate models in particular. Select simple models for the final models, unless strong support exists for the alternative complex model. Use geographically stratified estimates of density rather than predictions derived from cetacean-habitat models for sperm whales, killer whales (Orcinus orca), and coastal spotted dolphins. Image Quality Analysis (IQA; Wang et al. 2004), a quantitative, spatially-explicit method for comparing two images, was implemented as an additional model evaluation technique, but it was not used in final model selection because we found that people had difficulty interpreting the resulting statistics. Nevertheless, the IQA approach seems promising and future work into making the results accessible to a non-expert audience would be valuable. Density Estimation The values for the line-transect sighting parameters f(0) and g(0) used to compute population density in the ETP analysis came from published reports, as summarized by Ferguson and Barlow (2001). For species in which the f(0) values were stratified by group size, selection of the appropriate group size stratum for determining which value of f(0) to use was determined by the group size predictions from the preferred group size model for the species. Similar to the California Current analysis, the value of Beaufort sea state used to compute the final encounter rate and group size predictions for the SDSS was set to the average Beaufort, weighted by survey effort, of all segments used to build the models. The f(0) values for all beaked whales and Kogia were computed from data collected during Beaufort sea states from 0 to 2. Therefore, computation of weighted average Beaufort for beaked whales and Kogia predictions included only segments with average Beaufort conditions of 2 or less. 30
Encounter rate and group size were predicted to segment midpoints located directly on the survey transects, and the resulting densities were interpolated (as described under Density Interpolation in the California Current section above) to provide gridded density predictions throughout the study area. Grids were created for each of the individual survey years (1986- 1990, 1998-2000, 2003, and 2006) and interpolated at a resolution of 100 km. All data within a search radius of 10 degrees latitude (1,111 km) were included in the inverse distance weighting calculations. Model Validation Data from the 2006 line-transect surveys in the ETP were used to validate the encounter rate and group size models constructed using data from 1986-2003. Data processing for this model validation task followed that described under Data Extraction for the ETP above. To assess the models’ fit to the validation data set and to examine the inter-annual variability in model predictions, density was predicted separately for each survey year from 1986 to 2006. Methods used to evaluate model fit included visual inspection of geographic contour plots of the annual density predictions and computation of geographically stratified ratios of observed to predicted density. 3.5.3 Line-transect densities for unmodeled species The predictive habitat models described above were developed for all ETP and CCE species with sufficient sightings and survey data during the summer/fall season. Several additional species were observed during the surveys, but too few observations were made to develop models. Similarly, a SWFSC survey of waters surrounding Hawaii yielded too few sightings for modeling of cetacean densities in that region. Therefore, constant densities were derived for these species and regions, based on published line-transect estimates applied to the most appropriate species-specific strata. Coefficients of variation and lognormal 90% confidence limits were estimated from the published CVs, or re-calculated for specific strata using the same methods as the original studies. Within the California Current Ecosystem, line-transect estimates derived from the 1991- 2005 U.S. West Coast surveys (Barlow and Forney 2007; Table 6) were used for the following species during summer: long-beaked common dolphin (Delphinus capensis), short-finned pilot whale, bottlenose dolphin, killer whale, minke whale (Balaenoptera acutorostrata), Bryde's whale, sei whale, and a combined category for pygmy and dwarf sperm whales (Kogia spp.). Similarly, average winter densities estimated for cetaceans off California (Forney et al. 1995) based on aerial line-transect surveys were applied to appropriate geographic strata on a speciesspecific basis. These species included: common dolphins (Delphinus spp.), Pacific white-sided dolphin, northern right whale dolphin, Dall's porpoise, Risso's dolphin, bottlenose dolphin, killer whale, blue whale, fin whale, humpback whale, sperm whale, minke whale, North Pacific right whale (Eubalaena japonica) and a category of 'small beaked whales' which includes species of 31
Page 1 and 2: U N I R A P E D T T E M D S E N TA
Page 3: C O L A N IO T A N U N C I EA .S. D
Page 6 and 7: This report was prepared under cont
Page 8 and 9: Table of Contents Acronyms and Abbr
Page 10 and 11: C.1 Journal Publications ..........
Page 12 and 13: Figure 18. Encounter rate models bu
Page 14 and 15: List of Tables Table 1. Summary of
Page 16 and 17: Appendix B, Table B-6. Summary of m
Page 18 and 19: Acknowledgements This project was f
Page 20 and 21: of these choices as possible and us
Page 22 and 23: Although our models include most of
Page 24 and 25: 2.0 Background The Navy and other m
Page 26 and 27: comparison is based on a separate s
Page 28 and 29: Figure 1. Transects (green lines) s
Page 30 and 31: used to evaluate the ability of sum
Page 32 and 33: 3.1.5 Mid-trophic Sampling with Net
Page 34 and 35: variable. Interpolated maps of the
Page 36 and 37: Table 2. Variogram model results. A
Page 38 and 39: “number of individuals” as the
Page 40 and 41: Encounter Rate and Group Size Model
Page 42 and 43: were built separately for each of t
Page 44 and 45: Expanding models to the entire U.S.
Page 46 and 47: Table 4. Summary of the weighted ef
Page 48 and 49: Consistent with Barlow and Forney (
Page 50 and 51: incorporation of geographic coordin
Page 54 and 55: the genera Ziphius and Mesoplodon.
Page 56 and 57: Table 7. Geographically stratified
Page 58 and 59: above, and the data themselves, are
Page 60 and 61: (hereafter “summer”). SWFSC has
Page 62 and 63: avoid these problems, we decided to
Page 64 and 65: Figure 9. Thermocline depth (m) obs
Page 66 and 67: Attempts to adjust search parameter
Page 68 and 69: CAMMS 1991 PODS 1993 ORCAWALE 1996
Page 70 and 71: 4.2 Modeling Framework : GLM and GA
Page 72 and 73: 4.2.4 Conclusions Regardings Modeli
Page 74 and 75: Table 10 cont. Comparison of the si
Page 76 and 77: Table 11 cont. Comparison of the si
Page 78 and 79: Figure 15. The transect lines used
Page 80 and 81: A) Striped dolphin 10 km B) Short-b
Page 82 and 83: dependent. For example, the number
Page 84 and 85: Figure 19. Predicted average densit
Page 86 and 87: ecosystem, eastern spinner dolphins
Page 88 and 89: Table 13. Variables selected for mo
Page 90 and 91: Table 14. Starting and final AIC va
Page 92 and 93: Table 17. Ratios of observed to pre
Page 94 and 95: species represented in the acoustic
Page 96 and 97: 0.29 (Risso’s dolphin) to 3.20 (n
Page 98 and 99: Figure 25. Sample 2005 validation p
Page 100 and 101: Table 18. (continued) 1991 1993 Nor
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Blue whales had the greatest deviat
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Table 20. Abundance (number of anim
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Table 22. Proportion of deviance ex
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Figure 27. Average density (AveDens
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Table 23. Effective degrees of free
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We attempted to build encounter rat
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5.0 Conclusion The field of predict
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6.0 Transition Plan The models of c
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needed to ensure that the SDSS rema
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Administrative Report LJ-07-02. NOA
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Forney KA, Barlow J (1993) Prelimin
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Redfern JV, Barlow J, Ballance LT,
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Appendix A: Detailed Model Results
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Table A-1 (continued) Blue whale 19
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Figure A-1a. Striped dolphin 108
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Figure A-1c. Risso’s dolphin 110
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Figure A-1e. Northern right whale d
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Figure A-1g. Sperm whale 114
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Figure A-1i. Blue whale 116
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Figure A-1k. Baird’s beaked whale
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Figure A-2. Predicted average densi
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Figure A-2b. Short-beaked common do
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Figure A-2d. Pacific white-sided do
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Figure A-2f. Dall’s porpoise 126
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Figure A-2h. Fin whale 128
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Figure A-2j. Humpback whale 130
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Figure A-2l. Small beaked whales 13
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Table B-2. Summary of model validat
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Table B-10. Summary of model valida
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Figure B-1. Predicted yearly and av
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Figure B-1. b) Eastern spinner dolp
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Figure B-1. c) Whitebelly spinner d
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Figure B-1. d) Striped dolphin 168
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Figure B-1. e) Rough-toothed dolphi
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Figure B-1. f) Short-beaked common
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Figure B-1. g) Bottlenose dolphin 1
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Figure B-1. h) Risso’s dolphin 17
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Figure B-1. i) Cuvier’s beaked wh
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Figure B-1. j) Blue whale 180
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Figure B-1. k) Bryde’s whale 182
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Figure B-1. l) Short-finned pilot w
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Figure B-1. m) Dwarf sperm whale 18
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Figure B-1. n) Mesoplodon beaked wh
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Figure B-1. o) Small beaked whales
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Figure B-2. Predicted average densi
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Figure B-2. (cont.) c) Whitebelly s
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Figure B-2. (cont.) g) Bottlenose d
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Figure B-2. (cont.) k) Bryde’s wh
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Figure B-2. (cont.) o) Small beaked
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Ferguson MC (2005) Cetacean Populat
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Barlow J, Kahru M, Mitchell BG (In
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Memorandum NMFS-SWFSC-374, U.S. Dep
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