Ray Webster , Ph.D.

Ray Webster , Ph.D.

Quantitative Sciences Branch

206-634-1838 x 7685

Current IPHC Responsibilities:

  • Statistical modelling and data analysis; providing statistical support to Secretariat; reviewing IPHC sampling protocols and study designs


  • Originally from New Zealand where I majored in statistics at the University of Otago, after which I worked as a biometrician for Manaaki Whenua - Landcare Research. I moved to the USA in 2002 to undertake graduate studies at North Carolina State University, with Ken Pollock as thesis supervisor. In October 2006 I began work at the IPHC.


  • PhD, North Carolina State University, 2006
  • MSc, University of Otago, 1993
  • BSc (Honours), University of Otago, 1992  

Research Activities:

  • Spatio-temporal modelling; tag-recovery models; setline survey design and data analysis


  • Carpi P., Loher, T., Sadorus, L. L., Forsberg J. E., Webster, R. A., Planas, J. V., Jasonowicz A., Stewart I. J., and Hicks, A. C. (2021). Ontogenetic and spawning migration of Pacific halibut: a review. Reviews in Fish Biology and Fisheries.
  • Sadorus L. L., Goldstein E., Webster R. A., Stockhausen W. T., Planas J. V., and Duffy-Anderson J. (2020). Multiple life-stage connectivity of Pacific halibut (Hippoglossus stenolepis) across the Bering Sea and Gulf of Alaska. Fisheries Oceanography 30(2): 174-193.
  • Webster, R. A., Soderlund, E., Dykstra, C. L., and Stewart, I. (2020), Monitoring change in a dynamic environment: spatio-temporal modelling of calibrated data from different types of fisheries surveys of Pacific halibut. Canadian Journal of Fisheries and Aquatic Sciences 77(8): 1421-1432.
  • Loher, T., Webster, R. A., and Carlile, D. (2017), A test of the detection range of acoustic transmitters and receivers deployed in deep waters of Southeast Alaska, USA. Animal Biotelemetry, 5, 1-22.
  • Webster, R. A., Leaman, B. L., Clark, W. G., and Forsberg, J. E. (2013), Pacific halibut on the move: a renewed understanding of adult migration from a coastwide tagging study. Canadian Journal of Fisheries and Aquatic Sciences, 70, 642-653.
  • Leaman, B. M., Kaimmer, S. M., and Webster, R. A. (2012), Circle Hook Size and Spacing Effects on the Catch of Pacific Halibut. Bulletin of Marine Science, 88, 547–557.
  • Yoshizaki, J., Pollock, K. H., Brownie, C., and Webster, R. A. (2009), Modeling misidentification errors in capture-recapture studies using photographic identification of evolving marks. Ecology, 90, 3–9.
  • Webster, R. A., Pollock, K. H., and Simons, T. R. (2008), Bayesian spatial modeling of data from bird surveys. Journal of Agricultural, Biological and Environmental Statistics, 13, 121–139.
  • Webster, R. A., Pollock, K. H., Ghosh, S. K. and Hankin, D. G. (2008), Bayesian spatial modeling of data from unit-count surveys of fish in streams. Transactions of the American Fisheries Society, 137, 438–453.
  • Forsyth, D. M., Link, W. A., Webster, R., Nugent, G. and Warburton, B. (2005), Nonlinearity and seasonal bias in an index of brushtail possum abundance. Journal of Wildlife Management, 69, 976–981.
  • Barton, J., Gianotti, A. F., Morin, L. and Webster, R. A. (2003), Exploring the host range of Fusarium tumidum, a candidate bioherbicide for gorse and broom, Australasian Plant Pathology, 32, 203–211.
  • Harris, W., Beever, R. E., Parkes, S., Webster, R., and Scheele, S. (2003), Genotypic variation of height growth and trunk diameter of Cordyline australis (Lomandraceae) grown at three locations in New Zealand. New Journal of Botany, 41, 637-653.
  • Schipper, L. A., Clarkson, B. R., Vojvodic-Vulcovic, M. and Webster, R. (2002), Restoring cut-over restiad peat bogs: A factorial experiment of nutrients, seed and cultivation, Ecological Engineering, 19, 29–40.
  • Alley, J. C., Berben, P. H., Dugdale, J. S., Fitzgerald, B. M., Knightbridge, P. I., Meads, M. J. and Webster, R. A. (2001), Responses of litter-dwelling arthropods and house mice to beech seeding in the Orongorongo Valley, New Zealand. Journal of the Royal Society of New Zealand, 31, 425-452.
  • Booth, L. H., Heppelthwaite, V. J., Webster, R., O’Halloran, K. (2001), Lysosomal neutral red retention time as a biomarker of organophosphate exposure in the earthworm Aporrectodea caliginosa: laboratory and semi-field experiments, Biomarkers, 6, 1, 77-82.
  • Coleman, J. D., Cooke, M. M., Jackson, R. and Webster, R. (1999), Temporal patterns in bovine tuberculosis in a brushtail possum population contiguous with infected cattle in the Ahaura Valley, Westland. New Zealand Veterinary Journal, 47, 119-124.
  • Fletcher, D. and Webster, R. (1996), Skewness-adjusted confidence intervals in stratified biological surveys. Journal of Agricultural, Biological and Environmental Statistics, 1, 120-130


  • Calibration of data from different types of fisheries surveys for use in spatio-temporal modelling. International Biometric Conference, Barcelona, Spain. July 2018. Ray Webster.
  • Improving the estimation of Pacific halibut density indices through spatio-temporal modelling of survey data. Western Groundfish Conference, Monterey, USA. February 2018. Ray Webster.
  • Spatio-temporal modelling of Pacific halibut distribution incorporating environmental data. Wakefield Symposium, Anchorage, USA. May 2017. Ray Webster.
  • Covariate-dependent tag-recovery models for fisheries data with missing covariate values. International Biometric Conference, Florence, Italy. July 2014. Ray Webster.
  • Bayesian Spatial Modeling of Coastal Fisheries Survey Data. International Biometric Conference, Florianopolis, Brazil. December 2010. Ray Webster.
  • Bayesian Spatial Modeling of Data from Bird Surveys (invited). International Biometric Conference, Florianopolis, Brazil. December 2010. Ray Webster, Ken Pollock and Ted Simons.
  • Conflicting results from a large multi-stratum PIT tag study and the Pacific Halibut stock assessment. American Fisheries Society Conference, Ottawa, Canada. August 2008. Ray Webster.
  • Removal Sampling with Migration (poster). International Biometric Conference, Dublin, Ireland. July 2008. Ray Webster and Bill Clark.
  • Bayesian Spatial Modeling of Data from Bird Surveys. Joint Statistical Meetings, Seattle, WA, USA. August 2006. Ray Webster, Ken Pollock and Ted Simons.
  • Modeling Observer Effects on Animal Density and Detection for Combined Distance and Capture-Recapture Data (poster). International Biometric Conference, Montreal, Canada. July 2006. Ray Webster and Ken Pollock.
  • Presence/absence monitoring of juvenile coho salmon in streams. Workshop For Developing a Coastal Salmonid Monitoring Plan, Santa Cruz, CA, USA. March 2004. Ray Webster and Ken Pollock

Affiliations & Certifications:

  • International Biometric Society (WNAR)
  • American Statistical Association