Ruth Joy

Ruth Joy 2017-06-28T11:53:09+00:00
Cormac Booth

Ruth Joy

Senior Research Scientist (NA)


Ruth Joy is a senior statistician with SMRU Consulting Ltd and an adjunct professor at Simon Fraser University. She received her PhD from Simon Fraser University in the Department of Statistics and Actuarial Science at SFU. Her major focus has been on marine animal ecology, in particular the northern fur seal and Steller sea lion populations in Alaska’s Aleutian and Pribilof Islands. Her main research interest is developing models to describe how animal movement evolves over time, and integrating these with an animal’s (spatial) environment. Ruth has also been involved in designing and testing hypotheses about the physiological and behavioural responses of captive marine mammals to controlled changes in the abundance and quality of fish. Ruth has collaborated with teams of scientists, conservationists, and industry partners in designing simulation and field studies, and analysing data in a wide array of marine and terrestrial contexts. Her latest work is on the development of Bayesian frameworks for investigating spatial links between animal behaviour and habitat.

Link to SFU personal website:

  • Ecological modelling: Bayesian hierarchical modelling, state space modelling, population consequences of disturbance
  • Distance sampling: analysis of line transect data for Chinese white dolphins
  • Coding: R and SAS
  • Field skills: bat, bird (both aural and visual), and marine mammal surveys

Ainsworth, L.M., C.B. Dean, and R. Joy (in press) Zero-inflated spatial models: application and interpretation. International Symposium in Statistics ISS-2015 Proceedings Volume on Advances and Challenges in Parametric and Non-parametric Analysis of Correlated Data. Springer New York, NY. 37 pp.

Muir, J.E., R. Joy, Y. Bychkov, K. Bröker, G. Gailey, V. VLadimirov, S. Starodymov and G. Gailey (2015). Delineation of a coastal gray whale feeding area using opportunistic and systematic survey effort. Endangered Species Research. 29(2): 147-160

Muir, J.E., L. Ainsworth, R. Joy, R. Racca, Y. Bychkov, G. Gailey, V. VLadimirov, S. Starodymov, K. Bröker (2015). Distance from shore of gray whales during a seismic survey off Sakhalin Island, Russia. Endangered Species Research. DOI: 10.3354/esr00701

Joy, R., M.G. Dowd, B.C. Battaile, P.M. Lestenkof, J.T. Sterling, A.W. Trites, R.D. Routledge (2015). Linking northern fur seal dive behavior to environmental variables in the eastern Bering Sea. Ecosphere. 6(5): 75. DOI 10.1890/ES 14-00314.1

Fahlman, A., S.H.Loring, M. Ferrigno,, C. Moore, G. Early, M. Niemeyer, B. Lentell, F. Wenzel, R. Joy, M. Moore (2011). Inflation and deflation pressure-volume loops in breath-hold diving marine mammals. Journal of Experimental Biology. 214, 3822-3828.

Dowd, M. and R. Joy (2011). Estimating behavioural parameters in animal movement models using a state-augmented particle filter. Ecology. 92, 568-575.

Svärd C., A. Fahlman, D.A.S. Rosen, R. Joy, A.W. Trites (2009). Fasting affects the surface and diving metabolic rates of Steller sea lions (Eumetopias jubatus). Aquatic Biology. 8, 71-82.

Trites, A.W. and R. Joy (2005). Dietary analysis from fecal samples: How many scats are enough? Journal of Mammology. 86 44, 704-712.

Tollit, D.J., S.G. Heaslip, T.K. Zeppelin, R. Joy, K.A. Call, and A.W. Trites (2004). A method to improve size estimates of walleye pollock and Atka mackerel consumed by pinnipeds using digestion correction factors applied to bones and otoliths recovered in scats. Fishery Bulletin, 102 3, 498-508.

Buchanan, S., J. Fraser, T. Farrell, P. Gallaugher, R. Joy, and R. Routledge (2002). Reducing gillnet mortality of incidentally caught coho salmon. North American Journal of Fisheries Management. 22, 1270-1275.

For more on Ruth’s publications please see

  • Southern resident killer whale underwater noise exposure and acoustic masking study for Hemmera and Port Metro Vancouver
  • Humpback whale prey field mapping and foraging behaviour for the Tula Foundation
  • Habitat use of Indo-Pacific humpbacked dolphins for SMRU Consulting Asia Pacific
  • Was the decline of Steller Sea lions in the Aleutian Islands from 2000 – 2009 related to the Atka mackerel fishery?
  • Fraser River Eulachon biomass assessments and spawning distribution: 1995-2002
  • Habitat selection by bats in temperate old-growth forests, Clayoquot Sound, British Columbia
  • Long-term effects of prescribed fire in a grassland ecosystem of central British Columbia

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