Claude Dykstra

Claude Dykstra

Research Biologist
Biological & Ecosystem Sciences Branch

206-634-1838 x 7662

Current IPHC Responsibilities:

  • Conducts original fisheries studies related to biological and fishery aspects of Pacific halibut, and presents results of research in scientific reports and primary publications. Topics are related to halibut biology, behavior, and interactions with fishing gear.


  • International Pacific Halibut Commission (Seattle, WA).
    • Research Biologist (2015-present)
    • Survey Manager (2001-2015)
  • Archipelago Marine Research, Ltd. (Victoria, BC)
    • Groundfish Observer, Sablefish and Shrimp Data Coordinator, Program Manager (1996-2001)


  • M.S., Environmental Science, Alaska Pacific University, 2019 - Present
  • BSc., Specialized Honors Marine Biology, Minor Human Nutrition, University of Guelph

Research Activities:

  • Pacific halibut condition (fitness/physiology)
  • Fishery Discard Mortality
  • Electronic monitoring
  • Ichthyophonus sp. prevalence and intensity
  • Environmental contamination
  • Whale depredation of Pacific halibut from longline gear


  • van Helmond, A.T.M., Mortensen, L.O., Pletā€Hansen, K.S., Ulrich, C., Needle, C.L., Oesterwind, D., Kindt-Larsen, L., Catchpole, T., Mangi, S., Zimmermann, C., Olesen, H.J., Bailey, N., Bergsson, H., Dalskov, J., Elson, J., Hosken, M, Peterson, L., McElderry, H., Ruiz, J., Pierre, J.P., Dykstra, C., and Poos, J.J. Electronic monitoring in fisheries: Lessons from global experiences and future opportunities. Fish Fish. 2019; 00:1–28.
  •  Hershberger, P.K., Gregg, J.L., Dykstra, C.L. 2018. High-Prevalence and Low-Intensity Ichthyophonus infections in Pacific Halibut. Journal of Aquatic Animal Health. 30(1): 13-19.
  • Bentzen, R., Castellini, J.M., Gerlach, R., Dykstra, C., O’Hara, T. 2016. Mercury concentrations in Alaska Pacific halibut muscle relative to stable isotopes of C and N and other biological variables. Mar. Pollut. Bull. 113, 110-116
  • Soderlund, E., Randolph, D. L., Dykstra, C. 2012. IPHC setline charters 1963 through 2003. Int. Pac. Halibut Comm. Tech. Rep. 58. 264 p.
  • Yamanaka, K. L., Lochead, J. K., Cooke, K., Lacko, L. C. and Dykstra, C. 2007.Summary of non-halibut catch from the standardized stock assessment survey conducted by International Pacific Halibut Commission in British Columbia from May 31 to July 24, 2005. Canadian Technical Report of Fisheries and Aquatic Sciences 2689.55 p.


  • Improving Discard Mortality Rate estimates of Pacific halibut (Hippoglossus stenolepis) in the directed longline fishery. Dykstra, C., Simeon, A., Loher, T., Stewart, I.J., Hicks, A.C., Wolf, N., Harris, B.P., and Planas, J.V. North Pacific Marine Science Organization (PICES) – 2019 Annual Meeting, W2. Victoria, BC, Canada. 18 October, 2019 [Presentation].
  • Electronically monitoring release method as a proxy for Pacific halibut mortality rates in the directed Pacific halibut longline fishery. Dykstra, C., Loher, T., Stewart, I.J., Hicks, A.C., and Planas, J.V. 9th International Fisheries Observer and Monitoring Conference. Vigo, Galicia, Spain. 11-15 June, 2018 [Poster].
  • Epizootiology of Ichthyophonus sp. in Pacific halibut (Hippoglossus stenolepis) in the Northeast Pacific Ocean and Bering Sea. Dykstra, C., Gregg, J., Hershberger, P. 9th International Flatfish Symposium. Cle Elum, WA, USA. 9-14 November, 2014.  [Presentation]. 
  • Total mercury and selenium levels in Alaskan Pacific Halibut (Hippoglossus stenolpis) tissue from 2002-2012. Dykstra C., Gerlach, R. 2014 National Forum on Contaminants in Fish. Alexandria, VA, USA. 22-24 September , 2014. [Poster].

Affiliations & Certifications:

  • Seattle Aquarium Beach Naturalist.