Researcher Profile

Ian Birtwell

Job Title: Research Scientist
Employer: Fisheries and Oceans Canada
Place of Birth: Manchester, Lancashire, England.
High School attended: Stand Grammar School
Further Education: London University (B.Sc., Ph.D.).
Geographic focus of research: BC

Brief synopsis of current research:
The effects of sublethal exposures of contaminants and natural factors on the performance and survival of Pacific salmon.

Recent focus has been on the effects on juvenile chum salmon of a sublethal exposure to a combination of elevated temperature and dissolved gas supersaturation on their susceptibility predation.

New research is on the effects of sediment on chinook salmon growth and susceptibility to predation.

Recent Publications:

Birtwell, I.K., R. Fink, D. Brand, R. Alexander, and C. D. McAllister. 1999. Survival of pink salmon (Oncorhynchus gorbuscha) fry to adulthood following a 10-d exposure to the aromatic hyrocarbon water soluble fraction of crude oil and release to the Pacific Ocean. Can J. Fish. Aquat. Sci. 56 (11) 2087-2098.

Birtwell, I.K., J.S. Korstrom, R.P. Fink, J.A. Tanaka, D.I. Tiessen, and B.J. Fink. 1999. The effects of thermal change on juvenile chum salmon behavior, distribution and feeding: laboratory and field studies. Pp 87-92 In: Proceedings of the 19th Northeast Pacific Pink and Chum Salmon Workshop, Juneau, Alaska. National Marine Fisheries, Juneau, AK. 173p.

Korstrom, J.S., I. K. Birtwell, M. Komatsu, L. Richmond, B.J. Fink, and R.P. Fink. 1999. The susceptibility of juvenile chum salmon to predation following sublethal exposure to elevated temperature and dissolved gas supersaturation in sea water. Pp 93-101 In: Proceedings of the 19th Northeast Pacific Pink and Chum Salmon Workshop, Juneau, Alaska. National Marine Fisheries, Juneau, AK. 173p.

Birtwell I.K. 1999. Effects of sediment on fish and their habitat. Pacific Scientific Advice Review Committee (PSARC) Research Document HAB 99-1. Fisheries and Oceans Canada, Canadian Stock Assessment Secretariat, Ottawa 34 p.

Kruzynski, G.M., and I.K. Birtwell. 1994. A predation bioassay to quantify to ecological significance of sublethal responses of chinook salmon to the antisapstain fungicide TCMTB. Can. J. Fish. Aquat. Sci. 51: 1780-1790.

Comments:
Aquatic scientists must continue to recognize that the maintenance of individual health and performance of aquatic organisms is linked to the perpetuation of healthy populations, and that debilitation of organisms often leads to their demise in the competitive world in which they live. Reliance on the determination of gross population level effects in order to assess environmental change may miss the subtle changes that occur at the individual level, for population changes are often highly variable.

Studies that link sublethal effects to survival are essential research elements to study. In the natural world our beaches are not littered with corpses, yet countless organisms die all the time....thus if environmental change results in debilitation of an organism to the point that it cannot compete it is likely to die, but not necessarily be seen. Hence the need to provide the links between effects at the sublethal level and organism fitness and survival.