PARENT SESSION
Oral Session # 2: Paleoecology.
Presiding: B Lynch
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 101.

Paleoecology of salmon lakes on the west coast of Canada.

Pellatt, Marlow^{*,1, 2}, Holtham, Anita ³, Bos, Darren^{1, 2}, ¹ Parks Canada, Western Canada Service Centre, Vancouver, British Columbia, Canada² Simon Fraser University, Burnaby, British Columbia, Canada³ Queens University, Kingston, Ontario, Canada

ABSTRACT- Parks Canada has a mandate to maintain the ecological integrity of terrestrial and marine ecosystems in representative regions within Canada and its national waters. In order to understand the ecological integrity of any given ecosystem it is essential to understand the natural range of variability in which the system exists as well as the impact people and climate change have had on it. This study is a multiproxy investigation that uses paleoecological methods to reconstruct environmental conditions for the last ∼300 years in three lakes and their watersheds on the west coast of Vancouver Island. Pollen, diatoms, cladocera, sediment, and stable isotope analyses of ²¹⁰PB dated sediments from lakes in or near Pacific Rim National Park Reserve of Canada reveal changes in forest structure, limnological conditions, and possibly salmon populations. We also present data that investigates differences in sedimentary ¹⁵N amongst a suite of salmon lakes from British Columbia and relate these differences to the terrestrial sedimentary component and other environmental variables. The results of this research program contribute to our understanding of the role of marine derived nutrients in regard to lake productivity along the west coast of North America. This research indicates that while salmon derived nutrients may be of key importance in juvenile salmonid development in some lakes, this may not be the case in all systems, especially those in which flushing rates are high. In these systems diatom communities appear to be more sensitive to fluctuations in salmon populations than stable isotope methods, provided that other changes in trophic status are minor. The role of this type of research in ecosystem management is important to Parks Canada and will assist in understanding the complexities of land sea interactions and the interplay between terrestrial and marine protected areas.

Key words: marine derived nutrients, paleoecology, salmon, Pacific Ocean