Evaluating a Benthic Index of Biotic Integrity (b-ibi) to Measure Ecological Integrity in Pacific Rim National Park Reserve of Canada

The ease of application and effectiveness of a multimetric benthic index of biotic integrity (B-IBI) was evaluated for use as an ecological integrity monitoring tool in coastal National Parks of Canada. The B-IBI was developed in three phases: 1) analysis of land use impacts to select study watersheds along a gradient of disturbance; 2) collection and identification of benthic macroinvertebrates from study streams; 3) multimetric and multivariate analysis of benthic invertebrate data to evaluate the performance of the B-IBI approach for monitoring the ecological integrity of streams in Pacific Rim National Park Reserve of Canada, on the west coast of Vancouver Island. Land use impacts were analysed from Landsat-7 ETM+ satellite images. Potentially appropriate metrics were chosen through a literature review and evaluated by comparing metric scores with watershed impact scores for each study watershed. The ten best metrics for the study region were combined into a benthic index of biotic integrity for Pacific Rim NPR, and each study stream was given a biotic integrity score derived with this index. Additional analysis of the macroinvertebrate assemblages was conducted using multivariate ordination, in order to compare multimetric and multivariate approaches. The multimetric B-IBI approach produced relatively high overall biotic integrity index scores for most study creeks, but the scores did not correlate well with impact scores determined from satellite image analysis. Multivariate analysis of the macroinvertebrate data separated sites according to environmental variables, but did not separate sites based on impact scores from satellite image analysis. This may be attributable to a lack of impacts in the macroinvertebrate communities, but it is argued in this report that the results are better explained as a failure of the B-IBI method to detect impacts. The B-IBI approach could be improved by increasing sampling effort enough to determine reference conditions for macroinvertebrate assemblages in Pacific Rim NPR. Future studies will need to include streams further outside the boundaries of the Park, to sufficiently increase the number of samples for reliable measurement of the ecological integrity of Park watersheds. Acknowledgements I enjoyed the assistance of many people, at all stages of this project. I thank Dr. Marlow Pellatt and Parks Canada for funding, guidance, equipment, expertise, and patience. Dr. Wolfgang Haider and Dr. Ken Lertzman have always been instantly helpful and endlessly patient. Greg MacMillan, Steve Lobay, Dr. Cliff Robinson, Brian MacDonald and many others at the Western Canada Service Centre have given time, energy, and insight. Bob Redhead, Barry Campbell, Alrene Suski, Brock Fraser, Heather Holmes and other Field Unit staff in Pacific Rim have provided data, advice, and assistance (and some great jokes). Karen Leslie, J.P. Coors, Arlene Suski, Lisa Larson, and Susan Baron all braved raging waters, dense riparian vegetation and vengeful adult insects to collect macroinvertebrates on the wild wet coast. Dr. John Richardson and his lab gave time and expertise to verify my identifications. My classmates and professors at REM brought so much breadth and depth to the learning experience that this stack of paper is only the beginning.. . and certainly not the end. I thank my family, for taking me to meet my first bugs in the Muskokas. And I thank Josha, for helping me get this far. Table of