MARBLED MURRELET BRACHYRAMPHUS MARMORATUS MOVEMENTS AND MARINE HABITAT USE NEAR PROPOSED TANKER ROUTES TO KITIMAT, BC, CANADA

Received 22 May 2015, accepted 23 October 2015 SUMMARY BERTRAM, D.F., MacDONALD, C.A., O’HARA, P.D., CRAGG, J.L., JANSSEN, M.H., McADIE, M. & BOYD, W.S. 2015. Marbled Murrelet Brachyramphus marmoratus movements and marine habitat use near proposed tanker routes to Kitimat, BC, Canada. Marine Ornithology 44: 3–9. We report on movements and marine habitat use of breeding Marbled Murrelets Brachyramphus marmoratus offshore of Kitimat, British Columbia, Canada, with particular reference to the proposed “Northern Gateway” tanker traffic routes. Adult Marbled Murrelets were captured at night on the water during the pre-laying period (April 2014) in Wright Sound, near Hartley Bay, BC. Six birds were tagged with 5 g solar satellite transmitters. We had short-lived or no detections for two birds, detections for two weeks for three birds, and detections throughout the breeding season and beyond for one bird whose tag continued to transmit signals. Marine habitat use in relation to three alternative proposed tanker routes was examined for individual murrelets by using kernel density estimation to generate probability density functions of location, incorporating Argos location errors. Areas of high, medium and low encounter probabilities for each bird were generated. Use of marine habitats, coupled with a large population of birds in the area during the breeding season, suggests that there is a strong potential for interaction between tankers and murrelets along the proposed routes. However, based on the movement of one bird to south-central Alaska, individuals may migrate out of the area, reducing the likelihood of interactions post-breeding.