Spatiotemporal Patterns in Acoustic Presence of Sei Whales (Balaenoptera borealis) in Atlantic Canada

Abstract

The main objective of my thesis was to ascertain the spatiotemporal presence of sei whales in Atlantic Canada (Nova Scotia, Newfoundland, and Labrador) using passive acoustic monitoring. First, I first characterized sei whale vocalizations in Atlantic Canada (1.58 s long, 75.66 Hz to 34.22 Hz). Then, I examined whether downsweeps differed between two geographic regions in Atlantic Canada. I found downsweeps were significantly longer, and fewer doublets were recorded off Nova Scotia than Newfoundland/ Labrador. I then created and tested a tiered-detector approach, to reduce the overall time it takes to review sei whale detections. Finally, I determined the spatial and temporal occurrence of sei whales in Atlantic Canada over a two-year period. Sei whales were present year-round in Atlantic Canada and were heard mostly off-shelf, with low presence at stations <100 km offshore. Sei whales were absent from northern stations in winter, with a regional peak in October.