Application of (low cost) drifters with suspended hydrophone arrays to assess harbor porpoise use of the water column and spatial overlap with MRE devices in the Minas Passage

Principal Investigators:

Dr. Anna Redden, Dr. Brian Sanderson, Acadia University

Start Date: October 2017

End Date: August 2018

The project goal is to assess the activity and depth distribution of harbour porpoises utilizing the Minas Passage and Minas Channel, using new low-cost drifter technology. The study comprises three primary objectives. The first objective is to assess porpoise activity through the analysis of recently collected field data from a drifter fitted with two synced hydrophones. Second, the researchers will conduct a two-day field test using a drifting vertical array of four synchronized hydrophones, equipped with GPS, to quantify how porpoises utilize the water column in Minas Passage. As part of the field testing phase, there will be an attending boat with marine mammal observers (MMO’s) who will validate porpoise detections. The third objective is to assess the utility and practicality of drifters as a viable monitoring platform at time scales of weeks to months for future environmental effects monitoring (EEM) use.

The measurements collected from this study will provide data on the vertical distribution of porpoises in relation to a bottom moored turbine as well as where and when porpoises are active. Such information will be helpful for assessing risk of encounter with in-stream turbines.