Evaluating autonomous underwater vehicles as platforms for animal population density estimation

Speaker: Danielle Harris (CREEM)

Abstract

Autonomous underwater vehicles such as ocean gliders and vertical profiling floats have the potential to play a key role in future marine mammal monitoring efforts. When equipped with hydrophones, these vehicles can collect passive acoustic data and provide both broad spatial and temporal coverage of a survey area. While a variety of methods have been developed to estimate animal density from acoustic data collected by fixed or moving platforms, estimating cetacean density from autonomous ocean vehicles has required further investigation.

Here I will give an overview of a project, funded by the US Office of Naval Research, which ended in June 2019.  The project had the primary goal of estimating cetacean density from data collected by ocean gliders and profiling floats, taking into account species’ acoustic and behavioural differences.  There were four broad objectives: (1) evaluate whether glider data can be analysed using design-based density estimation methods; (2) quantify glider/profiling float survey effort and evaluate encounter rates of example cetacean species; (3) estimate the probability of detecting cetacean vocalizations on gliders/profiling floats; and (4) estimate animal densities of example species using glider data.

In this seminar, I will present results from across the project focusing on Blainville’s beaked whales (Mesoplodon densirostris) as the primary study species.