| "Some people talk to animals. Not many listen though. That's the problem."
Integrating Passive Acoustics with Visual Data
|Ship-based visual survey:
NOAA Ship Gordon Gunter
| Aircraft visual survey:
NOAA Twin Otter 56
|Ship-board visual observations
on NOAA Ship Henry Bigelow
Visual surveys have long been used as the standard for collecting marine mammal data, both for understanding distribution, seasonal occurrence and abundance. As passive acoustic technology and analytical approaches mature, they provide a different angle from which to collect data. They provide a unique long term window into marine mammal occurrence and distribution since acoustic recorders can listen for sounds 24/7 regardless of weather or darkness.
However, what the best approach is to merge these techniques is what we need to work at next. There are attempts to estimate abundance from sounds already underway. However, abundance is not always an achievable goal when studying some species whom change their calling rate depending on the behavioral situation, age class, or social grouping. Other species produce more stereotyped calls and are good candidates for current suggested methods for estimating abundance.
At PSB we are taking two approaches to addressing these issues. Firstly, we are using our wealth of data to look at which density estimation from acoustic approaches may work, or even if we don't reach actual abundance, what can we gain from these approaches.
Secondly, we are looking at radically different ways of approaching this question and starting to explore how we can use occupancy modeling as an approach to the question of how we best use two rich data sources: visual sightings and acoustic detections.