Monitoring for marine mammals in Alaska using a 360° infrared camera system
Several countries require monitoring to be conducted near activities that have the potential to disturb or harm marine mammals in order to estimate the possible impacts and/or to trigger appropriate mitigations measures. Monitoring typically involves the use of trained personnel to conduct visual observations. However, visual observations are limited to animals at the surface and further by periods of darkness and inclement weather conditions. Various technologies for improving the effectiveness of monitoring continue to be developed, including passive and active acoustics and low-light and infrared (IR) imaging devices. The use of IR imaging technology may allow the detection of marine mammals at night and improve the detection during all periods through the use of automated detection algorithms. An advanced IR camera system capable of simultaneously monitoring 360° around a vessel was tested during a two month seismic operation in the Alaskan Chukchi Sea. This particular installation allowed monitoring of 270° ahead and to the sides of the vessel with a picture refresh rate of 5 Hz. The IR pictures were displayed in real-time on two monitors and visual observers recorded video during marine mammal sightings for retrospective analyses. Approximately 180 whale blows were detect-able in the recorded IR imagery. Smaller whales (Dall’s porpoise) were detectable at distances of several hundred meters, while blows from large baleen whales were seen at distances up to 7 km. The IR camera was also able to detect the majority of walrus that surfaced within 1 km of the vessel, with some detection out to a maximum distance of 1.5 km. Detection and tracking software recorded the swimming path of some Pacific walrus as the seismic vessel passed the animals. The IR camera system showed substantial promise for improving the effectiveness of detecting marine mammals at the surface, although improvements to auto-detection software are necessary.