Vocal behaviour in baleen whales is most often recorded on breeding grounds and is therefore often associated with breeding. Baleen whales are also known to call at other times of year -for example bowhead whales are thought to use their vocalizations to navigate through ice fields during their spring migrations. But up until now there have been virtually no recordings of minke whale vocalizations on their feeding grounds in the Northeast Pacific. In the 1980's and 1990's Jon Stern and Rus Hoezel tried many times to record minke whale calls around the San Juan Islands but never succeeded, leading them to the hypothesis that the whales just weren't vocalizing –a hypothesis that makes sense if you are a whale trying to avoid the detection of transient killer whales!
More recently there have been some attempts to record minke whales in Johnstone Strait, with some apparent success (for more information see MERS). This pilot study and the recent recording by Ocean Networks Canada suggest that in fact minke whales are likely vocalizing while on their feeding grounds in the Northeast Pacific. Humpback whales also vocalize when engaged in feeding and a new study suggests that some humpbacks use calls whilst engaged in cooperative feeding. Minke whales are also thought to produce click type sounds, though it is unclear if they produce this type of vocalization in the Northeast Pacific.
Understanding minke whale acoustic ecology allows scientists greater insight into their habitat preferences, feeding ecology and even population size. Also it is becoming increasingly important to understand how varying levels of ambient noise, particularly in areas with increased shipping activities, might impact minke whales. Clearly there is still much to learn about this elusive little whale, but hopefully better hydrophone technology will once again allow us to start listening for this whale in the Salish Sea, letting us start to answer some of the questions related to foraging ecology, habitat use and population patterns in the regions as well as how minke whales may be impacted by an increasingly noisy ocean.