March 20, 2014 — The following was released by NOAA Fisheries:
Scientists using passive acoustic monitoring to track minke whales in the Northwest Atlantic have found clues in the individual calling behaviors and movements of this species. These findings, recently published online in the journal Behaviour, provide insight into one of the least studied baleen whales.
“Although we regularly observe minke whales in our Gulf of Maine surveys, we know very little about minke whale vocalizations and how they use sound in their behavioral and social interactions,” said Denise Risch, lead author of the study and a marine mammal researcher at NOAA’s Northeast Fisheries Science Center (NEFSC).
Information on individual calling behaviors and source levels are important in understanding marine mammal social interactions. Risch and colleagues used passive acoustic recordings to track and assess the sound production behavior of 18 minke whales in the Stellwagen Bank National Marine Sanctuary (SBNMS) in the Gulf of Maine. The study periods were October – November 2009 and August – October 2011.
The recordings came from arrays of bottom-mounted marine autonomous recording units, MARUs, deployed in the sanctuary since December 2007 to continuously record low-frequency sounds. The recordings are analyzed for the presence of vocally active baleen whales and fish species. The sound data are also being used to calculate a noise budget for the sanctuary and to examine potential effects of human-induced noise on the acoustic communication of marine animals.
Sounds produced by minke whales in the Gulf of Maine region have only recently been described in more detail, thanks in part to the recordings from the Stellwagen Bank MARUs. A 2013 study by Risch and others on minke whale acoustic behavior and vocalization patterns in Massachusetts Bay described seven distinct pulse train types, which fall into three main categories and occur with varying frequency. The behavioral significance of these vocalizations and whether they are specific to sex, age, recording site, or season is unknown.
Given that the minke whale vocal repertoire has several typical call types, the main objective of this study was to investigate whether individual minke whales use the full vocal repertoire, or combine pulses in predictable sequences. How individuals use the different call types when they interact with other individuals was also a study priority.
Read the full press release at NOAA Fisheries