250 likes | 263 Views
Research on marine mammals, including white-beaked dolphins and humpback whales, using acoustic techniques such as echolocation and automatic gain control. Investigating humpback whale songs in Icelandic waters and comparing them to other populations. Future plans include deploying Ecological Acoustic Recorders to study cetacean distribution in Skjálfandi Bay and recording Blue whale and killer whale sounds.
E N D
HVALATAL „ACOUSTIC TECHNIQUES TO STUDY MARINE MAMMALS“ Rannsókna- og fræðasetur Háskóla Íslands á Norðausturlandi, Húsavík Húsavík Research Center Marianne Helene Rasmussen
Markmið - Aim • Rannsóknir á sjávarspendýrum • Research on marine mammals
The past • Research on white-beaked dolphins • Humpback whales singing in Icelandic waters?
Automatic gain control? Rasmussen et al., 2002
A click sequence Click intervals (ms) Time (ms) Rasmussen and Miller, 2002
Whistles Rasmussen and Miller, 2002 kHz 40 End frequency 20 Start frequency 5 1 2 duration seconds
Directionality of the signals? • Narrow beam for echolocation • Broad beam for communication Rasmussen et al, 2006 Rasmussen et al., 2004
High frequency on-axis click F0= 63 kHz, SL=163 dB F0= 56 kHz, SL=159 dB F0= 94 kHz SL=176 dB F0= 87 kHz, SL=173dB -60 dB -72 dB
Audiogram of a dolphin? • We netted two dolphins in > 340 hrs on the water
Audiogram of a dolphin? • Nachtigall et al., 2008
Acoustic tagging and foraging 19 fouraging events
Migration of a white-beaked dolphin • 8 August 2006 to 24 February 2007 (201 days) Aug Total distance traveled=5280 km (1090 km in August) Average speed=4 km/hr Spent 44% of time in Faxaflói Bay Dec 100 m depth contour Sept Breiðafjörður Oct Jan Faxaflói Aug, Oct to Feb Nov, Feb Vestmannaeyjar
Humpback whale song • The goal was to compare humpback whale song from the Northeast Atlantic population. Do they sing the same song in Icelandic waters as by the Cap Verde islands?
song theme 1 phrase 1 phrase 1 units song theme 2 phrase 2
The future • Deploying Ecological Acoustic Recorders (EAR’s) in Skjálfandi Bay in Cooperation with Dr. Marc Lammers, University of Hawaii to study the annual distribution of Cetaceans in the Bay
EAR’s • Variable bandwidth up to 30 kHz
The future • Recordings of Blue whales • Recordings of killer whales