Post on 02-Jan-2016
HVALATAL „ACOUSTIC TECHNIQUES TO STUDY MARINE MAMMALS“
Rannsókna- og fræðasetur Háskóla Íslands á Norðausturlandi, Húsavík Húsavík Research CenterMarianne Helene Rasmussen
Markmið - Aim
Rannsóknir á sjávarspendýrum Research on marine mammals
The past
Research on white-beaked dolphins Humpback whales singing in Icelandic
waters?
White-beaked dolphins
Echolocation
Automatic gain control?
Source levels of clicks
150
160
170
180
190
200
210
220
230
240
250
1 10 100Range (m)
So
urc
e l
eve
l (d
B r
e.
1P
a (p
-p))
two way transmission loss (40logR)
y = 19log(x) + 192R2 = 0.68
Rasmussen et al., 2002
A click sequence
Rasmussen and Miller, 2002
Click
inte
rvals (m
s)
Time (ms)
Start frequency
End frequency
duration1 2
seconds
40
kHz
20
5
Rasmussen and Miller, 2002
Whistles
Directionality of the signals?
Narrow beam for echolocation Broad beam for communication
Rasmussen et al., 2004
Rasmussen et al, 2006
High frequency on-axis click
F0= 94 kHz
SL=176 dB
F0= 56 kHz, SL=159 dB
F0= 87 kHz, SL=173dB
F0= 63 kHz, SL=163 dB
-60 dB
-72 dB
Audiogram of a dolphin?
Audiogram of a dolphin?
We netted two dolphins in > 340 hrs on the water
Audiogram of a dolphin?
Audiogram of a dolphin?
40
60
80
100
120
10 100 1000
40
60
80
100
120
10 100 1000Frequency (kHz)
SP
L (
dB
re:
1 µ
Pa)
40
60
80
100
120
10 100 1000
40
60
80
100
120
10 100 1000Frequency (kHz)
SP
L (
dB
re:
1 µ
Pa)
Audiogram of a dolphin?
Nachtigall et al., 2008
Acoustic tagging and foraging
08/03/-2006 1:00:00 08/03/-2006 3:00:00 08/03/-2006 5:00:00 08/03/-2006 7:00:00
Fo
rag
ing
de
pth
(m
)
0
10
20
30
40
19 fouraging events
Migration of a white-beaked dolphin
8 August 2006 to 24 February 2007 (201 days)
Total distance traveled=5280 km(1090 km in August)Average speed=4 km/hrSpent 44% of time in Faxaflói BayFaxaflói
Breiðafjörður
100 m depth contour
Vestmannaeyjar
Aug
Sept
Dec
Oct
Nov, Feb
Aug, Oct to Feb
Jan
Release of dolphin
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?
theme 1
phrase 1units
theme 2
phrase 2
song
song
phrase 1
Humpback whale song
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
Thank you for your attention