Lisa Munger, Marine Ecologist
Interview: April, 2002
residents in Nelson Lagoon, Alaska found a strange object washed
a remote Bering Sea beach after a big storm in January, 2002. Luckily,
a note on the side said finders should call Scripps
Institution of Oceanography in San Diego and collect a reward. Students from Nelson Lagoon School
and their principal, Mr. Concilus, were on it! (See
Videotaped interview by the students.) It turned out to be a
lost whale study/tracking device with a sonar probe and computer
whales as they migrate. Designed to lay on the sea bottom about 285 feet
down, it was deployed in 2000. When it was time for the device
home," the scientists sent an electronic signal to release ballast,
and planned to collect the device by ship. PhD student Lisa Munger was
sent to Alaska in 2001 to retrieve the thing -- called an Acoustic Recording
Package -- couldn't find it. In March 2002, she came back to extract
computer hard drives and retrieve the acoustical data from the lost-now-found.
Here's what Lisa told Journey North:
Q. Where are you
studying for your PhD?
Munger explains the ARP to students at Nelson Lagoon School.
The lucky sixth graders were involved as she took it apart to access
Two round floats suspend the hydraphone about
15 or 20 feet above the ocean bottom.
tubes on the bottom house computer equipment, and
two SCSI hard drives to record data.
Lisa extracts the computer hard drives to retrieve
the acoustical data. Photos John Concilus
A. I am a first-year Ph.D. student at the Scripps Institution of
Oceanography (which is part of UC San Diego). I'm in the Biological Oceanography
department. (When you say marine biology here, people think mostly of molecular
biochemistry type stuff.) I guess you could call me a marine ecologist.
My advisor is Dr. John Hildebrand, whose background is mainly in geophysics.
Recently, interest and funding have increased for cetacean acoustics research,
and Dr. Hildebrand has several other students and research associates
on various whale projects, such as blue whales off the California coast
and whales in the Antarctic. We collaborate with many other scientists
agencies on all of our projects.
Q. What is your focus or specialty?
A. My project, right whales in the northeastern Pacific, will probably
be the subject of my dissertation. We're working with a few government agencies
under NOAA (National Marine Mammal Laboratory, National Marine Fisheries
Service, and the Pacific Marine Environmental Laboratory), Oregon State
University, and Mark McDonald of Whale Acoustics (check out his website
at whaleacoustics.com). I'm sorry to neglect your animal of interest, but
as you know, gray whales exist in pretty good numbers in the Pacific, so
they're not as high a priority as right whales from a government funding
Q. Can you tell us how many right whales are in the northern Pacific?
A. There are probably two populations in the north Pacific; one off
Japan and the one we're interested in, known mainly in the Bering Sea from
visual surveys (aerial and ship-based). Based on these surveys and photo-id
matches, this population numbers pretty low (probably in the tens), and
no females have been identified in the small number of genetic samples (only
5 or so).
Q. What information on right whales are you looking for?
A. Our first and foremost question right now is: when are the right
whales in the Bering Sea? We'd like to know more about the abundance, demographics,
distribution, and timing of arrival and departure of right whales in the
Bering Sea (basically everything about them!). Visual surveys can only tell
us certain things about the whales, and can't be done constantly, so we
have large gaps in our knowledge. Right now we have almost no idea how long
the right whales are in the Bering Sea and where they go otherwise. There
have been isolated sightings in Hawaii, the Channel Islands, and off of
Kodiak island, but these don't give us a clear picture of migration or potential
Q. What techniques are you using to study right whales?
A. We are trying to use acoustic methods to monitor the right whales
and answer some questions that are hard to answer with visual methods.
Q. Describe the instruments.
A. The Acoustic Recording Packages (ARP) have one job. Recording sound
is all they do-- no photographs, no data on temperature, nothing else. Acoustic
- are anchored
on the bottom (supposed to be, anyway!),
- run on
at rate of 500 Hz (which means continuously for our purposes),
- and record
the data to disks.
kind of recordings are made by an ARP?
A. An ARP only record sounds between 0 and 250 Hz (relatively low
frequencies), at a range of up to 10-20 miles (depending on ocean conditions,
weather, etc). The recordings are not like on a tape or CD player; they're
in a binary data format, which means we need a computer program to run
the data by so we can look for whale noises.
Q. Did you say you LOOK for whale noises?
A. That's right — look, not listen. I use software to graphically
present the data in a frequency-versus-time plot. This allows us (me)
to visually scroll through the data much quicker than listening to it
in real time.
Q. Can you tell different whale species apart on the recordings?
A. Whale species each "speak different languages", that
is they have different call types, but sometimes humpbacks and right whale
calls can be hard to distinguish from each other (especially as the frequency
range of our instruments is so limited). If I see something that looks
like a right whale call, then I listen to it also; this helps somewhat.
Much of the data is just background noise, storms, ships, etc.
Q. Where are your Acoustic Research Packages located?
A. In October 2000, colleagues deployed four of these instruments
in an area of the Bering Sea where right whales have been sighted every
summer since 1997, around 57 degrees North and 163-165 degrees West. (That's
about 70-80 miles offshore from Nelson Lagoon). We went out in 2001 and
recovered two instruments out of four; we also deployed two new instruments
in the same area.
Q. What are some difficulties in your work?
A. Each instrument we successfully recovered holds about 7 months'
worth of recorded data, from October 2000 to April/early May 2001. This
is not a complete time frame to monitor migration, as it leaves out the
summer months when right whales could be arriving or departing. The process
of scrolling through the data, even visually, is still time-consuming,
and I'm busy with classes so haven't made much progress. So far, the data
have only been examined on one instrument for just the first month of
operation (October 2000). I have seen loads of fin whale calls and many
humpbacks throughout the month, and a few right whales in the first couple
weeks of that month. Lots more work needs to be done, and we're trying
to speed up the process of scrolling through data (we're using a computer
program that can automatically detect certain call types). Plus, this
summer (2002) we hope to recover two more instruments, with batteries
that lasted longer than the first prototypes, so we'll have more than
double the data we have now.
Q. Do you expect to always get your Acoustic Research Packages back?
A. We are concerned about our instrument recovery rate, although the
one found in Nelson Lagoon brings us up to 75%, which is much better than
our previous 50%. The area where we deployed the instruments is pretty
shallow (around 80 m = 250 feet), so strong storms or currents may shift
or damage the instruments. The deployment area also corresponds to a seasonal
crabbing closure area, but I'm told that fishermen still occasionally
drag there, so it's possible our instrument was dragged up or damaged,
enabling it to drift away.
Q. Have any gray whale noises shown up on your recordings?
A. No gray whales — I think the instruments might be too far offshore
to pick them up, and the timing is probably off too.
Q. In looking at the data, has anything surprised you?
A. A couple of interesting things have arisen from looking at the
data; one is that the right whales are up there at least into October,
which is later than previously thought, and the second is that humpback
whales appear to sing in winter and not just during the summer breeding
Q. What would you MOST like students to know?
A. There are two points I'd like to impart to kids. One is that science
is a cooperative process. Not only are we working with researchers from
different agencies and with different specializations, but we also cooperate
with fishermen, policy makers, and the public (such as residents of Nelson
Lagoon or visitors to your Web site). Only in this way can science contribute
something meaningful and lasting to the "real world."
Another point is that there are still MANY unanswered, exciting questions
out there. I've heard it said that we know more about outer space than
we do about our own oceans. Even big questions, like where do the right
whales go in winter, are still a mystery. There's unlimited potential
in marine sciences (and other sciences too) to make a living, and it's
so fun and worthwhile!
Scripps Institution of Oceanography
La Jolla, CA 92037-0205