Popular version of paper
2aAO1
Presented Tuesday morning, May 17, 2005
Joint ASA/CAA Meeting, Vancouver, BC
Want to
know the true story behind the 1.3 million missing sockeye from the
Fraser River? Is cleaning up our rivers enough to save the salmon?
Are changes in ocean conditions affecting the fish populations? Can
we do better than just guess at what happens after the fish left the
rivers?
Yes,
now we can. The Pacific Ocean Shelf Tracking project (POST) uses
tiny transmitters in young salmon to tell conservationists about
their fate.
POST is
one of the 13 field projects under the Census of Marine Life (http://www.coml.org/),
which is a decade long program involving scientists from more than
70 countries, designed to assess the diversity, distribution and
abundance of ocean life.
Acoustic tracking
POST is putting tiny
acoustic transmitters in thousands of young salmon and following
their journey from freshwater to sea. It is like assigning barcodes
to individual fish. As they pass over sensors installed on the
seafloor, they are telling scientists where they are at what time.We
no longer have to guess where the fish went, but will have precise
factual records.
Making
the transmitters and sensors work is challenging. Scientists have to
worry about how long the batteries last in the mini transmitters. To
conserve battery life, some transmitters are programmed to go to
sleep after the fish move out to the deep ocean, and start beeping
again at the time of home migration to find out how many return. The
sensors on the seabed have to withstand the ocean conditions, and be
equipped with a modem to send data to boats passing overhead, or to
satellites.
Biologists have to be exceptionally skilled in inserting the
transmitters into thousands of young fish in a matter of days,
working by the side of streams and rivers in MASH-style operations.
Going boldly where no one goes
before
The grand scale
of the system, however, is its most remarkable aspect and has never
been attempted before. Imagine 2000 sensors sitting permanently on
the ocean floor, along 30 listening lines, each extending from shore
seawards for 50 km, from Baja to the Bering Sea, listening to more
than 250,000 animals at one time. The concept worked remarkably well
in a demonstration in the Salish Sea region in 2004 which yielded
the first mapping of the migration corridors of 14 stocks of salmon.
POST will have the continental-scale system completely in place by
2010.
Dr.
David Welch, Chief Scientist of POST, will be discussing the
findings in the Salish Sea study in his presentation (2aAO1) at the
meeting of the Acoustical Society of America,May 17, 2005 in
Vancouver. He will explain the data showing the sockeye moved very
quickly out to the open ocean while the coho appeared to stay around
close to shore. Also, the fact that a lot more of the steelhead
stocks made it to the deep ocean (15-31%) than expected, challenges
the conventional belief that the historical record of 2-4% return of
these fish is mainly due to die-offs at the river mouths.
More than just tracking
fish
What is even more exciting is that
the seabed array can also host temperature, salinity, current or
other oceanographic sensors. Knowing this information, scientists
can relate where animals go and their survival, to changes in the
ocean.
POST is
a powerful science tool, which carries a relatively low overhead,
and is generating high expectations from managers and policy makers
responsible for marine resource conservation.
Map of marine life highways
POST will
not only track salmon. Scientists are beginning to use the
technology on sturgeon, rockfish, squid and other marine animals.
Thanks to POST, we are on the way to having the first ever map of
the marine life highways. POST will serve as the prototype for
similar systems in other parts of Canada and the world.
For further information please contact:
Chief Scientist, David Welch
Tel:
1-250-714-3526
Email: david.welch@kintamareseasrch.org
Executive Director, Peggy Tsang
Tel:
1-604-659-3587
Email: peggy.tsang@vanaqua.org
Web:
http://www.postcoml.org/
Tiny Acoustic Transmitters
Help Map Salmon Tracks in the Ocean