The proposed study provided a
method for directly measuring the in situ target strength
of lake trout using integrated multibeam, split beam
and biotelemetry technologies. Pulse coded ultrasonic
tags engineered to ping at 200 kHz will be surgically
implanted into lake trout and released. The study
area will be surveyed with an SM2000 multibeam sonar
and an EK60 multi-frequency echosounder system in
an effort to locate and track tagged fish. Data recorded
will include target strength measurements, habitat
information, and information about potential prey
items.
From this work we
expect to provide a target strength and frequency
response model for lake trout that will incorporate
fish size and activity patterns (swimming speed and
angle) under varying light conditions. This work will
also provide a unique opportunity to describe the
spatial distribution and behavioural patterns of lake
trout as they relate to the schooling behaviour of
their prey.
Objectives
1. To provide a
methodology for detecting and uniquely identifying
lake trout implanted with ultrasonic tags using a
SM2000 multibeam acoustic
system.
2. To estimate the in situ target strength and frequency
response of lake trout in relation to fish size, target
depth, and activity.
3. To describe the predatory behaviour of lake trout
in response to the spatial distribution of the prey.
4. To demonstrate the use of an integrated remote
sensing methodology and its application in describing
the
trophic transfer dynamics
of an oligotrophic ecosystem.
5. To determine the frequency response of single targets
as a method of classifying species in a mixed
assemblage oligotrophic system.
Field Work
This work was completed
out of the Harkness
Laboratory of Fisheries Research on Lake Opeongo,
Algonquin Park, Canada. The field work began at the
end of June and continued through July, 2007.
Preliminary Results
- Lake Trout Interactions
Click on the following
links to replay a series of echogram segments that
were recorded from the 2007 tracking surveys. Shown
below are examples for several tagged lake trout.
Lake
Trout Tag Number
Date
Link
Tag
ID "1" (22 Mb)
July
6, 2007
Tag
ID "1"
July
15, 2007
Tag
ID "2"
July
14, 2007
Tag
ID "2" a (11 Mb)
July
17, 2007
Tag
ID "2" b (6 Mb)
July
17, 2007
Tag
ID "4" a (7 Mb)
July
16, 2007
Tag
ID "4" b
July
16, 2007
Tag
ID "6" (6 Mb)
July
5, 2007
Tag
ID "6"
July
17, 2007
Tag
ID "8" (9 Mb)
July
11, 2007
Tag
ID "14"
July
15, 2007
Tag
ID "15"
July
16, 2007
Note:
You will require Adobe FlashPlayer to view the media
content . Download it here.
Preliminary Results
- Lake Trout Movement
Click on the following
links to view the movements of tagged lake trout throughout
the study period. Results have been summarized
by the date of the survey and by the lake trout tag
number.
