Habitat
mapping and substrate classification of Lake Opeongo
In the summer of 2008, Milne
Technologies conducted hydroacoustic surveys for the
purpose of classifying the substrate of Lake Opeongo,
Ontario. Echo integration of the primary and secondary
bottom reflections was used to provide a measure of
relative substrate roughness and hardness. Several
substrate classes were statistically identified using
Quester Tangent's Impact
seabed classification software. Further assessment
of the identified substrate classes was then done
using an underwater camera and Ekman dredge. The
association of fish targets, including lake trout,
with certain types of substrate and habitat can further
be analyzed from these and similar future surveys. Click
here for more information on how hydroacoustics
can be used for habitat mapping and substrate classification.
Services provided for:
Harkness
Laboratory of FIsheries Research and the Ontario
Ministry of Natural Resources
Field technology utilized for this
project:
•
Simrad EY500 120 kHz Split-beam
• Splashcam Deep Blue underwater
camera
• Ekman dredge
Products delivered by Milne Technologies:
•
Detailed bathymetric and substrate maps
• Lake bottom substrate classification
and analysis (QTC, E1 Roughness and E2 Hardness)
• Data on the distribution
of pelagic fish targets in relation to specific habitat
features
Lake Huron Double-crested
Cormorant Experimental Management Program
The purpose of
this project is to provide hydroacoustic data processing
and fisheries assessment services in support of the
“Lake Huron Double-crested Cormorant Experimental
Management Program”. The program was a multi-year
study (2000-2005) aimed at monitoring the potential
effects of double-crested cormorants on the nearshore
and pelagic fish communities in the coastal areas
of Georgian Bay and the North Channel.
Services provided for:
Ontario Ministry of Natural Resources
Field technology utilized for this
project:
•
Simrad EY500 120 kHz Split-beam
• Fish sampling equipment
including suspended gill nets and trap nets
Products delivered by Milne Technologies:
•
Acoustic estimates of pelagic fish abundance and biomass
• Fish schooling behaviour
analysis in relation to cormorant abundance
• Analysis of the spatial
distribution of pelagic fish in relation to cormorant
abundance
• Near-shore index trap-netting
data analysis
• Bathymetric and habitat
mapping
Report:
•
Double-Crested Cormorant and Coastal Fish Monitoring
and Assessment in the North Channel and Georgian
Bay, Lake Huron:
Field Methods, Site Descriptions and Analysis Information.
Download
Full Report.
Integrating Remote Sensing Technologies:
A Method for Sampling from Multiple Trophic Levels
in Lakes
The purpose of this project was
to develop a “rapid resource assessment methodology”
that provides the ability to simultaneously sample
from multiple trophic levels and across a wide size
spectrum of organisms. Five coldwater lakes in Southern
Ontario were surveyed with a suite of remote sensing
technology. The lakes surveyed were Lake Opeongo (Algonquin
Park), Smoke Lake (Algonquin Park), Drag Lake (Haliburton
County), Dickey Lake (Hastings County), and Harp Lake
(District Municipality of Muskoka).
Services provided for:
Aquatic Ecology Group at the University of Toronto.
Field technology utilized for this
project:
•
120 kHz split-beam to assess the pelagic fish community
• 710 kHz single beam acoustic
system to determine the abundance and spatial distribution
of zooplankton
• Optical plankton counter
(OPC) to assess the abundance and size distribution
of zooplankton at depth.
• SM2000 200 kHz multi-beam
sonar was also deployed to observe and map the spatial
distribution of lake herring
schools.
Products delivered by Milne Technologies:
•
lake trout density and biomass estimates
• analysis of the morphology
and spatial distribution of lake herring schools
• model developed to estimate
abundance and size distribution of zooplankton from
high-frequency hydroacoustics
to compare with OPC estimates
• substrate analyses and
classification
• bathymetric mapping products
Using Mulit-beam and Split-beam
Hydroacoustic Technology to Detect and Track Ultrasonic
Tagged Fish
The
purpose of this project is to provide a method for
directly measuring the in situ target strength of
lake trout using integrated multibeam, split beam,
and biotelemetry technologies. 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. The field work is being conducted on Lake Opeongo
in Algonquin Provincial Park, Ontario, Canada.
Partners:
Ontario Ministry of Natural Resources, Kongsberg-Mesotech
Simrad Ltd., SonarData Pty Ltd., and the University
of Toronto at Mississauga.
Field technology utilized for this
project:
•
SM20 multibeam sonar
• EK60 multi-frequency echosounder
system
• 200 kHz pulse coded ultrasonic
tags
Products delivered by Milne Technologies:
•
methodology and results summary report
• in situ measurements of
target strength of tagged lake trout
• lake trout behaviour manuscript
• combined frequency echogram
analysis
• lake bottom substrate classification
and analysis (QTC, E1 Roughness and E2 Hardness)
Report:
•
Using Hydroacoustic Technology to Detect and
Track Ultrasonic Tagged Fish: Methodology and Preliminary
Results.
Download
Report Excerpt.
•
Click here to see
replays of a series of multibeam echogram movies that
were recorded during the 2007
tracking surveys. Go
to our lake trout behaviour
page.
Understanding the Impact of
the Double-crested Cormorant Management Program and
the Walleye Rehabilitation Program on the Prey Fish
Community of Lac La Biche
The aquatic communities of lakes
across Canada are impacted by a number of stresses
including habitat degradation, introduction of exotic
species, water diversion, climate change, and over-exploitation.
Alberta's Lac La Biche has been impacted by the effects
of hyper-eutrophication resulting in blooms of toxic
blue-green algae, declines in water quality, and fluctuating
water levels. Another concern is the observed declines
in the commercial and sport fisheries that have been
attributted to factors including the increase in piscivorous
bird populations (pelicans and cormorants), over-exploitation,
and larval fish bottlenecks as a result of increased
planktivorous fish production. Recently, the Alberta
Sustainble Resource Development introduced a series
of management initiatives to return trophic stability
to the system. Measures taken include the intensive
reintroduction and rehabilitatation of walleye and
northern pike within the system as well as intensive
management and culling of double crested cormorant
colonies. These management changes are expected to
impact the species composition and abundance of the
planktivorous fish community in the lake.
The purpose of this project was
to design and implement a long-term hydroacoustic
survey program for assessing changes in the size,
spatial distribution, and abundance of prey fish in
Lac La Biche in response to management decisions.
The time series of data provided by annual and biannual
hydroacoustic surveys will allow the early detection
of ecosystem changes and perturbations that will enable
managers to respond using an adaptive management plan.
To detect and quantify the number
of fish that might have been undersampled within the
vertical surveys, a second 200 kHz transducer was
used to sample the shallower (< 4 m) regions of
the water column. With this method, the split beam
transducer was mounted on the tow-body to point away
from the survey vessel in a horizontal orientation
thus insonifying a large volume of water just below
the surface.
Services provided
for: Sustainable
Resource Development, Government of Alberta
Field technology utilized for this
project:
•
BioSonics DTX 200 kHz split-beam
Products delivered by Milne Technologies:
•
echo integration estimates of pelagic fish density
and biomass
• spatial distribution of
fish density and biomass
• lake bottom substrate classification
and analysis (QTC, E1 Roughness and E2 Hardness)
• bathymetry, habitat and
submerged macrophyte mapping
Reports:
•
2006 Lac La Biche Hydroacoustic Survey Report: Methodology
and Summary of Results.
• 2007 Lac La Biche Hydroacoustic
Survey Report: Methodology and Summary of Results. Table
of Contents.
The Potential Impacts of the
2005 Oil Spill on the Fish Community and Habitat of
Wabamun Lake
Wabamun Lake recently received
national attention when, in August 2005, a train derailment
near the town of Whitewood, Alberta spilled 750,000
litres of heavy bunker oil into the lake. The short-term
impacts were obvious (e.g., contaminated drinking
and bathing water, beach closures, wildlife fouling,
etc.), but the long-term ecological impacts of the
spill on the lake are unknown. To further understand
the ecological impacts of the oil spill and to effectively
manage the fish communities within the lake, the Alberta
Sustainable Resource Development (SRD) has initiated
a long-term fisheries assessment and monitoring program.
In consultation with Milne Technologies, the Alberta
SRD has designed and implemented a hydroacoustic survey
program to assess changes in the size and abundance
of the lake whitefish population in the lake.
To detect and quantify the number
of fish that might have been undersampled within the
vertical surveys, a second 200 kHz transducer was
used to sample the shallower (< 4 m) regions of
the water column. With this method, the split beam
transducer was mounted on the tow-body to point away
from the survey vessel in a horizontal orientation
thus insonifying a large volume of water just below
the surface.
Services provided for:
Sustainable Resource Development, Government of Alberta
Field technology utilized for this
project:
•
BioSonics DTX 200 kHz split-beam
Products delivered by Milne Technologies:
•
echo integration estimates of pelagic fish density
and biomass
• spatial distribution of
fish density and biomass
• lake bottom substrate classification
and analysis (QTC, E1 Roughness and E2 Hardness)
• bathymetry, habitat and
submerged macrophyte mapping
Reports:
•
2006 Wabamun Lake Hydroacoustic Survey Report: Methodology
and Summary of Results.
• 2007 Wabamun Lake Hydroacoustic
Survey Report: Methodology and Summary of Results. Table
of Contents.
Hydroacoustic Assessment of
Lake Trout in Grist Lake and Cold Lake
Cold Lake and Grist Lake are
two of only a handful of lakes in Alberta that provide
suitable habitat for naturally reproducing populations
of lake trout. There is increasing pressure on Alberta’s
wetlands, lakes, and rivers from stresses including
climate change, introduction of exotic species, over-exploitation,
and loss of biodiversity. The effective management
and conservation of lake trout populations throughout
the province is critical to ensure protection of the
resource for generations to come.
The purpose of this project was
to design and implement a long-term hydroacoustic
survey program to assess and monitor changes in the
size, spatial distribution, and abundance of lake
trout. This project also provided a direct comparison
of abundance estimates generated from the hydroacoustic
method and the Alberta standardized gill net index
(SPIN) program.
Services provided
for: Sustainable
Resource Development, Government of Alberta
Field technology utilized for this
project:
•
BioSonics DTX 200 kHz split-beam
Products delivered by Milne Technologies:
•
echo integration estimates of pelagic fish density
and biomass
• fish tracking analysis
and echocounting estimates of lake trout density and
biomass
• analysis of the morphology
and spatial distribution of lake herring schools
• spatial distribution of
fish density and biomass
• lake bottom substrate classification
and analysis (QTC, E1 Roughness, and E2 Hardness)
• bathymetry, habitat and
submerged macrophyte mapping
Reports:
•
2006 Cold Lake Hydroacoustic Survey Report: Methodology
and Summary of Results.
• 2007 Cold & Grist Lake
Hydroacoustic Survey Report: Methodology and Summary
of Results. Table
of Contents.
The
Response of Lake Trout Populations to Re-opened Winter
Fisheries
In collaboration with Milne Technologies
and the Ontario Ministry of Natural Resources, the
Wildlife Conservation Society of Canada designed and
implemented a hydroacoustic survey program in an effort
to detect potential changes in the population abundance
and size distribution of lake trout in Myrt and Hood
Lakes (Thunder Bay district of Ontario). Both
lakes were closed to ice fishing but in February 2008,
the Ontario Ministry of Natural Resources re-opened
the lakes to winter angling. This management change
provided a unique opportunity to directly measure
the response of the lake trout populations to the
change in regulations and the increased level of fishing
effort.
Services provided for:
Wildlife Conservation Society
Field technology utilized for this
project:
•
BioSonics DTX 120 kHz split-beam
• OMNR standardized index
gill nets
Products delivered
by Milne Technologies:
•
lake trout density and biomass estimates
• lake bottom substrate classification
• bathymetry and habitat
mapping
Report:
•
2007 Myrt and Hood Lakes Hydroacoustic Survey Report:
Abundance and spatial distribution of lake trout
(Salvelinus namaycush)
in two Northern Ontario lakes. Table
of Contents.
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