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No. 81
May, 1%5
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v
RESOURCE MANAGEMENT REPORT
ONTARIO
DEPARTMENT OF LANDS AND FORESTS
Hon. A. Kelso Roberts, Q.C.
Minister
F. A. MacDougall
Deputy Minister
(These Reports are for Intra-Departmental Information
and Not for Publication)
No. 81 May, 1965
RESOURCE MANAGEMENT REPORT
Fish& Wildlife Branch
ONTARIO
DEPARTMENT OF LANDS AND FORESTS
Hon. A. Kelso Roberts, Q.C. F. A. MacDougall
Minister Deputy Minister
(These Reports are for Intra-Departmental Information
and Not for Publication)
Digitized by the Internet Archive
in 2013
http://archive.org/details/resourcemanmay1965onta
RESOURCE MANAGEMENT REPORT
TABLE OF CONTENTS
No. 31 May, 1965
Page
Wildlife Status Reports.
- by A. B. Stephenson 1
Moose Tagging in the White River District,
1964.
- by S. B. Woods ide and D. J c Rice 23
Pesticides and Water Quality.
- by C. F. Schenk 30
Pheasant Harvest Report, Lake Simcoe
District, 1964,
- by J. S. Borland 37
Report on the Use of Four Inch Mesh in
Harvesting the Walleye of Makoop Lake,
J. J. Armstrong 46
(THESE REPORTS ARE FOR INTRA- DEPARTMENTAL
INFORMATION ANB NOT FOR PUBLICATION)
1
WILDLIFE STATUS REPORTS
by
A. B. Stephenson
liologist, Research Branch, Maple
Abstract
Questionnaires completed by Fish and Wildlife
personnel pertaining to the status of 13 mammalian
species for the period 1954=55 to 1963-64 have been
analysed. Graphs illustrating the 10 year trends
in relative abundance and maps showing the 1963-64
population statuses are presented. These data
indicate population trends and provide a basis for
prediction of future population changes. They
illustrate changes brought about by range extension,
predation, disease and other factors, many of which
are still unknown.
Introduction
Since 1954 the Fish and Wildlife Branch has been conduct-
ing an annual enquiry to determine the population status of several
animals for which information was not available from other sources.
Information on the relative abundance of each of the 13 mammalian
species collected during the past 10 years is summarized in this
report along with their 1963-64 status by District.*
The use of annual questionnaires to ascertain the status
of Ontario wildlife populations had its beginning in 1924 when the
National Parks Branch in Ottawa started a two year snowshoe hare
enquiry (Elton, 1933). There was a lapse of five years before the
Bureau of Animal Populations in Oxford continued these questionnaires
for the National Parks Branch. This organization collected data
from 1931-32 to 1947-48 when the enquiry was discontinued (Elton,
op. cit.; Chitty, 1950). In 1932 the Royal Ontario Museum of Zoology
initiated a much broader questionnaire which included a diversity of
birds and mammals. They continued their records until 1953-54
when they discontinued the enquiry in view of the increased interests
in wildlife populations by provincial governments. At that time
the Ontario Department of Lands and Forests initiated its own
questionnaire pertaining to the status of a few species of particular
interest to wildlife management.
* A series of 13 maps accompanied the original article which is on
file in the Fish and Wildlife Library, Maple.
Status Reports
A mimeographed questionnaire , as shown in Fig. 1, has
been distributed to all Fish and Wildlife field personnel at the
end of each fiscal year. The reporter indicated the occurrence of
a species and the trend in the population by checking the appropriate
columns. This technique assumed that each individual was familiar
with the local status of the various populations and could give a
subjective opinion of the current status relative to that of the
previous year. In a few cases no comment was reported on the status
of a population . This was taken into account when calculating the
percentage of returns indicating occurrences and trends.
Table I shows the number of reports received from each
District for 1963-64 and an average for the 10 year period. No
reports were obtained for 1956-57. Only the percentage of reports
indicating abundance was used in illustrating the population trends
from 1554 (Graphs 1-13) since this criterion reflected any relative
changes which took place.
Table I. Number of Wildlife Status Reports
Aves
rage No. of
No. of Reports
District
Annual Reports
in 1963-64
Lake Erie
14.1
16
Lake Huron
13.9
13
Lake Simcoe
11.4
12
Lindsay
10.2
10
Tweed
10.4
13
Kemptville
9.6
11
Pembroke
6.2
5
Parry Sound
10.5
15
North Bay
9.9
10
Sudbury
6.9
7
Sault Ste. Marie
7.0
7
Chapleau
4.4
5
Gogama
3.6
4
White River
5.7
5
Swastika
6.7
9
Kapu ska sing
4.9
7
Cochrane
6.3
9
Geraldton
5.0
5
Port Arthur
4.2
5
Fort Frances
4.4
8
Ken or a
4.7
6
Sioux Lookout
Total
4.9
5
154.8
187
Wildlife Status
Snowshoe Rabbit
-This species exhibits noticeable fluctuations in numbers
and consequently has been a subject of investigation for a number
of years. Its periodic peaks of abundance have been well documented
since 1785, initially from the Hudson's Bay Company fur returns and
during the past four decades by special status enquiries. In Ontario ,
snowshoe rabbits attained peak abundance in 1923=24, 1933-34, 1942-43,
1951-52 and 1959-60. Questionnaire reports do not indicate the
magnitude of these peaks but from general accounts of their status,
it appears that they were most numerous during the early 30' s and
relatively lower during their peak in the early 40' s. The popul-
ation reached a low level in 1946-47 but for some unknown reason
they did not increase to a major provincial peak in the early 50' s.
Their numbers fluctuated at a relatively low level during this
period although local areas did experience a fair abundance of
hares. Following the next population low in 1954-55 their numbers
increased to a provincial peak in 1959-60 (Graph I). Subsequently
the population declined although the reports for 1963-64 indicated
that snowshoe hares were common in most Districts (Map I).
Peak populations may not be attained in all areas at the
same time. Indeed, there are many local populations which are
separated by only a few miles which will be out of phase with each
other. During the most recent cycle peak populations were first
attained in the south and central portions of the Province and
gradually progressed to the western Districts where they were most
abundant one year later in 1960-61.
From the history of fluctuations in snowshoe hare numbers
it appears that they are currently at a low population level, and
that their numbers will i.ncrease to a provincial peak between 1968
and 1970.
This species was introduced into southern Ontario in 1912
when a few individuals escaped from captivity in the Brantford area.
Their population spread up to 1952 is well documented by Reynolds
(1955). Since that time the European or brown hare (commonly called
jack rabbit) has continued to extend its range throughout the southern
agricultural areas, especially into eastern Ontario. Presently
they are found in the southwestern portions of Grenville County with
the occasional specimen being taken in the south of Lanark and
Carleton Counties.
In southwestern Ontario their numbers were relatively low
between 1955 and 1>57 (Graph 2). During the next three years they
exhibited a continuous increase which was also evident throughout
the rest of their range. What effect predation had on this increase
is unknown but it was during this period that foxes were drastically
reduced in numbers by rabies which was spreading eastward throughout
southern Ontario.
Since 1960-61 the European hare has been relatively
common and even abundant in some local areas, although the 1963-64
reports indicated a general decrease in abundance (Map 2).
Cottontail Rabbit
This species j which is confined to the agricultural
regions of southern Ontario, was relatively stable in numbers from
1954 through to 1960-61 (Graph 3). During this period over 25 per
cent of the reports indicated that rabbits were abundant, especially
in southwestern Ontario. In 1961 and 1962, there appeared to be
a sharp increase in their numbers with nearly 50 per cent of the
reports indicating an abundance. This was followed by a decrease
in 1963-64 although they were still reported to be relatively
common except in the Kemptville District.
This species is commonly found throughout southern Ontario
where it attains its highest densities in the agricultural areas.
The northern limit of its range extends into Pembroke District and
throughout most of Parry Sound District to Lake Panache in the
Sudbury District. It is also found in the urban areas of North
Bay and Sudbury. In 1961, four individuals were introduced to
Cockburn Island in the Sudbury District. Occasionally a few
individuals have been reported in the western portion of Fort
Frances District. These are a northern extension of the Minnesota
population of. black squirrels.
Reports showed a peak population in 1955-56 with a gradual
decline to 1960-61 (Graph 4). The reports for the next three years
indicated a relatively common, but stable population with the
exception of Tweed District where there was an increasing population
in 1963-64 (Map 4).
Red Squirrel
This species is found throughout the Province and during
the last 10 years has exhibited two years of peak abundance;
1957-53 and 1961-62 (Graph 5), It has seldom been reported as
scarce except in the Lake Erie District. The 1963-64 reports
indicated that red squirrels were relatively common with little
to no change in their population status (Map 5).
Chipmunks
The chipmunk population has been relatively stable over
the past 10 years with minor fluctuations in abundance (Graph 6).
All Districts reported no change in the population trend in 1963-
64 . However, both Port Arthur and White River Districts reported
chipmunks relatively abundant in 1963-64 and Lake Erie and Lake
Simcoe Districts reported them relatively scarce (Map 6).
Woodchuck
Although this species is found throughout the Province ii
attains its highest numbers in southern Ontario, especially in the
agricultural areas. The status of the woodchuck population was
relatively stable between 1954 and 1961 but in 1962 there was a
noticeable increase in their numbers (Graph 7). The reports for
1963-64 indicated that they were relatively abundant and still
increasing in some Districts in southern Ontario (Map 7). This
change was not evident in northern and western Ontario where the
population is relatively low and stable.
This species was most abundant in 1954 and 1962 although
it has never been abundant in northern Ontario (Graph 8). There
are only a fex<7 local areas where the porcupine has become fairly
numerous; mainly in Parry Sound District and the northern portions
of Lindsay and Tweed Districts. In the Parry Sound District
porcupines have been reported abundant every year since 1954.
The 1963-64 reports indicate that there is no change in
the population status following the slight increase in 1962 (Map 3).
Skunk
This species has been common to abundant in southern and
south-central Ontario for the past 10 years (Graph 9). It has also
been relatively common in the Districts of Fort Frances, Kenora
and Port Arthur. Although the skunk has decreased in relative
abundance during this 10 year period it is still considered common
in all areas except northern Ontario where it is relatively scarce.
The 1963-64 reports indicated no change in this status (Map 9).
Raccoon
The major population of raccoons is found throughout
southern Ontario although they are extending their range northward
in the North Bay, Sudbury and Sault Ste. Marie Districts.
Occasionally a few are reported from Gogama and other northerly
Districts where they are usually found near railroads. There is
a minor population in western Ontario where their numbers have re-
mained relatively scarce.
Raccoons were most abundant between 1954 and 1957
(Graph 10). The}?- decreased in 1958 when rabies was prevalent in
southern Ontario and have remained at a relatively stable level
through to 1963-64 (Map 10).
Red Fox
The red fox exhibited a similar trend in abundance to
the raccoon except that it decreased to a much lower level in 1958
following the relatively abundant level between 1954 and 1957
(Graph 11). This marked reduction in population took place largely
in southern Ontario probably as the result of rabies. In the rest
of the Province foxes remained relatively stable during this
period .
The 1963-64 reports indicated that foxes were still scarce
in a large portion of southern Ontario but they were generally
increasing in numbers (Map 11). Throughout central and northern
Ontario they were relatively common and increasing in several
Districts. In Fort Frances and Port Arthur foxes were reported
to be relatively abundant with little indication of any decrease
in numbers.
Black Bear
This species showed a general increase in abundance
from 1954 to a peak population in 1957-58 (Graph 12). The reports
indicated a sharp drop in 1958, although they remained relatively
common through to 1963-64. The northern and western Districts
showed an increasing population in 1962-63 and this was continuing
in a few of these Districts in 1963-64 (Map 12). The remainder
of the Districts reported no change in the population trend in
1963-64.
Bobcat
According to Peterson and Downing (1952) the bobcat is
found in three discrete areas of the Province; southern Ontario,
Sault Ste. Marie and western Ontario. The recent status reports,
however, indicate that the Sault Ste. Marie and western populations
are now contiguous in the White River District, There is still,
however, no indication that the southern Ontario population is
linked with the Sault Ste. Marie population.
Bobcats have been relatively scarce in Ontario since
1954 but in 1962 they showed signs of increasing, especially in the
western portions of their range (Graph 13). The 1963-64 reports
indicated a continued increase in bobcats although they are still
only relatively common in the centres of their ranges (Map 13).
Conclusions
Field personnel can provide a good general assessment of
the status of wildlife populations from one year to the next. The
changes which -take place in different animal populations may not,
however, be equally conspicuous. For example, the behavioural
characteristics of the snowshoe hare and their great fluctuations in
numbers are readily apparent while the chipmunk is not as conspi-
cuous and probably does not have as large a change in numbers from
one year to the next.
Since the reports are based on subjective information
they do not permit comparison of abundance or scarcity from one
area to another: abundance in one area, especially toward the limits
of a species range may be considered to be scarce in the centre of
its range. This does not, however, preclude comparisons from one
year to the next providing the area in question remains the same.
Trends in populations are independent of relative
abundance hence an increase or decrease in one area can be compared
with that in another area.
The reports have their value in indicating general trends
from which predictions can be made. These trends may be the result
of inherent properties of the population, as in the case of
snowshoe hares; range extension and possibly the reduction of
predators, in the case of European hares; and disease, in the case
of foxes and raccoons.
Status reports are also useful in indicating range
extensions, as were reported for the European hare, black squirrel,
raccoon and bobcat,
References
Chitty, Helen. 1950. The Snowshoe Rabbit Enquiry 1946-43.
J. Animal Ecol. 19(1): 15-20.
Elton, C. 1933. The Canadian Snowshoe Rabbit Enquiry 1931-32.
Can. Field -Nat. 47(4): 63-69; 47 (5): 84-86.
Peterson, R. L. and S. C. Downing. 1952. Notes on the Bobcats
( Lynx ruf us ) of Eastern North America With Description
of a New Race. Contribution of the R.oy. Ont. Mus. Zool
and Fael. No. 33:1=23.
Reynolds, J. K. 1955. Distribution and Populations of the
European Hare in Southern Ontario. Can. Field Nat.
69(1): 14-20.
Figure I
Fish and Wildlife Branch
WILDLIFE STATUS REPORT
Name Address -
District . April 1 , 196 ... to March 31
Description of area covered in this report
Absent
1
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1
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During
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Horned Owl
Snowy Owl
Goshawk
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Comment j
Snowsh oe P, abb i t
Cottontail
European Har e
Woodchuck
Black
Chipmunk
Black Be a:
Raccoon
Skunk
Red^Fox
Bob_ca_t_
Porcupine
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Indicate if Scarce s Common or
Increased during the past 12 months.
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23
MOOSE TAGGING IN THE WHITE RIVER DISTRICT, 1964
by
S. B. Woodside and D. J. Rice
Conservation Officers
Abstract
A new method of noose tagging employing a rubber
collar set on an automatic snare- type release was
investigated. Owing to the limited nature of this
season* s work (only 12 collars released) no definite
conclusions could be drawn. Temperature was found
to be a limiting factor to this method as below
42°F the rubber collar lost its elasticity. It is
concluded that the economy of this method over present
techniques of moose tagging warrants further study
into its possibilities.
Purpose
To determine animal movement in direction and distance,
during a recorded period of time, with thought to establishing
movement patterns.
Method
Forward
A rubber collar set on a snare-type release.
This project has so far been limited to time spared from
the normal enforcement and management duties of two conservation
officers, and materials picked up at random within the District.
The only material expense was the purchase of 150 feet of "'SIMATCO
RUBBER TUBING" from the Fisher Scientific Company of Montreal at a
cost of $30.00. The idea for this method of tagging was obtained
from a newspaper article describing similar project being carried
out by Mr. Pierre Des Meules, of the Quebec Department of Tourism,
Fish and Game.
Procedure
It is first necessary to find locations where moose are
consistantly using definite trail to water or feeding areas. Since
this project was to be carried out in conjunction with our normal
enforcement and management duties, we chose only those locations
24
which could be visited with little deviation from our regular patrol
routes. These trails were rather easy to locate during the months
of June and July, but became quite obscure and little-used by mid-
August. The best set locations always occurred within 10 to 30
feet of the water. Beyond this point, the main trail invariably
fanned out into numerous secondary trails. The ideal site for erect-
ing the collar release mechanism is between two trees located
approximately 46 to 50 inches apart, on opposite sides of the
trail. The larger the trees, the less work involved. It was
noted that trees under 8 inches DBH were susceptible to considerable
sway in a heavy wind and this resulted in the mechanism being
tripped, the collar being released and often landing far enough
away from the set to require a lengthy search in locating it.
If trees under 8 inches DBH must be used, they should be
wired firmly together about 8 to 10 feet from the ground and wired
back to a heavier tree on either side of the trail. In some cases,
only one tree could be found in a suitable location. Here, it was
necessary to plant a post on the opposite side of the trail and wire
it firmly in place as outlined above. In one instance, the trail
was in a cleared area where no trees were available. In this case,
two Jackpine trees about 6 inches DBH were cut, planted whole on
either side of the trail and wired firmly in place. This set was
successful in obtaining six releases.
On completion of each set, it is important that it be left
as natural looking as possible. This often requires considerable
camouflage. Small spruce or balsam (7 to 10 feet high) wired to the
set trees, proved quite effective.
Equipment
1
a
axe
1
-
hand saw
1
-
pr„ pliers (with cutter)
1
-
long handle shovel
1
-
hammer
1
-
8 foot step-ladder
1
-
8 inch rat- tail wood rasp
1
-
steel pocket tape
Material
For one set.
2 steel rods - 5/16" x 70"
4 "I" bolts - 1-1/2" eye - 6" shank
50 feet (approx.) haywire - gauge
1 pc. hardwood dowel - 48" x 1/2" - stained dark
brown or dark green
25
1 pec hardwood dowel - 4" x 3/8"
1 roll black "electric tape" (Plastic)
1 pco "Sinatco Rubber Tube" - 38" x 5/16" Bore
1/16" walls
18 inches plastic coated "twist- tie" wire
1 identification tag.
Collar Constr uction
See Figure 2,
V!
Cut a piece of "Sinatco Rubber Tubing" to a length of 38
Insert a piece of hardwood dowel (4" x 3/8") into one end of the
tubing for a distance of 2 inches. Bend the tubing in a circle and
insert the remainder of the dowel into the open end and force it
en until both ends of the tubing neetc Bind this joint firmly with
the plastic coated "Twist-tie" wire leaving length of about 6 inches
protruding. Wrap the joint firmly with plastic electrical tape.
Identification^ Tag
Bright yellow "Dymo Embossing Tape" was used for the
identification tags., The required information (tag number and Return
to Lands and Forests - White River) was printed on two separate lengths
of tape and these were glued back to back This offered double stre-
ngth to the tape, A small hole punched in one end of the tape allowed
for its attachment to the twist- tie wire protruding from the joint
of the collar „
Collar P,oleas e Cons true t ion
Gee figure 2,
Take a 70 inch length of 5/16" steel rod. Measure 4
inches from either end and bend it 90° . From this bend measure
12 inches and bend it 90°. Measure 4 inches and bend 180°. Meas-
ure 4 inches and bend 90°. Measure 42 inches and bend 90°. The
rod should now appear as in figure 2, Two such rods are required
for each set, The eyelets were made from the broken coil springs
off "Conibear" beaver traps. Cut the shank to about 6 inches and
sharpen to a point on the grindstone. Four eyelets are needed for
each set.
Making the Set
See figure 1.
When the desired trees have been located as previously
described ? measure from the ground, 30 inches up the side of one
of the trees , Drive an eyelet into the tree at this point. Before
26
driving the eyelet securely, decide what position it oust be in so
that when the set is complete, the "trip- stick" and collar will sit
at close to a right angle to the trail. Place one of the steel rods
against the side of the tree with the inside am (the double-one)
resting on top of the secured eyelet. Drive a second eyelet
into the tree at the inside angle of the top arm on the rod. Place
the rod into the e3^elets (top first, bottom last) and repeat the
process on the opposite tree, checking to see that the two bottom
eyelets are level with each other. Make sure the rods turn freely in
the eyelets. With the rods turned so the arms point parallel to the
moose trail, place one end of the I/2 s: hardwood dowel against the
side of the bottom arm of the rod and measure the distance to the
same point on the opposite rod. Cut the dowel to this length (which
should be close to 42 inches) and file a shallow groove in each end.
This groove should only be deep enough to allow the dowel to set
firmly between the two steel rods.
It requires two men to set the release. The first man
holds the wooden dowel in place between the bottom arms of the rods
as close to the ends as possible. This man should kneel at the side
of the release opposite to the ends of the rod arms. The second
man stands on the side of the release facing the ends of the rod arms.
Re stretches the collar first over the two top arms, then down under
the second set of arms, making sure that the tension of the rubber is
close to equal on all four sides. The first man cautiously releases
his grasp on the dowling and the set is made. Note : At no time
should you allow any part of your body to come in line with the stretch
of the collar while placing it on the release. The tension on this
rubber is great enough to cause considerable pain and possible injury
should it accidentally slip and strike you.
Before leaving the set, take a spruce bow and sweep out
all tracks on the trail in the immediate vicinity of the set. This
serves a three- fold purpose; 1. When returning to check the set, the
fresh tracks may indicate as to whether it was a moose, other animal,
or a human who released the collar; 2. If there are no tracks present,
the collar was likely wind-tripped; 3. Tracks may show that a moose
approached the set and for some reason (likely poor camouflage) had
by-passed it.
Conclusions
Temperature was found to be a controlling factor in this
project in that at any temperature below 42°F the rubber had lost
all of its elasticity and when the set was released,- the collar
simply fell to the ground in the form of a 42 inch square.
27
Due to the very United nature of the project this year,
it is rather difficult to draw many concrete and proven conclusions.
Fron three different set locations we released a total of twelve
collars during the period from June Sth to July 15th. To date, with
the bulk of the hunting season over, we have had no returns. Obser-
vations were made of collared noose as late as August 25th by the
writer and the public. The collars appeared to fit the aninals
quite comfortably, at least at the tines of observation. The lack
of returns could be attributed to possibly three factors; 1, An
insufficient number of animals were collared; 2. The collars have
become snagged and torn off the aninals; 3. The collared aninals
have moved from the release sites to areas inaccessible to the hunters
However, it is felt that the economy of this method over
present techniques of moose tagging definitely warrants a much more
intensive study into its use. This will be conducted in the spring
of 1965.
Mr. Pierre Des Meules, Director, Terrestial Game Division,
Department of Tourism and Game, Quebec: Mr. Des Meules was very
co-operative in providing complete infomation of his collar release
apparatus. Although we have nodified the mechanism to a certain
extent, the basic principle is identical.
Figure 1
Figure 2
COLLAR
Wooden Dowel
4" x
3/8
S TEEL RO D
Ml
"Simatco" Rubber Tube
38" x 5/16" x 1/16"
EYELET
Plastic Tape
Twist-tie Wire
Dymo-tape"
v Identification
2 e
r~7^
Broken
"Conibear" Beaver
Trap Spring
/s
42"
<S<
^Z.
^v
Cut & Point
n
A'
/
12
k-4 t8 -^l
30
PESTICIDES AND WATER QUALITY*
C. F. Schenk, Biologist
Ontario Water Resources Commission
Abstract
The contribution made by pesticides in increasing
food production is recognized. On the other hand,
the writer points out the combined effect on water
resources of synthetic pesticides, detergents and
industrial wastes. The paper discusses at some length
the role of pesticides as a destructive component in
water .
A tremendous acceleration of technological development has
characterized America's pest control industry within the last two
decades and, more specifically, there has been an entire re-
orientation of emphasis to the production of organic pesticide
chemicals, as opposed to previous emphasis on inorganic compounds
such as arsenlcals and salts of copper, zinc and sodium. Throughout
the United States and Canada during this post-war period, the
insecticide DDT and the herbicide 2,4-D have maintained dominant
positions with respect to production, although the use of some of
the newer chlorinated hydrocarbon insecticides such as dieldrin,
aldrin and lindane has increased dramatically in the last few
years. The total value of pesticides manufactured in the United
States increased from just over $75 million in 1939 to $300 million
in 1961 (1) and it is anticipated that this figure will more than
double itself by 1975 (2).
The substantial contribution that pesticides have made
in increasing the production of food, feed and fibre to meet the
challenge of increasing human populations, in reducing spoilage
and improving the quality of produce, and in effecting spectacular
reductions in the severity and incidence of vector-borne communicable
diseases, cannot be denied and should not be de-emphasized.
However, accelerated technical and industrial progress
of all kinds is producing an increasingly complicated array of
^Presented at the Annual Convention of the Ontario Soil and Crop
Improvement Association, Toronto January 29, 1965.
31
unnatural forces at work in nature,, which if left to proceed without
appropriate checks and balances, would soon lead to a deterioration
of our natural surroundings. One important aspect of this broader
problem is the combined effect on our water resources of discharges
of sanitary and industrial wastes, and the use of a large number of
synthetic pesticides, detergents and other compounds which are
reaching our waters from homes, farms and forested areas. The focal
point of this presentation is to be the role of pesticides as a
destructive component in water. I hope that I can objectively
demonstrate that, while it is my firm belief that the search for
effective pesticides that will be more specific as control agents
should proceed unstinted, that progress along this line must be
counter-balanced by equivalent emphasis in other directions. I
am thinking of the development of refined methods of analyses to
detect these compounds in water, the accumulation of data on residue
levels in waters throughout the province and the promotion of studies
related to the side-effects of the use of pesticides.
How Pesticides Reach Our Waters
Agricultural insecticides and herbicides applied to vege-
tation or soil are subject to both biologic breakdown and processes
of chemical alteration, the degree of change varying with different
types of chemicals. The chlorinated hydrocarbons are extremely
resistant to breakdown and indeed a generalized figure that has
been established for the rate of loss of aldrin in soil indicates
only a partial reduction of about 29 per cent of the applied rate
over a six-year period. (West lake and San Antonio in Dugan et al,
1963) (1).
Pesticides may be transported to watercourses following
periods of heavy rainfall. Stable compounds such as DDT and
dieldrin are particularly hazardous in water since levels can
increase over prolonged periods. On the other hand, these
same chemicals tend to remain tightly bound to soil particles and
this minimizes somewhat the hazard of surface and ground water
pollution. Much depends on the timing of the application.
The more volatile compounds may drift into streams or lakes during
aerial and ground applications and this possibility is sometimes
aggravated by carelessness on the part of persons applying the
pesticides. Cleanup of spraying equipment in watercourses is
often another source of contamination, for which there seems to
be little excuse. Additionally, some pesticides are purposely
added to water to control aquatic vegetation, algae, undesirable
species of fish, aquatic insects, snails and leeches. Here in Ontariq
32
the addition of aquatic pesticides to water is regulated by a permit
system administered by the Ontario Water Resources Commission, to
forestall any detrimental effects that might result from such
practices.
Effects on Water
There is little doubt that the use of pesticides is the
most important of the several agricultural practices that affect
water quality. The hazards associated with the presence of
pesticides in water that have been quite well demonstrated by
actual pest control operations and by laboratory studies are as
follows:
1. Toxicity to fish and aquatic invertebrate life upon which
fish feed.
2. The effect of accumulated pesticides on the reproductive
capacity of female fish and the hatching success of fish
eggs.
3. The tainting of fish flesh, making them unfit to eat.
4. The creation of adverse tastes and odours in municipal water
supplies.
Fish are extremely sensitive to pesticidal compounds,
more so than birds and mammals, as a general rule. They are
especially susceptible to the chlorinated hydrocarbon pesticides.
Endrin is the most toxic chemical to fish that is known to man,
causing mortality at a concentration of less than 1 ppb in labor-
atory tests (i.e., 1 pound of endrin to 100 million gallons of
water) (3). Laboratory studies have shown DDT to be toxic at a
concentration of approximately 16 ppb (3). The organic phosphorus
insecticides, such as malathion and parathion, together with the
herbicidal compounds, are considerably less toxic than the chlor-
inated hydrocarbons, generally at concentrations expressed in
parts per million rather than parts per billion. The toxicity
of DDT to aquatic insects and other invertebrate life has been
well established by studies in Maine, Montana and New BrunswicK,
following applications of DDT for control of forest insects (4) (5) (6)
It is necessary to cite only a few examples where pest
control operations have decimated fish populations and have affected
municipal water supplies, to emphasize the potential dangers that
exist .
o
3
In August, 1950, extensive fish kills resulted in 15 streams
of the Tennessee River Valley of Alabama, following the use of
organic insecticides in this area for the first time to control
boll weevil in cotton. Toxaphene was reported to be the principal
insecticide involved and the contamination of the streams was
associated with excessive runoff caused by above-average rainfall
and too frequent applications of the insecticide (7). Another
example of a heavy fish kill was that experienced within a 2,000=
acre salt marsh in Florida where dieldrin was applied at a rate
of one pound per acre to eliminate sand fly larvae. It was esti-
mated that 20 to 30 tons of fish were killed as a result of the
treatment (8). Studies in New Brunswick showed that populations
of young salmon and brook trout were drastically affected by
aerial applications of DDT for control of spruce budworm (9).
One of the most highly publicized fish kills in the history
of the United States developed on the lower Mississippi River
in the fall of 1963, following sporadic and less serious
mortalities as far back as 1960. A tangled sequence of investi-
gations, consultations and hearings involving government and the
chemical industry centered around whether or not pesticide
residues in agricultural runoff or discharges from chemical
processing plants, or a combination of both, were responsible for
the deaths of several millions of fish. Though pesticides were
definitely implicated, the question of the source of contamina-
tion does not yet appear to be satisfactorily resolved and further
studies are currently in progress. One extremely worthwhile
outcome of the controversy has been the tremendous impetus given
to the development of specialized analytical procedures to detect
the presence of minute quantities of pesticides in water. The
final conclusions with respect to this situation on the lower
Mississippi are being anxiously awaited.
Closer to home, we have been fortunate in Ontario that
large-scale fish kills related to pest control operations have
never materialized. However, there have been several significant
fish kills in the province which have been attributed to careless-
ness in the use of these compounds. Cleanups of potato spraying
equipment in the Nottawasaga River near Alliston in 1963 destroyed
several hundreds of fish, including brown trout and rainbow trout.
In a canal southeast of Leamington in July of 1962, fish were
hauled away by the truckload following the use of aldrin for
control of grubs in a radish crop and an application of DDT for
control of mosquitoes and flies on the other side of the canal
about the same time. In this case, it was reported that the
spray bar on the water side was not shut off when the strip in the
radish field adjacent to the canal was treated with aldrin.
34
The accumulation of DDT by lake trout and the subsequent
effect on the survival of young fish at the Lake George fish hatch-
ery was proven beyond doubt by a comprehensive study undertaken in
New York State between 1958 and 1962. Survival of hatched eggs
collected throughout the watershed and retained at the hatchery
was completely lacking or negligible over a period of several years.
This mortality was caused by the extensive use of DDT, mostly for
black fly and mosquito control in the area surrounding the water-
shed (10) . Another study in New York State has demonstrated the
ability of fish to concentrate DBT in their tissues, particularly
in their internal body fat and reproductive organs (11).
With respect to production of tastes and odours, studies
undertaken at the laboratory of the Ontario water Resources
Commission have demonstrated the ability of 2,4-B and other
herbicides to cause tastes and odours in water at low concentrations
(12). Toxaphene can be detected in water at an extremely low
level of a few parts per billion and other insecticides are offensive
to a lesser degree. One of the most famous incidents related to
the production of tastes and odours in water occurred at Montebello,
California, in 1945. A small plant began to manufacture 2,4-D and
discharged its waste water into the local sewage system. The
sewage plant, in turn, discharged its treated effluent to the
Pvio Hondo River. Within 17 days following the commencement of
operations at the manufacturing plant, tastes and odours developed
in shallow wells downstream and it was reported that lawns and shrubs
were killed when the well waters were used for irrigation. These
wells remained contaminated for a period of three years (13). The
possible contamination of waters used as sources of municipal water
supplies necessitates a cautious approach where aquatic herbicides
or fish poisons are used to control nuisance populations. Further-
more, persons using such chemicals should be aware that claims for
damages might arise should their activities interfere with the use
of water for irrigation or other rightful purposes by adjacent or
downstream riparian landowners.
Although this is an impressive resume of problems
associated with the use of pesticides, it is to be admitted that,
in the main, problems have been sporadic and generally localized
when compared with the total utilization of pest control compounds
throughout the entire U.S. and Canada. The widespread use of
herbicides and insecticides has not resulted in concentration
levels in surface waters used for public water supplies that can
be considered to present any immediate hazard to human life.
Nonetheless, studies undertaken by the U.S. Public Health Service
o
5
have revealed the presence of detectable residues of DDT In
several of the major water sheds of the United States and, of more
interest to us, in Lake St. Glair and the Detroit River. Concentra-
tions measured by the technique employed were in the range of 1 to
20 ppb (14). Pesticides are getting into our waters and we do not
understand all of the implications of their presence.
In drawing to a close, the fact that much is still to
be learned about the possible effects to man of long-term
exposure to low concentrations of the more toxic pesticides,
together with the ability of fish and possibly other forms of
aquatic life to concentrate these compounds to their own detriment,
point up the need for an accelerated programme to accumulate data
concerning pesticide residue levels in water. The best means of
providing an expansion of essential analytical services is
currently being given careful consideration by the Ontario Water
Resources Commission and rapid progress to this end is anticipated.
Plans have been laid for this year to collect several species of
fish from selected waters throughout the province to determine
whether fish contain residues of DDT and possibly dieldrin. Since
fish tend to concentrate these materials, it is felt that this study
will provide a useful means of determining whether surface waters
are being contaminated to a significant degree. Additionally, a
single watershed draining an agricultural area receiving repeated
heavy applications of pesticide compounds is to receive special
attention, in order to determine what residue levels are present
in the watercourse and whether fish populations are being
detrimentally affected.
In conclusion, may I re- iterate my realization of the
need for high standards of agricultural production and I hope that
continuing research will provide effective and specifically toxic
pesticides to make this a certain accomplishment. All too often,
this whole matter is presented as a choice - between high standards
of agricultural production and uncontaminated waters, or on a
broader scale, an uncontaminated environment. There really is
no choice to be made, for we need both! A spirit of co-operation
is required on the part of all parties concerned to see that both
are maintained.
References
1. Dugan, Patrick R., Rcbert M. Pfister and Margaret L. Sprague,
Syracuse University Research Corporation. Evaluation of the
Extent and Nature of Pesticide and Detergent Involvement in
Surface Waters of a Selected Watershed. Prepared for New
York State Department of Health, Project No. GL-WP-3
(August, 1S63).
36
2. Johnson, C, et al, Pesticides - Part 1: Insecticides,
Mi tic ides, Nematocides, Rodent ic ides. Chemical Week Report
McGrav7-Hill Publication (May 25, 1963).
3. Henderson, C, Q. H. Pickering, and C. M. Tarzwell.
Relative Toxicity of Ten Chlorinated Hydrocarbon Insecticides
to Four Species of Fish. Trans. An. Fisheries Soc, 88_: 23
(1959),
4. Warner K., and 0. C. Fenderson. Effects of DDT Spraying
for Forest Insects on Maine Trout Streams. Journ. Wildl.
Mgt., 26: 86(1962).
5. Graham, R. J., and D. 0. Scott. Effects of Forest Insect
Spraying on Trout and Aquatic Insects in Some Montana Streams.
Final Rept., Montana Fish & Game Dept. (1958).
6. Ide, F. P., Effect of Forest Spraying with DDT on Aquatic
Insects of Salmon Streams. Trans. Amer. Fisheries Soc, 86_:
208 (1957).
7. Young, L. A., and H. P. Nicholson. Stream Pollution
Resulting from the Use of Organic Insecticides. Prog.
Fish Cult., 13, 4:193 (1951).
8. Harrington, R. W., Jr., and W. L. Bidlingmayer . Effects
of Dieldrin on Fishes and Invertebrates of a Salt Marsh.
Journ. Wildl. Mgmt, 22:76 (1958).
,.
Keenlyside, M. H. A., Effects of Spruce Budworm Control
on Salmon and Other Fishes in New Brunswick. Canadian Fish
Culturist, 24:17 (1959).
10. Bur dick, G. E. et al. The Accumulation of DDT in Lake Trout
and the Effect on Reproduction. Trans. Amer. Fish. Soc,
93:127 (1964).
11. Mack, G. L. et al. The DDT Content of Some Fishes and
Surface Waters of New York State. New York Fish and Game
Journ., p. 143 (July, 1964).
12. Swabey, Yvonne K. and C. F. Schenk. Studies Related to the
Use of Algicides and Aquatic Herbicides in Ontario. Proc
Aquatic Weed Control Soc. Meeting, P. 20 (February, 1963).
13. Swenson, H. A, The Montebello Incident. Proc Soc. Water
Treatment, 11:34 (1962).
14. Middleton, F. M. , and J. J. Lichtenberg. Measurements of
Organic Contaminants in the Nation's Rivers. Ind. and Eng.
Chem., 52:99A (19(
37
PHEASANT HARVEST REPORT
LAKE SIMCOE DISTRICT - 1964
by
J. S. Dor land
Assistant Senior Conservation Officer
Abstract
A total of 5,518 township hunting licences consisting
of 2,047 resident and 3,471 non-resident were sold in
the thirteen regulated townships, up to and including
November 7, the close of the pheasant season. This
is a decrease in total licences purchased by hunters
of 10.6? o from the previous year. Nine thousand, four
hundred pheasants, 4,750 day-olds, 4,000 poults, and
650 adults were distributed to the regulated townships,
excluding Markham, E. Whitby, Toronto and Albion
townships. A field check of 1,795 hunters during the
open season produced a harvest figure of 964
pheasants, for a hunter success of .53 of a bird per
hunter checked, an increase of 15.1% over 1963. Time
to kill a bird took 6.4 man-hours, a decrease in time
from 1963 of about one hour. In Markham township
where no pheasants were released this year an average
of .85 of a bird per hunter was obtain-:;! during the
opening day and .61 of a bird for the entire season.
Open Seasons
October 21 - November 7 - Counties of Dufferin, Peel and
York. The townships of Adjala,
Essa, Tosorontio, Innisfil,
Tec urns eth and West Gwillimbury
in Sir.coe County and the townships
of Pickering, Reach, Scott, Uxbridge,
Whitby and East Whitby in the
County of Ontario.
October 3 - November 30 » Remainder of the District.
Statistics
Although the hunting of pheasants was open throughout the
entire District, this report covers only nine regulated townships
in the District. The remaining regulated townships, Adjala, Tecumseth,
West Gwillimbury in Simcoe County, the township of East Gwillimbury
in York County and the townships of Toronto and Albion in Peel County
on
JO
either produced little pheasant hunting or closed their township
to hunting during the pheasant season. The remainder of the District
that is northward is well outside normal pheasant habitat and no
figures are available.
Entire Season
No. of Parties Checked In Field 251 712
Mo. of Parties Using Dogs 141 427
No. of Hunters Checked in Field 670 1,795
No. of Man-hours Hunted 1,941 6,132
No. of Cocks Bagged 251 578
No. of Hens Bagged 175 386
Total Pheasants Bagged 425 964
Per Hunter Cock .37 .32
Per Hunter Hen .26 .22
Per Hunter Total .63 .54
Man-hours hunted to Bag a Pheasant 4.6 6.4
Cock Pheasants Seen but not Shot 431 935
Hen Pheasants Seen but not Shot 381 778
Sex Ratio c/h Shot 1.4-1 1.5-1
Sex Ratio c/hSeen-not Shot 1.1-1 1.2-1
See Table I for complete coverage by townships
Distribution
A total of 11,000 pheasants made up of 5,700 day-olds,
4,500 poults and 800 adults were received in the District for
distribution. As usual day-olds were raised to poult size by town-
ships, Game Commissions and interested sportsmen before release.
In the case of Whitchurch township 426 adult birds carried over
the winter by the Whitchurch Game Commission were released in early
spring, at a ratio of one cock for every five or six hens. In
Pickering township, 1,400 day-olds and poults were received by the
Game Commission, of this number 974 were released just prior and
during the open season and an additional 68 are being wintered
over for further experimentation. A loss of some 25.6 per cent
here was attributed to the lack of space to raise a healthy well-
feathered bird. See Table 2 for complete distribution figures.
Costs of Raising Chicks by Townships
Whitchurch Township 426 birds released = $675. or $1.55 per
bird released (winter carry-over)
Pickering Township 1,400 birds (974 released) = $1,805.15 or
$1.76 per bird released (Put and Take Project)
King Township 700 birds received = $691. or 99$ per bird
received (shown only for comparison sake)
39
Licences
A total of 5,518 township licences were sold up to the
close of the pheasant season., November 7. This figure is made up
from 2,047 resident licences, a decrease of 26.6 per cent from
1963 and 3,471 non-resident licences, a decrease of 3.9 per cent
from 1963. Although the new township licence which was placed on
sale for the first time this year made additional work for the
issuers, no complaints were received from the townships. In
regard to the Township Back Patch a numbered patch issued with the
licence and to be worn by the hunter, only praise was received.
See Table 3 for complete coverage by Townships.
Weather
Unlike the previous year's opening day, when temperatures
were above normal, this year's opening presented the hunter with a
cool drizzling rain which turned to snow by mid- afternoon. The
remainder of the season was a mixture of cool, overcast and sunny
warm weather which was, in most cases, excellent for both dog and
hunter .
Harvest
Hunter success, bird in the bag and hours to kill a bird
all show a nice increase towards better pheasant hunting this year.
Although our figures are taken from one township less than the
previous year, our hunter success of bird per hunter is up 15.1
per cent and the time to kill a pheasant has decreased by one hour,
figuratively shown as .53 bird per hunter and 6.4 man-hours to kill
a bird. See Table 1.
1962 1963 1964
No. of Townships reporting
No. of Hunters reporting
No. of Parties Using Dogs
No. of Pheasants reported shot
No. of Pheasants reported seen (not shot
Hunter Success
Man-hours to kill a bird
Distribution of birds to Regulated Twp.
9
10
9
1,455
2,097
1,795
263
457
427
672
942
964
1,679
1,403
1,713
.46
.45
.54
7.4
7.5
6.4
15,550
15,000
9,400
B.emarks
In comparison with 1963 hunter success figures which are
shown above as comparable with 1962, this year's hunter success
figures for the regulated townships were upwards. In dealing with
some of the townships individually, however, we find some interesting
harvest figures which might tend to change our thinking as to the
proper types of yearly introduction or if such introduction in some
townships is needed at all. Three types of planting were in opera-
tion this year, spring , s ummer , and fall , and in two townships
where introduction has been carried out yearly in the past, no
plantings were made this year. (A Special Pheasant Report is being
prepared on these different types of plantings).
Discussion
In this report, and owing to the different procedures
of re-stocking in some townships this year's harvest results have
been erratic. Summarized very briefly they indicate to us seven
things. First, spring plantings of hen pheasants in the Township
of Whitchurch in the hope of producing more natural hatched birds,
failed. This, we feel, was due to some extent to poor survival of
the bird shortly after release, a poor hatch, cause unknown, and
poor reproduction from 1963 plantings. Second, poor harvest of
pheasants planted in the township of Pickering just prior and
during the open season could be attributed to the release, in some
cases, of an underweight, poorly-feathered bird brought about from
the conditions under which they had been raised; inclement pheasant
hunting weather during the opening day and insufficient publicity
as to release spots. Third, the very poor harvest in the township
of E. Whitby where in previous years a good number of birds have
been released and this year none, is mainly due to lack of reproduction
and release of birds, plus the publicity given by the township that
no birds were to be released. Four, the much improved harvest over
previous years in the township of Markham where, like E. Whitby,
no birds were released this year, is difficult to explain. From
checking hunters over the years in this township, one factor appears
to stand out and it could be one of the main reasons that much of
this year's harvest came from the southwest corner above No. 7
highway which has many acres of grassy and legume fields. In
previous years the best hunting came from the north-central areas,
where many corn, grain field and low lands are to be found. Five,
in the township of King where in past yeais this township was normally
known for its rabbit hunting and where pheasant hunters have been
difficult to locate this year enjoyed exceptionally good pheasant
hunting. Although the number of licences issued has changed little
in the past three years, planting of pheasants during August and
September this year increased some 31 per cent over the 1962-63
figures. These, with little hunter competition and well-feathered
birds released, are some factors which, we feel, account for the
41
near doubling of hunter success from the previous year. Six, as
in previous years, those regulated townships such as E. Gwillimbury,
West Gwillimbury j Tecumseth and Adjala which are very marginal
pheasant lands produced little or no hunting. Seven, the contin-
uation under improved supervision of the raising and releasing of
adult pheasants during the cpsn season should be furthered, plus
improved supervision and more encouragement given to those townships
raising and releasing poults.
Acknowledgments
I would like to thank Conservation Officers B, Smith,
R. Toth, W. Danby, G. Love, F. Marshall, E. Smith, J. Catcher, the
many deputy conservation officers in the regulated townships and
the members of the District office staff who supplied the figures
used in the compilation of this report.
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TABLE 2
44
PHEASANT DISTRIBUTION - 1964
LAKE SB'ICOE DISTRICT
Township
Whitby
Pickering
King
E. Gwillimbury
Caledon
Chingaucousy
Toronto Gore
Tecumseth
W. Gwilliiabury
Tosorontio
N. Gwillimbury, Georgina
Orillia G & F
Orangeville School
Stayner Rod & Gun
Tiny Marsh
Little Lake
TOTALS :
Da£_Clds
Poults
Stock
Total
1,000
800
100
1,500
1,100
300
1,400
/ uu
1,000
200
1,900
500
300
100
900
200
500
75
775
700
500
75
1,275
200
50
250
550
300
50
soo
200
150
600
200
5,700
j
4,500
50
50
100
100
200
150
soo
200
100
300
11,000
45
TABLE 3
Township
Whitby
E. Whitby
Pickering
Markham
Whitchurch
King
E. Gwillimbury
Toronto Gore
Chingaucousy
Caledon
Adjala
Tecimseth
W • Gwi 1 1 irab ur y
REGULATED TOWNSHIP HUNTING LICENCES
SOLD UP TO AND INCLUDING NOV. 7
LAKE SIMCOE DISTRICT 1964
Resident
289
45
410
320
170
320
159
22
151
35
24
36
66
Non-Resident
300
88
415
347
600
200
222
100
239
210
200
300
250
TOTAL:
2,047
3,471
5,518
46
REPORT ON THE USE OF FOUR INCH MESH IN HARVESTING
THE WALLEYE (Stizostedion vitreum) OF MAKOOP LAKE
WITH RECOMMENDATIONS OF THE USE OF THIS MESH SIZE
IN THE PATRICIAS
by
J. J. Armstrong, Biologist
Sioux Lookout Forest District
Abstract
An investigation was begun on a Precambrian Shield
lake to study the effects of a reduction in mesh size
from 4=1/2 inch to 4 inch extension measure. An
analysis of a representative sample of 537 wallejres
captured in the 4 inch commercial nets showed that
approximately fifty per cent of the catch is ten years
old and younger. The average age of the sample is
10.8 years. The growth of walleyes from Makoop Lake
is very similar to the average growth of walleyes of
nine Patricia lakes and to the walleyes of the Red
Lakes, Minnesota. A length-weight equation is pres-
ented for a representative sample of 100 walleyes
from Makoop Lake. An analysis of maturity data
indicates that male walleyes from this lake probably
mature at age VII followed by females a year later.
An analysis of a segment of a catch curve for this
walleye population indicates an annual mortality rate
of twenty-eight per cent. When this information is
used in conjunction with the relative growth rate, the
age at maximum biomass occurs at 5.8 years. The
large difference between the age at maximum biomass
and the average age of the sample collected from 4
inch mesh indicates that the 4-1/2 inch mesh currently
in use in Makoop Lake is inefficient in harvesting
the walleye. Recommendations on the use of 4 inch
mesh in the Patricias is presented.
Introduction
Lewis (1964) recommended that a study be inaugurated
on the effects of a reduction in mesh size from 4-1/2 inch to 4
inch (extension measure) on the whitefish and walleye populations
in Patricia lakes. In this report Lewis used catch per unit effort
data to show that the 4-1/2 inch mesh currently in use is very
inefficient in harvesting the slow growing populations in this
47
section of the province. He suggested that the use 4-1/2 inch
mesh "...nay be one factor in preventing a greater and more
efficient harvest of walleye (Stizostedion vitreum) and whitefish
( Coregonus clupeaf omis ) c: >
The use of catch per unit effort is not satisfactory by
itself to justify a reduction in mesh size unless this information
has been collected on an unfished population. Where a population
has been previously fished by a given mesh size, the effect of such
exploitation is to remove the larger fish which are expected to be
old and which are generally slower growing. The end result is a
younger population in which the average size of fish -is too small
for efficient capture by the gear in use, and a subsequent reduction
in the catch per unit of effort, This chain of events is especially
true where only the oldest and largest fish in the population are
harvested. With further reductions in mesh size the effects of
recruitment and growth become more important and modify the
situation described above „
Lewis apparently recognized the limitations to which
catch per unit effort data are subject, and recommended a study on the
population dynamics of the two species in at least one Patricia
lake. This proposed study was to specifically examine the case
for or against a reduction in mesh size. In accordance with this
recommendation the present study was begun on Makoop Lake by this
author with the assistance of Mr, E. A, Driver.
Makoop Lake is situated at Long. 90 50', Lat. 52 25',
approximately 205 air miles north of Sioux Lookout on the Precambrian
Shield. A limited amount of physical, chemical and morphometric
data is available in a report by Monk and Lessard (1963).
Makoop Lake was selected for this type of study since
Monk and Lessard had found that the walleye captured in the 4 and
4-1/2 inch mesh nets were rather old and that the catch per unit
of effort for these mesh sizes was low relative to the smaller
mesh sizes. They found that the greatest catch per unit of effort
occurred in the 2=1/2 inch mesh, (Figure I) These authors
recommended that 4 inch mesh would afford a better return to the
commercial fishermen. That the potential yield of this lake was not
being realized was apparent on examination of the production records
in comparison with the potential fish production calculated using
Ryder's (1964) morphoedaphic index. Using this method a potential
fish production of approximately 4.5 pounds per acre, or a yield of
123,000 pounds for the entire lake was calculated. Although a quota
of 45,000 pounds was set for this lake, the effort required to harvest
this poundage of fish made the venture unprofitable. This quota
was removed only once in three years of fishing (1959), and was almost
entirely composed of whitefish (13,100 lbs.). During the winter of
1952 intensive netting with 10,000 yards of 4-1/2 inch mesh net daily
for 14 days yielded only 340 pounds of walleye (Pers. comm. - C.
St. Paul). The general attitude was that the lake has been "fished
out !! ,
L?
11
10
<u 8
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6
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03
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4 inch mesh
4-2 inch mesh
1*
3 3-ir 4 4*
Mesh Size
5 5i5*
Figure I - Catch of walleyes per hundred feet of net for ten mesh
sizes from 1-1/2 to 5-1/2 inch. Data calculated from
Monk and Lessard.
L
f>
Methods and Materials
The nain objective in the work at Makoop Lake was to
representatively sanple walleye and whiteflsli caught by the 4 Inch
mesh nets in use for the first tine In this lake. In order that
a representative sanple was collected the f ishemen were asked to
bring all walleye and whitefish caught back to canp for examination.
Excellent co-operation was received. When the fishermen were checked
on the lake while they were removing their catch from the nets, no
small walleyes or whitefish were being discarded although some very
small walleyes were caught. As a further check, locations where
unwanted fish were discarded were examined. No walleyes were found,
although a few whitefish which were probably culls were present. It
is, therefore, felt that the sample of walleyes reported in this
paper is representative of the catch harvested by the 4 inch mesh.
Scale samples, total lengths, sex and the state of
maturity were collected on each fish. A total of 633 walleyes were
sampled for this information. Total weights were collected on
100 walleyes. In addition weights were collected on samples of
dressed (without heads) walleyes to determine the average dressed
weight harvested by the 4 Inch mesh.
Scale samples were removed from the area below the
anterior insertion of the soft dorsal fin below the lateral line.
Total lengths were recorded to the nearest one- tenth of an inch.
Weights were recorded to the nearest ounce using a balance type
scale.
The determination of the state of maturity is difficult
in the walleye especially if the fish have been collected early in
the growing season. Although mature females are fairly simple to
identify by the noticeable presence of eggs retained from previous
spawnings, the immature fish are difficult to separate from those
fish which have only spawned once or twice, and in which the presence
of retained spawn is not readily apparent. Where maturing eggs are
visible the fish must be mature, but these are very difficult to
find in the early part of the growing season. For the same reason
the incidence of mature walleyes that were not going to spawn the
following spring could not be evaluated; probably samples collected
in August or September would clear up these difficulties. Since
the samples of walleye reported in this paper were collected in the
early part of the growing season, many walleyes just reaching maturity
were undoubtedly recorded as Immature. The values reported for the
percentage of immature fish are, therefore, probably too high. Since
maturing eggs were difficult to find, the incidence of mature walleyes
that were not going to spawn the following spring could not be eva-
luated.
50
At Sioux Lookout, the scale samples were arranged in an
ascending order of length and the information on the scale sample
envelopes was recorded on previously prepared forms. Scale
impressions were made on cellulose acetate slides, and the
impressions were read using a Leits Trichinoscope following the
method described in Appendix A of Lev/is et al (1964).
Re suits
Age and Growth
Table 1 shows the percentage composition of walleyes
caught in the 4 inch mesh at Makoop Lake in 1964, and the cumula-
tive percentages at each age. The sample is predominantly composed
of- old fish. Approximately fifty per cent of the sample was ten
years old and younger with age groups IX and X accounting for forty-
four per cent of the entire sample. Approximately ninety-eight per
cent of the sample was older than six years. The average age of the
entire sample was 10.8 years.
The growth of the walleye in Makoop Lake is presented
in Figure II. Triangles represent back- calculated values on a
sample of age group IX walleyes collected in 1964. Circles
represent the average lengths of each age group of walleyes
collected in 1964. This growth curve is very similar in the older
age groups to the curve presented by Monk and Lessard (opus cit.),
but shows a faster growth rate in the younger age groups. When
the original scales were examined it was found that the locations of
the first annulus and in some cases the last were probably misinter-
preted. Thus the ages were one year less than the ages designated by
this author. When a correction was applied to their growth curve
and the two curves compared they were almost identical.
Differential growth between the sexes is general after
the age at maturity has been reached. In this study the females
grew faster than the males (plots not shown), but both sexes were
combined in calculating the growth rate from age groups IX to X
represented in Figure II, Since the females greatly outnumbered
the males (SO females to 20 males) this section of the curve more
closely represents the growth of the females than the combined
growth which should be lower.
51
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52
Table I - Percentage composition of the catch of 537 walleyes
from 4 inch mesh at Makoop Lake in 1964
— ...... mm
Cumulative
Cumulative
Age Group
Numbei
Percentage
Percentage
Percentage
IV
2
.37
.37
99.95
V
2
.37
.74
99.58
VI
1
.18
.92
99.21
VII
4
.75
1.67
99.03
VIII
24
4.47
6.14
98.28
IX
120
22.34
28.48
93.81
X
119
22.16
50.64
71.47
XI
81
15.08
65.72
49.31
XII
72
13.40
79.12
34.23
XIII
61
11.35
90.47
20.83
XIV
30
5.58
96.05
9.48
XV
16
2.97
99.02
3.90
XVI
4
.75
99.77
.93
XVII
1
.18
99.95
.13
Average age
- 10.8
years.
The average growth of walleyes from nine Patricia lakes
(Lewis et al, 1964), and from the Red Lake of Minnesota (Smith
and Pycha, 1961) are presented for comparative purposes. The
similarities of the curves is apparent, and will be discussed
in other sections.
Length-weight Relationship
The length-weight relationship for the walleyes of
Makoop Lake can be expressed by the regression equation: Y ■
2.8930X - 2.1701 where Y is the log of the weight in ounces and
53
X is the log of the total length in inches (Figure III). In
order to avoid the tedious work involved by using observations
on 100 fish, the average weight of fish in ounces was calculated
for each one-tenth inch interval and the regression analysis
was calculated using forty=one observations. The method of
regression analysis is presented by Snedecor (1956). A summary
of the computations is presented in Appendix A,
Maturity
Table II shows the percentage of mature and immature
walleyes of both sexes caught in the 4 inch mesh at Makoop Lake.
It is quite apparent that this size of mesh captures a predominance
of mature fish, at least when first used in a lake. With removal
of greater proportion of the older year classes the percentage
of immature fish will probably increase slightly.
Table II - The percentage of mature and immature walleye of both
sexes sampled from the 4 inch mesh used in Makoop Lake
in 1964.
Mature
Immature
Males
97.8
2.2
Number
132
3
Females
90.3
9.7
Number
446
48
Totals
100%
135
100%
494
The data are not sufficient to accurately determine
when the walleye of this lake first become mature, but are
presented in Table III to serve as a rough indication.
LENGTH IN INGRES
Figure III - The length- weight relationship of Makoop Lake walleye.
The regression equation is presented in the text.
55
Table III - The percentage of nature and immature walleye for
each age group caught in the 4 inch mesh at Makoop
Lake, 1964,
Age Group
IV
V
VI
VII
VIII
IX
X
XI
XII
XIII
XIV
XV
XVI
XVII
Males
Immature Mature
100
33
No.
1
67
3
100
7
100
17
100
19
100
23
100
20
100
22
100
3
100
2
100
1
Feme
lies
Immature
Mature
No.
100
1
100
2
-
-
100
2
41
59
17
13
87
102
10
90
102
2
98
59
100
52
100
38
100
27
100
100
4
1
Probably male walleyes become mature for the first time
at age VII and females at age VIII.
When the log of the frequencies of the age groups in a
representative sample of fish is plotted against the age of those
fish, the resulting curve is called a catch curve (Ricker, 1948).
The catch curve for Makoop Lake walleye is presented in Figure IV.
When such a curve is straight in the right-hand limb constant
survival rate is indicated. Nonlinearity in this section of the
curve may have several causes when the population being considered
has previously been fished, but in a relatively unfished population
11 12
AGE IN YEARS
13 14 15 16
Figur e IV - Catch curve of Makoop Lake walleyes samples from
•4" nesh nets, 1964,
57
such as Makoop Lake, the convexity is probably caused by two factors:
1. An increase in natural mortality with age, and: 2. The
effects of previous fishing effort on the older age groups when
4-1/2 inch mesh was used. The straightness of part of this curve
under the situation of a relatively unexploited fishery should
give some indication of the annual survival rate between the ages
of such a section of the catch curve. This section has been
assumed to be between age groups ten and fifteen, inclusive. Using
the method described by Rob con and Chapman (1561) in analysing a
segment of a catch curve, an annual survival rate of 72 per cent was
calculated. The computations are presented in Appendix 3. The
mortality rate, which in this case would be the natural mortality
rate, is the complement of the survival rate and was found to be
28 per cent. It is assumed that this mortality rate is constant
and applies to age XV and younger.
Discussion
If the relative rate of growth in weight of a species is
known in addition to the rate of natural mortality, the minimum
size at which maximum biomass occurs can be calculated. This
information is presented for the walleye of Makoop Lake in
Figure V. The . descending curved line represents the increase
in weight added each year relative to the weight at the beginning
of the year expressed as a percentage. This information was
obtained by determining the average lengths at the end of each year
from Figure II and calculating the weights corresponding to these
average lengths by the regression equation represented in Figure
III. A curve showing the growth rate in terms of weight would be
just as satisfactory. Next the difference between the weights of
successive age groups was determined and the percentage change in
weight in relation to the weight at the beginning of the year was
calculated. This method is presented by Fry (1964). The method
of estimating the rate of natural mortality has been presented
previously. The age at which the curve of the relative
growth rate intersects the line representing the rate of natural
mortality is the point where the mass of weight added each year
equals the mass of weight removed each year through the factors of
natural mortality. Maximum biomass of the species occurs at this
point, and is represented by the vertical line A in Figure V (5.8
years). The vertical line B represents the average age of the fish
samples from the 4 inch mesh nets used on Makoop Lake in 1964
(10.3 years). The broken line with the solid triangles is the
percentage age distribution of a sample of the catch, and is presented
to show the contributions of each year class relative to the estimated
point of maximum biomass and the average age of the sample.
58
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59
No average age for the sample of fish caught in the
4-1/2 inch mesh nets was ever obtained, but this value must be
greater than the average age of the fish caught in the 4 inch
nets. Even so, the difference between the average age of fish
caught in the 4 inch nets and the age at maximum biomass is
startling and indicates that with the use of 4-1/2 inch nets, the
lake was being grossly underfished. The fish which were passing
through the 4° 1/2 inch mesh nets were simply dying through the
factors of natural mortality.
With continued use of 4 inch mesh nets in Makoop Lake,
it can be expected that the average age of the sample will
decrease slightly, but will not become less than the average
age at maximum biomass simply because this size of mesh is
too inefficient in capturing the size of fish at this age. In
making this statement it is realised that with increased
exploitation the characteristics of growth and mortality of the
walleye in this lake will change, but the extent of this change
should not invalidate this statement.
The average dressed waLght of 303 walleyes (dressed
without heads) was 1.28 lbs. The average round weight of 100
walleyes was 1.08 lbs. These weights are suitable for government
and commerce.
Theoretically, when the effects of future exploitation
with 4 inch nets are more fully known, it may be found that the
use of 3-1/2 inch nets will more fully realize the potential of
this lake, having due regard for the requirements of government
and commerce for a desirable size of fish. This mesh size has
been used in the Red Lakes of Minnesota for many years with no damage
to the fishery (Smith and ?ycha, 1961). Since the growth rates of
walleyes from Makoop Lake and the Red Lakes are very similar,
Figure II, especially in the older year classes, the use of 3-1/2
inch mesh should be investigated in the future. No specific
recommendations for the immediate use of this size of mesh are
given here.
Since the growth rate of walleyes from Makoop Lake is
very similar to the average growth of nine Patricia lakes, it
can be safely argued that 4 inch mesh nets can be used in this
area.
Recommendations
1. That 4 inch mesh nets be used for existing Patricia Indian
fisheries after a fishery investigation has been conducted for the
harvest of walleye and whitef ish in lakes where lake trout are
not present.
60
2. That adequate representative samples of walleye and whitefish
be collected by standard gill net sets and the data analyzed before
licenses for 4 inch mesh nets are issued for any lake, providing
that this restriction would be removed when adequate information
is available to justify the use of this mesh size in Patricia
lakes in general.
3. That an intensive tagging programme be conducted on at least
one, preferably two, Patricia lakes (Makoop and/or Sachigo if
feasible) to more accurately determine the natural mortality
rate. The use of trap nets capable of capturing the younger year
classes is recommended.
4. That detailed analysis be conducted on the data collected
at Sachigo Lake in 1964 from the commercial fishery and
experimental netting. This recommendation is especially important
since Sachigo is the only lake in which representative samples
have been collected by standard gill net sets before 4 inch
mesh nets were used for the first time. Much valuable information
has been collected from this lake.
5. That follow-up procedures be conducted on the changes in
the age, sex, and size composition of the commercial catch of
4 inch mesh nets, especially in Sachigo and Makoop Lakes.
6. That long-term studies be inaugurated on the feasibility of
using 3=1/2 inch mesh nets in the future. Caution in making
recommendations on the extensive use of this mesh size is
recommended.
I wish to personally thank Mr, C. E. Perrie, Fish
and Wildlife Supervisor, for permitting me to undertake this
interesting study, and for advice on the problems I encountered.
For assistance in the field I am indebted to Mr. E. k. Driver and
Mr. T. Beardy. For information on the past history of Makoop Lake
I wish to thank Messrs. G. St. Paul, C. Milko, C.Monk and J.
Lessard. For critically reading the manuscript my thanks are
expressed to Mr. A. E. Armstrong. Finally, my thanks to Mr. H.
Speight, pilot of Otter ODV for the transportation and suggestions.
61
References Cited
Armstrong, J. J. 1961. Patricia Inventory Fish-ageing Techniques,
Appendix A, Progress Report #2 of the Fisheries Inventory
Work in the Patricia 1961-53 by C. A. Lewis et al. 1964.
Mimeo. Ontario Department of Lands and Forests.
Fry, F.E.J. 1964. Anglers arithmetic, Chapter VI, Fish and Wildlife,
edited by J. P.. Dymond, Longmans Canada Limited, Toronto.
Lewis, C. A. 1964. Some current fisheries problems in Patricia
lakes and recommendations for future work on the Patricia
Inventory Programme. Mimeo. Ontario Dept. of Lands
& Forests.
Lewis, C. A., C. H. Olver, W. A. West, and F. J, Atkinson. 1964.
Progress Report #2 of the Fisheries Inventory Work in
the Patricias 1961-63. Mimeo. Ontario Department of
Lands and Forests „
Monk, C. E. and J. L. Lessard. 1963. Lake Survey Report on
Makoop Lake, Field Notes and Data on File at Sioux
Lookout, Ontario.
Ricker, W. E. 1945. Abundance, Exploitation and Mortality of the
Fishes of Two Lakes. Invest. Ind. Lakes and Streams,
2(17). Vol. 2, pp. 345-448.
Robson, D. S. and D. G. Chapman. 1961. Catch Curves and
Mortality Rates. Trans. Amer. Fish. Soc. Vol. SO (2):
181-189.
Ryder, R. A. 1964. Chemical Characteristics of Ontario Lakes with
Reference to a Method for Estimating Fish Production.
Sect. Eept. (Fish) No. 48, Research Branch, Ontario
Department of Lands and Forests, Maple.
Smith, L. L. and R. L. Pycha, Jr. 1961. Factors Related to
Commercial Production of the Walleye in Red Lakes,
Minnesota, Trans. Amer. Fish. Soc. Vol. 90(2) :1S0-217.
Snedecor, G. W. 1956. Statistical Methods. The Icwa State
College Press, Ames, Icwa.
St. Paul, C. Personal Communication, Indian Affairs Branch,
Sioux Lookout.
62
APPENDIX LA
Computations of the length - weight regression equation for
walleyes sampled from the 4 inch mesh used In Makoop Lake in 1964,
SX - 51.6S73
x = 1.2607
SY
60.5625
uj-A.1 "
■ 76.65775517
1.4771
C.F. -
= 76.34907576
50.37177603
Sxy -
.30367941
C.F.= 65.16041417 C.F.- 89.45893673
2
Sx 2 =
.1067327^
Sy~ - .91283930
N = 41
h - Sxy/Sx 2 = .30868/.1067 = 2.8930
Y - 2.3930X - 2.1701
APPENDIX B
Analysis of a segment of the catch curve presented in Figure IV
using the method of Rob son and Chapman (1961)
A^e
10
11
12
13
14
15
Coded_ Age
1
2
3
Number in Catch
11-
81
72
61
30
16
X = Tk
n
Total 379
L^2 = 1.604
^ "7 j "\
3 1 y
Using the above author's Table 3 (page 107) for K = 5, the
survival rate Is .72.