Project Re ort No. 16
Canada. [Dept. of] Fisheries.
Industrial Development Service
PROJECf REPORT
A QUANTITY SURVEY OF IRISH MOSS AND OTHER SEAWEEDS
IN THE MIMINEGASH AREA
"By
H.D. Johnston and F.L. Herring,
Federal Department of Fisheries
Marine Plants Experimental Station,
Miminegash, Prince Edward Island, Canada
Industrial Development Service
Department of Fisheries of Canada, Ottawa
February, 1968
A QUANTITY SURVEY OF IRISH MOSS AND OTHER SEAWEEDS
IN THE MIMINEGASH AREA
•
By
•
H.D. Johnston and F.L. Herring.
Federal Department of Fisheries
Marine Plants Experimental Station.
Miminegash. Prince Edward Island. Canada
Opinions expressed and conclusions reached by
the author of this report are not necessarily
endorsed by the sponsors of this project
This was a joint project carried out by the
fisheries authorities of Canada and
Prince Edward Island
•
,
•
•
-INDEX-
TITLE
•
PAGE NO.
INTRODUCTION
APPARATUS AND EQUIPMENT
METHOD
SAMPLE CALCULATION
REMARKS
CONCLUSION
PROPOSED IMPROVEMENTS IN METHOD
RECOMMENDATIONS
CHART
TABLE B
TABLE C
1
2
2
5
6
7
8
9
11
12
13
INTRODUCTION
For the past several years underwater surveys have been conducted and their results have been of great value to the seaweed
industry.
But important as they were. they lacked detail enough
to estimate the quantity of seaweeds.
These surveys gave a general
report of seaweed species and geographic locations.
productive areas wait to be surveyed in detail.
Now the more
As a result. this
project was undertaken to find an accurate method of determining
.
the quantity of seaweeds in a Chondrus crispus bed.
,
was located between Cape Gage and Horse's Head. a distance of three
miles.
The bed used
-
2
-
APPARATUS AND EQUIPMENT
For this survey two boats were used; one was approximately
45 feet in length and the other was a l2-foot aluminum rowboat.
The large boat was powered by a diesel engine while the smaller
boat had a
3~
h.p. outboard.
Two scuba divers would dive together,
one carrying a sample bag,. the other a metal square yard measure.
The sample bag was the size of an onion bag.
type of bag was quite satisfactory.
fishermen use were set as markers.
and had 3/8" rope for anchor lines.
•
The mesh of this
Buoys of the size that lobster
The buoys were made of plastic
The anchors were made from
concrete poured into one-quart oil cans, and rope hooks were
cemented into the top of each can.
A portable reel with 2000 feet
of light plastic twine was used for measuring.
Measured lengths of
100 feet were marked by colored pieces of cloth.
On the shore triangular wooden markers were used.
They
measured 28"w x l4"h and were set on poles four feet high.
They
were placed one behind the other, from 10 to 30 feet apart.
If
the visibility had been better, diving sleds would have been used .
These are
sid,e.
2~-foot
circular plywood tows with a handle along
From 40 to 60 feet of rope is used fOF
e~c~
10wi~g~
ME'BHOD
All estimation of seaweed quantities from a large stretch of
coast must be based on some sort of sampling which is representative.
•
-
3 -
The technique applied in the Miminegash area was as follows:
the coast was divided into a number of shore transects at a distance of 200 yards.
At each station, two triangular markers,
28"w x 14"h, on poles, were placed one behind the other, one near
"
•
the high tidal mark and the other on the upper part of the sand
dune about 30' behind the first •
Both'were aligned on a course
approximately perpendicular to the shore.
The next step was to
locate the inner and outer boundaries of the Chondrus crispus bed.
This was determined by spot dives at locations in line with the
two markers per station ashore, as judged from the larger boat.
Once the inner boundary was determined (usually . ~ bound~ry consisted
of about 30% Chondrus crispus, estimated by the diver),
marker buoy was placed there.
hand' and collected in a
an orange
A square yard was picked clean by
gatheri~g
bag at this point to give an
accurate % species by weight for that area.
Similarly at the outer
boundary, a marker buoy was released and a sample was taken.
At
the approximate midpoint between these two buoys a third sample
was taken and another buoy released.
It was found that if the divers felt they were near the bound-
•
ary they would then take along a yard square, a collecting bag and
a small marking buoy, in order to save time.
In all cases for
security of the divers in the murky and current ridden waters, a
rope attached the men to each other.
ity at all times.
A compass was also a necess-
This proved to be an important aid where the
- 4 -
visibility on the bottom in turbulent waters often was less than
one foot.
The next stage, once the buoys had been released on line with
the shore markers, was to make an accurate measure of the distances
between the high tidal mark on shore and the first buoy, from the
first to the second buoy and finally from the second to the third
buoy.
This was obtained by running out a line from the high tidal
mark to the first
boat.
buoy~
utilizing a small
3~
o
h.p. outboard motor
Once the shore to first buoy measurement was taken, the
boat would return to the larger survey boat anchored beside the
second or inner buoy.
The procedure would then be to run the line
via the small boat between the first and second buoy, then the
small boat would again take the line, but this time from the second
to the third buoy.
The small boat would then take up all the buoys
at the station'where the last measurements were taken.
In this. way
a number of stations would be speedily measured.
After the square yard measure sample had been picked by hand
off the bottom, it was taken to the lab in a moistureproof container.
Here it was broken down into species and then weighed.
The per•
centage was found for each species out of the total weight.
Table B is a breakdown of the seven (7) stations that were
surveyed.
The last digit in the series, ex. 2001, refers to the
station, in this case station one.
The letters A, B, and C refer
to the position of the bed being surveyed.
Letter A would mark the
inner edge, B the approximate mid point and C t h e outer most edge
•
- 5 -
As shown on the data sheet the depth, percent cover, number
of snails, number of starfish, number of sea urchins and the type
of bottom were recorded.
The following is a legend to explain the terms on the station
sheets.
TABLE A
•
LEGEND OF SEAWEEDS
I. M. = Irish Moss or Chondrus crispus
Cor. = Corallina offi cinalis
M.F. = Monkey Fur or Halopteris scoparia
Phy. = Dead or False ' Moss or Phyllophora membranifolia
Fucus = Rockweed or Fucus
Furc. = Wireweed or Furcellaria
Lam. = Kelp or Laminaria
A few moisture contents were taken but not enough to form any
conclusion, due to the length of time the sample was kept in trans-
•
•
fer from the bottom to the lab .
SAMPLE CALCULATION
Area between Stations 2001 and 2002.
(See chart Page 11)
Average lengths of sides = 358.3 + 318.3
338.3 yds.
2
Perpendicular distance between stations = 194.0 yds.
Therefore, Area between stations
= 194 x 338.3 = 65,600 yd 2
- 6 -
Average density between Stations 2001 and 2002.
(See Table B)
Average density for stations 2001 and 2002
2.42 + 1.77
=
=
2.095 lb/yd 2
2
Weight of moss between stations 2001 and 2002.
65,600 yd 2 x 2.095 lb/yd 2 =
"
68.6 TONS
2000 lb
REMARKS
The following figures will show the area in the bed of
Chondrus crispus where the highest concentration was found.
STAT~ON
2001
2002
2003
2004
2005
2006
2007
INSIDE A
MIDDLE B
OUTSIDE C
69.6%
75.0%
92.0%
64.0%
50.0%
79.0%
64.0%
97.3%
97.0%
96.5%
91. 0%
88.0%
80.5%
42.0%
72.0%
42.3%
89.0%
21. 0%
30.0%
43.0%
00.0%
7(493.6%
70.5%
7(592.3%
84.6%
7(297.3%
42.4%
•
This shows that the middle area has the best growth of
Chondrus crispus and the inner area the second best.
-
7 -
These figures will show how the Phyllophora concentration will
vary within different areas of the bed.
STATION
2001
2002
2003
2004
2005
2006
2007
•
INSIDE A
MIDDLE B
00.0%
00.6%
00.0%
02.0%
09.0%
15.0%
35.5%
00.2%
00.0%
00'.2%
02.0%
07.0%
05.0%
55.0%
7(62.1%
8.8%
7(69.9%
9.9%
OUTSIDE C
25.2%
54.4%
08.7%
72.0%
61. 0%
57.0%
100.0%
7(378.3%
54.04%
The outside of the Chondrus crispus bed was found to be outgrown by Phyllophora.
An increase in % Phyllophora can also be
noticed as the bed widens.
For instance,
at station 2001, where
it is narrowest, there is the smallest concentration of Phyllophora,
·while at station 2007 the highest concentration is recorded.
For
reference see chart on Page 11.
CONCLUSION
•
1.
The preceding results apply only to the 7/l0th of a mile that
was completed in the Cape Gage Area.
It would not be accurate to
say that any other geographic locations would be closely similar
to this area.
2.
The practice of using twine for measurement must be replaced
as it requires too much time.
this job.
A transit is the instrument for
-
3.
8 -
Evaluation of this method should be conducted before a full-
scale survey.
This could be done by determining the quantity of
Irish Moss in a specific area, three successive times.
PROPOSED IMPROVEMENTS IN METHOD
To conduct a survey of this
present.
certain factors must be
The first and most important is good weather, with under-
water visibility.
this.
natur~
The summer months afford the best chance for
Two boats are essential, one a 40- to 50-foot "mother
ship" and the other a small, fast,
shallow-draft runabout.
At
least. two divers are needed and a person to engineer the transit
on shore.
Then there is the skipper of the large boat and a
fifth person to record results.
The operator of the small boat
could be the skipper or the observer.
To speed up the survey, a sea sled should be used for determining the inner and outer edges of the stations.
The diver on
the sled would t .owtwo brightly coloured buoys and release them as
he came to the inside and outside edges of the bed.
This diver
would be given a square yard measure and then he would pick a
~eaweed
sample at this outside edge.
a sample on the inner edge.
The other diver would pick
It would be most convenient and safe
to have the large boat anchored between these two buoys.
The
outside diver would be towed into the middle area for a sample
and then the inside diver would be towed on the sled, and the
- 9 -
next station could have its edges marked by buoys.
Meanwhile the
person with the transit records the angle between each of the two
buoys and the shoreline, and then he can find the distances
required.
It would take roughly 75 minutes of diving to do a station.
A mile could be done in a day of 10 -" 12 hours.
•
Visibility and
underwater motion are factors that could affect the amount of
work done in a day.
RECOMMENDATIONS
1.
This sort of detailed survey should be carried out under
ideal conditions,
therefore the summer would be much better than
the fall.
2.
Use of the underwater sled is dependent on good conditions
such as visibility, but would greatly speed up the survey in time
used, and would also reduce the amount of compressed air used by
the divers •
•
r
3.
The use of a runabout with a powerful motor would shorten the
time and assist greatly in the transportation of the divers from
one area of a station to the next.
Possibly a 22-foot boat with
an inboard-outboard or just an outboard motor.
4.
The use of a transit on shore would greatly increase the de-
gree of accuracy while measuring the distances between buoys.
shortening of time would be reason enough in itself.
The
-
5.
10 -
Aerial photographs of the area surveyed would be of great
value, especially if they were to be scaled down to charts.
For
example, the width of the bed as found by the survey crew and the
width found from the air would be a valuable comparison to the
accuracy made by the survey.
6.
A project should be initiated whereby the growth rate can be
determined.
A quantity survey conducted in June could be compared
with one made in July if the growth rate were known.
7.
Sea animals such as Echinoderma and Mollusca should be counted
from the yard-squ~re sampling areas so that an estimate af their
populations could be made.
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11 -
NORTHUMBERLAND STRAIT
169yd.
169)'d. 15'
l82yd.
194 yd.
166yd.
166yd.
115'
\
\
(
\
It
408.3yd.
318.2yd.
358.3yd.
181
181
181
\
\
\
640yd.
623.3yd.
181
733.3'(d.
691.6yd.
\
\
\
\
*
'* \\\ +
'*
\
181
\
\
158.3 yd.
\
\
\
\
.\
\
266.6 yd.
cr==:.::.15°
.
2001
200y~ ____ .
CAPE GAGE 2002~320
4.
316.6 Yd.
4. . 200 yd.
~320
4.
\\
\
\
\
\
\
291.6 yd.
300yd.
200~
2OO~-270
A
200~.283'3Yd'
200
SCALE
I
•
Y2 in. a
A
100yd.
5 , , ,
5
LEGEND
TRIANGULAR WOODEN MARKER A.
SAMPLE AREA
181
CHONDRUS CRISPUS
PHYLLOPHORA
UNDERWATER LEDGE
,,"~
----3!S°
333.3yd.
A
A
200~ ____ 'lII
~::~./HIGH TIDE
• 20\10
*
+
A
2~A
~#P ~------~~----______-J
GENERAL OUTLINE OF CHONDRUS BED AT CAPE GAGE.
EAST NORTH EAST OF MIMINEGASH. P.E.I., SEPT.,OCT. 1967
- 12 TABLE B
SEA
I.M. LBS/ PERCENTAGE ESTIMATED DEPTH IN I SNAI LS STARFISH
PLANT SPECIES - GRAMS/YD2
STATTON
URCHINS
PER
YD2
PER
YD2
FEET
COVER
MOSS
%
OF
I.
FURC.
FUC.
LAM.
I.M. PHY. ,M.F. COR.
YD2/STA.
NU~IB ER
REMARKS
I
2001 A
B
C
2002 A
B
C
2003 A
a
..-
C
2004 A
B
C
.-
.. 2005
--
I
3
385
220
10
2
20
20
40
480
4
1120
817 1052
150
1
1
2
21
45
513
622
-- 1701
1755
38
2
20
2
20
25
770
1410
1110
A
B
C
2006 A
B
C
2007 A
._-- C
B
I
2.42
7
1. 77
6
2
2.13
9
12
15
40
60
50
75.0%
97.0%
42.3%
35
85
100
7
12
15
-60
60
60
92.0%
96.5%
89.0%
30
45
100
0.47
50.0%
88.0%
30.0%
20
35
75
8
12
20
79.0%
80.5%
43.0%
80
1. 52
8
29
48
0.76
116
339
185
30
28
384
126
10
14
9
4
24
1390
377
303
262
26
403
60
45
67
685
308
381
405
IllT2
5
8
23
64.0%
42.0%
0.73
45
35
---
- - --
1
3
I
I
I
i
I
•
I
5
1 - - - --
4 sm •
60
50
50
65
I
I
Cob. St. on Sf.
rock
"
- _.50
50
50
She1frock
Cobblestone on
Shelfrock
10
------ 1---
7
12
12-25
10
12
15
198
7
6
13
35
90
100
25
55
90
10
9
582
-- -
69.6%
97.3%
72.0%
04.0%
91. 0%
21. 0%
392
464
173
I
I
100
I
-..
3 sm.
"
"
"
Sf. Rk. on Lg. b 1.
Cobblestone, Green
& Red Sponge. Shelf
rock at 12 ' & running to 25 I
•
- 13
TABLE
;TATION I • MOSS AVE
lUMBER
C
AVE. WGT, . IN GMS. WGT. OF I. MOSS AREA IN YD 2
AVERAGE DENSITY IN
YIELD IN TONS
%/YD2/STA. OF SEAWEED/YD2jSTA, IN LBS/YD2/STA. BETWEEN STA. LBS./YD2 BETWEEN STA.
2001
79.60
1362.60
2.42
2002
71. 40
1238.60
1. 77
2003
92.75
1057.30
2.13
2004
58.66
643.00
0.76
2005
56.00
477.40
0.47
2006
67.50
977.66
1. 52
2007
35.30
979.00
0.73
BETWEEN STA.
65,6'00
2.095
68.60
61,300
1. 950
59.95
88,800
1. 445
64.40
115,000
0.615
35.45
112,700
0.995
55.80
118,000
-1. 125
66.00
TOTAL WEIGHT
YIELD/MILE
=
1200 yds.
1760 yds.
=
=
350.20
350.20 TONS
350.20 x 1760 = 512
TONS/MILE
1200
1,024,000 LBS. OF WET MOSS/MILE