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Biological Results of the Strait of Georgia Spiny
Dogfish (Squalus Acanthias) Longline Survey
October 10-22, 2008
J.R. King and G.A. McFarlane
Fisheries and Oceans Canada
Science Branch, Pacific Region
Pacific Biological Station
Nanaimo, British Columbia
V9T 6N7
2009
Canadian Data Report of
Fisheries and Aquatic Sciences 1220
Canadian Data Report of
Fisheries and Aquatic Sciences
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Canadian Data Report of
Fisheries and Aquatic Sciences 1220
2009
BIOLOGICAL RESULTS OF THE STRAIT OF GEORGIA SPINY DOGFISH (Squalus
Acanthias) LONGLINE SURVEY OCTOBER 10-22, 2008
by
J.R. King and G.A. McFarlane
Fisheries and Oceans Canada
Science Branch, Pacific Region
Pacific Biological Station
Nanaimo, British Columbia
V9T 6N7
ii
©Her Majesty the Queen in Right of Canada, 2009
Cat. No. Fs 97-13/1220E ISSN 0706-6465
Correct citation for this publication:
King, J.R., and McFarlane, G.A. 2009. Biological results of the Strait of Georgia spiny
dogfish (Squalus Acanthias) longline survey October 10-22, 2008. Can. Data Rep.
Fish. Aquat. Sci. 1220: iii + 27 p.
iii
ABSTRACT
King, J.R., and McFarlane, G.A. 2009. Biological results of the Strait of Georgia spiny
dogfish (Squalus Acanthias) longline survey October 10-22, 2008. Can. Data
Rep. Fish. Aquat. Sci. 1220: iii + 27 p.
From October 10 to 22, 2008, a spiny dogfish (Squalus acanthias) longline survey was
conducted in the Strait of Georgia aboard the CCGS Neocaligus. Fishing occurred at ten
sites selected in previous surveys to be representative of commercial fishing areas:
Active Pass, Porlier Pass, Sturgeon Bank, French Creek, Hornby Island, Cape Lazo,
Cape Mudge, Grants Reef, Sinclair Bank and Epson Point. Five depth strata were fished
during this survey: 0 to 55 m, 56 to 110m, 111 to 165m, 166 to 220m and deeper than
220m. All captured spiny dogfish were measured for length and sex. Second dorsal
spines were removed for age estimation from size selected male dogfish and site specific
female dogfish. Maturity condition was collected for all females, for all fish from which
spines were collected and from a random subsample of males. Other encountered species
were enumerated.
RESUMÉ
King, J.R., and McFarlane, G.A.. 2009. Biological results of the Strait of Georgia spiny
dogfish (Squalus Acanthias) longline survey October 10-22, 2008. Can. Data
Rep. Fish. Aquat. Sci. 1220: iii + 27 p.
Nous avons effectué un relevé de l’aiguillat commun (Squalus acanthias) à la palangre
du 10 au 22 octobre 2008 dans le détroit de Georgia à partir du NGCC Neocaligus. La
pêche a été pratiquée à 10 sites choisis lors de relevés précédents comme représentatifs
de zones de pêche commerciale : la passe Active, la passe Porlier, le banc Sturgeon, le
ruisseau French, l’île Hornby, le cap Lazo, le cap Mudge, le récif Grants, le banc Sinclair
et la pointe Epson. Cinq strates de profondeur ont été échantillonnées : 0 à 55 m, 56 à
110 m, 111 à 165 m, 166 à 220 m et les profondeurs de plus de 220 m. Nous avons établi
la longueur et le sexe de tous les aiguillats capturés; prélevé, aux fins d’estimation de
l’âge, la deuxième épine dorsale de mâles choisis selon la taille et de femelles choisies
selon le site, déterminé l’état de maturité de toutes les femelles, de tous les individus
dont des épines ont été prélevées et d’un sous-échantillon aléatoire de mâles a été
déterminé; et dénombré les autres espèces capturées.
iv
INTRODUCTION
Spiny dogfish (Squalus acanthias) were an important component of Canada’s
Pacific fishery from the late 1800s to the mid 1950s (Ketchen 1986). A resurgence in
interest in the fishery led to an increase in catches in the late 1970s, particularly in the
Strait of Georgia. Based on tagging studies (McFarlane and King 2002), the Strait of
Georgia stock is considered to be discreet. The increase in fishing catches in the late
1970s prompted the initiation of an assessment program. As part of this study, longline
surveys were conducted in the Strait of Georgia in 1986 and 1989 (McFarlane et al 2005a)
and 2005 (McFarlane et al. 2006) to provide baseline biological, catch and effort data for
selected sites. A longline calibration survey was conducted in 2004 to account for catch
rate changes that might have occurred in the commercial fishery due to a change from
using J-hooks to using circle hooks (McFarlane et al. 2005b). This report provides catch
and biological summary data for a fourth survey conducted in the Strait of Georgia from
October 10-22, 2008. It is our intention to continue these surveys on a tri-annual basis in
order to monitor the status of spiny dogfish in the Strait of Georgia.
METHODS
From October 10 to 22, 2008 the spiny dogfish longline survey was conducted
onboard the CCGS Neocaligus.
Longline fishing occurred at ten sites throughout the Strait of Georgia (Figure 1)
selected to be representative of commercial fishing areas which were surveyed in previous
surveys. The sites were located near Active Pass, Cape Lazo, Cape Mudge, Epson Point,
French Creek, Grant Reef, Hornby Island, Porlier Pass, Sinclair Bank and Sturgeon Bank
(see Appendix 2 for positional data). At each site, four depth strata were fished in random
order, however the depth strata were selected to correspond to the depth strata fished in the
2005 survey. The depth strata fished were the following:
1. 0 to 55m,
2. 56 to 110m,
3. 111 to 165m and,
4. 166 to 220m.
5. greater than 220 m
Once the vessel arrived at the pre-selected site the appropriate depth range was
located and fishing proceeded along the depth contour.
Each longline set consisted of 2 groundlines (5/16 inch leaded copolym) with an
anchored buoyline (3/8 inch polysteel) hooked on at each end. Model 72 snaps (3 cm in
width; 13 cm in length), made from 3.2 mm stainless steel wire, were snapped onto the
groundline every 2 meters as the gear was set. Attached to the snap, crimped Perlon snap
gangions 30 cm long were fitted with circle hooks. Size #14/0 Mustad circle hooks were
used. Each hook was baited with a third of a 6 inch herring.
2
For each location the groundline was deployed with 300 baited hooks per set. This
number is lower than previous surveys which used 500 baited hooks per set (1986 and
1989) or 400 baited hooks per set (2005). To access differences in catch rates, four extra
sets were conducted at French Creek with 400 baited hooks per set. These sets were fished
four days after (October 22, 2008) the initial four sets were fished (October 18, 2008).
Hook number in this survey was reduced due to high catch rates in the previous surveys
and to reduce the number of hours required for sampling the catch.
The effective fishing time for each set was recorded as the time from when the first
hook was deployed until the main groundline anchor was onboard. In order to minimize
bias in catch rates due to differences in effective fishing time, all longline sets were fished
for approximately 2 hours. Catch per unit effort (CPUE) for a longline set was calculated
as the total number of spiny dogfish caught per thousand hooks.
All fish, other than those lost at the surface, were removed from the hooks,
identified to species and counted. All dogfish lost at surface were noted and included in
the total catch numbers. All spiny dogfish brought on board were retained for sampling;
other species were identified and immediately released.
Length and sex were recorded from all captured spiny dogfish. Length was
measured (mm) as the total length of the fish; from the tip of the snout to the tip of the
upper lobe of the caudal fin when it was directed downward in a straight line with the
body. Sex was determined externally for both male and female dogfish. Maturity was
determined for all female dogfish, for all dogfish for which spines were collected for
ageing and for a random subsample of male dogfish. Maturity was determined internally
for females, externally for males. Maturity stages are described in Appendix 2. Briefly, the
female maturity has two stages, one describing the condition of the ovary and a second
describing the condition of the uteri. Males were grouped into 3 categories; immature,
maturing and mature. Females were grouped into 16 categories with 4 for immature fish, 6
for maturing and 6 for mature fish. When maturity was determined for a female, if uterine
pups were present, the number were recorded.
Second dorsal spines were removed for age determination (Beamish and McFarlane
1985) from a random subsample of fish at each location and stored individually in pre-
numbered envelopes. Spines were frozen onboard, to be later thawed, air dried and stored.
3
RESULTS
From October 10-21, 2008, 12,299 hooks were set over 41 sets at 10 sites; and
1600 additional hooks were set at French Creek on October 22, 2008 for effort comparison
(Table 1). At each site, 4 depth strata were fished except for Cape Lazo were all 5 depth
strata were fished (Appendix 2). The end time of hook retrieval was not recorded for the
first 21 sets, so effective fishing time could not be calculated (Appendix 2). However, the
start time of hook retrieval was recorded, and was typically 2 hours after the end time of
hook deployment for all sets (Appendix 2). Generally, the time required to retrieve all
hooks was about 35 minutes (Appendix 2); so the effective fishing time for these first 21
sets should be comparable to the remaining sets. The mean effective time for the
remaining sets was 171 minutes (Table 1). A total of 6,366 spiny dogfish were captured
(Table 2). Longnose skate (Raja rhina), Ratfish (Hydrolagus colliei), Quillback rockfish
(Sebastes maliger), Yelloweye rockfish (S. ruberrimus) and were the most frequent
bycatch encountered (Table 2). Biological data were recorded for spiny dogfish captured
during the effort comparison at French Creek (Effort 2), however those results are not
reported in the summaries below.
CATCH PER UNIT EFFORT
For the three depth strata common to all locations (2, 3 and 4) the mean CPUE for all
spiny dogfish was 447 fish/1000 hooks (Table 1). CPUE by site ranged from 354 (Hornby
Island) to 554 (Cape Lazo) fish/1000 hooks. The CPUE for male spiny dogfish was typically
higher than for female spiny dogfish (Table 1). Sites with the highest dogfish CPUE were
Cape Lazo, Sturgeon Bank and Grant Reef. Hornby Island, Epson Point and French Creek
had the lowest CPUE. The CPUE for French Creek Effort 1 (300 hooks per set) was higher
than for Effort 2 (400 hooks per set) (Table 1). CPUE varied by depth with increasing CPUE
by depth (Table 3).
LENGTH FREQUENCY
Length and sex was recorded for 5,728 dogfish (93 fish were lost at surface; 5 fish
were missed for length measurements). Detailed spiny dogfish length frequency catch data
for sex by fishing site and sex by depth strata is presented in Tables 4 and 5 and Figures 2
and 3.
A total of 1969 females and 3759 males were measured (Table 4). Male spiny
dogfish ranged in size from 487-946 mm with a mean length of 767 cm (Table 5). Female
spiny dogfish ranged in size from 450-1120 mm with a mean length of 815 mm (Table 5).
Mean female and male dogfish size decreased with increasing depth. The mean total
length for females was greater than males in all depth stratum, except the deepest (Table
5). The smallest spiny dogfish was a female (450 mm) caught in depth stratum 4; the
largest was also a female (1120 mm) caught in depth stratum 2 (Table 5).
By depth and area, the size distribution for female spiny dogfish was more uniform
across the size range than that of male spiny dogfish, which often had a definitive mode
(Figures 2 and 3).
4
SEX DISTRIBUTION BY DEPTH STRATA AND SITE
Depth strata
For all sites combined in the Strait of Georgia, there was a larger proportion of
male spiny dogfish caught in each depth strata (Figure 4). Female dogfish were present in
increasing proportion by depth (Figure 4).
Site Seven of the ten sites had a larger proportion of male spiny dogfish ranging from
30% to 95% of the catch. At the remaining three sites, Epson Point, French Creek and
Sinclair Bank, female spiny dogfish proportion ranged from 52% to 70% of the catch
(Figure 5).
MATURITY
Maturity condition was assessed for selected male and for female spiny dogfish (full
description of maturity condition in Appendix 1).
Male spiny dogfish maturity
Of all male spiny dogfish sampled, 79.9% were mature; 6.22% maturing; and
13.88% immature (Table 6). In all depth strata mature male dogfish were the most
abundant. Varying by depth mature male spiny dogfish ranged from 66.67-92.45% of
male dogfish catch, maturing male dogfish ranged from0-25.49 % and immature male
dogfish ranged from 0-7.84% of sampled male catch (Table 7).
Female spiny dogfish maturity
Of the female dogfish sampled, 72% were immature; 7.23 % were maturing; and 20.69
% were mature (Table 6). Immature female dogfish were the most abundant in depth strata 3-
5 (Table 7). Depth strata 1 and 2 were dominated by mature female dogfish, although only 4
females were captured in depth stratum 1 (Table 7). Varying by depth, immature female spiny
dogfish ranged from 0-91.17% of female dogfish sampled, maturing female dogfish ranged
from 0-12.63% and mature female dogfish ranged from 4.19-100% of sampled female catch
(Table 7).
Uterine pups
A total of 363 female dogfish (17% of all females examined; 89% of mature
females) had uterine pups (Table 8). The largest number of fish with uterine pups was
observed at French Creek (n=159 fish), followed by Epson Point (n=87 fish) and Porlier
Pass (n=68 fish; Table 8). Approximately 58% of the female dogfish with uterine pups
had litter sizes between 4 and 6 (Table 9). Generally, litter size increased with length
(Table 9).
5
DISCUSSION
This is the fourth longline survey conducted in the Strait of Georgia designed to
monitor the status, and collect biological samples of spiny dogfish. The information from
these surveys will provide the basis for examining current and future spiny dogfish
dynamics and abundance trends in the Strait of Georgia.
ACKNOWLEDGMENTS
The survey was conducted by V. Hodes, M. Surry and B. White.
6
REFERENCES
Beamish, R.J., and McFarlane, G.A. 1985. Annulus development on the second dorsal spine
of the spiny dogfish (Squalus acanthias) and its validity for age determinations. Can.
J. Fish. Aquat.Sci. 42: 1799-1805.
Ketchen, K. S. 1986. The spiny dogfish (Squalus acanthias) in the Northeast Pacific and
a history of its utilization. Can. Spec. Publ. Fish. Aquat. Sci. 88: 78 p.
McFarlane G.A and King, J.R. 2002. Migration patterns of spiny dogfish (Squalus
acanthias) in the Northern Pacific Ocean. Fish.Bull. 101: 358-367
McFarlane, G.A., King, J.R, Hodes, V.R., and Andrews, W.T. 2005a. Biological results of
the Strait of Georgia spiny dogfish (Squalus Acanthias) longline surveys conducted
in October 1986 and 1989. Can. Manuscr. Rep. Fish. Aquat. Sci. 2736: iii + 42 p.
McFarlane, G.A., King, J.R., Hodes, V.R., and Andrews, W.T.. 2005b. Strait of Georgia
Spiny Dogfish (Squalus acanthias) Longline Survey: Hook Comparison Study,
November 12-25, 2004. Can. Manuscr. Rep. Fish. Aquat. Sci. 2721: iv + 19 p.
McFarlane, G.A., King, J. R, and Hodes, V.R.. 2006. Biological results of the Strait of
Georgia Spiny Dogfish (Squalus Acanthias) Longline Survey October 18-31,2005.
Can. Data Rep. Fish. Aquat. Sci. 1182: iii + 24 p.
7
Table 1. Summary by fishing area of number of sets, mean effective fishing time, number of hooks deployed, number of measured
spiny dogfish, catch per unit effort (fish per 1000 hooks; CPUE) for all depth strata fished at a location and for three core depth strata
that were fished at every location (56-110 m; 111-165 m; 166-220 m) from the October 10 to 22, 2008 Strait of Georgia spiny dogfish
longline survey. French Creek was fished twice: 1-October 18, 2008 with 300 baited hooks per set (Effort 1); 2-October 22, 2008
with 400 baited hooks per set (Effort 2).
CPUE
All depth strata Three depth strata
Location Number
of sets
Mean
effective
fishing
time Number
of hooks
Number
of spiny
dogfish Male Female Total Male Female Total
Active Pass 4 162 1200 599 326 163 499 311 124 450
Cape Lazo 5 -- 1500 740 407 80 793 470 78 554
Cape Mudge 4 -- 1199 591 363 120 493 362 91 464
Epson Point 4 172 1200 542 153 293 452 134 220 360
French Creek (Effort 1) 4 176 1200 554 215 237 462 130 258 397
Grant Reef 4 -- 1200 598 279 209 498 277 194 479
Hornby Island 4 -- 1200 330 245 24 275 317 30 354
Porlier Pass 4 171 1200 552 351 103 460 292 107 404
Sinclair Bank 4 -- 1200 643 161 370 536 144 323 473
Sturgeon Bank 4 169 1200 677 531 27 564 506 19 530
Total 12299 5826 Overall 474 Overall 447
French Creek (Effort 2) 4 174 1600 540 222 183 415 94 114 215
8
Table 2. Number of fish caught by species during the October 2008 spiny dogfish longline survey. Recorded species include: Spiny dogfish (Squalus acanthias), Sixgill
shark (Hexanchus griseus), Brown cat shark (Apristurus brunneus), Big skate (Raja. binoculata), Longnose skate (R. rhina), Ratfish (Hydrolagus colliei), Pacific cod
(Gadus macrocephelus), Pacific tomcod (Microgadus proximus), Copper rockfish (Sebastes caurinus), Quillback rockfish (S. maliger), Greenstripe rockfish (S.
elongates), Yelloweye rockfish (S. ruberrimus), Sablefish (Anoplopoma fimbria), Lingcod (Ophiodon elongates), Red Irish lord (Hemilepidotus hemilepidotus),
Flathead sole (Hippoglossoides elassodon), and Pacific halibut (Hippoglossus stenolepis). A total of 6,366 spiny dogfish were hooked; 106 were lost at surface; 6,259
were sampled.
Set
Spiny
dogfis
h Sixgill
shark
Brown
cat
shark Big
skate Longnose
skate Ratfish
Pacific
cod Pacific
tomcod Copper
rockfish Greenstripe
rockfish Quillback
rockfish Yelloweye
rockfish Sablefish Lingcod
Red
Irish
lord Flathead
sole Pacific
Halibut
1 116 -- -- -- 8 -- -- -- -- -- -- -- -- -- -- -- --
2 172 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
3 31 -- -- -- -- -- -- -- -- -- -- 2 -- -- -- -- --
4 11 -- -- -- 2 -- -- -- 1 -- -- -- -- 1 -- -- --
5 217 -- -- -- -- -- -- -- -- -- 5 -- -- -- -- -- --
6 184 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
7 24 -- -- 1 1 2 -- -- -- -- -- -- -- -- -- -- 1
8 109 -- -- -- -- 2 -- -- 1 -- -- 1 1 -- -- -- --
9 206 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
10 55 -- -- -- 1 3 -- -- 1 -- 2 -- -- -- 1 2 --
11 185 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
12 178 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
13 173 -- -- -- 1 -- -- -- -- -- -- -- -- -- -- -- --
14 86 -- -- -- -- -- -- -- -- -- 2 5 -- -- -- -- --
15 173 -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- --
16 167 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
17 172 -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- --
18 176 -- -- -- 1 -- -- -- -- -- 4 -- -- -- -- -- --
19 220 -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- --
20 217 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
21 30 -- -- -- -- -- -- -- -- -- 1 5 -- -- -- -- --
22 218 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
23 228 -- -- -- 1 -- -- 1 -- -- -- -- -- -- -- -- --
24 2 -- -- -- -- -- -- -- 1 1 5 -- -- -- -- -- --
9
Table 2 continued. Number of fish caught by species during the October 2008 spiny dogfish longline survey. Recorded species include: Spiny dogfish (Squalus
acanthias), Sixgill shark (Hexanchus griseus), Brown cat shark (Apristurus brunneus), Big skate (Raja. binoculata), Longnose skate (R. rhina), Ratfish (Hydrolagus
colliei), Pacific cod (Gadus macrocephelus), Pacific tomcod (Microgadus proximus), Copper rockfish (Sebastes caurinus), Quillback rockfish (S. maliger), Greenstripe
rockfish (S. elongates), Yelloweye rockfish (S. ruberrimus), Sablefish (Anoplopoma fimbria), Lingcod (Ophiodon elongates), Red Irish lord (Hemilepidotus
hemilepidotus), Flathead sole (Hippoglossoides elassodon), and Pacific halibut (Hippoglossus stenolepis). A total of 6,366 spiny dogfish were hooked; 106 were lost at
surface; 6,259 were sampled.
Set
Spiny
dogfis
h Sixgill
shark
Brown
cat
shark Big
skate Longnose
skate Ratfish
Pacific
cod Pacific
tomcod Copper
rockfish Greenstripe
rockfish Quillback
rockfish Yelloweye
rockfish Sablefish Lingcod
Red
Irish
lord Flathead
sole Pacific
Halibut
25 94 -- -- -- -- 1 1 -- -- -- -- 2 -- -- -- -- --
26 144 -- -- -- -- -- -- -- -- -- -- -- -- 1 -- -- --
27 197 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
28 174 -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- --
29 39 -- -- -- 1 -- -- -- -- -- 2 5 -- -- -- -- --
30 194 1 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
31 53 -- -- -- -- -- -- -- -- 1 1 -- -- 1 -- -- 1
32 117 -- -- -- -- -- -- -- -- 1 1 1 -- 1 -- -- --
33 188 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
34 188 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
35 210 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
36 7 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
37 194 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
38 200 1 1 -- -- -- -- -- -- -- -- -- -- -- -- -- --
39 201 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40 192 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
41 84 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
42 74 -- -- -- -- -- -- -- -- -- 2 -- -- -- -- -- --
43 282 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
44 143 -- -- -- 1 3 1 -- -- -- -- -- -- -- -- -- --
45 41 -- -- -- 1 -- -- -- -- -- -- 7 -- -- -- -- --
Total 6366 2 1 1 18 11 2 1 4 3 25 32 1 4 1 2 2
10
Table 3. Summary of CPUE (fish per 1000 hooks), mean effective fishing time (minutes) and number of spiny dogfish captured by depth
stratum. Data do not include depth strata repeated at French Creek (October 22, 2008) conducted for effort comparison.
Number of spiny dogfish CPUE
Depth
stratum Depth
range Number
of sets
Mean
effective
fishing
time Number
of hooks Males Females Lost Total Males Females Total
1 0-55 2 120 600 31 4 0 35 52 7 58
2 56-110 10 119 3000 193 395 13 601 64 132 200
3 111-165 10 121 3000 1049 412 27 1488 350 137 496
4 166-220 10 121 3000 1205 695 31 1931 402 232 644
5 >221 9 122 2700 1079 670 22 1771 400 248 656
11
Table 4. Spiny dogfish total length frequency data by 50 mm length intervals sex. Data do not include depth strata repeated at French
Creek (October 22, 2008) conducted for effort comparison.
Length
interval Number
of males Number
of females
450-499 2 1
500-549 20 24
550-599 121 146
600-649 226 278
650-699 477 326
700-749 917 286
750-799 1235 221
800-849 568 187
850-899 159 202
900-949 34 169
950-999 0 77
1000-1049 0 36
1050-1099 0 15
1100-1149 0 1
Total 3759 1969
12
Table 5. Summary (minimum, maximum and mean) of total length (mm) data for spiny dogfish captured by depth stratum. Data do not
include depth strata repeated at French Creek (October 22, 2008) conducted for effort comparison.
Male spiny dogfish Female spiny dogfish All spiny dogfish
Depth
stratum Minimum Maximum Mean Minimum Maximum Mean Minimum Maximum Mean
1 717 946 829 904 982 946 717 982 842
2 597 940 780 571 1120 895 571 1120 818
3 530 922 758 518 1069 783 518 1069 765
4 487 945 742 450 1082 743 450 1082 743
5 520 932 726 512 1044 710 512 1044 720
13
Table 6. Number of male and female spiny dogfish observed for each maturity stage. Proportions
are percentages of totals by sex. Data do not include depth strata repeated at French Creek (October
22, 2008) conducted for effort comparison. Detailed description of maturity codes are in Appendix
1.
Sex Maturity
state Maturity
code Number
of fish Proportion
of sex total
Female Immature 10 1184 60.29
50 67 3.41
51 141 7.18
53 22 1.12
Total immature 1414 72
Maturing 55 4 0.2
56 72 3.67
70 8 0.41
71 25 1.27
73 21 1.07
75 12 0.61
Total maturing 142 7.23
Mature 77 250 12.74
78 2 0.1
79 12 0.61
95 6 0.31
97 11 0.56
98 104 5.3
99 21 1.07
Total mature 406 20.69
Male Immature 10 29 13.88
Maturing 30 13 6.22
Mature 90 167 79.9
14
Table 7. Number and proportion (percentage of depth stratum total) of female and male spiny
dogfish by maturity stage in each depth stratum. Data do not include depth strata repeated at French
Creek (October 22, 2008) conducted for effort comparison.
Immature Maturing Mature
Sex Depth
stratum Number Proportion Number Proportion Number Proportion
Males
1 0 0 0 0 0 0
2 2 3.77 2 3.77 49 92.45
3 2 3.85 3 5.77 47 90.38
4 13 25.49 4 7.84 34 66.67
5 12 22.64 4 7.55 37 69.81
Females
1 0 0 0 0 4 100
2 20 10.53 24 12.63 146 76.84
3 266 65.2 23 5.64 119 29.17
4 519 75 64 9.25 109 15.75
5 609 91.17 31 4.64 28 4.19
15
Table 8: The number of female spiny dogfish observed with pups by location. Data do not
include depth strata repeated at French Creek (October 22, 2008) conducted for effort
comparison.
Location Number
of fish
Active Pass 13
Cape Lazo 2
Cape Mudge 0
Epson Point 87
French Creek 159
Grant Reef 10
Hornby Island 3
Porlier Pass 68
Sinclair Bank 13
Sturgeon Bank 8
Table 9. Number, proportion (percentage of total females with pups) and total length (mm) data
of female spiny dogfish sampled with uterine pups by litter size. Data do not include depth strata
repeated at French Creek (October 22, 2008) conducted for effort comparison.
Litte
r size Number
of fish Proportion Minimum Maximum Mean
1 8 2.2 834 907 871
2 17 4.68 762 940 875
3 38 10.47 800 1022 888
4 64 17.63 760 992 902
5 82 22.59 809 1063 916
6 66 18.18 816 1007 931
7 32 8.82 892 1010 954
8 23 6.34 891 1071 991
9 13 3.58 928 1034 983
10 11 3.03 987 1080 1045
11 7 1.93 927 1082 1036
12 1 0.28 -- -- 1079
13 0 0 -- -- --
14 0 0 -- -- --
15 1 0.28 -- -- 1120
16
Figure 1. Set locations from the Strait of Georgia spiny dogfish longline survey conducted
October 10-22, 2008. For detailed positional information see Appendix 2.
17
Stratum 1 Females; n=4
0
5
10
15
20
25
30
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total leng th (cm)
Frequency (%)
Stratum 2 Females; n=193
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 3 Fe males; n=412
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 1 Males; n=31
0
2
4
6
8
10
12
14
16
18
20
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 2 Males; n=395
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 3 Males; n=1049
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 2. Spiny dogfish length frequency by depth stratum (2: 56 to 110m, 3: 111 to 165m, 4:
166 to 220m and 5: deeper than 220m). Data do not include depth strata repeated at French
Creek (October 22, 2008) conducted for effort comparison.
18
Stratum 4 Females; n=690
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 5 Females; n=670
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Stratum 4 Males; n=1205
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total leng th (cm)
Frequency (%)
Stratum 5 Males; n=1079
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 2 continued. Spiny dogfish length frequency by depth stratum (2: 56 to 110m, 3: 111 to
165m, 4: 166 to 220m and 5: deeper than 220m). Data do not include depth strata repeated at
French Creek (October 22, 2008) conducted for effort comparison.
19
Active Pass Females; n=195
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Cape Lazo Females; n=119
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Cape Mudge Females; n=143
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Active Pass Males; n=391
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Cape Lazo Males; n=691
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Cape Mudge Males; n=435
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 3. Spiny dogfish length frequency by location. Data do not include depth strata repeated
at French Creek (October 22, 2008) conducted for effort comparison.
20
Epson Point Females; n=351
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
French Creek (Effort 1) Females; n=284
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Grant Reef Females; n=250
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Epson Point Males; n=184
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
French Creek (Effort 1) Males; n=258
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Grant Reef Males; n=335
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 3 continued. Spiny dogfish length frequency by location. Data do not include depth
strata repeated at French Creek (October 22, 2008) conducted for effort comparison.
21
Hornby Island Fe males; n=29
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (c m)
Frequency (%)
Porlier P ass Females; n=123
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total le ngth (cm)
Frequency (%)
Si nclair Bank F emales ; n=443
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Hornby Island Males; n=294
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (c m)
Frequency (%)
Porlier P ass Males; n=421
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total le ngth (cm)
Frequency (%)
Si nclai r Bank Ma les; n=193
0
1
2
3
4
5
6
7
8
9
10
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 3 continued. Spiny dogfish length frequency by location. Data do not include depth
strata repeated at French Creek (October 22, 2008) conducted for effort comparison.
22
Sturgeon Bank Females; n=32
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Sturgeon Bank Males; n=637
0
2
4
6
8
10
12
14
45 50 55 60 65 70 75 80 85 90 95 100 105 110
Total length (cm)
Frequency (%)
Figure 3 continued. Spiny dogfish length frequency by location. Data do not include depth
strata repeated at French Creek (October 22, 2008) conducted for effort comparison.
23
0
10
20
30
40
50
60
70
80
90
100
12345
Depth stratum
Percentage
Figure 4. Spiny dogfish sex ratio by depth stratum (1: 0 to 55m, 2: 56 to 110m, 3: 111 to 165m,
4: 166 to 220m and 5: deeper than 220m). Black bars are males; white bars are females. Data
do not include depth strata repeated at French Creek (October 22, 2008) conducted for effort
comparison.
24
0
10
20
30
40
50
60
70
80
90
100
Active Pass
Cape Lazo
Cape Mudge
Epson Point
French Creek
Grant Reef
Hornby Island
Porlier Pass
Sinclair Bank
Sturgeon Bank
Location
Percentage
Males
Females
Figure 5. Spiny dogfish sex ratio by location. Data do not include depth strata repeated at
French Creek (October 22, 2008) conducted for effort comparison.
25
Appendix 1. Description of maturity codes used for spiny dogfish.
Maturity Maturity
Code Stage
10 Immature
30 Maturing
90 Mature
Maturity Maturity
Code Stage
10
Ova small, 0-5 mm diameter
white firm ovary<1/4 length of
body cavity.
Thin no thickening
Immature
50
Ova 5-10mm, white firm,
ovary flaccid, flocculent
external surface.
Thin no thickening
Immature
51 Ova 5-10mm, white firm,
ovary flaccid, flocculent
external surface.
Thin, <5mm thickened section,
<1/4 length of body cavity Immature
53
Ova 5-10mm, white firm,
ovary flaccid, flocculent
external surface.
About 5mm thickened section
< 1/4 length of body cavity Immature
55 Ova 5-10mm, white firm,
ovary flaccid, flocculent
external surface.
Thickened section at least
10mm or wider, flaccid; >1/3
length of body cavity Maturing
56 Ova 5-10mm, white firm,
ovary flaccid, flocculent
external surface.
Encapsulated uterine eggs
(candles) Maturing
70 Ova yellow firm <30mm Thin no thickening diameter Maturing
71 Ova yellow firm <30mm Thin, <5mm thickened section,
<1/4 length of body cavity Maturing
73 Ova yellow firm <30mm About 5mm thickened section
< 1/4 length of body cavity Maturing
75
Ova yellow firm <30mm Thickened section at least
10mm or wider, flaccid 1/3
length of body cavity Maturing
77 Ova yellow firm <30mm Yolk sac pups Mature
78 Ova yellow firm <30mm Term pups (no yolk sac) Mature
79 Ova yellow firm <30mm Flaccid Mature
95
Ova white firm <10mm in
diameter and yellow firm >
30mmin diameter; ovary flacid
1/3 length of body cavity
Thickened section at least
10mm or wider, flaccid; >1/3
length of body cavity Mature
97
Ova white firm <10mm in
diameter and yellow firm >
30mmin diameter; ovary flacid
1/3 length of body cavity
Yolk sac pups
Mature
99
Ova white firm <10mm in
diameter and yellow firm >
30mmin diameter; ovary flacid
1/3 length of body cavity
Flaccid and empty
Mature
Male
Description
Claspers do not extend past tips of anal fins; testes flat creamy.
Female
Ovaries Uterii
Claspers extend past tips of anal fins; not stiff; testes, even
creamy coulour, not brown
Claspers extend past tips of anal fins; stiff; testes, cramy-brown,
bloodshot, very firm
26
Appendix 2. Bridge log from the October 10-22, 2008 spiny dogfish longline survey aboard the CCGS Neocaligus. Effective fishing
time in minutes; all depths in meters; latitude and longitude in decimal degrees; distance in nautical miles; vessel speed in knots; direction
in degrees true.
Date Location
Set
number Depth
stratum Number
of hooks Start
latitude Start
longitude End
latitude End
longitude Start
time End
time
Effective
fishing
time Direction
Distance
traveled Vessel
speed Start
depth End
depth
10-Oct-08 Hornby Island 1 3 300 49.5439 124.6069 49.5352 124.5818 8:18 -- -- 123 1.1 3.5 126 153
10-Oct-08 Hornby Island 2 4 300 49.5578 124.5847 49.5657 124.5957 9:21 -- -- 311 0.6 2.5 177 --
10-Oct-08 Hornby Island 3 2 300 49.541 124.6193 49.5464 124.6306 13:30 -- -- 311 0.55 2.5 77 97
10-Oct-08 Hornby Island 4 1 300 49.5413 124.6233 49.5447 124.6366 14:30 -- -- 293 -- 2.7 50 45
10-Nov-08 Cape Lazo 5 5 300 49.7908 124.845 49.7818 124.2515 8:39 -- -- 144 -- 3 240 235
10-Nov-08 Cape Lazo 6 4 300 49.7882 124.8556 49.7948 124.8659 9:38 -- -- 318 -- 3 181 181
10-Nov-08 Cape Lazo 7 1 300 49.75 124.9252 49.76 124.9259 13:30 -- -- -- 0.63 2.7 30 47
10-Nov-08 Cape Lazo 8 2 300 49.7766 124.9132 49.7738 124.899 8:40 -- -- 110 0.6 2.7 68 70
12-Oct-08 Cape Lazo 9 3 300 49.7905 124.8739 49.7822 124.8654 9:32 -- -- 147 -- 2.7 157 156
12-Oct-08 Cape Mudge 10 2 300 49.9763 125.1157 49.9767 125.1195 13:55 -- -- 275 0.7 2.7 88 66
13-Oct-08 Cape Mudge 11 4 300 49.9885 125.0965 49.9789 125.092 8:45 -- -- 160 0.6 3 183 207
13-Oct-08 Cape Mudge 12 3 300 49.9956 125.1092 49.9886 125.103 9:46 -- -- 131 0.5 2.8 157 141
13-Oct-08 Cape Mudge 13 5 299 49.9943 125.0911 50 125.2624 13:07 -- -- 245 0.46 3 258 267
14-Oct-08 Grant Reef 14 2 300 49.8621 124.7737 49.8585 124.9105 8:21 -- -- 125 0.56 2.7 80 98
14-Oct-08 Grant Reef 15 3 300 49.8404 124.7378 49.8317 124.7315 9:08 -- -- 160 -- 2.7 161 161
14-Oct-08 Grant Reef 16 5 300 49.8162 124.7667 49.8077 124.7564 12:54 -- -- 140 0.65 2.7 222 229
14-Oct-08 Grant Reef 17 4 300 49.8238 124.742 49.814 124.7488 13:48 -- -- 205 0.64 2.7 183 217
15-Oct-08 Sinclair Bank 18 3 300 49.7106 124.2918 49.7208 124.2987 7:17 -- -- 333 -- 2.7 119 141
15-Oct-08 Sinclair Bank 19 4 300 49.7126 124.3048 49.7223 124.3103 8:05 -- -- 340 -- -- 190 188
15-Oct-08 Sinclair Bank 20 5 300 49.7192 124.3115 49.7078 124.3079 11:14 -- -- -- 0.7 2.7 238 235
15-Oct-08 Sinclair Bank 21 2 300 49.6934 124.2789 49.7027 124.2827 12:08 -- -- 349 0.6 2.7 80 78
17-Oct-08 Epsom Point 22 5 300 49.475 124.0518 49.4681 124.042 8:58 11:00 184 130 -- 2.7 247 255
17-Oct-08 Epsom Point 23 4 300 49.4735 124.0419 49.4671 124.0294 10:08 12:15 184 124 -- 2 182 186
17-Oct-08 Epsom Point 24 2 300 49.4928 124.042 49.5064 124.0525 14:14 16:12 156 156 -- 2.9 88 87
17-Oct-08 Epsom Point 25 3 300 49.4944 124.0558 49.5073 124.064 15:03 17:02 165 345 -- -- 154 153
18-Oct-08 French Creek 26 2 300 49.3569 124.3283 49.3506 124.3121 7:56 9:57 172 -- -- -- 68 75
18-Oct-08 French Creek 27 5 300 49.3901 124.3506 49.3841 124.3361 8:50 11:01 179 -- -- -- 250 231
18-Oct-08 French Creek 28 4 300 49.3759 124.3317 49.3689 124.3158 12:52 14:53 173 120 -- 2.8 184 175
18-Oct-08 French Creek 29 3 300 49.3743 124.34 49.3677 124.3268 13:57 15:55 178 120 -- 2.8 135 133
27
Appendix 2 continued. Bridge log from the October 10-22, 2008 spiny dogfish longline survey aboard the CCGS Neocaligus. Effective
fishing time in minutes; all depths in meters; latitude and longitude in decimal degrees; distance in nautical miles; vessel speed in knots;
direction in degrees true.
Date Location
Set
number Depth
stratum Number
of hooks Start
latitude Start
longitude End
latitude End
longitude Start
time End
time
Effective
fishing
time Direction
Distance
traveled Vessel
speed Start
depth End
depth
19-Oct-08 Porlier Pass 30 4 300 49.0218 123.5308 49.0146 123.5202 8:36 10:35 171 132 -- 2.1 188 190
19-Oct-08 Porlier Pass 31 2 300 48.9888 123.5276 48.9973 123.5387 9:40 11:37 160 315 -- 2.4 90 56
19-Oct-08 Porlier Pass 32 3 300 49.0929 123.6216 49.0844 123.6185 13:17 15:20 175 161 -- 2.6 144 122
19-Oct-08 Porlier Pass 33 5 300 49.081 123.5787 49.0758 123.5682 14:20 16:24 179 128 -- 2.5 227 256
20-Oct-08 Active Pass 34 3 300 48.9293 123.3879 48.9356 123.401 8:05 10:03 165 308 -- 2.5 162 137
20-Oct-08 Active Pass 35 4 300 48.9212 123.3286 48.9287 123.3365 9:29 11:26 163 -- -- -- 190 191
20-Oct-08 Active Pass 36 2 300 48.9313 123.4048 48.9359 123.4118 13:00 14:57 156 308 -- 2.3 87 95
20-Oct-08 Active Pass 37 5 300 48.9885 123.4081 48.9851 123.3977 14:02 16:00 162 119 -- 2.2 275 268
21-Oct-08 Sturgeon Bank 38 5 300 49.1827 123.3821 49.1911 123.3807 8:40 10:39 171 10 -- 2 247 251
21-Oct-08 Sturgeon Bank 39 3 300 49.1765 123.329 49.1843 123.3274 9:37 11:47 180 10 -- 2.2 154 154
21-Oct-08 Sturgeon Bank 40 4 300 49.1882 123.3447 49.1946 123.3417 13:19 15:18 156 10 -- 2.2 188 187
21-Oct-08 Sturgeon Bank 41 2 300 49.1898 123.3047 49.1822 123.3039 14:11 16:10 170 180 -- 2.3 97 89
22-Oct-08 French Creek 42 2 400 49.35 124.311 49.3554 124.3242 8:11 10:09 160 305 -- 1.8 72 68
22-Oct-08 French Creek 43 5 400 49.3851 124.3384 49.3911 124.3526 9:23 11:20 183 305 -- 2.1 233 251
22-Oct-08 French Creek 44 4 400 49.3693 124.316 49.3761 124.333 13:11 15:09 180 -- -- -- 183 177
22-Oct-08 French Creek 45 3 400 49.369 124.3266 49.3747 124.3432 14:21 16:12 173 -- -- 2.5 139 124
