post-release survival of blue marlinin marlin using psats graves et al. 2002. fish. bull....
TRANSCRIPT
Post-release Survival of Blue Marlin
Mike Musyl, Chris Moyes, Rich Brill, Andrew West
John Sibert, Anders Nielsen, & Lianne McNaughton
Our goals were:
1. Assess the survival blue marlin released from sports fishing.
2. Develop biochemical predictors of survival.
3. Assess factors affecting post-release survival.
PSATs can be used to determine mortality by examination of vertical data.
PSATs jettison from fish under three circumstances:
1. Reach programmed pop-off date.
2. Exceed depth threshold (1200 – 1500 m).
3. Remain at constant depth for 4 days.
Can differentiate “dead” from “shed”.
Mortality of a Blue Shark (Prionace glauca)
1124m
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12004/11/01 4/12/01 4/12/01 4/14/01 4/14/01 4/14/01 4/16/01
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Depth (m) Temperature (oC)
Fail safe mechanism jettisons PSAT after reaching 1200m
Swivel to reduce torque of tag head in tissue
Speargun barbs added to increase surface area
37 blue marlin (100-500 lbs) tagged in Hawaii
2 striped marlin (120 lb) tagged in Hawaii
1 black marlin (1000 lb) tagged in Australia
fight times: 5 - 60 min
16% on bait, 84% on lures
PSAT
12
64
2140
Total Days at Liberty
1(100%)
1(100%)
28(78%)
No. Reporting(%)
12
64
76(1-245)
Mean(Range)
2*1
Striped Marlin(Tetrapturus audax)
1Black Marlin (Makaira indicus)
37*1
Blue Marlin (Makaira nigricans)
Number Tagged *No. Waiting
Species
Results to date
30 tags reported data (79%)
8 tags failed to report (21%)
4 tags reached pop-off date (13%)
Evidence for delayed mortality in one blue marlin
Blue marlin movement patterns
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150
2007/24/2003
0:007/25/2003
0:007/26/2003
0:007/27/2003
0:007/28/2003
0:007/29/2003
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Hawaii Standard Time
Dept
h(m
)Full MoonFirst Quarter
Hourly Depth Preferences
0102030405060
14:00 17:00 20:00 23:00 2:00 5:00 8:00 11:00Hawaii Standard Time
Avg.
Dep
th(m
)
First Quarter New Moon
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2506/5 6/25 7/15
Dept
h(m)
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Temp
(o C)
Full Moon
Perc
ent o
f Tot
al T
ime
Blue MarlinStriped MarlinBlack Marlin
0102030405060708090
100
0102030405060708090
100
10.5-50 50.5-100 100.5-150 150.5-250 250.5-350
Night
Depth (m)
Day Time at depth summaries
Depth distribution of blue marlin tracked near Hawaii using acoustic telemetry.
Depth distribution of blue marlin tracked near Hawaii using acoustic telemetry.
0102030405060708090
100
0102030405060708090
100
10.5-50 50.5-100 100.5-150 150.5-250 250.5-350
Night
Depth (m)
Day
Day
Night
Blue marlin movement patterns
Evidence for delayed mortality in Blue marlin after 82 days
Deployed
7 June 2003
Pop-off
29 September 2003
Caught on live bait
Approx. 25 minutes of fight time
130 lb monofilament test line
Hooked corner mouth
Moved almost due South 855 nmi (7.6 nmi /day)
0200400600800
10001200
7/7 7/17 7/27 8/6 8/16 8/26 9/5 9/15 9/2505101520253035
Max. Depth (m) SST Min. Temp.
Fail safe mechanism jettisons PSAT after reaching 1200m
Evidence for delayed mortality in Blue marlin after 82 days
SummarySummary
• 29 of the 30 tags reporting data indicate post-release survival (i.e., only one mortality).
• Fail-safe mechanism worked as expected.
• Unlikely that mortality after 82 days was the result of the initial insult.
Previous studies investigating post-release survivability
in marlin using PSATs
Graves et al. 2002. Fish. Bull. 100:134-142.
• 9 blue marlin tagged in Atlantic
• Estimated sizes: 150- 425 lbs.
• Caught marlin on lures and bait
• Pop-off times set at 5 days
• 8 survived
• Fate of one tag unknown
• No evidence of mortality
Kerstetter et al. 2003. Fish. Bull. 101: 939-948
9 blue marlin tagged in Atlantic
Estimated sizes: > 100 lbs.
Caught on longlines
Pop-off times set at 5-30 days
7 survived
Fate of two tags unknown
No evidence of mortality
Gunn et al. 2003. Mar. FW Res. 54: 515-525
• 7 black marlin tagged in Coral Sea• Estimated sizes: 200-600 lbs.• Caught on live and dead bait• Variable pop-off dates (4 days – 5 months)• 5 of 7 survived for 3 – 64 days• Fate of 2 tags was unknown• No evidence of mortality
Domeier et al. 2003. Mar. FW Res. 54: 435-445
• 80 striped marlin tagged near Baja California• Estimated sizes: 90-188 lbs • Caught on live bait using circle & J-hooks
• 45 fish survived • 16 of 61 fish (26%) died within 5 days
• Fate of 19 tags unknown
Blue marlin show a huge increase in blood lactate
Lactate Hsp70 mRNA0
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Blue shark Blue marlin
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Lowest marlin lactate is close to the highest shark lactate level
Survivor Moribund Unknown
Mahalo’s to:
•Jody Bright & Crew of Tropidilla Productions
•Roy Morioka, PORF, HIBT
•Peter Fithian, PORF, HIBT
•John Sibert, PFRP
•Pacific Islands Fisheries Science Center
•Chris Boggs, Mike Laurs, Sam Pooley, NOAA
•CABO Yachts
and the Captains and Crew who Deployed PSATs:
Camelot Foxy Lady
Happy Times Holly Ann
Ho’okele Ihu Nui
Jacque Apito Linda Sue
Maui Jim Pacific Blue
Pamela Start Me Up Again
Top Shape
Blue sharks Four parameters show clear differs between
survivors & moribund
0
0.5
1.0
1.5
2.0
Survivor Moribund Unknown
K+ Mg2+
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Lactate Hsp70 mRNA
K+ shows much greater increases in marlin
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1.0
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K+ Mg2+
Blue sharkMg+ increases ~50%
Blue marlinMg+ increases ~400%
05
10152025303540
Survivor Moribund Unknown
Blue marlin show greater Hsp70 induction
0
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Lactate Hsp70 mRNA
Blue sharkHsp70 increases ~3-fold
Blue marlinHsp70 increases > 5-fold
Black marlin movement pattern