35
Fishermen & scientists collaborate to monitor lobster nurseries in New England & Atlantic Canada Richard A. Wahle University of Maine
Fishermen & scientists collaborate to monitor lobster nurseries in
New England & Atlantic Canada
Richard A. WahleUniversity of Maine
Overview
• The vision• The tool kit• A Case study: the Rhode Island collapse• Implications & Future
The Vision: Linking Life Stages/ Probing
Processes PelagicPre-settlement
Processes
BenthicPost-settlement
Processes
Egg ProductionLarval Settlement
LarvaePostlarvae
Juveniles Adults
NEAq
Inshore
Trawl Surve
ys
Suction Sampli
ngPassive Collect
ors
Suction sampler
Passive Collector
MA
NH
ME
NB
NL
NSSuction samples only
Collectors only
Suction samples & collectorsRI
QC
2008
Wilson/ ME DMRCarloni/ NH F&GGlenn/ MA DMF
Gibson/ RI DEM
Tremblay/ DFOFishermen & Scientists RS
Lawton/ DFO
Rochette/ UNB
Comeau/ DFOPEI Fishermen
Burdett-Coutts/MUNNL Fishermen
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
Suction Samples2008
Collectors 2008
Geographic Patterns 2008
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
Suction samples2007
Collectors2007
YoYOlder
juv
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
Suction Samples2008
Collectors 2008
Geographic Patterns 2008
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
ME
NH
MARI
NB
NS
NLQC
PEI
Gulf of St. Lawrence
Gulf of Maine
Suction samples2007
Collectors2007
YoYOlder
juv
Bay of Fundy
Gulf of
MaineSo. New England
50
05101520
50
05101520
50
05101520
Temperature (°C)
Jan
Feb
Mar Apr
May Jun Jul
Aug
Sep
Oct
Nov
Dec
Dep
th (
m)
100
50
0100
50
0100
50
0 BOF
GOM
SNE
Contrasting thermalregimes
0 1 2 3 4 5
Shallow
Mid
Deep
0 1 2 3 4 5
Shallow
Mid
Deep
0 1 2 3 4 5
Shallow
Mid
Deep
N/m2
20072008
Gulf of Maine
Bay of Fundy
YoY
Southern New
England
Temp (C)
0
20
40
60
80
0 5 10 15 20 25
Dept
h (m
)2007
2008
Temp (C)
0
20
40
60
80
0 5 10 15 20 25
Dept
h (m
)
20072008
Temp (C)
0
20
40
60
80
0 5 10 15 20 25
Dept
h (m
)
2007
2008
Temperature
0
3
6
91. Beaver Hbr W, NB
0
1
22. Jonesport, ME
0
1
23. Mt Desert Is, ME
0
1
24. Outer PenBay, ME
0
1
2
35. Mid-coast, ME
0
1
2
36. Casco Bay, ME
0
1
2
3
7. York, ME
0
1
2
38. Beverly, MA
0
1
29. Cape Cod Bay, MA
0
110. Buzzards Bay, MA
0
1
2
198819901992199419961998200020022004200620082010
11. Rhode Is.
Beaver Hbr, NBJonesport, ME
Mt. Desert, ME
Pen. Bay, ME
Mid-coast, ME
Casco Bay, ME
York, ME
Beverly, MA
Cape Cod Bay, MA
Buzzards Bay, MA
Rhode Island
Suction Sampling Time Series
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0
1
2
Rhode Is.
Settl
emen
t Ind
ex (N
/m2 )
Pre-recruits
0
10
20
30
1979 1984 1989 1994 1999 2004
Catc
h Pe
r Tow
Rhode Island: PredictingPre-recruitsfrom Settlement
Photo ME DMR
Shell Disease
njscuba.com
Alistair Dove
Roxanna Smolowitz
Remaining polysac matrix
Bacteria
Protists
Healthychitin
0
10
20
30
40
0
10
20
1990 1993 1996 1999 2002 2005
Dise
ase
Prev
alen
ce (%
)
Pre-
recr
uits
(lo
bste
rs p
er to
w)
Land
ings
(MT
x 10
0)
Prerecruits
Landings
Disease Prevalance
A.
Landings
Pre-recruits
Disease
Rhode Island’s time line: landings, pre-recruits and shell disease
Rhode Island: Joint effects of settlement & disease on pre-recruits
(Wahle et al. 2009)
0.0000.0300.1000.2000.4000.6000.8001.0001.2001.4001.6001.8002.000
0
2
4
6
8
10
00.2
0.4
0.6
0.81
Settlement
Pre-
recr
uits
Disease
tdIbtt eaSR
3
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 20030.0
2.0
4.0
6.0
8.0
10.0
ObservedModel Predicted
Pre-
recr
uits
00.4
0.8
0
2
4
6
8
10
0.0
0.1
0.40.8
1.21.6
2.0
Disease
Pre-r
ecru
its
Settlement
B.
But what drives variable settlement?
0
1
2
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Settl
emen
t Ind
ex (N
m-2 )
Settlers
0
5
10
15
0
1
2
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Spaw
ners
(N pe
r tow
)
Settl
emen
t Ind
ex (N
m-2)
Observed Settlers
Spawners (RI DFW)
-1.0
-0.5
0.0
0.5
1.0
1.5
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
NAO
Inde
x
NAO Index
Declining NAO Index
2010
-1 0 +10
0.5
1
02
46
810
1214
NAO Index
Settl
emen
t (N/
m2)
Spawners (N per tow)
R=α S e-
βS-γC
Joint effects of Spawners & NAO on Settlement R= recruitment (settlers) S= spawning stockC= auxiliary variable (NAO Index) α= max rate of recruitment β= coeff compensatory mortalityγ= coeff mortality due to auxiliary factor
0
1
2
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Settl
emen
t Ind
ex (N
m-2)
Observed SettlementPredicted Settlement (RIDFW)
-1 0 +10
0.5
1
02
46
810
1214
NAO Index
Settl
emen
t (N/
m2)
Spawners (N per tow)
Recap
• ALSI collaborative widens scale of monitoring
• RI case study – Closing the life cycle • Prior to 1996, settlement predicts pre-recruits. A first for clawed lobster!
• Since 1996, joint effects of settlement + disease model (Wahle et al. 2009). A first for marine invertebrates!
• Spawners + NAO predict settlement (Gibson in prep.). A first for clawed lobster!
Implications• We’re part drivers, part passengers on this train
• Dynamics more local than we thought.
What’s next?• Evaluate predictive power by region• Formalize the ALSI collaborative• Dedicated Web portal: data submission & reporting.
20
Grad students - Charlene, MahimaInterns
Charlene Bergeron(Tech., Grad
student)
Mahima Jaini (Grad student)
Noah Oppenheim (NSF REU)
Katherine Thompson
(Intern)Lee Reeve(Intern)
Rhode Island: Settlement predicts Pre-recruits 3 years later
(Wahle et al. 2009)
1990-1996 cohorts
R = 4.62 S0.4302
r2 = 0.849
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0.0 0.5 1.0 1.5 2.0
Settlers at t (n/m2)
Pre-
recr
uits
t+3
(cat
ch p
er
tow
)
1990-2002 cohorts
R = 2.61 S0.3449
r2 = 0.0913
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.5 1.0 1.5 2.0
Settlers at t (n/m2)
Pre-
recr
uits
t+3
(cat
ch p
er
tow
)
1990 -19961997-2002
Nearshore Trawl Surveys
Photo ME DMRAvg Settlement (00-03) vs Fall Trawl surveys (01-02)
0
100
200
300
400
0 0.5 1 1.5Settlement
Cat
ch p
er 1
5 m
in to
w Without RIy = 162.93x + 111.21
R2 = 0.6292p = 0.0597
Rhode Island
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003-3.5
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
Year class
Rel
ativ
e M
orta
lity
Inde
x
Relative Natural Mortality = -ln(prerecruits/settlers)
Pre-disease
Disease
Is the Gulf of Maine Next?
Fall 1997
1998
1999
Spring
2000
Fall 2000
2002
2003-2010
R. Glenn, MA DMF
Warming Temperatures?
Deviation from the Average Number of Days above 20C
-40
-30
-20
-10
0
10
20
30
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
Year
Dev
iatio
n fro
m A
vera
ge (D
ays)
From Sea Surface Temperatures, Woods Hole, MA 1945-2004(Glenn & Pugh 2006)
Projected Recruitment TrendAssuming 50% recruited at age 6 yr
0.0
0.2
0.4
0.6
0.8
1.0
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Year
Recr
uitm
ent i
ndex
Projected Recruitment TrendAssuming 50% recruited at age 7 yr
0.0
0.2
0.4
0.6
0.8
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Year
Recr
uitm
ent in
dex
Projected Recruitment TrendAssuming 50% recruited at age 8 yr
0.0
0.2
0.4
0.6
0.8
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009Year
Recr
uitm
ent i
ndex
Settlement - Mid-coast, ME
0.0
1.0
2.0
1988 1993 1998 2003
Settl
emen
t (N
/m2 )
Proportion Legal Size at Age
0.0
0.5
1.0
0 2 4 6 8 10 12
Age (Years)
0.0
0.2
0.4
0.6
0.8
1997 1999 2001 2003 2005
Age 6Age 7Age 8
R50Mid-coast Maine Projections
Projecting to the Future
Recap: Emerging Patterns in Post-settlement ProcessesSettlement
& Crowding
Predation Pressure
Disease
NH
ME
NB
NL
RI
QC
Mid-coast 8MA
1992 - 1994
Rhode Is. 6
Beaver Hbr 2
1993 Lawton,
DFO,
The American Lobster Settlement Index:
Fishermen and scientists collaborate to
monitor lobster nurseries in New England & Atlantic Canada
Richard A. Wahle University of Maine
Rhode Island: Following cohorts through time
Settlers
1 yrolds
(from Wahle et al. 2004)
0
10
20
30
40
50
60
70
80
90
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
141516171819202122232425262728
9 10 11 12 13 14 15 16 17 18 19 20
1 Yr
upp
er si
ze lim
it
Rhode IslandYOY to 17 mmY1 to 25 mm
y = 0.2641x + 0.1512R2 = 0.5528
0.00148
y = 0.409x0.5316
R2 = 0.63570.00037
0
1
0 1 2YoY (N/m2)
1 ye
ar o
lds (
N/m
2 )
YoY
1Yr
YoY upper size limit (mm)
A. B.
C. Carapace length (mm)
Freq
uenc
y
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0
1
2
Rhode Is.
Settl
emen
t Ind
ex (N
/m2 )
MA
NH
ME
NB
NL
NS
RI
QC
2009
MA
NH
ME
NB
NL
NSSuction samples only
Collectors only
Suction samples & collectorsRI
QC
2008
NH
ME
NB
NL
RI
QC
MA
1987 - 1991Magdelan Islands
Hudon (1987)
Rhode Island
MidcoastMaine
The American Lobster Settlement Index:
Fishermen & scientists collaborate to monitor lobster nurseries in New England &
Atlantic Canada
Richard A. Wahle, Charlene Bergeron, University of Maine, USAJohn Tremblay, Dept Fisheries & Oceans, Halifax, CanadaCarl Wilson, Maine Dept Marine Resources, USAMichel Comeau, Dept Fisheries & Oceans, Moncton, CanadaRémy Rochette, University of New Brunswick, St. John, Canada Peter Lawton, Dept Fisheries & Oceans, St. Andrews, CanadaVictoria Burdett-Coutts, Memorial University, St. Johns, CanadaRobert Glenn, Massachusetts Div. Marine Fisheries, USAMark Gibson, Rhode Island Dept Fish & Wildlife, USA
Bay of Fundy
Gulf of
MaineSo. New England
