Regime Shifts in the Ocean: from Detection to Prediction

Document technical information

Format ppt
Size 9.9 MB
First found May 22, 2018

Document content analysis

Category Also themed
Language
Type
not defined
Concepts
no text concepts found

Persons

Organizations

Places

Transcript

Ecosystem
state
Regime Shifts in the Ocean: From Detection to Prediction?
Brad deYoung
DEFINITION OF THE REGIME SHIFT
Working definition : a regime shift is a relatively abrupt
change between contrasting persistent states in an ecosystem
Environmental state
Erosion of resilience
Erosion of resilience
Environmental driver
Review of a few examples
• Scotian Shelf – driven primarily by fishing, cascading
trophic impacts
• North Sea – combined drivers: natural=biogeographic
shift and human=fishing
• North Pacific – complex natural state change(s)
• Coral reef systems – driven by human action by ‘tipped’
by natural driver
Explore characteristics of the drivers and response of
differing examples – time and space scales, trophic
structure, predictability
-30%
+30%
Scotian Shelf – Frank et al. 2005
Colour display of 60+ indices
for Eastern Scotian Shelf
Grey seals - adults
Pelagic fish - #’s
Pelagic:demersal #’s
Pelagic:demersal wt.
Inverts - $$
Pelagics - wt
Diatoms
Grey seals – pups
Pelagics - $$
Greenness
Dinoflagellates
Fish diversity – richness
3D Seisimic (km2)
Gulf Stream position
Stratification anomaly
Diatom:dinoflagellate
Sea level anomaly
Volume of CIL source water
Inverts – landings
Bottom water < 3 C
Sable winds (Tau)
SST anomaly (satellites)
chlorophyll – CPR
Temperature of mixed layer
NAO
Bottom T – Emerald basin
Copepods – Para/Pseudocal
Shelf-slope front position
Storms
Bottom T – Misaine bank
Groundfish landings
Haddock – length at age 6
Bottom area trawled (>150 GRT)
Cod – length at age 6
Average weight of fish
Community similarity index
PCB’s in seal blubber
Relative F
Pollock – length at age 6
Calanus finmarchicus
Groundfish biomass – RV
Pelagics – landings
Silver hake – length at age
Condition – KF
Depth of mixed layer
Condition – JC
Proportion of area – condition
RIVSUM
Sigma-t in mixed layer
Oxygen
Wind stress (total)
Wind stress (x-direction)
Wind stress amplitude
SST at Halifax
Groundfish - $$
Salinity in mixed layer
Ice coverage
Wind stress (Tau)
Number of oil&gas wells drilled
Nitrate
Groundfish fish - #’s
Shannon diversity index –fish
Seismic 2D (km)
Grey seals, pelagic fish
abundance, invertebrate
landings, fish species
richness, phytoplankton
Red –
below
average
Green –
above
average
Bottom temp., exploitation,
groundfish biomass &
landings, growth-CHP, avg.
fish weight, copepods
1970
1975
1980
1985
1990
1995
2000
Top Predators
+
(Piscivores)
Forage (fish+inverts)
-
(Plankti-,Detriti-vores)
Zooplankton
+
(Herbivores)
Phytoplankton
-
(Nutrivores)
North Pacific regime shift – Hare and
Mantua (2000)
Physical
forcing – air
temperature but there are
dozens, and
dozens of
other such
time series
North Sea regime shift – a mixture of
biogeography, environmental change and fishing
Line in black: warm-temperate species
Line in red: temperate species
60
55
50
-10
-5
Before 1980
12
11
M 10
North Sea
O 9
8
N 7
France
T 6
5
0
10
H 5
S 4
3
2
After 1980
1
5
4.5
4
3.5
3
2.5
2
1.5
1
Mean number of species
per CPR sample
58 62 66 70 74 78 82 86 90 94 98
Years
Mean number of calanoid
species per CPR sample
Second principal
component (31.36%)
3
2
1
0
-1
-2
-3
3
Gadoid species (cod)
4
2
Flatfish
0
-2
-4
plankton change
plankton change
1
No match for any of the
calanoid copepod assemblages
0
-1
-2
2
SST
2
Mean umber of
species per assemblage
Second principal
component (31.36%)
Mean umber of
species per assemblage
2
salinity
3
2
1
0
-1
-2
-3
3
2
1
0
-1
-2
2
SST
(central North Sea)
1
0
-1
-2
NHT anomalies
0.8
0.4
0
-0.4
SST
(central North Sea)
58
66
70
74 78 82 86 90
Years (1958-1999)
94
98
1
1
0
0
-1
-1
-2
-2
0.8
NHT anomalies
62
NHT anomalies
Westerly wind
2
0.4
1
0
0
-1
-0.4
58 62 66 70 74 78 82 86 90 94 98
Years (1958-1999)
-2
58 62 66 70 74 78 82 86 90 94 98
Years (1958-1999)
Standard deviate
1.6
1.2
0.8
0.4
0
-0.4
-0.8
-1.2
-1.6
-2
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
Beaugrand G (2004) Progress in Oceanography
Standard deviate
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2
1.6
1.2
0.8
0.4
0
-0.4
-0.8
-1.2
-1.6
-2
-2.4
Calanoid copepods
Beaugrand & Ibanez (in press, MEPS)
Fi sh tota l biomass (5 species)
Calanoid copepods
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
Standard deviate
2
1.6
1.2
0.8
0.4
0
-0.4
-0.8
-1.2
-1.6
-2
-2.4
Beaugrand G (2004) Progress in Oceanography
1.6 Fish tota l biomass (5 species)
1.2 Ca la no id copepods (17 i ndicato rs)
0.8
0.4
0
-0.4
-0.8
-1.2
-1.6
-2
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
Standard deviate
Beaugrand & Ibanez (in press, MEPS)
Long-term changes in the abundance
of two key species in the North Sea
80%
C. finmarchicus
60%
40%
20%
0%
C. helgolandicus
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Percentage of
C. helgolandicus
100%
Reid et al. (2003)
Consequences of plankton changes on higher
trophic level
Mismatch between the timing of calanus prey and larval cod
Abundance of C. finmarchicus
1.4
1.2
1.0
0.8
0.6
0.4
0.2
Gadoid Outbu rst
60 65 70 75 80 85 90 95
12
11
10
9
8
7
6
5
4
3
2
1
Ga doid Outburst
60 65 70 75 80 85 90 95
Beaugrand, et al. (2003) Nature. Vol. 426. 661-664.
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Abundance (in log 10(x+1))
1.6
Abundance (in log 10(x+1))
12
11
10
9
8
7
6
5
4
3
2
1
Abundance of C. helgolandicus
But there is also a
significant
influence of
fishing – how
much??
1
0.8
0.6
0.4
Spawning biomass ('000T)
0.2
1960
300
250
200
150
100
50
1950 1960 1970 1980 1990 2000
Year
1970
1980
Year
1990
2000
Propn. of eggs from age 5+ co
Fishing mortality rate (age 3+)
North Sea - dynamics
Biogeographic shift
Meteorological/oceanographic
forcing
Fishing
Ecosystem status
and function
Coral reef systems – Jamaican example
Loss of resilience
Overfishing
Nutrient loading
Healthy state
Parasite infection
Stressed state
Sea urchin collapse
Rock
Natural and
anthopogenic
Coral system
Natural and
anthopogenic
Ecosystem drivers
Natural and
anthopogenic
Coral
Demersal -NWA
Demersal - P
Pelagic NWA
Pelagic -P
Ecosystem response
How predictable are regime shifts?
Should differentiate prediction of the drivers and the
response.
• Simulation of the environmental, met and ocean, drivers
seems possible in a number of cases. How to develop
the transfer function to the response? Possibly without
use of a numerical model
• Diagnostic calculation – in which one uses key data to
drive an ecosystem model, perhaps a mix of biological
and physical data
• Full integrated biophysical simulation – purely
deterministic??
Example North Pacific model – Yamanaka, Rose, Werner et al.
80
g year
-1
(a)
40
o
C
0
11.5
11.0
10.5
10.0
9.5
(b)
0.092
(c)
0.088
-1
0.084
uMN L
Time series
output
(d)
0.060
0.056
0.052
0.048
(e)
0.18
0.16
0.14
1950
1960
1970
1980
1990
2000
Year
Zooplankton and
temperature
time series
COCO – Toykyo
3-D Nemuro
Nemuro Pacific herring model
Observations- Biological
and Physical
Validation
NCEP 6 hourly data
1948-2002
(includes interannual variability)
NEMURO.FISH
80
o
Temperature
11.5
11.0
10.5
10.0
9.5
(b)
0.092
(c)
0.084
uMN L
-1
Predatory
zooplankton
40
0.088
Small zooplankton
Large zooplankton
(d)
0.060
0.056
0.052
0.048
(e)
0.18
0.16
0.14
1950
Rose et al. (2005), submitted to EM.
WCVI
0
C
Herring growth
rate (age 3 to 4)
g year
-1
(a)
1960
1970
Year
1980
1990
2000
Possible regime shift modelling excercises
Region
Issue
Model
North
Pacific
Ecosystem
structure – how
deep?
BioPhysical model –
partially diagnostic
Trophic cascade
arising from fishing
Predator-prey coupling,
spatially explicit,
including life history
Scotian
Shelf
North Sea
Biogeographic shift Ecosystem response,
circulation, trophic
Fishing
coupling
Next is application to management
>> for another day
North Pacific
Coral - Jamaica
North Sea
Drivers
Response
Drivers
Response
Drivers
Response
Complex
physical
climate (AO,
PDO, ENSO)
Zooplankton to
fish and
mammals
Fishing
Eutrophicatio
n
Species
composition
(urchinsalgae-coral)
Oceanic
(circulation
temperature)
atmospheric
(NAO), fishing
Phytoplankton to fish
Time
scale
Shift – 1-5
years
Persistence –
10-20 years
Shift: 1-5 years
Regime: > 10
years
Parasite
(Trigger) – 12 years
Erosion of
resilience (10
year)
Shift – 1-2
years
Persistence –
> 20 years
Shift 1-5 years
(NAO) Oceanic
persistence –
10 years
Erosion of
resilience – >
10 years fishing
Shift – 1-5 years
Regime: > 10 years
Spatial
scale
10,000 km
(basin)
1,000 -2,000
km (regional)
10-100 km
10-100 km
1000 km
(fishing,
oceanic) to
10,000 km
(atmospheric)
1000-2000 km
(extends beyond
North Sea)
Detect
2 years
3-5 years
< 1 year
1-2 years
2 years
2-5 years
Predict
Little skill
Following from
detection
Erosion
fishing impact
is predictable
Trigger – no
Probabilistic
Little skill,
Erosion fishing impact
is predictable
Following from
detection
Manage
Not possible
Fishing
management
after detection
- adaptation
Marine
management
of resilience
and trigger
>> prevention
Marine
management rehabilitation
( ?)
Climate – not
possible
Fishing prevention
Fishing management
after detection adaptation
Long-term change in the plankton index and cod
recruitment (at age 1, one-year lag)
Beaugrand et al. (2003) Nature. Vol. 426. 661-664.
warming of
temperature
(+)
Larval metabolism
(-)
Decrease in the
number of prey (-)
(-)
(+)
Mean umber of
species per assemblage
Second principal
component (31.36%)
(+)
3
2
1
0
-1
-2
-3
3
2
1
0
-1
-2
2
SST
(central North Sea)
1
0
-1
-2
NHT anomalies
0.8
0.4
0
-0.4
58
Energetic demand
62
66
70
74 78 82 86 90
Years (1958-1999)
94
98
Energetic imbalance
(-)
Growth and survival
(-)
Overfishing
Reduction in recruitment
Energetic gain

Similar documents

×

Report this document