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Oceanographic conditions in Galicia and the Southern Bay of Biscay and their influence on
the Prestige oil spill
M. Ruiz Villarreal, P. Otero, C. González Pola, A. Lavín, G. Díaz del Río and JM Cabanas
Instituto Español de Oceanografía
Oil spill transport - Main driving agent was wind, but coastal circulation apparently has an impact in stranding points and affected area
- What is the fate of the fuel deposited at the bottom and fuel in the water column?
Impact on ecosystems- System subject to strong interannual variability. Difficult to ascribe an effect to the impact of oil spill. Conditions following spring are determinant for the response of the ecosystem
Oceanographic conditions during the Prestige oil spill: need for analysis
Historical IEO Demersales survey
Demersales0903Hidroprestige0303Accion Especial
Prestige
Historical IEO Pelacus survey
Prestige Plataforma1202
Prestige Plataforma0103
IEO Standard Sections
-6000
-5000
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
2002 2003
1st Spring upw elling pulse
Up
wel
lin
gD
ow
nw
elli
ng
Prestige trawl and spill
Prestige1202
Prestige0103
HP0303
Demersales02
Demersales03
Pelacus03
6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
Summer 2002 to Autumn 2003
Upwelling index at 43N 11W
Salinity 100db Autumn 2002 Autumn 2003
Ruiz-Villarreal et al., Oceanographic conditions in Galicia and the Southern Bay
of Biscay and their influence on the Prestige oil spill, Submitted to MPB, 2005
0 5 10 15 20 25 30 35 40
Distancia ( K m )
- 700
- 600
- 500
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0
Pro
fun
did
ad
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)
4 5 6 8 7
1 1
1 1 . 5
1 2
1 2 . 5
1 3
1 3 . 5
1 4
1 4 . 5
1 5
Perfil 4 TPontevedra
0 5 10 15 20 25 30 35
D istancia (K m )
- 400
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- 100
0
Pro
fun
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ad
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1 4 1 3 1 7 1 2 1 1 1 0
1 1
1 1 . 5
1 2
1 2 . 5
1 3
1 3 . 5
1 4
1 4 . 5
1 5
Perfil 14 T Lira
0 5 10 15 20 25 30 35 40 45
D istancia (K m )
- 500
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- 100
0
Pro
fun
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ad
(m
)
2 7 2 8 2 9 3 0 3 3
1 1
1 1 . 5
1 2
1 2 . 5
1 3
1 3 . 5
1 4
1 4 . 5
1 5
Perfil 27 T S isargas
0 5 10 15 20 25 30 35 40
D istancia (K m )
- 700
- 600
- 500
- 400
- 300
- 200
- 100
0
Pro
fun
did
ad
(m
)
4 5 6 8 7
3 4
3 5
3 5 . 1
3 5 . 2
3 5 . 3
3 5 . 4
3 5 . 5
3 5 . 6
3 5 . 7
Perfil 4 SPontevedra
0 5 10 15 20 25 30 35 40 45
D istancia (K m )
- 500
- 400
- 300
- 200
- 100
0
Pro
fun
did
ad
(m
)
2 7 2 8 2 9 3 0 3 3
34.9
35
35.1
35.2
35.3
35.4
35.5
35.6
35.7
Perfil 27 S S isargas
0 5 10 15 20 25 30 35
Distancia (Km)
- 400
- 300
- 200
- 100
0P
rofu
nd
ida
d (
m)
1 4 1 3 1 7 1 2 1 1 1 0
34.5
34.9
35
35.1
35.2
35.3
35.4
35.5
35.6
35.7
Perfil 14 S Lira
1 2 3
1
2
3 Poleward Slope current carrying subtropical watersDownwelling conditions
Poleward slope current
Freshwater plumes
Poleward current domain
River plumes
PLATERIAS project
Coastal circulation before stranding of 2nd spill
2nd spill drift simulation: wind + coastal circulation
-6000
-5000
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
2002 2003
1st Spring upw elling pulse
Up
wel
lin
gD
ow
nw
elli
ng
Prestige trawl and spill
Prestige1202
Prestige0103
HP0303
Demersales02
Demersales03
Pelacus03
6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
Summer 2002 to Autumn 2003
Upwelling index at 43N 11W
Spring transition in Galicia
Autumn-Winter
Spring
at 5 dbar Geostrophic vel. at 5 dbar
- Upwelling pulses- Poleward current waters exported offshore during pulses- Eddy activity
- Freshwater plumes- Poleward current at the slope (warmer and saltier)
Garcia-Soto, Prestige oil spill and Navidad flow, JMBA, 2004
Santander slope Cantabrian. Intrusion of subtropical waters
Ruiz et al. Submitted to MPB, 2005
NCEP wind vector progressive diagram
Early commencement of spring in the Cantabrian Sea
Upwelling in the Cantabrian Sea during
Pelacus
December January
February March
MERCATOR-OCEAN PSY2 1/12º
mruiz:
Velocidad filtrada a un dia
mruiz:
Velocidad filtrada a un dia
Low passed filtered velocity (cm/s)
Galicia Bank
*
Prestige wreck mooring
Conclusions- Circulation during Prestige accident:
- end autumn-winter situation. Shelf and slope intense circulation: river plumes, slope current
- more research needed on response of plumes and slope current to wind forcing (Platerias and Zotracos projects)
- propagation in the Cantabrian driven by the poleward current needs further analysis: poleward flow in December, but no signals of intrusion of subtropical waters
- Circulation during spring
- Cruises performed during “spring transition”: upwelling pulses influence circulation, poleward weakens and is exported offshore
- Early commencement of spring in the Cantabrian, and this could have affected ecosystem response
- Galicia Bank impact on circulation: tidal distortion, mesoscale activity… Further research is needed. Seamount ecosystem?