âThe Arctic Paradox: Biogeochemical similarities between Arctic and ...
“The Arctic Paradox: Biogeochemical similarities between Arctic and Semi-Arid Estuaries”. Hg biogeochemistry & climate changes Luiz Drude de Lacerda, Rozane Valente Marins & Francisco José da Silva Dias INCT de Transferência de Materiais Continente-Oceano (INCT-TMCOcean) Laboratório de Biogeoquímica Costeira, LABOMAR/UFC
Contrasts & Similarities Jaguaribe R.
Dias; Marins & Maia. Acta Limnol. Bras. (2009)
Dry
Mackenzie R. (Leitch et al., 2007)
Ice
v
v
v
v
v RT v v v
RT v
v
Res. Time
v
Distance from river
v
v
v v
RTv
v v v v
Conceptual hydrodynamics model of Arctic rivers, adapted from Greydon et al. (2009) River
River Summer Freshet
Spring melting
Free delta Margin al Lakes
Margin al Lakes Frozen delta
Arctic
Arctic
Total Hg and the percentage of MeHg in the Mackenzie River and marginal lakes between spring and the freshet in summer (from Leitch et al., 2007)
River Open lakes
Concentraton
Semi-enclosed lower lakes Chooked higher lakes
Hg-Org
Frozed River
Melting Delta
Freshet Sea
¾Increasing air temperature and continental runoff. ¾Increasing primary productivity and biological uptake. ¾Increasing human exposure.
Hg & C-Org. in marginal lake sediments of the Mackenzie river and total Hg in fish tissues, (Carrie et al., 2010) Global climate change scenario
(MacDonald et al., 2005)
Present day environmental setting of the NE Brazil semiarid coast
Positive runoff flow to the ocean Flow velocity (ADCP) during the rainy season at the semiarid coast of Brazil: Lasting 4 to 5 months Jaguaribe R., Fortim, CE
Faster flow during the ebb tide in the rainy season Contour Variable: Velocity - Direction
Contour Variable: Velocity - Direction
1.0
Flood
1.5
Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
(deg)1.0 300 250 2.0
R a n g e (m )
R a n g e (m )
2.5 3.0 3.5
4.5
4.0 50
5.0
4.5 20
30
40
100
150 3.0
3.5 100
10
120
200 2.5
4.0
5.5
Ebb
1.5
2.0
(deg) 140
0 5.0
80
60
40 10
20
Negative contiental flow to the ocean Flow velocity (ADCP) during the rainy season at the semiarid coast of Brazil: Lasting 4 to 5 months
Contour Variable: Velocity - Direction
Contour Variable: Velocity - Direction
1.0 1.5
(deg) 140
Flood
(deg) 300
1.5 120
2.0
250
2.0 2.5
2.5
100
R a n g e (m )
Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
1.0
3.0 80
3.5
Ebb
R a n g e (m )
Jaguaribe R., Fortim, CE
Faster flow during the flood tide in the rainy season
3.0
200
150
3.5
100
4.0 4.0
60
4.5 5.0
40 10
20
4.5
50
5.0 5.5
0 10
20
30
40
9Spatial and temporal water mass distribution between the estuary and the continental shelf breakdown. Note the presence of tropical (oceanic ) waters during the dry season. Dias, Castro & Lacerda Cont. Shelf. Res. (2011. sub) Inner shelf
Wet season
Wet season Middle & outer shelf
Dry season
Dry season
Long TR
Short TR
Blocking estuarine water mass inside the higher estuary during the dry season. Dias, Castro & Lacerda Cont. Shelf. Res. (2011. sub)
The reduced continental runoff and sea level rise results in the blocking of the continental water flux inside the estuary, mimicking the role played by ice in the Arctic estuaries. Note that Tropical Waters invade the continental shelf during the dry season and help pushing coastal waters inside the estuaries.
Water mass residence time at the Jaguaribe estuary during the dry and wet seasons (Lacerda , Dias & Marins Theor. Adv. Ecol., 2011)
Spatial distribution of suspended matter (mg.L-1) in the Jaguaribe estuary and inner shelf during the wet season (A) and dry season (B – ebb tide, Cflood tide) in 2009. Scale: 0 to 100 mg.L-1. (Dias, Castro, Lacerda, Cont. Shelf. Res.. 2011 Sub)
Conceptual hydrodynamics model of semiarid rivers (Lacerda , Dias & Marins Theor. Adv. Ecol., 2011)
River Dry season flow
River Wet season flow
Mangroves
Mangroves
High salinity lower course
SWAO
SWAO
Water balance at the Jaguaribe Estuary Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
River Estuary Sea
dry wet
Hg transport at the continent-ocean interface. (Lacerda, Marins, Soares, Dias Sci.
.
Tot. Environm. 2011 Sub)
dry
dry wet
wet
Hg speciation in the dry and wet seasons in the Jaguaribe river estuary (Lacerda, Marins, Soares, Dias Sci. Tot. Environm. 2011 Sub.)
dry
we t
dr y
we t
River Estuary Sea
Import
(Lacerda, Marins, Soares, Dias Sci. Tot. Environm. 2011 Sub. )
R>E
E>M
Plurianual Balance
?
Export
Acumulation uin the estuary 18 kg/s Import
Import
E>M
R>E E>M R>E
Export
Balanço plurianual
Acumulation in the estuáry de 3 mg/s
Export
Export to sea 0.45 mg/s
Plurianual Balance
Changes in island area in the Jaguaribe River estuary between 1988 and 2008 (Godoy, MSc Dissert., UFC, 2010)
October, 2009
August, 2010
Mangrove expansion in choked estuary of the NE semiarid coast
Lacerda & Godoy , Ciênc. Hoje (2010)
Bioavailable Hg enrichment in river waters after crossing mangroves areas, similarly to water flowing out of Arctic rivers marginal lagoons (Marins, Lacerda, Mounier, Paraquetti & Marques Geochim. Brasil. 2002)
Concentração
Hg Dissol (ng/L)
Hg Part (ng/L x 10-1)
Hg TSS (ug/g)
1,4 1,2 1 0,8 0,6 0,4 0,2 0 River Rio
Mangrove Manguezal
River Fozmouth
Generation and export of DOC- Hg complexes (Mounier, Lacerda, Marins & Benaim, Bull. Environm. Cont. Toxicol. 2001)
Lacerda et al. (2001) Mounier et al. (2001)
Hg speciation in interstitial waters in mangroves (Mounier, Lacerda, Marins & Benaim, Bull. Environm. Cont. Toxicol. 2001)
O cenário das mudanças climáticas globais Subida do nivel do mar
Decrécimo da chuva no Ceará
(Moncuil, IXSBSR, 2006)
Global precipitation and runoff anomalies from Dai et al. (2009)
Brazil’s semi-arid coast
Annual rainfall at the Jaguaribe basin, CE (Lacerda, Godoy & Maia, Cienc. Hoje 2010)
(Marins, LOICZ R&S 21, 2002)
Dry season rainfall in the Jaguaribe Basin (Godoy, MSc Dissert. UFC, 2010) 12.6 mm 4.4 mm
3.6 mm 1.9 mm
Origins of alterations identified in 27 estuaries of the semiarid littoral of northeast Brazil. Comparing Landsat, SPOT & Quickbird data from 1999 to 2006 (lLacerda, Godoy & Maia, Cienc. Hoje, 2010) New mangrove areas
16%
29% Without human intervention
Engineering works
25% 30% Dams
0
1
Hg (ng/l) 2
3
4
Sediment depth (cm)
5
Hg-Org
15
30
50 DGM
HgII-react
Hg-org
Hg-total
Tidal choking & water residence time
Reactivity & bioavailability
Human exposure
CONCLUSION “The results to now strongly suggest that water blocking inside semiarid estuaries results in increasing production and export of bioavailable Hg to coastal waters, similarly to what happens in Arctic rivers. As in the Arctic, global climate changes may increase water residence time in estuaries due to stronger blocking of river outflow by oceanic waters”.
If the “Arctic Paradox” is a robust theory some empirically testable, non-tautological hypothesis could be advanced. Below some which has already started being tested.
¾ 1) In the short term quantitative fluxes may not be altered but and augmenting the percent contribution of more reactive, bioavailable species should increase.
¾ 2) This increase in bioavailable forms will result in increasing Hg concentrations in the biota.
¾3)
The result in the middle term of the increasing blocking of water masses and water residence time in estuaries may result in further increase in sediment accumulation in the estuary.
¾ 4) Dissolved organic carbon export shall also increase due to augmenting the area subjected to the sulfate reducing metabolism typical of mangroves.
¾5) Increasing deposition rates of pollutants may occur in coastal and deltaic coastal areas.
Thank you! www.inct-tmcocean.com.br
www.institutomilenioestuarios.com.br
Contrasts & Similarities Jaguaribe R.
Dias; Marins & Maia. Acta Limnol. Bras. (2009)
Dry
Mackenzie R. (Leitch et al., 2007)
Ice
v
v
v
v
v RT v v v
RT v
v
Res. Time
v
Distance from river
v
v
v v
RTv
v v v v
Conceptual hydrodynamics model of Arctic rivers, adapted from Greydon et al. (2009) River
River Summer Freshet
Spring melting
Free delta Margin al Lakes
Margin al Lakes Frozen delta
Arctic
Arctic
Total Hg and the percentage of MeHg in the Mackenzie River and marginal lakes between spring and the freshet in summer (from Leitch et al., 2007)
River Open lakes
Concentraton
Semi-enclosed lower lakes Chooked higher lakes
Hg-Org
Frozed River
Melting Delta
Freshet Sea
¾Increasing air temperature and continental runoff. ¾Increasing primary productivity and biological uptake. ¾Increasing human exposure.
Hg & C-Org. in marginal lake sediments of the Mackenzie river and total Hg in fish tissues, (Carrie et al., 2010) Global climate change scenario
(MacDonald et al., 2005)
Present day environmental setting of the NE Brazil semiarid coast
Positive runoff flow to the ocean Flow velocity (ADCP) during the rainy season at the semiarid coast of Brazil: Lasting 4 to 5 months Jaguaribe R., Fortim, CE
Faster flow during the ebb tide in the rainy season Contour Variable: Velocity - Direction
Contour Variable: Velocity - Direction
1.0
Flood
1.5
Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
(deg)1.0 300 250 2.0
R a n g e (m )
R a n g e (m )
2.5 3.0 3.5
4.5
4.0 50
5.0
4.5 20
30
40
100
150 3.0
3.5 100
10
120
200 2.5
4.0
5.5
Ebb
1.5
2.0
(deg) 140
0 5.0
80
60
40 10
20
Negative contiental flow to the ocean Flow velocity (ADCP) during the rainy season at the semiarid coast of Brazil: Lasting 4 to 5 months
Contour Variable: Velocity - Direction
Contour Variable: Velocity - Direction
1.0 1.5
(deg) 140
Flood
(deg) 300
1.5 120
2.0
250
2.0 2.5
2.5
100
R a n g e (m )
Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
1.0
3.0 80
3.5
Ebb
R a n g e (m )
Jaguaribe R., Fortim, CE
Faster flow during the flood tide in the rainy season
3.0
200
150
3.5
100
4.0 4.0
60
4.5 5.0
40 10
20
4.5
50
5.0 5.5
0 10
20
30
40
9Spatial and temporal water mass distribution between the estuary and the continental shelf breakdown. Note the presence of tropical (oceanic ) waters during the dry season. Dias, Castro & Lacerda Cont. Shelf. Res. (2011. sub) Inner shelf
Wet season
Wet season Middle & outer shelf
Dry season
Dry season
Long TR
Short TR
Blocking estuarine water mass inside the higher estuary during the dry season. Dias, Castro & Lacerda Cont. Shelf. Res. (2011. sub)
The reduced continental runoff and sea level rise results in the blocking of the continental water flux inside the estuary, mimicking the role played by ice in the Arctic estuaries. Note that Tropical Waters invade the continental shelf during the dry season and help pushing coastal waters inside the estuaries.
Water mass residence time at the Jaguaribe estuary during the dry and wet seasons (Lacerda , Dias & Marins Theor. Adv. Ecol., 2011)
Spatial distribution of suspended matter (mg.L-1) in the Jaguaribe estuary and inner shelf during the wet season (A) and dry season (B – ebb tide, Cflood tide) in 2009. Scale: 0 to 100 mg.L-1. (Dias, Castro, Lacerda, Cont. Shelf. Res.. 2011 Sub)
Conceptual hydrodynamics model of semiarid rivers (Lacerda , Dias & Marins Theor. Adv. Ecol., 2011)
River Dry season flow
River Wet season flow
Mangroves
Mangroves
High salinity lower course
SWAO
SWAO
Water balance at the Jaguaribe Estuary Dias, Lacerda, Marins, Paula & Ovalle. Hydrol. Proc. (2011)
River Estuary Sea
dry wet
Hg transport at the continent-ocean interface. (Lacerda, Marins, Soares, Dias Sci.
.
Tot. Environm. 2011 Sub)
dry
dry wet
wet
Hg speciation in the dry and wet seasons in the Jaguaribe river estuary (Lacerda, Marins, Soares, Dias Sci. Tot. Environm. 2011 Sub.)
dry
we t
dr y
we t
River Estuary Sea
Import
(Lacerda, Marins, Soares, Dias Sci. Tot. Environm. 2011 Sub. )
R>E
E>M
Plurianual Balance
?
Export
Acumulation uin the estuary 18 kg/s Import
Import
E>M
R>E E>M R>E
Export
Balanço plurianual
Acumulation in the estuáry de 3 mg/s
Export
Export to sea 0.45 mg/s
Plurianual Balance
Changes in island area in the Jaguaribe River estuary between 1988 and 2008 (Godoy, MSc Dissert., UFC, 2010)
October, 2009
August, 2010
Mangrove expansion in choked estuary of the NE semiarid coast
Lacerda & Godoy , Ciênc. Hoje (2010)
Bioavailable Hg enrichment in river waters after crossing mangroves areas, similarly to water flowing out of Arctic rivers marginal lagoons (Marins, Lacerda, Mounier, Paraquetti & Marques Geochim. Brasil. 2002)
Concentração
Hg Dissol (ng/L)
Hg Part (ng/L x 10-1)
Hg TSS (ug/g)
1,4 1,2 1 0,8 0,6 0,4 0,2 0 River Rio
Mangrove Manguezal
River Fozmouth
Generation and export of DOC- Hg complexes (Mounier, Lacerda, Marins & Benaim, Bull. Environm. Cont. Toxicol. 2001)
Lacerda et al. (2001) Mounier et al. (2001)
Hg speciation in interstitial waters in mangroves (Mounier, Lacerda, Marins & Benaim, Bull. Environm. Cont. Toxicol. 2001)
O cenário das mudanças climáticas globais Subida do nivel do mar
Decrécimo da chuva no Ceará
(Moncuil, IXSBSR, 2006)
Global precipitation and runoff anomalies from Dai et al. (2009)
Brazil’s semi-arid coast
Annual rainfall at the Jaguaribe basin, CE (Lacerda, Godoy & Maia, Cienc. Hoje 2010)
(Marins, LOICZ R&S 21, 2002)
Dry season rainfall in the Jaguaribe Basin (Godoy, MSc Dissert. UFC, 2010) 12.6 mm 4.4 mm
3.6 mm 1.9 mm
Origins of alterations identified in 27 estuaries of the semiarid littoral of northeast Brazil. Comparing Landsat, SPOT & Quickbird data from 1999 to 2006 (lLacerda, Godoy & Maia, Cienc. Hoje, 2010) New mangrove areas
16%
29% Without human intervention
Engineering works
25% 30% Dams
0
1
Hg (ng/l) 2
3
4
Sediment depth (cm)
5
Hg-Org
15
30
50 DGM
HgII-react
Hg-org
Hg-total
Tidal choking & water residence time
Reactivity & bioavailability
Human exposure
CONCLUSION “The results to now strongly suggest that water blocking inside semiarid estuaries results in increasing production and export of bioavailable Hg to coastal waters, similarly to what happens in Arctic rivers. As in the Arctic, global climate changes may increase water residence time in estuaries due to stronger blocking of river outflow by oceanic waters”.
If the “Arctic Paradox” is a robust theory some empirically testable, non-tautological hypothesis could be advanced. Below some which has already started being tested.
¾ 1) In the short term quantitative fluxes may not be altered but and augmenting the percent contribution of more reactive, bioavailable species should increase.
¾ 2) This increase in bioavailable forms will result in increasing Hg concentrations in the biota.
¾3)
The result in the middle term of the increasing blocking of water masses and water residence time in estuaries may result in further increase in sediment accumulation in the estuary.
¾ 4) Dissolved organic carbon export shall also increase due to augmenting the area subjected to the sulfate reducing metabolism typical of mangroves.
¾5) Increasing deposition rates of pollutants may occur in coastal and deltaic coastal areas.
Thank you! www.inct-tmcocean.com.br
www.institutomilenioestuarios.com.br
