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Bioavailability and bioaccumulation: keys for quality ecosystem

European Joint Master in Water and Coastal Management

University of Cadiz (May 2016)

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Today’slecture

• Basic concepts• Monitoring contamination: Advantages and

disadvantages of the environmental compartments

• Interaction between trace metal and aquatic organism (FIAM model)

• Case study: Aznalcollar mining accident. Estuary biomonitoring

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Basicconcepts• Bioconcentration factor (BCF) at equilibrium

BCF= Corganism/CwaterUnits= mL/g Unitless 1mL=1 g• Bioaccumulation factor (BAF) at equlibrium

BAF= C organism/C sedimentWet weight or dry weightUnitless 1-104

BAF/BSAF are employed in ERA• Biomagnification

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• Biological indicators (bioindicators). Organisms their own absence or presence indicate la existence or abundance of a particular critical factor (Capitella capitata)

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Environmental monitoring

Repetitive data collection for the purpose to determining trends in environmental parameters “a priori” and“posteriori”

Which is the objective?

- To screen effluents, receiving waters or biota for potentiallyharmful toxicants

- To investigate the effects of environmental quality on human health

- To study the sources, transport pathways and sinks for contaminants

- To provide historical records

- To investigate specific environmental impacts of individual ormultiple developments

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• Biological monitors

The means for regular surveillance

They can be used to quantify theamount of a pollutant present in aparticular environment

Goldberg et al. 1978 sentinel

Hellawell, 1986 bioaccumulativeIndicator

Biomonitor

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Tracemetal?Heavymetal?

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Nieboer and Richardson 1980 Lewis acid properties metal

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EnvironmentalcompartmentsWater (ng/L to mg/L)• Nutrients• Pb (10-50 ng/L) Sample contamination• Clean lab (at least for open ocean sites)• Estuaries (flow intensity, intermittency of contaminated discharges, tidal,

current,..)• Lack correlation between the contaminant concentrations and their biological

availability

Sediment• Contaminant tend to associate preferentially with suspended matter• Al, Fe, Pb, Mn particulate matter• As, Cd, Se present in solution in natural waters• Short-term variations problem tend to be reduced• Concentrations in sediment are also several orders of magnitude greater than in

natural waters

Concentrations do no reflect the absolute magnitude in sampling site. Complexfunction of the relative fluxes of contaminant and suspended particles in thesystem

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Organisms

• Accumulate significant quantities of contaminantin their tissues

• Trace metals is a complex phenomenonTake up and retain are different between phylaand also between individual species withinphyla. Evolutionary strategies for detoxifyngtrace metals

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Zn (µ

g/g

dw)

0

20

40

60

80

100

120

140

160

37º 4

5’ N

6º 35’ W

Iberian Peninsula

Squilla mantis (Linnaeus, 1758)

Guadalquivir River

Chipiona

F

Region 2Region 1

Region 3

Region 4

6º 43’W 36º 49’N

6º 44’W 36º 50’N

6º 42’W 36º 48’N 6º 41’W

36º 48’N

6º 36’W 36º 49’N

6º 32’W 36º 49’N

6º 40’W 36º 45’N

6º 39’W 36º 47’N

6º 34’W 36º 46’N

6º 35’W 36º 45’N

6º 37’W 36º 43’N

6º 34’W 36º 40’N

6º 39’W 36º 38’N

6º 33’W 36º 40’N

M

KL

IH

G

E

AB

C D

N J

10 km

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-sessile or sedentary

-abundant and easy to identify

-tolerating wide ranges of contaminants and variables as salinity

-strong accumulators of the relevant trace metals

C. angulata

R. philippinarum

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Problems of biomonitor organisms-capacity regulation-Sex, size-Seasonal variability

-Local variability

Scrobicularia plana

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Biomonitoring- metal concentrations in organisms are ten or hundred fold the concentrations in water- concentration reflects the bioavailabity of metal for biota

Biomonitoring programsMussel Watch, Monitoring of Temporal Trends in Chemical Contamination (NOAA), ICES, MAFF, RNO, MEDPOL, OSPAR

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Interactiontracemetal– aquaticbiota

1. Metal speciation in the external environment

2. Metal interactions with the biological membrane

3. Metal partitioning with the organism and the attendantbiological effects

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Factors affecting metal permeationRoutes• Hydrophobic solution in the membrane• Attachment to the membrane proteins (and carbohydrates)• Attachement to the membrane lipids• Endocytosis of membrane components• Permeation through water channels• Permeation through nonspecific channels• Permeation through specific channels• Permeation by general active processes (e.g. electrochemical potentials)• Permeation by specific active processes (eg. ATPase)

Forms of metals• Metal ions (e.g. M2+)• Hydrated ions (e.g. M(H2O)62+)• Charged metal complexes (e.g. MCl(H2O)5+)• Uncharged ionic complexes (e.g. MCl20)• Organometallic complexes (e.g. CH3M+n)

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Qualitative evidence exists to the effect that the total aqueous concentration of a metal is not a good predictor of its “bioavailability”

Does FIAM (free ion activity model) explain the available data?

- Only applicable for dissolved cations (e.g. Al, Cd, Cu, Fe, Mn, Ni, Pb, Zn)

- No applicable to organic metallic species nor particulate metals

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1. Advection or diffusion of the metal from bulk solution to the biological surface

2. Diffusion of the metal through the outer protective layer3. Sorption/surface complexation of the metal at passive

binding sites within the protective layer, or at sites on the outer surface of the plasma membrane

4. Uptake or internalization of the metal

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HistoricalDevelopment

• Early (pre 1975) metal-organism interaction. Influence biological variables

• Computing facilities, Chemical equilibrium programs (limitations stability constant database).

• Unicellular algae (small size, access to large populations, ease of culture, rapid growth,..)

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ApparentexceptionstotheFIAM• Organic ligands forming lipohilic complexes with

metal

• Inorganic anions

• Low molecular weight organic ligands forming hydrophilic complexes with the metal

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Inorganicligands• Ag(I)

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Lowmolecularweighto

rganic

ligands

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FIAMINSYSTEMSCONTAININGDOM• Laboratory bioassay experiments (isolated natural

organic matter) [Mz+]

• Dilution experiments in which DOM-rich natural waters is diluted with synthetic media in order to vary DOM and metal bioavailability as function of [Mz+]

• Biological monitoring of natural ecosystems (surface water samples are collected over an annual cycle and tested in lab with the same assay organism, test protocol and same metal)

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• Case study: Aznalcóllar mining accident

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AznalcóllarAznalcóllar

Balsa minera

Aznalcázar

El Rocío

Río Guadalquivir

La Esparraguera (F)

La Salina (E)

Parque Nacional de Doñana

Matalascañas

Dirección

del vertido

Las Piletas (C)La Pantoca (D)

Montijo (B)

Caladero (A)

Sampling strategy

Biweekly

Monthly

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C. angulata Uca tangeri

Melicertus kerathurus Palaemon longirostris3/5/16

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Liza ramada

Other species

Nereis diversicolor

Pomatoschistus minutus

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4846

1094

7590

1219

0

1000

2000

3000

4000

5000

6000

7000

8000

ppm

(dry

wei

ght)

1968 1998Year

ZnCu

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50

0

2000

4000

6000

8000

10000

12000

T=0

T=1 mes

T= 2 meses

T= 3 meses

Fe

MnZn

Cu

ug/g

dry

wei

ght

0

1

2

3

4

5

6

T=0

T=1 mes

T= 2 meses

T= 3 meses

CdPb

Ni AgTlCo

ug/g

dry

wei

ght

C. angulata

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1/1/1998 1/7/1998 1/1/1999 1/7/1999 1/1/2000 1/7/2000 1/1/2001 1/7/2001

Zn (u

g/g

dry

wei

ght)

0

5000

10000

15000

20000

1/1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02

Cu

(ug/

g dr

y w

eigh

t)

-500

0

500

1000

1500

2000

2500

3000

3500

1/1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02

Cd

(ug/

g dr

y w

eigh

t)

0

2

4

6

8

10

12

C. angulata

Zn: 9134 ug/g dw

Cu: 1460 ug/g dw.

Cd: 5.45 ug/g dw

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1/1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02

Zn (u

g/g

dry

wei

ght)

0

200

400

600

800

1000

1200

1400

1/1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02

Cu

(ug/

g dr

y w

eigh

t)

0

10

20

30

40

50

60

70

Scrobicularia plana

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Finalwork(Individual)√ ObjectiveTo design a monitoring program to establish the impact of chronic or acute

contamination• To select a coastal or estuary area• To present its physical and chemical characteristics• Environmental compartment?• How do you implement bioavailability? • Extension (3 pages)• Send the report (tentative project) to the following email address:

– julian.blasco@csic.es

To include a report of the practice workIn the message cc to aguas.mundus@uca.es

– Deadline: 15th July 2016

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References• Paquin PR, Farley K, Santore RC, Kavvadas CD, Mooney KG,

Winfield RP, Wu K-B, DiToro DM. (2003) Metals in aquatic systems. A review of exposure, bioaccumulation and toxicity models. Pensacola, FL.,USA. SETAC, 168 p.

• Campbell PGC. (1995). Interaction between trace metals and aquatic organisms: a critique of the free ion actiity model. In “Metal Speciation and Bioavailability in Aquatic Systems” (Tessier A & Turner DR,editors). John Wiley and Sons, West Sussex, England, 205-259 pp.

• Phillips DJH, Rainbow PS. (1994) Biomonitoring of trace aquatic contaminants. Chapman & Hall, Oxford (UK) 371 p.

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