TRACE ELEMENT KINETICS IN CONTAMINATED POSIDONIA OCEANICA MEADOW

J. Richir , N. Luy , G. Lepoint, A. Alvera Azcarate, R. Biondo, S. Gobert

Essaouira05-2012

Mediterranean submitted to anthropic pressures

Introduction

INTRODUCTION

bioindicator : Posidonia oceanica- monitoring of coastal ecosystem pollution;- representative accumulation;- pollutant biologically accessible.

pollution trace elements (TEs)

TE Cd Pb Cu Zn Cr Fe Ni

# ref. 39 30 28 26 23 15 14

TE As Ag Co Mn Al Bi V Mo

# ref. 4 3 3 3 2 1 1 1

Luy et al. (2012)

Mediterranean submitted to anthropic pressures

Introduction

INTRODUCTION

bioindicators : Posidonia

oceanica

pollution trace elements (TEs)

TEs uptake and loss kinetics of P. oceanica contaminated in their natural environment?

e.g.: Ledent (1992); Warnau et al. (1996)

Mediterranean submitted to anthropic pressures

Introduction

INTRODUCTION

bioindicators : Posidonia

oceanica

pollution trace elements (TEs)

TEs uptake and loss kinetics of P. oceanica contaminated in their natural environment?

Objectives:

To study TEs kinetics and tissue compartmentalization of P. ocenica contaminated in situ at 2 experimental levels:

- moderate: 21x Calvi SW conc.; 4x world ocean mean conc. - acute: 151x Calvi SW conc.; 31x world ocean mean conc.

e.g.: Ledent (1992); Warnau et al. (1996)

In situ experimental contaminations

MATERIAL - METHODS

MATERIAL

-

METHODS

Contamination at moderate levels

• 5 days of contamination in June 2009;

• 410L bell-shaped mesocosm;

• Contamination every 12 hours (9am-9pm);

• 15 days of decontamination.

MATERIAL

-

METHODS

Contamination at moderate levels

MATERIAL

-

METHODS

Contamination at acute levels

• 24h00 of contamination in June 2009;

• 54L rectangular-box mesocosm;

• 5 contaminations, 1 every 3 hours (9am-9pm);

• 15 days of decontamination

Posidonia oceanica

(A) shoot of leaves on a plagiotropic rhizome (Rz); (B, C) adult leaves (AL); (D) intermediate leaf (IL); (E) juvenile leaf. Libes and Boudouresque,1987

plagiotropic shoot

orthotropic shoot

rhizome

blade

roots

MATERIAL

-

METHODS

limb

ligula

leaf base (petiole)

EDCB

A

rootleaf base

stipule

scale

rhizome

RESULTS

Ag moderate conta.: kinetics

RESULTS

Ag moderate conta.: kinetics

RESULTS

Ag moderate conta.: kinetics

RESULTS

Ag moderate conta.: kinetics

RESULTS

Ag moderate conta.: compartmentalization

RESULTS

Ag moderate conta.: compartmentalization

RESULTS

Ag moderate conta.: kinetics

RESULTS

Ag acute conta.: kinetics

RESULTS

Ag acute conta.: kinetics

RESULTS

Ag acute conta.: kinetics

RESULTS

Ag acute conta.: compartmentalization

RESULTS

Ag acute conta.: compartmentalization

RESULTS

Ag acute conta.: kinetics

CONCLUSION

Conclusion

• P. oceanica takes up TEs from the beginning of experiments;

• Moderate contamination design are preferred;

• Once contaminations end, TE concentrations rapidly decrease;

• Leaves exhibited different uptake kinetics: the younger growing leaves forming new tissues incorporated chemicals more rapidly than the older senescent leaves;

• Rhizomes did not show any clear trend.

P. oceanica is a sensitive sentinel to delineate punctual pollutions similar to what might be measured in contaminated Mediterranean waters routine use in regularly scheduled monitoring programs.

QUESTIONS

Thank you for your attention

RESULTS

Cu moderate conta.: kinetics

RESULTS

Cu moderate conta.: compartmentalization

RESULTS

Cu moderate conta.: kinetics

RESULTS

Cu acute conta.: kinetics

RESULTS

Cu acute conta.: compartmentalization

RESULTS

Cu acute conta.: kinetics

RESULTS

Fe moderate conta.: kinetics

RESULTS

Fe moderate conta.: compartmentalization

RESULTS

Fe moderate conta.: kinetics

RESULTS

Fe acute conta.: kinetics

RESULTS

Fe acute conta.: compartmentalization

RESULTS

Fe acute conta.: kinetics

Analytical steps:

• homogeneous sample

• acidic digestion in a microwave oven

• measures : inductively coupled plasma mass spectrometer

MATERIAL

-

METHODS

Laboratory analyses

Ethos D

ELAN DRCII

adult leavesshoots 1/6/9

Calvi