Implementation of an automatic monitoring program with high frequency measurements (MAREL Carnot) in the eastern English Channel : a close watch on a potential.

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Implementation of an automatic monitoring programwith high frequency measurements (MAREL Carnot)

in the eastern English Channel : a close watch ona potential problem area with regard to the eutrophication status

A. Lefebvre - Laboratoire Environnement & RessourcesCentre Ifremer Manche Mer du Nord, Boulogne/Mer

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Once upon a time …Preliminary studiesDecember 2001 – April 2002

Hydrology : main biological and physico-chemical parameters

Courantology : ADCP

Lefebvre A. , Repecaud M., Facq J.-V., Lefebvre G. & B. Hitier, 2002. Projet d’implantation de la stationDe mesures automatisées MAREL dans le port de Boulogne sur mer - Mesures in situ et résultatsdu modèle d’advection-diffusion Mars 2D. Rapport Ifremer DEL/BL/RST/02/07, 51 pages.

Hébert C. & A Lefebvre, 2004. Circulation des masses d’eau dans la rade de Boulogne sur Mer.Étude préalable à l ‘implantation de la station de mesures automatisées MAREL Carnot.Rapport Ifremer DEL/BL/RST/04/08, 18 pages.

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Sea wall « CARNOT »

Location of the system

Harbour

English Channel

MAREL Carnot

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Building site

End of the installation(18/12/2003)

Understructure

Installation of the tube : 12 m high, 2 m diameter et 15 t.

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Instrumentation

The buoyThe tube and the buoy

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Studied parameters

Seawater Temperature Air temperature Conductivity Relative Humidity pH P.A.R. (Photosynthetically Active Radiation)

Turbidity NitrateDissolved oxygen PhosphateChlorophyll (Fluorescence) Silicate

 Frequency : 1 series / 20 minutes (to be adjusted if special needed)

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lfre

mer Monthly percentages of acquire data in 2008.

  January

February

March April May June

% données acquises

75,6 75,9 69,1 94,8 95,6 94,0

  July August September

October November

December

% données acquises

93,9 83,8 93,7 92,8 91,6 86,8

Main characteristics of the studied parametersParamètres physico-

chimiquesRange Uncertainty

Temperature - 5 à + 30 °C 0,1 °C

Conductivité 0 à 70 mS/cm 0,3 mS/cm

Dissolved oxygen 0 à 20 mg/L 0,2 mg/L

PH 6,5 à 8,5 UpH 0,2 UpH

Turbidity 0 à 4000 NTU 10 %

Fluorescence 0 à 50 FFU 10 %

Nitrate 0,1 à 100 µmol/L

5 %

Phosphate 0,1 à 100 µmol/L

5 %

Silicate 0,1 à 100 µmol/L

5 %

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Access to data

Quality Assurance on data series

Free data and reports available onhttp://www.ifremer.fr/difMarelCarnot/

Dedicated web page

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Expected results

Improvement of the knowledge on the dynamic of a coastal systemunder marine and anthropogenic controls Region Of Freshwater Influence (ROFI) + riverine inputs Occurrence of regular and intense blooms of the foaming

and noxious Prymnesiophyceae Phaeocystis globosa

Eutrophication = Nutrient inputs + excessive algal growth + harmful consequences

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ResultsUsual monitoring strategy:

SRN Network* (monthly/bi-monthly frequencies)

0

5

10

15

20

25

30

35

22/0

1/20

08

14/0

2/20

08

18/0

3/20

08

10/0

4/20

08

22/0

4/20

08

05/0

5/20

08

02/0

6/20

08

17/0

6/20

08

21/0

7/20

08

29/0

8/20

08

17/0

9/20

08

28/1

0/20

08

19/1

1/20

08

08/1

2/20

08

NO

3- et

SiO

H (

en µ

mo

l/L

) et

Ch

loro

a

(en

µg

/L)

0

0,5

1

1,5

2

2,5

3

3,5

4

PO

43-,

NO

2- et

NH

4+ (en

µm

ol/

L)

SiOH NO3- Chloro a PO43- NO2- NH4+m

g/m

3

05

1015

2025

30

2003002 - Point 1 SRN Boulogne - Chlorophylle a

1992 1994 1996 1998 2000 2002 2004 2006 20080

510

1520

2530

mg/

m3

-10

-50

510

1520

2003002 - Point 1 SRN Boulogne - Anomalies Chlorophylle aMéthode de calcul des anomalies : médiane par mois

1992 1994 1996 1998 2000 2002 2004 2006 2008

-10

-50

510

1520

05

1015

2025

30

Jan Fev Mar Avr Mai Jun Jul Aou Sep Oct Nov Dec

mg/

m3

2003002 - Point 1 SRN Boulogne - Variations saisonnières 2008 Chlorophylle aBoxplots calculés sur la période : 1992 - 2008

05

1015

2025

30

9298

0300

0897949901010202

* Regional Nutrient MonitoringNetwork (Ifremer / Artois-PicardieWater Agency)

The bloom in 2008 !?

Well-fitted with the seasonal cycle but …

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Results

Fluorescence 2008 - MAREL Carnot

The same bloom with HF measurements !

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Nutrients and phytoplanktonic dynamics

Fluorescence

Nitrate

Phosphate

Silicate

February – May 2007

(In Babin et al, 2008 - modified from Dickey 1991)

According to the objectives : ! Elementary knowledge on time scale !

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Uptake of silicate by DiatomsDiatoms

Fluorescence

Silicate

Nutrients and phytoplanktonic dynamics

March 2006

Complementarity between MAREL Carnot & S.R.N. :information on phytoplanktonic community involved

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Fluorescence

Nitrate

Silicate

Salinity

February– May 2007

Nutrients and phytoplanktonic dynamics

Early nutrient inputs => contribution to the main bloom

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Fluorescence

Nitrate

Silicate

Salinity

February – June 2006

Late nutrient inputs => secondary blooms :noxious diatoms or flagellates ?

Nutrients and phytoplanktonic dynamics

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0

5

10

15

20

25

30

35

01/0

1/20

06

01/0

2/20

06

01/0

3/20

06

01/0

4/20

06

01/0

5/20

06

01/0

6/20

06

01/0

7/20

06

01/0

8/20

06

01/0

9/20

06

01/1

0/20

06

01/1

1/20

06

01/1

2/20

06

NO

3- ,

SiO

H (

en µ

mol

/L)e

t C

hlor

o a

(en

µg/L

)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

PO

43-,

NO

2- e

t N

H4+

(en

µm

ol/L

)

SiOH NO3- Chloro a NO2- NH4+ PO43-

Role of the ammonium during the bloom

Results from the S.R.N.

In progress : Implementation of the CHEMINI CHEMINI system(CHEmical MINIaturized analyser)

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Effect of the sampling strategyon fluorescence distribution and his P90

Use of 4 filters on the 2005-2007 database:

• diurnal (7-19 h);

• diurnal et operationnal (Monday to Friday) ;

• diurnal et March-October ;

• diurnal, operationnal et March-October.

Control on sampling frequency:

• Monthly ;

• F1 : monthly then bi-monthly in March-april and September-October;

• F2 : monthly then bi-monthly from March to May and from August to October;

• Bi-monthly ;

• Weekly.

=> BOOTSTRAP methodology applied for a given year (study of the annual variability) then for 6 years (WFD management plan)

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P90 for simulated fluorescencefor a 6 years management planwith diurnal and operationnal data,and for monthly, bi-monthly andweekly sampling frequencies

=> Good assessment of the P90Good assessment of the P90

Effect of the sampling strategyon fluorescence distribution and his P90

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Effect of the sampling strategyon fluorescence distribution and his P90

P90 for simulated fluorescencefor a 6 years management planwith diurnal and operationnal datafrom March to October,and for monthly, F1, F2, bi-monthlyand weekly sampling frequencies

=> Over-estimation of the P90Over-estimation of the P90

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mer Access to data via the Nausicaa

browser within 24 h

MAREL Carnot and satellite imagery:High frequency and meso-scale approach

Sea Temperature:

Marel Carnot vs. Pathfinder data

February 2007 to February 2008

Water Framework Directive contextWater Framework Directive context : chlorophyll, turbidity, sea surface temperatureTo be continued To be continued (offshore and ecosystemic approach) : Marine Strategy Framework Directive

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Project Partners

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MAREL Carnot

10 meters

Thanks to the MAREL TEAM

Michel RepecaudRenaud VuilleminKarenn BucasDavid Le PivertLoïc QuémenerJean-Valery FacqVincent DuquesneCamille Blondel

Usual sampling conditions !

Who want to sample from a 5 meters long boat ?

THANKS FOR YOUR ATTENTION