About the HIMOM project (running from 2002-2005)

Jacco Kromkamp and Rodney Forster at NIOO-CEME

We are developing a system of Hierarchical Monitoring Methods for use in European estuaries

This toolkit includes calibrated methods for measuring sediment properties such as microalgal biomass and photosynthesis

We are using remote sensing to estimate primary production of estuaries around the North Sea

We work together with DIVPROD to quantify ecosystem function and microphytobenthic activity on intertidal flats of the Westerschelde estuary

A model has been developed to provide accurate estimates of daily primary productivity at each of the DIVPROD collection sites

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Irradiance (relative units)

Dep

th (

um)

A detailed sediment optical model lies behind the primary production calculations

Benthic chlorophyll concentration in upper 1 cm up to 10 000 mg m-3

Highest natural phytoplankton concentrations 250 mg m-3

Forster & Kromkamp 2004

High resolution primary production model

14C photosynthetron

02468

101214

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Pm

ax

(mg

C m

g c

hl a

-1 h

-1)

00.0010.0020.0030.0040.0050.0060.0070.0080.009

alp

ha

Pmax alpha

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PA

R

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Te

mp

erat

ure

PAR Temperature

1) PAR / SST - time0.01

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1

10

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Chl a (mg g-1 dw)

Dep

th (

mm

)

06:30 07:30 08:30 09:30 10:30 11:30

3) Chl-depth0

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Irradiance (mmol photon m-2 s-1)

De

pth

(m m

)

'11:30' '9:30'

4) Irradiance-depth

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Photosynthetic rate (mg C m-2 h-1)D

epth

(m m

)

(1) Light and temperature at the sediment surface

(2) Vertical profile of microalgae chlorophyll with depth

(3) Vertical profile of irradiance in the first 1mm of the sediment

(4) Site-specific photosynthetic parameters are measured in the lab during each sampling event

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Photosynthetic rate (mg C m-2 h-1)

Dep

th (m m

)

Photosynthetic rates are integrated over depth and time

Σt Σz P

to obtain daily gross primary production

(units: g C m-2 d-1)

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Dec-02 Jan-03 Mar-03 May-03 Jun-03 Aug-03 Oct-03 Nov-03

Gro

ss p

rim

ary

pro

du

ctio

n (

mg

C m

-2 d

ay-1

)

09-2003 sampling

y = 0.88x

y = 0.4x

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Quanta (mol m-2 day-1)

gC g

chl

a-1

day

-1

Daily primary production per unit biomass shows a linear relationship with light availability

Light use efficiency of MPB is higher than that of phytoplankton

phytoplankton

MPB

CASI chlorophyll distribution of the Molenplaat