the effect of food composition on feeding, growth and reproduction of bivalves sofia saraiva 1,3,...

The effect of food composition on feeding, growth and reproduction

of bivalvesSofia SARAIVA1,3, Jaap VAN DER MEER1,2, S.A.L.M. KOOIJMAN2, T.

SOUSA3

[email protected]

1. Royal NIOZ, P.O. Box 59, 1790 AB Den Burg , The Netherlands2. Free University Amsterdam, Amsterdam, The Netherlands

3. Instituto Superior Técnico. Environment and Energy Section, Av. Rovisco Pais, 1, 1049-001, Lisboa, Portugal

April 2009

DEB Theory: 30 years of research for metabolic organization

DEB2009 Symposium

April 2009

April 2009

DEB Theory: 30 years of research for metabolic organizationDEB2009 Symposium

The effect of food composition on feeding, growth and reproduction of bivalves

AimCouple a size-structured population model for several bivalve

species to a hydrodynamic and biogeochemical model

Individual Based Population Model

Integrated Modelling ToolTo simulate properties evolution in estuaries and coastal areas where bivalves are abundant (natural or cultured populations)

Set of couple models

www.mohid.com

Dynamic Energy Budgets theoryHydrodynamic, eulerian and lagrangian advection-

diffusion, sediment transport and biogeochemical/ecological models

Bivalve activity over the pelagic system

Influence of different climate scenarios in the production and distribution of different bivalve species

April 2009



Why do we need an ecosystem Model?

Estuaries and Coastal Areas

Ecological Processes

Ecosystem Model

Organisms

Tide, WindFresh Water DischargesDensity driven currents

FoodTemperature

Predation

Hydrodynamics

FoodAvailability

Particulate MatterErosion/Deposition

Residence TimeLight

Nutrients (N/P)Temperature



Bivalve model AND Ecosystem Model

DEB

DEB

DEB

DEB

Cohorts

PhytoplanktonZooplanktonParticulate Organic MatterSedimentsNutrients (N and P)

FILTRATION

INORGANIC FLUXESFAECESPSEUDOFAECES

Bivalve StructureBivalve ReservesBivalve Reproduction BufferBivalve Maturity

INGESTIONASSIMILATION

FOOD QUALITYFOOD QUANTITY



Standard DEB Model

FOOD

GROWTH

k 1-k

FAECES

MOBILIZATION

MATURITY MAINTENANCE

SOMATIC MAINTENANCE

REPRODUCTIONBUFFER

RESERVES

STRUCTURE

REPRODUCTION

SPAWNING GAMETES

MATURITY

INORGANIC COMPOUNDS

CO2

H2O

O2

NH3

PO4• structures/ reserves• isomorph• k-rule• maturity concept• maintenance

ASSIMILATION

FILTRATION

FAECES

FOOD

PSEUDOFAECES

INGESTION

ZooplanktonPhytoplanktonOrganic Matter

Sediments

Variable Compositi

on

DEB Model

Variable Compositi

on



Feeding Processes in Bivalves

FILTRATION INGESTION ASSIMILATION

RESERVES

…

PSEUDOFAECES FAECES

( )i inX F

( )i outX FiX F

J

PFiP F

J FiP IJ

iX IJ

iE AJ

ZooplanktonPhytoplankto

nOrganic Matter

Sediments

Synthesizing Units

SequentialSubstitutable

SequentialSubstitutable

ZOOPLANKTON

STRUCTURERESERVES

Yield Coefficient

PHYTOPLANKTON

STRUCTURE

Yield CoefficientRESERVES

ParallelComplementary

DETRITES Yield Coefficien

t

-Any property can be processed independently from the others-The binding of each property is affected by the presence of others

-A specific ratio N/C is needed-No interaction at binding level



Parameters in Feeding Processes

FILTRATIONASSIMILATION

FILTRATIONINGESTION

ASSIMILATION

Maximum surface area-specific filtration rate, m3d-

1cm-2Maximum surface area-specific uptake rate, molCd-

1cm-2

Yield coefficient of reserves on food,

molC(reserves)/molC(food)

Maximum surface area-specific filtration rate, m3d-

1cm-2Maximum surface area-specific uptake rate, molCd-

1cm-2Yield coefficient of reserves

on food, molC(reserves)/molC(food)

Maximum surface area-specific property i ingestion

rate, m3d-1cm-2

One more parameter

for each type of food

“measure” of the bivalve selectivity for

each type of food



Model vs. Observations

Mussels - 6cmTemperature – 6.5 oCSeveral lab experiments with increasing silt and detritus concentration in the waterMeasurements in filtration and pseudofaeces



Model vs. Observations



Model vs.

Observations

-Filtration, Ingestion and Pseudofaeces computed by the model follow the main patterns of observations

- Some differences can be found but many assumptions had been made

-Not all the model capacities were tested

-More work in the calibration and validation of the model has to be done



“Playing with the model”Test the influence of food quantity and quality in the bivalve feeding, growth and reproduction

-2 Types of food (A and B)-Same concentration, constant-High concentration (1mgC/l)-Constant temperature

No selection (same affinity)

Selection for food A (different affinity)

-At high food concentration the ingestion of each type of food is only limited by the bivalve selectivity-Without selectivity there is no production of pseudofaeces but with selectivity some of the “less selected” type of food will be rejected-If concentrations are the same in the water column, selectivity can lead to lower growth rate and lower length-Low food, low growth, low reproduction buffer, less spawning events



“Playing with the model”-2 Types of food (A and B)-Same concentration, constant-Low concentration (0.05mgC/l)-Constant temperature

No selection (same affinity)

Selection for food A (different affinity)

-The ingestion is limited by filtration and there is no selectivity by the bivalve-The bivalve ingestes everything that is filtered and there are no production of pseudofaeces



Still “playing with the model”: a more realistic scenario

Temperature and Food Algae N/C ratio? NutrientsLightTemperature

Nutrients Uptake

Lightα Temperature

CarbonUptake



Constant vs. Seasonal N/C algae ratio

-Seasonal changes in algae N/C ratio => difference in the nitrogen uptake => differences in assimilation => differences in growth-Algae N/C ratio changes could be important to explain bivalve performances in different places

The model presented is based on:



Conclusions

To simulate food quality an extension of the standard DEB model is needed

Food quality and quantity is a key factor for mussels growth/performance

Filtration/Ingestion/Assimilation as different processesSynthesizing units mechanism

Pseudofaeces and Faeces productionSeveral types of food

Food quality (ex. algae N/C ratios) can have significant influence in bivalve’s growth and variations should be consider when comparing different populations in different locations

Model results globally agree with patterns described in literature but more work could be done in calibrating/validating the model using more data sets (if available)

Useful model and conceptually a good approach to deal with the bivalves food quality changes at the ecosystem scale


Sofia SARAIVA1,3, Jaap VAN DER MEER1,2, S.A.L.M. KOOIJMAN2, T. SOUSA3

[email protected]

1. Royal NIOZ, P.O. Box 59, 1790 AB Den Burg , The Netherlands2. Free University Amsterdam, Amsterdam, The Netherlands

3. Instituto Superior Técnico. Environment and Energy Section, Av. Rovisco Pais, 1, 1049-001, Lisboa, Portugal April 2009

DEB Theory: 30 years of research for metabolic organization

DEB2009 Symposium

April 2009

Thank you!!

the effect of food composition on feeding, growth and reproduction of bivalves sofia saraiva 1,3,...

Documents

effect of food composition

years of research

structures reserves

couple models

energy section

free university amsterdam

sediment transport

properties evolution