MUMM

Bivalves adaptation in the

BCS: a trait-based approach

E. Martini, X. Desmit, G. Lacroix, F. Kerckhof, S. Degraer

Liége ColloquiumMay 15, 2013

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMIntroduction

Species distribution+

Environmental factors distribution

Correlation

No mechanistic linkMacoma balthica Abra alba

Degraer et al. 2008

Hypothesis: bivalves growth and survival depends on TSM

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMM

The bigger the organs the better their function

TSM

Food for bivalves: algae + detritus

Gradient in the BCS

Palps

Compton et al. 2007© Barbara Harmon

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMHypothesis and conceptual model

Hypothesis: bivalve communities in the BCS are structured by food availability and quality, and the traits determining the fittest species are gills and palps masses.

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMBivalves model equations

(Filgueira et al. 2008)

(Prins et al. 1991, Kiorboe et al.1981)

𝑑𝐵𝑑𝑡

=𝐵 (𝐴−𝑅 )

𝐴=𝑎𝑒∙𝑆∙𝐶𝑅 ∙𝑇𝑆𝑀𝑅=𝑟 𝐵𝑏

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMMeasuring traits - Methods

Campaign on board Belgica

In the lab

• Burned in the muffle furnace at 500° C for 4 hours

• Weighted to the 0.1 mg

• dissection of gills and palps within the 24 h

• 8 m beam trawl on several transects

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMM

Abra alba (33)

Macoma balthica (50)

Donax vittatus (49)

Spisula solida (60)

Feeding strategy Deposit Deposit Suspension Suspension

Gill/Palp 0.36±0.15 0.37±0.11 2.34±0.73 2.67±0.61

Gills + palps/Body (%) 8.6±2.2 4.8±0.4 12.0±0.2 4.8±0.8

Measurements results

Remote sensing TSM (g m-3)

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMMeasurements results

Compton et al. 2007

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMM

Palp: 4.3 mgGill/palp : 2.9

Measurements results

2

1

Palp: 5.9 mgGill/palp : 2.4

Remote sensing TSM (g m-3)

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMPreliminary model results

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMPreliminary model results

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMM

• Data show that in the BCS gills and palps masses respond to TSM and food concentration in line with our hypothesis

• Size of the feeding apparatus (gills+palps) seems to play a role (feeding time)

• Lack of parameters for model rates

• Physiological plasticity to adapt to different conditions can widen the range of values for the traits.

Final thoughts

For the future

• Refine model parameters, also through experiments that measure the rates

• Extend the measurements to more conditions and species

To summarize:

• Improve the model

Liège Colloquium 2013 May 15, 2013 http://www.mumm.ac.be

Management Unit of the North Sea Mathematical ModelsMUMM | BMM | UGMMAcknowledgments

TRIPS. Assessing macrobenthos adaptation with a trait-based model in the Southern bight of the North Sea

Thank you for your attention!