Agence de Conseil et de Recherche Océanographiques, 19320 La Roche Canillac, France.

1. Exopolymeric secretions in HABs : How flow, diffusion and bioengineering may depend on length scale (as well as on rheology, turbulence, behaviour, chemistry, surface properties at membranes, etc) Ian R. Jenkinson Tim Wyatt Consejo Superior de Investigaciones Cientificas,Instituto de Investigaciones Mariñas 36208 Vigo, Spain.twyatt@iim.csic.es Agence de Conseil et de Recherche Océanographiques,19320 La Roche Canillac, France. ian.jenkinson@wanadoo.fr

2. Two vessels with exit holes of radius R

3. Dry powder of grain“radius” r r << R/5 r >>R/5 Two vessels with exit holes of radius R

4. Dry powder of grain“radius” r R << 5r R >> 5r Clogs (Jams) X Flows Two vessels with exit holes of radius R

5. Vessel with exit hole of radius R

6. Newtonian liquid Vessel with exit hole of radius R

7. Newtonian liquid Flows Vessel with exit hole of radius R

8. Newtonian liquid Assuming no inertial effects (low Re), flow rate F ~ / where is hydrostatic pressure and is dynamic viscosity Flows Vessel with exit hole of radius R

9. Monodisperse liquid or paste with yield stress Y Y >> Y << Two vessels with exit holes of radius R

10. Monodisperse liquid or paste with yield stress Y Y >> Y << Gels Flows F~(-Y)/ X F = 0 Two vessels with exit holes of radius R

11. Summary

12. Summary 1. Hard, dry suspensions (powders, sand, etc.)

13. Summary 1. Hard, dry suspensions (powders, sand, etc.) If hole diameter D >> ~5 . grain diameter, then material flows. Otherwise is jams however high τ.

14. Summary 1. Hard, dry suspensions (powders, sand, etc.) If hole diameter D >> ~5 . grain diameter, then material flows. Otherwise is jams however high τ. 2. Monodisperse materials (liquids, solids, gels...)

15. Summary 1. Hard, dry suspensions (powders, sand, etc.) If hole diameter D >> ~5 . grain diameter, then material flows. Otherwise is jams however high τ. 2. Monodisperse materials (liquids, solids, gels...) Material properties (viscosity, elasticity, yield stress) constant across all length scales.

16. Summary 3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid.

17. Summary 3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid. Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges

18. Summary 3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid. Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges 4. Suspensions of soft particles and bubbles.

19. Summary 3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid. Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges 4. Suspensions of soft particles and bubbles. Same as above, but increasing τ can cause particles or bubbles to yield in the hole.

20. Summary 5. Suspensions of aggregates, flocs, etc. including soft particles aggregated in matricesof softer aggregates (lumpiness)

21. Summary 5. Suspensions of aggregates, flocs, etc. including soft particles aggregated in matricesof softer aggregates (lumpiness) Very complex, but empirically viscosity and yield stress are a negative function of hole size(and probably of length scale in general)

22. Summary 5. Suspensions of aggregates, flocs, etc. including soft particles aggregated in matricesof softer aggregates (lumpiness) Very complex, but empirically viscosity and yield stress is a negative function of hole size(and probably of length scale in general) Maybe natural waters are mostly like this, but with aggregates very dilute and tenuous, compared to, say, what we are used to in foodsor industrial reactors.

23. Intertidal organic aggregates

24. Pampin Mudflat Fluff obtained here 10 km

25. Mud flatswith fluid mud Mud flatswith intertidalfluff

26. ?? Harmful algae ?? Mud flatswith fluid mud Mud flatswith intertidalfluff

27. ?? Harmful algae ?? Is this alga-rich fluff suffocating young sole ? Mud flatswith fluid mud Mud flatswith intertidalfluff

28. ?? Harmful algae ?? Is this alga-rich fluff suffocating young sole ? Between birds andsuffocation? Mud flatswith fluid mud Mud flatswith intertidalfluff

30. Didymosphenia geminata invading New Zealand rivers Pictures received from Christina Vieglais via Diatom-L list21 August 2006

31. Y h The Kasumeter (Yield stress viscometer) Mud flatswith fluid mud Mud flatswith intertidalfluff

32. Y h The Kasumeter has been adopted as an EU standard for measuring the « flowability » of sewage sludges (HORIZONTAL Report No. 21, 2004) The Kasumeter Mud flatswith fluid mud Mud flatswith intertidalfluff But sewage sludge, like pelagic and benthic marine organic aggregates, consist of a hierarchical (quasi-fractal) mixture of exopolymeric flocs, or aggregates

33. Yield stress of sewage sludge for different sludge concentrations (%) as a function of tube diameter. (Drawn from data in Spinosa and Lotito (2003) Adv. env. Res. 7:655-659). Y h The Kasumeter Mud flatswith fluid mud Mud flatswith intertidalfluff

34. Yield stress of sewage sludge for different sludge concentrations (%) as a function of tube diameter. (Drawn from data in Spinosa and Lotito (2003) Adv. env. Res. 7:655-659). Y h The Kasumeter Mud flatswith fluid mud Mud flatswith intertidalfluff Y ~ d-2

35. Rheosole ichthyoviscometer Jenkinson, Claireaux and Gentien, (2006) Mar. Biol., in press and published online It gets the scales and measurement geometry right

36. Procedure: • A dead sole is arranged so that the tap nozzle fits in its mouth • Test material flows from SR to LR through a tap, into the mouth and through the gills of the dead sole • As the material flows, the hydrostatic pressure difference, H(t) (~water level difference) between the water in each cylinder is measured using a pressure probe, and recorded on computer every 0.5 s.

38. Rheosole ichthyo-viscometer Pure seawaterLin-lin Pure seawaterLog-lin P increased by 10 Pa Plots of hydrostatic pressure difference P vs. time t, obtained with the ichthyoviscometer. 50% fluff [POM]=(8.4 g.L-1)Log-lin 50% fluff [POM]=(8.4 g.L-1)Lin-lin 1 cm water ~ 100 Pa

39. Rheosole ichthyo-viscometer Pure seawaterLin-lin Pure seawaterLog-lin P increased by 10 Pa Plots of hydrostatic pressure difference P vs. time t, obtained with the ichthyoviscometer. 50% fluff [POM]=(8.4 g.L-1)Log-lin 50% fluff [POM]=(8.4 g.L-1)Lin-lin Straight line for log(Y) vs t 1 cm water ~ 100 Pa

40. Rheosole ichthyo-viscometer Juvenile sole (25 g) can produce a cross-gill hydrostatic pressure P of ~30 Pa So if Y > P they can'tventilate

41. From Žutić and Svetličić in CIESM, 2006, Workshop Monograph N° 28(Cambados)

43. Adriatic – artist's impression

44. Mucus event in Adriatic, 1983. Giant mucus streamer in 5 m depth. Field of view approx. 8 m2 (Stachowitsch, 1984)

45. Adriatic: Normal appearance of benthos, 1983 (Stachowitsch, 1984)

46. Adriatic: Mare sporco mucus event, 1983. Sponge with mucus cover, and entangled crab. (Stachowitsch, 1984)

47. J. Plankt. Res., 17: 2251-2274 (1995) Viscous modulus (µPa) (Viscosity at shear rate = 1/s) measured in a Couette rheometer

48. HAB 2000, Hobart, 2000

49. t (s) Pure seawater 1 cm water ~ 100 Pa

50. Quasi yield-stress behaviour Pure seawater 1 cm water ~ 100 Pa 1 cm water ~ 100 Pa