Summer School on "Turbulence, Plankton, and Marine Snow"

Organizers: Herman Clercx, Tim Pedley, Jaume Piera, Francois Schmitt and Anton van Steenhoven

From 1-5 September 2008 the Summer School on Turbulence, Plankton and Marine Snow was held in Vilanova i la Geltru (Spain). The aim of the one-week summer school was to provide an intense course on current advances in the field with six keynote lectures by specialists in the subject, and four specialised lectures. The main emphasis was put on the fluid-mechanical aspects of ocean flows, patchiness of plankton and bloom formation, the dispersion of species in small-scale turbulence, the role of small-scale hydrodynamics on the swimming behaviour and contact rates of plankton and on the fate of marine snow. Attention has also been paid to the theory and modeling of geophysical turbulence, laboratory experiments, and in situ observation of plankton in estuarine turbulent flows.

More than 60 applications were received, most of them PhD and Postdoctoral researchers, which clearly indicates the interest in this multidisciplinary topic where marine biology and fluid mechanics come together. Almost all applications fitted very well within the scope of the summer school. Unfortunately, we could only accept 28 applications (45% female; 55% male). The participants came from laboratories well-distributed over Europe (and a few from the USA): France (5), UK (5), Spain (4), Germany (3) USA (3), Norway (2), Netherlands (2), Sweden (1), Italy (1), Ireland (1), Estonia (1). Almost all students gave a brief presentation (5-10 minutes) to present themselves and to give an overview of their research interests and ongoing research activities.

In the keynote lectures the following topics have been addressed:

1) "Turbulence in the ocean: an introduction to its physics" by Steve Thorpe (Bangor, UK). This lecture focused on turbulence in non-stratified systems, introduction in the theory of dispersion, turbulence in stratified systems, and boundary layers (the near-surface mixed layer and the benthic boundary layer).

2) "Small-scale hydrodynamics and plankton" by Andy Visser (DTU, Copenhagen, Denmark). This lecture addressed the kinematics of encounter rates, the role of small-scale hydrodynamics on moving and swimming of plankton, and the basic mechanisms of hydrodynamic signalling.

3) "Mesoscale turbulence and plankton patchiness" by Marina Levy (LOCEAN-IPSL, Paris, France). An introduction in the mesoscale transport of phytoplankton in geophysical flows was presented and the basic mechanisms of bloom formation were discussed. The role of oceanic mesoscale turbulence on the modulation of biological production was reviewed.

4) "Experiments and observation of plankton in turbulence" by Francesc Peters (IMS, Barcelona, Spain). After a brief review of turbulence and its role on plankton in aquatic systems different laboratory experiments and measurement tools for studies of plankton in turbulence were discussed. An outline of typical results was given and discussed and connected with observations from small- and large-scale systems.

5) "The formation and fate of marine snow: the role of hydrodynamics" by Thomas Kioerboe (DTU, Copenhagen, Denmark). The first part of this lecture fully focused on the formation, fate and significance of marine snow and its role as a source of small-scale heterogeneity. The second part reviewed the bacterial colonization of (marine snow) particles and the optimal swimming strategies of plankters.

6) "Animal and robot strategies for tracking odors underwater" by Frank Grasso (CUNY, New York, USA). This contribution focused on (turbulent) plumes, plume tracking by animals and in particular lobster chemo-taxis in a turbulent plume.

Four short lectures on special topics were given:

"Turbulent exchange in the benthic boundary layer" by Luca van Duren (Deltares, Delft, Netherlands), "Planktonic contact and capture rates in turbulent environments" by Hans Pecseli (UIO, Oslo, Norway), "Using CFD to investigate the copepod hydrodynamics" by Houshuo Jiang (WHOI, USA), and "Physical gradients and biological responses across the edge of the continental shelf" by Jonathan Sharples (POL, Liverpool, UK).