EURO-BASIN WP2 Mesocosm 2012:

Status Report

Basic Info• Goal: To explore how different phytoplankton populations and the

presence or absence of macrozooplankton affect primary production, remineralization, aggregation, sinking fluxes, and the flow of material through the food web

• Experiment: A 3.5 week experiment with 18 mesocosms (+6 for a side experiment)

• Facility: NTNU (Norwegian University of Science and Technology)Sletvik field station, Bay of Hopavågen (a HYDRALAB IV facility)

• Access: 15-17 people, 36 days (mid July to late Aug 2012)– more people possible if funds for travel & accommodation are paid

Sletvik field station, Bay of Hopavågen

• Hopavågen is a semi-enclosed lagoon, 120 km west of Trondheim and 20 km west of the outlet of the Trondheimsfjord.

• It is sheltered from wind and waves, has an area of 27 ha, a volume of 5,5 million m3, and a depth that varies between 22 m and 32 m.

• Due to tidal forcing, about 14% of its water is exchanged per day, through a narrow inlet.

Bergen

Trondheim

Sletvik Field Station,Hopavågen

Sletvik field station, Bay of Hopavågen

Sletvik field station, Bay of Hopavågen

• The Sletvik field station is located 300 m from the lagoon and has a laboratory space of 250 m2, kitchen facilities, nearby catering possibilities, and dormitories for 50 people.

• It has also a pier and a small laboratory at the shore of Hopavågen.

• Hopavågen is ideal for testing instrumentation as well as testing and validating ecological models.

Sletvik field station, Bay of Hopavågen

they are no stranger to mesocosm experiments

Sletvik field station, Bay of HopavågenAccess is funded through the HYDRALAB IV

European transnational facilities project(i.e., they provide the travel costs, room & board, and access to the field site for 15-17 people)

BASIN (WP2 funds to CDLR) pays for core measurements, sampling equipment, & consumables related to core measurements

Side experiments supported through external funding (e.g., NERC, CNRS)

Participants

1. C. De La Rocha (IUEM) 11. M. Koski (DTU)

2. H. Stibor (Munich) 12. R. Lampitt (NOC)

3. B. Moriceau (IUEM) 13. S. Giering (NOC)

4. P. Pondaven (IUEM) 14. M. Le Goff (IUEM)

5. M. Gallinari (IUEM) 15. R. Bellerby (Norway) ?

6. T. Jansen (Kiel) 16. P. Assmy (Norway) ?

7. J. Butorh (IUEM) 17. M. Iversen (Bremen) ?

8. N. Coffineau (IUEM)

9. V. de Schryver (Munich)

10. A. Leynaert (IUEM)

Local participants: Olav Vadstein, Yngvar Olsen, Øystein Leiknes

Provisional Timeline

• Day 1-7 Setup (small group); others trickle in• Day 8-20 Begin; add Si, N, P daily• Day 21-30 No addition of nutrients• Day 31-36 Finish experiment, wrap up onsite

analyses, pack up, leave

Matrix of Mesocosms unfiltered SW

macrozoops removedunfiltered SW

copepods added back

diatoms

dinos

coccos

mineral addition

Vertical Sampling Plan

10 m

0 m

3 m

6 m

9 m

Temporal Sampling Plan

• 7-11 sampling dates within the ~22 days of the experiment (i.e., every 2nd or every 3rd day)

• This would yield 500-800 water column samples for each core measurement… and 3x that if done in triplicate– strategies to reduce this number for labor intensive or

expensive measurements need to be discussed

Core MeasurementsNutrients: DSi, NO3

-, NO2-, NH4

+, PO4 (LeGoff)

bacteria counts (Gallinari)

PIC, BSi (Moriceau, Butorh) oxygen production (to yield GPP and NPP) (?)

PAM (light use efficiency, chlorophyll, etc) (Stibor, deSchryver)

respiration rates (?)

POC, PON, POP (LeGoff) grazing rates (Pondaven, Coffineau, others?)

size fractionated POC, PON, POP (Gallinari, DLR)

primary production (via gross growth rate) (Pondaven, Coffineau, Leynaert, others?)

zoop POC, PON, POP (Pondaven, Coffineau)

species specific growth rates (phyto, zoop) (Pondaven, Coffineau, Leynaert, others?)

DOC, DON, DOP (Gallinari, CDLR) CTD (LeGoff)

pigments (Stibor, deSchryver) Sediment :

TEP, CSP (Moriceau, Butorh) POC, PON, POP (Gallinari, DLR)

phyto counts (Gallinari) PIC, BSi (Moriceau, Butorh)

zoop counts (Pondaven, Coffineau, others?)

TEP, CSP (Moriceau, Butorh)

Additional Measurements

composition of POM (Moriceau, Butorh)

compound specific sulfur isotopes (Jansen)

lipids for tracking flow of materials (Jansen)

flow cytometry (cell viability, etc) (Moriceau, Gallinari, Butorh)

silicon isotopes of DSi; BSi in diatom mesocosms (CDLR, Gallinari)

Proposed Side Experiments

grazing induced changes in silicification

Pondaven, Coffineau, Moriceau, Gallinari, Butorh, CDLR

jellyfish (if present) Stibor & Jansen

mixotrophy deSchryver

impact of calcium carbonate on food web; impact of food web on calcium carbonate dissolution/CO2 sequestration

Lampitt & Giering (& Bellerby?)

aggregation under the different conditions

Iversen (?)

feeding of zooplankton on aggregates

Koski & Iversen (?)

Tasks for the Next Few Months

• receive exact dates for experiment• finalize participant, measurement, and side

experiment lists• finalize sampling plan• submit data management plan to HYDRALAB• begin purchasing consumables and sampling

equipment