EU network of mesocosms facilities for research on marine and freshwater ecosystems open for global collaboration.

Task 7.4

Task 7.1 Conceptualisation of a prototype AQUACOSM
Task 7.2 Construct offshore water collection devices to fill AQUACOSMS from exposed sites
Task 7.3 Construction of a prototype mesocosm(s) and testing of the AQUACOSMS in Umeå
Task 7.4 Conceptualization and testing of methods to avoid or handle wall growth
Task 7.5 Construction the AQUACOSMS
 Task 7.6 Testing of the AQUACOSMS under Arctic conditions in NyÅlesund

Conceptualization and testing of methods to avoid or handle wall growth (Lead: WCL, Co-
Lead: FVB-IGB, Participants: GEOMAR, Month 18-48)

Less laborious cleaning systems than presently available in e.g. KOSMOS will be developed by a new method to keep fouling inside the mesocosms at a low level without adding or removing any material from the mesocosms. Non-pellucid double layer mesocosm bags, where the inner layer is turned ca. weekly (WCL-Ptacnik and FVB-IGB-Berger unpublished) should effectively allow long-time/seasonal studies, also in these medium-sized Aquacosms. This is especially important as many previous mesocosm studies may have been too short to reveal true long-time effects of ecosystem disturbances. Alternative systems for handling wall growths, e.g. modification of the KOSMOS system will also be tested with the prototype to evaluate which one functions best with the AQUACOSMS under ice and ice-free conditions. Best construction will be selected, 6-9 units produced and sent to NyÅlesund with the AQUACOSMS (Task 7.6) for the Arctic test (WP9.2.2)