Mesocosms employ a battery of tools from experimental science (hypotheses testing with parallels, controls, factorial designs and reproducibility) with the advantage of making them available on a scale that permits their use under near natural ecosystems.
Research in this field is both fundamental, in the sense that the aim is to understand generic properties of the system; and applied, in the sense that one wants to know the consequences of these properties in fields like e.g. ecotoxicology, aquaculture or climate change. In fact, the study of the fundamental properties of aquatic ecosystems has, to a large extent been driven by the use of mesocosm facilities.
There is further no abrupt transition between studying generic system properties and more applied studies. One applied aspect closely related to generic studies is the behaviour of a mesocosm system in specific environments and the differences between environments.
Increased use of mesocosm-facilitated research is indispensible to the understanding of the functioning of whole ecosystems, especially in light of the recent focus on global change and the urgent need to be able to predict the response of the ocean system to factors such as increased pCO2/decreased pH, temperature and stratification (influencing both light and nutrient availability).
Mesocosm studies can bring together scientists from a variety of disciplines, ranging from e.g. molecular and cell biology, physiology, marine ecology and biogeochemistry to marine and atmospheric chemistry and physical oceanography. Thus, a joint mesocosm experiment is a very efficient tool for fostering a culture of co-operation. The need to collectively plan such experiments, to provide high-quality data within given dead lines, to collectively publish the result, and not least the social pleasure of doing this as a member of a multi/disciplinary team, tends to create networks and working relationships that last far beyond the period of any single project.