Marine macroalgae and seagrass communities are an important element of the world's coastal ecosystems. In eutrophicated areas, mats of green macroalgae, mainly consisting of Ulva spp., can often be observed. These mats have a strong negative impact on seagrass communities through competition for nutrients and light. To be able to assess and to predict the (in)stability of these systems there is a strong need to develop markers of physiological stress in marine plants.
The proposal has the following research objectives:
1) to develop stress indicators in macroalgae and seagrasses in mats;
2) use these indicators to determine (physiological) acclimation mechanisms of algae and seagrasses in living in the intertidal zone. The project will combine field and laboratory studies. The study wil cover different scales, from the ecosystem level to physiological and biochemical approaches.
Potential stress markers will be evaluated experimentally for responses to specific environmental stress variables in a restricted number of species and seasonal development of the markers will be monitored in the field. This proposal combines the use of traditional physiological analyses with more recently developed techniques, such as chlorophyll fluorescence. Additionally, the glutathione redox ratio and proteolytic activity will be determined, of which very little is known of in marine photosynthetic organisms. This proposal will be one of the first studies exploring these two markers in rnarine macrophytes.