As base of the benthic trophic web marine macroalgae play a key role within coastal communities. They serve as food source for fishes and many invertebrate grazers, and form microhabitats for smaller demersal fishes, invertebrates and microorgansims. Macroalgae can stabilise sediments, are commercially important as natural products, and play an essential role in terms of biodiversity. Due to their ecological key role, a change in seaweed communities will affect the whole marine ecosystem, including fisheries.
To understand the algal dynamics within coastal ecosystems, it is essential to gain a better knowledge of the change and development of benthic communities. In particular early settlers play a crucial role, as they settle under certain environmental conditions and either facilitate or inhibit the settlement of other species. This will in the long run affect the whole biodiversity of the ecosystem. In order to understand the benthic dynamics, the focus of my research is on the investigation of natural algal succession and the identification of early settlers, e.g. microorganisms and early macroalgal stages.
Macroalgae provide a valuable substratum for different epiphytic organisms, including benthic macro-and microalgae, as well as different invertebrates and microorganisms. Epiphytic loads can alter the flexibility of the host thallus by increasing the probability of axis breakage, can shade their host from incident light, release or compete for nutrients and change the thickness of the diffuse boundary layer over the host’s surface. The consequences may be an alteration in growth and reproduction, a change in chemical components and even a shift in the distribution of the host. In addition to these epiphyte-host specific interplays, the macroalgal associated organisms can directly or indirectly affect the surrounding ecosystem.
Among the macroalgal associated biota, we find dinoflagellates of the genus Ostreopsis, which form toxic blooms, increasingly observable in the Mediterranean region. Despite there is an urgent need to understand the factors driving the formation and toxicity of these blooms, only little is known on the eco-physiology of this benthic-pelagic taxon. In the frame of the cross-border European project "Risk Monitoring, Modeling and Mitigation of Benthic Harmful Algal Blooms along Mediterranean coast" (M3-HABs). I focus on the ecological connectivity of Ostreopsis cf. ovata and its phytobenthic substrates. The ongoing research shall investigate potential interspecific relations and aim to increase the detection sensitivity of Ostreopsis in its natural environment. This will increase the ecological understanding and support the toxic bloom monitoring activities in the Mediterranean coastal area.