| title: | Allelopathy in toxic haptophytes - functional relationships |
|---|---|
| reg no: | ETF6470 |
| project type: | Estonian Science Foundation research grant |
| status: | accepted |
| institution: | University of Tartu |
| head of project: | Kalle Olli |
| duration: | 01.01.2005 - 31.12.2008 |
| description: | Haptophytes (syn Prymnesiophytes) are a group of planktonic algae, some of which excrete highly potent directly into the surrounding environment. Frequent blooms in brackish waters cause death of other aquatic organisms and can lead to catastrophic consequences to the ecosystem. One of the manifestation of toxic haptophyte blooms is mass mortality of fish. Fisheries and aquaculture industry suffer from vast economic losses. The exact chemical composition of haptophyte toxins, which are secondary metabolites, is not know yet, making analytical measuring of concentrations impossible. However, toxin concentrations can be assessed indirectly through the level of impact on other organisms. The evolutionary significance of toxin production is not known, though, there are numerous hypothesis. At low or moderate concentrations the toxins repress the growth of other phytoplankton species - this is called allelopathy. Toxins can also deter herbivores, stimulate mixotrophic nutrition by paralysis of potential prey cells. This project aims to study the functional relationships between a gradient of toxin concentrations and the level of impact on other planktonic organisms. The project is based on laboratory experiments with monospecific cultures, including chemostat experiments. Other specific hypothesis focus on the degradation kinetics of toxins in the water; the sensitivity of a variety of plankton organisms with different phylogenetic distance from the causative species to the toxins; the impact of toxins to the causative species themselves; and the role of allelopathy in nutrient competition with other phytoplankton species. This project grow out from the results of a EU 5th framework project 'FATE' (Transfare and fate of harmful algal bloom toxins in European waters'), which ends in 2004. Our hypothesis are based on numerous preliminary experiments and ideas generated during pilot studies. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Kalle Olli | University of Tartu | Senior research fellow | |