Directory entires that have specified Germany as the primary or lead country for the project/activity and are included in the AMAP, ENVINET, SAON and SEARCH directories. To see the full list of countries, see the countries list. The specified country may not be the geographic region where the activity is taking place - to select a geographic region, see the list of regions.
It is also possible to browse and query the full list of projects.
To edit or add records to any of the catalogs, log in or create an account.
In contrast to many other marine regions, chemical interactions between organisms in Arctic waters are little understood. This project investigates natural products and chemical interactions in the sponge genus Haliclona in temperate and polar waters. Several new secondary metabolites isolated from Haliclona show feeding deterrence and activity against bacteria and fungi, but the compound composition varies with habitat and year. That raises the question whether sponges of the genus Haliclona as a model are able to adapt to changing environmental factors such as water temperature and colonization by bacteria by varying their secondary metabolite composition.
Plankton of shallow polar freshwater water bodies is exposed to increasing levels of ultraviolet radiation (UVR) due to the limited water depth. Daphnia (Crustacea, waterflea) and algae are common representatives of the food chain in these water bodies. Daphnia almost exclusively use lipids for energy storage, which they obtain from their food (mainly algae). Therefore, Daphnia and algae are closely linked to each other. Preliminary experiments on the UV-induced damage in phyto- and zooplankton point to lipids as one of the key players. With this application we want to identify how algae specific lipids and fatty acids (FA) are modified by UVR. The factors modifying UV-doses to the animals and their food are depth of the waterbody and DOC (absorbs UV). A pondsurvey shall provide a wide spectrum on ponds which vary in DOC and depth. Lipid analysis of Daphnia and their food of these ponds as well as physical parameters of the pond waters shall identify correlations between UV-exposure and specific fatty acids. This shall enable us to estimate the effect of solar UVR on the freshwater plankton community in polar ponds.
The aim is to study the diversity and function of marine bacteria closely associated with marine sponges. The special character of life strategy of the community (symbiosis – commensalism), with special emphasis to the identity and the recruitment of bacteria during live cycle of the sponges will be described.
Little is known about the consistency or phylogenetic affiliation of accociated intra- or extracellular bacterial populations in Echinodermata. Because certain taxa harbour bacteria and other not, these associations are presumably originated by coevolution and not by ecological circumstances. The intestine of echinodermata is populated by huge amounts of bacteria. Due to the different feeding strategy of echinoderms it is controversly discussed whether these bacteria are passively taken up or if they are permanently present. Hence it will be possible to elucidate if vertical transmission occurs or bacteria are recruted. With the knowledge of phylogenetic affiliations of microbial symbionts and their distribution (or localization) in different hosts, the physiological/biochemical status of the association will be investigated. The main emphasis will be the characterization of the in situ situation by adequate histological techniques (crysectioning) and “passive” (FT-IR) or “active” chemical imaging (confocal imaging, using fluorescent enzyme substrates or physiological dyes). The main experimental work in this WP bases on the creation of 16S-rDNA sequence libraries of echinoderrm associated bacteria (SCB & intestinal). Signature sequences will be analyzed and specific gene probes will be designed and applied.
The main research goal of this project is focused on trophic interactions within microbenthic communities in aquatic systems. Grazer-microalgae interactions are investigated by conducting field and laboratory experiments in order to get a closer idea of the microphytobenthos community structure itself. Especially the role of morphological and physiological adaptations of microalgae in the presence of specific meio- and macrofaunal predators are of great interest. In addition to that we have devised a new benthic sensor for the quantitative and qualitative assessment in situ of diverse populations of microphytobenthos with high spatial and temporal resolution, enabling rapid evaluation of the community structure and distribution.
HIMOM will aim to provide a system of methods, the so-called Hierarchical Monitoring Methods (or HMM), to determine system status and changes which are expressed by biological and physical variations within inter-tidal areas. The HMM will aim to provide a management strategy tailored to the needs of End User involved in activities relating to the sustainable development of tidal flat areas around Europe. The HMM system will represent a hierarchical suite of activities, ranging from simple ground measurements of biota and physical characteristics to remote sensing of spectral reflectance properties for the analysis of basin scale systems.
To study the organisms involved in phytoplankton succession and the Key factors involved. This includes Bacteria-Algae, Algae-zooplankton and Zooplankton-Fish interactions. Aspects such as algal-grazer defence mechanisms and digestability of alage are core topics.
The succession of macro- and microalgal communities in the Antarctic will be investigated in field experiments under various UV radiation (UVR) conditions and in the absence or presence of grazers. The observed differences in the succession process will be correlated to physiological traits of single species, especially in spores and germlings, which are the most vulnerable stages in their life histories. Photosynthetic activity of the different developmental stages will be measured routinely. Additionally we plan the determination of pigment composition, C:N ratios, content of UV protective pigments and of possible DNA damage. The experiments will start in spring, concomitant to the time of highest UVBR, due to the seasonal depletion of the ozone layer in the Antarctic region. Supplemental laboratory experiments will be conducted to determine the effects of UVR on spores and germlings of individual species. In addition to the above analyses, we plan to examine of UVR induced damage of cell fine structure and of the cytoskeleton. The results of both the field and laboratory experiments will allow us to predict the consequences of enhanced UVR for the diversity and stability of the algal community.
Detection of UV-B induced DNA damage on zoospores of brown algae
The aim of this project is to investigate and understand those factors that play a role in the seasonal dynamics of different functional groups in the pelagic zone of coastal seas. We investigate the interactions between bacteria, phytoplankton, zooplankton and juvenile fish in order to assess the importance of biological interactions in the seasonal succession.
The aim of this project is to investigate natural products from polar macroalgae. As arctic waters represent an extreme habitat, formation of secondary metabolites is limited - besides other factors - by light conditions. Therefore, the influence of light, particularly different photon fluence rates and UV radiation, on secondary metabolism and on regulation of associated genes will be studied.
Observation how UV-radiation affects recruitment on hard substrate in the upper sublitoral zone.
The objective of the planned work with arctic higher plants is to study the range of adaptation of photosynthetic metabolism, of antioxidative and sun screen compounds in a cold and reduced UV-B climate in comparison of data already raised from high alpine plants, which live partially under stronger cold and under different light regimes, especially higher UV-B. Further, the ultrastructure of leaf cells will be studied to clear, whether adaptations found in some high alpine plants occur similarly in arctic plants, and to connect such cytological results with metabolic functions. An additional comparison will be made with snow algae from Svalbard compared to those harvested on high alpine snow fields. It is the advantage of the planned work, that a number of investigations ranging from ultrastructural studies over different aspects of photosynthesis to assays of UV-B sensitive compounds and antioxidants will be conducted mostly with measurements and sample collection in the field during the same experimental day at one place. Therefore we expect a good connection of the data raised, back to the plant system and expect a much broader description of vitality and adaptation under the current conditions.
The polar pteropod Clione limacina is characterised by high quantities of lipids with ether components (1-O-alkyldiacylglycerol=DAGE) in combination with odd-chain fatty acids. It is unknown why Clione and probably other pteropods have specialised in this manner. Furthermore the precursor of the biosynthesis of these compounds is still unknown. Therefore samples of Clione limacina and its only prey Limacina helicina will be collected by using plankton nets from small boats. The species will be kept in aquaria and feeding experiments with both species and food of different composition and nutritional value are planed.
Benthic macroalgae communities of the arctic ocean provide habitat, protection, nursery and nutrition to a large number of invertebrates. In contrast to temperate and tropical regions the basic ecological interactions between zoo- and phytobenthos of the Arctic are little understood. Therefore this project for the first time investigates biological and chemical interactions between invertebrates and macroalgae on Spitsbergen/Svalbard (Koldewey Station) with special emphasis on defense mechanisms against grazing pressure. Initial diving-investigations will map the invertebrate fauna which is associated with the macroalgae; the following feeding-experiments with herbivorous animals aim to selectively identify generalists, generalists with preference or specialists. Additional bioassays serve to reveal structural and/or chemical properties of those plants, which affect a specific impact on the grazing of herbivores. Our investigations on the chemical protection of the algae against grazing focus on the basic mechanisms and the chemical structure of potent secondary metabolites carried out in cooperation with natural product chemists.
Succession of communities and individual growth of benthic invertebrates are more or less unknown in polar waters, but nevertheless are the basic parameters of understanding the benthic sub-ecosystem, delivering data for modelling and prediction of the system´s development. Three localities, two in the Antarctic and one in the Arctic, the Kongsfjord in Spitsbergen, have been choosen as investigation localities. Hard and soft substrates, which will be sampled in regular intervalls during the duration of the project, will be deployed at different depths. The analysis includes species composition, species growth and, with respect to soft substrates, sediment parameters.
This study will be designed to determine the response mechanisms of representative species of macrophytes along the tide flat to provide the physiological basis for answers for ecological questions, in particular how the community structure of various beds of macroalgae from the intertidal to the subtidal (eulittoral to sublittoral) region of the coastal ecosystem is affected by enhanced UV radiation. In situ measurement of photosynthetic efficiency, growth, community structure and succession will be conducted to investigate how do different species of macrophytes respond to changes in the light environment over a depth gradient and across seasons of the year. It is hypothesized that the differences in the ability to tolerate stress are the main factors controlling the distribution pattern of macrophytes. With the limited understanding in the control of tolerance, elucidating the mechanism of stress in the physiology and ecology of the organisms will allow us to quantify the impediments encountered by organisms inhabiting the tide flats. Objectives: 1. To measure the daily and seasonal variation in photosynthetically active and ultraviolet radiation. 2. To characterize the macrophyte community structure of the coastal habitat. 3. To perform UV exclusion and UV supplementation experiments in order to assess its effect on the growth of some macrophyte species in the field and in mesocosms. 4. To assess the prevention of UV damage in selected macroalgae by production of sunscreen pigments. 4. To determine the recruitment rate, recolonization pattern and succession under PAR and varying UVR condition.
Due to its high energy, UV radiation can induce severe damage at the molecular and cellular level. On the molecular level proteins and lipids, as well as nucleic acids are particularly affected. Conformation changes of certain proteins involved in photosynthesis, such as the reaction center protein (D1) of photosystem II or the CO2 fixing enzyme in the Calvin cycle (RuBisCo) lead to an inhibition of photosynthesis, and consequently to a decrease in biomass production. This might shift certain algal species into deeper waters, not reached by UV radiation. The aim of the studies is to demonstrate how strong an increase of UV radiation due to stratospheric ozone depletion will influence the depth distribution and biomass production of macroalgae, and which molecules and processes are most severely affected. Moreover, it will be studied, which stage in the life cycle of the individual species is most sensitive to UV radiation as it will be this particular stage, which in the end determines the upper distribution limit of a certain species on the shore.