The full list of projects contains the entire database hosted on this portal, across the available directories. The projects and activities (across all directories/catalogs) are also available by country of origin, by geographical region, or by directory.
Since nearly all microalgae are associated with bacteria and some harbor intracellular bacteria, it is most likely that these bacteria are involved in the development or termination of natural occurring plankton assemblages. The diversity and development of associated bacteria in microalgae cultures and during phytoplankton succession will be described by molecular analysis of the bacterial community structure and by phylogenetic analysis of involved microorganisms.
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 photosynthetic productivity and the factors affecting it are measured in the nival zone of the Alps. Patterns of CO2 exchange for several lichen species are determined whilst recording environmental factors such as light and temperature and lichen water content. Whilst these records will show the lichen response over the year they can most easily be interpreted when the photosynthetic ability of individual lichens is well known. To achieve this the response of each species to light intensity, temperature, thallus water content and humidity will be determined under fully controlled conditions in the laboratory. The final aim is to achieve an initial carbon balance model for the lichen species. This will be aided considerably by the deploying of a continuously recording chlorophyll fluorescence system that will provide activity data for one lichen species on a better than hourly basis throughout the year.
Cellphysiological investigations of the effects of marine secondary metabolites on isolated (sensory) cells
Effects of UV-B radiation on microbial communities in Kongsfjorden in relation to metal and dissolved organic matter availabillity.
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.
Marine invertebrates have highly active digestive enzymes which can exhibit extraordinary catalytical properties with respect to specificity, turnover performance and thermal stabilty. Highly specific bio-active substances are important for various biotechnological applications. The project is aimed to investigate the catalytic properties of digestive enzymes in marine invertebrates from a wide geographical and thus ecological range. Target species will be preferably crustaceans and echinoderms.
Detection of UV-B induced DNA damage on zoospores of brown algae
Description of parameters of the population dynamics of polar bivalve communities, first year: growth and reproductive cycle of the dominant Greenland cockles (Serripes groenlandicus)
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.
The goal is to understand, how bacteria in Arctic sediments are adapted to low temperature and how (climatic) changes of temperature may affect the rate and pathways of carbon cycling and the balance of mineral cycles. The diversity and physiology of bacterial populations of fjord sediments on West-Spitzbergen will be studied by a combination of molecular (16S rRNA sequence analyses and in situ hybridization) and microbiological (isolation and physiology of pure cultures) approaches. The metabolic activity of these bacteria in the sea floor and the temperature regulation of the dominant mineralization processes will be analysed by experimentel techniques during the research period in Ny Ålesund. The focus will be on the enzymatic cleavage of polymeric carbohydrates, the anaerobic respiration through sulfate reduction, the reduction of iron and mangenese oxides, and the turnover of volatile fatty acids and hydrogen. Subsequently, psychrophilic bacteria are isolated from the anoxic sediments and studied in pure culture. The bacterial populations in the sediment are studied by molecular methods to analyze their diversity and metabolic activity.
Arctic islands of genetic diversity or fragments of an ancient clone. The history and future of Dryas octopetala in a changing environment.
As a result of the increasing atmospheric CO2 levels and other greenhose gases due to anthropogenic activities, global and water temperature is rising. The objectives of our project might be summarized as follows: I. To measure the activity of the enzymatic systems involved in carbon, nitrogen and phosphorus uptake (carbonic anhydrase, nitrate reductase and alkaline phosphatase) in selected macroalgae. To assess the optimal concentration of inorganic nitrogen and phosphorus for growth and photosynthesis. To study the total concentration of carbon and nitrogen metabolites in the macroalgae (proteins, total carbohydrates, and lipids) in order to define the possible existence of nutrient limitation. II. To simulate the conditions of climate change, represented as CO2 enrichment and increasing UV radiation, on the activity of carbon, nitrogen and phosphorus uptake mechanisms. III. To screen the activity of the enzymatic systems previously detailed in macroalgae from the Konjsfjord, in order to know their nutritional state.
Seasonal ozone depletion in now occurring both in the Arctic and Antarctic, thus increasing levels of UV-B radiation reaching polar bilogical systems.
To investigate arctic foxes physiological adaptations to life at high latitudes. Resting and running metabolic rates, body weight, food intake, body core temperature, heart rate, and blood parameters were examined during different seasons and during periods of food deprivation.
Effects of POPs on the immune system in the glaucous gulls
Biomarkers for orgaic pollution components
The objectives of this project is to study the effect of environmental stochasticity on the Svalbard reindeer population dynamics, nad further evaluate how this may affect reindeer-plant interactions.
Observation how UV-radiation affects recruitment on hard substrate in the upper sublitoral zone.
1. To quantify benthic community parameters for all size classes of fauna across the Oxygen Minimum Zone (OMZ) 2. To make a detailed assessment across the OMZ of a) sediment accumulation, mixing and irrigation rates and depths and b) environmental factors acting as controls on faunal activity 3. To characterise solid phase and porewater geochemistry of sediments across the OMZ 4. To assess a) faunal digestive Organic Matter (OM) alteration, b) the relative importance of chemo- and photosynthetic food sources, and c) benthic food web structure, across the OMZ 5. To determine porewater profiles and benthic solute fluxes in situ, and to assess faunal OM assimilation and trophic relationships by monitoring tracers during shipboard and in situ incubations 6. To obtain high resolution porewater profiles of oxygen and other key analytes, free of pressure and other effects potentially introduced by core recovery 7. To determine in situ oxygen consumption rates and benthic fluxes 8. To use labelled tracers to assess mixing and irrigation rates, faunal OM assimilation, and size-selective ingestion and mixing 9.To determine sediment denitrification and sulfate reduction rates and their contributions to OM remineralisation