Projects/Activities

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 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.

Marine invertebrates show a large variety of feeding strategies. These comprise mechanisms for catching prey, the uptake of food and the utilisation of various food sources. Morphological and anatomical adaptations allow for the capture and the ingestion of the food. However, the organism's physiological properties are the key for the efficient digestion, the nutrient uptake and the assimilation of food. In response to environmental factors marine organisms have developed highly specialised biochemical adaptations which are particularly reflected by the immeasurable diversity of digestive enzymes. The detailed function of digestive enzymes in marine invertebrates and, particularly, their synergistic interplay is still poorly understood.The overall aim is to investigate the mechanisms of enzymatic food utilisation and enzyme induction in different taxa of marine invertebrates in response to environmental factors.

Radioactivity in the Arctic environment is a central topic within environmental pollution issues. Increased discharges of technetium-99 (99Tc) from the nuclear fuel reprocessing plant Sellafield to the Irish Sea has caused public concerns in Norway. This project (acronym “RADNOR”) includes model and monitoring assessments and improvements, assessment of current and novel abiotic and biotic dose parameters and dose calculations and use of realistic climatic background scenarios in order to assess corresponding consequences for transport of radioactive pollutants. RADNOR consists of three main components: part 1, the determination of levels and time series of 99Tc in benthic and pelagic food webs; part 2, containing working packages on improvements to the understanding of site-specific and time-dependent sediment-water interactions (KD), kinetics of accumulation (CF) and body distribution in marine organisms, including contaminated products for the alginate industry and part 3, dealing with model hindcasts and observations for spreading of 99Tc from the Sellafield nuclear reprocessing plant during the 1990s and improvement of the NRPA dose assessment box model. From the model outputs, doses to man and environment will be calculated resulting in a valuable database for use within environmental management and for decision makers.

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.

In the late seventies, ELLIOTT and KINGSTON (1987) discovered a polychaetous annelid in various North Sea estuaries that had previously been found only in North American estuaries. Further specimens of what appeared to be the same species were found in the mid-eighties in the coastal waters of the Baltic Sea (BICK and BURCKHARDT, 1989). The distribution of these events in time and space led to the assumption that a North American species had immigrated to the North Sea and then extended its range of distribution to the Baltic. Within several years this species became one of the most dominant species in these estuaries. Identification of the immigrant was beset with problems from the start. It was identified as M. wireni AUGENER, 1913 or as M. viridis (VERRILL, 1873). It was the population genetic studies by BASTROP et al. (1995) and ROEHNER et al. (1996a, b) that showed the presence of genetically distinct forms in the North and Baltic Sea as well as in different regions of the north eastern coast of America. The morphological studies undertaken against this background allowed a good discrimination between these species (BICK & ZETTLER, 1997). Though, all authors dealing with the two species immigrated into the European estuaries were unable to name these species. The main reasons for this uncertainty are: - species identification is difficult, because diagnostic characters vary with growth (BICK, 1995), - the geographical distribution of Marenzelleria species is far from clear, - type material no longer exists or it is in poor condition (BICK & ZETTLER, 1997). Specimens of the type species of the genus, Marenzelleria wireni, were recorded from the Arctic region, Franz-Joseph Land and Spitzbergen (WIREN, 1883 and von MARENZELLER, 1892). As mentioned above, these specimens deposited in the Zoologisches Museum Hamburg and the Swedish Museum of Natural History, Stockholm are in poor condition. As far as we know further material from these regions does not exist. In order to eliminate the taxonomic uncertainty it is necessary to investigate morphologically and genetically specimens from the type locality.

Description of parameters of the population dynamics of polar bivalve communities, first year: growth and reproductive cycle of the dominant Greenland cockles (Serripes groenlandicus)

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.

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.

Biological nitrogen fixation by cyanobacteria is a key process for productivity in terrestrial Arctic ecosystems and the activity is dependent of size and diversity of cyanobacterial populations. Changes in biodiversity after pertubations of different types of habitats simulating climatic changes or other antropogenic effects will be studied by molecular methods and correlated to variations of nitrogen fixation activity.

The structure and role of the cyanobacterial communities that colonise bare soils and fix nitrogen in the arctic ecosystem will be studied. The planned activities will focus on the isolation, identification and characterisation of cyanobacteria from arctic habitats and on the changes of the cyanobacterial community along a transect from a retreating glacier front to a more stable habitat characterised by the presence of mature vegetation. For these purposes, a polyphasic approach encompassing microbiological, morphological and molecular techniques will be applied to environmental samples and isolated cultures. The obtained results will give new insights on the diversity and role of nitrogen fixing cyanobacteria in the arctic and, in more general terms, on ecosystem development under changing climatic conditions.

To evaluate temporal variation in arctic fox numbers and their food resourses in the Kongsfjorden area. The number of foxes captured per 100 trap-days are used as an index of fox density termed "Fox Capture Index". The observations of denning activity i.e. observation of number of arctic fox litters and litter size at den are termed "Fox Den Index" as a second index of fox abundance. A third index is termed "Fox Observation Index". This index is based on both observations of adult foxes seen away from breeding dens pr 100 h field work and reports on request from scientists and local people on observations of adult foxes during summer. In addition, reports on observation of fox tracks in the study area were collected in 1990-2001 as a fourth index, which were called "Fox Track Index". The field census are conducted for 10 days starting at the end of June. All dead foxes in the area should be collected.