Svalbard: projects/activities

Marine foodwebs as vector and possibly source of viruses and bacteria patogenic to humans shall be investigated in a compartive north-south study. Effects of sewage from ships traffic and urban settlements, on animals of arctic foodwebs will be studied.

A co-operative project between France and Norway is proposed to study the physiological mechanisms (hormones and metabolic rate) involved in the regulation of parental effort (brood size) in an Arctic-breeding seabird, the kittiwake Rissa tridactyla. This project will be carried out at Kongsfjorden (Ny Ålesund, Svalbard) which constitutes one the northernmost (79° N) breeding site of the species. The main goal of this project is to understand the reasons of the very poor productivity of the species in this high-arctic area (only one chick/pair/year compared to 2-3 chicks/ pair/year in more temperate areas). To do so, we will concurrently study the metabolic cost of chick rearing and the metabolic cost of foraging. To test whether parent kittiwakes are apparently unable to rear more than one chick, we will manipulate brood size and will measure its consequences on basal metabolic rate (BMR) and foraging activity. We will experimentally manipulate the brood size by swapping chicks between nests shortly after hatching. Parent birds of the different experimental groups will be captured, weighted and a small blood sample (500 µL) will be taken for thyroid hormones. BMR will be estimated through thyroïd hormones (Chastel et al. 2003, J. Avian Biol. 34: 298-306), a method that reduces handling time imposed by the use of a respirometer, whereas activity at sea will be estimated using miniature activity recorders (Daunt et al., 2002 Mar. Ecol. Prog. Ser.245 : 239-247, Tremblay et al. 2003, J. Exp. Biol. 206: 1929-1940). Nests of the different groups (12 nests with 2 chicks and 12 nest with 1 chick) will be observed during 2 weeks after what parent birds will be recaptured, and bled again for T3 assay. On an other group of birds (N=10), we will calibrate these miniature activity recorders (N=10, weight:5 g) by observing the activities (rest, brooding, flying, etc..) of the instrumented birds in the colony. Food samples (N=12) will be collected from parent birds during capture and recapture sessions (kittiwakes spontaneously regurgitate food when handled). Breeding adults and chicks will be maked with plastic rings that allow identification from a distance.

The aim of this research program is to examine the response of animal populations to environmental variability at different spatial scales. We attempt to determine how individuals respond to the spatial heterogeneity of their environment, and what are the consequences of this response for the dynamics of subdivided populations. Specifically, we consider an ecological system involving biotic interactions at three levels: seabirds, their tick _Ixodes uriae_, and the microparasite _Borrelia burgdorferi_ sensu lato (Lyme disease agent). Colonies of seabirds represent discrete entities, within and among which parasites can circulate. Our previous work on this system in the norwegian arctic has enable us to show that (1) host dispersal can be affected by local conditions, (2) seabird tick populations are specialised among different host species, namely between sympatric kittiwakes _Rissa tridactyla_ and puffins _Fratercula arctica_, (3) in the kittiwake, females transmit antibodies against _Borrelia burgdorferi_ when their chicks have a high probability to be exposed to the tick vector. We propose to combine different approaches, incorporating field surveys and experiments and population genetic studies (of hosts and parasites), in order to better understand the role of local interactions and dispersal in the dynamics of such a system. The research program implies collaborations with researchers from other french groups, as well as with Canadian (Queen’s University) and Norwegian colleagues (from NINA and the University of Tromsø).

Surveillance of sea birds, west Spitsbergen

This study aims at reconstructing the Barents Sea marine ecosystem before the exploitation by man. This reconstruction will be made by using the existing archival resources on catch statistics from the 17th to 19th centuries in the Netherlands, Germany, Denmark and the United Kingdom, in combination with the present knowledge an animal behaviour and food web structure. Fieldwork is planned in two former hunting areas in Spitsbergen: the Smeerenburgfjord and the Storfjord to study both the structure of the recent marine ecosystem and the composition, size and dating of the recent bird rookeries. This information in combination with the historical data will be used to reconstruct the original ecosystem.

In the seventeent and eighteenth centuries intensive European whaling and walrus hunting took place in the waters around Spitsbergen, with many stations on the coast of the islands. The hunt was carried out in areas along the edge of pack ice and is therefore very sensitive to changes in the ice situation and climate. When, around 1650, climate and ice distribution changed, whales moved to the north. The whaling stations in the south of Spitsbergen were abandoned when stations in the north were still functioning. When, later, the ice situation deteriorated in the north as well, the stations were abandoned there too. Shore whaling changed into pelagic whaling. Because of these whaling and walrus hunting activities two very numerous large mammals were largely depleted and almost disappeared from the Spitsbergen waters. The pelagically feeding Greenland Right Whale and the bentically feeding walrus, whose initial stocks are estimated at 46,000 Greenland Right Whales and 25,000 walrus, were eliminated. This elimination has caused a major shift in the foodweb. The plankton feeding seabirds and polar cod strongly increased because of the elimination of the Greenland Right Whale, and the eider ducks and bearded seals increased because of the decrease of the number of walruses. This development has led to the enormous amount of seabird rookeries on the West coast of Spitsbergen.

The present project includes one pilot study of wild adult glaucous gull (Larus hyperboreus) and one experimental study of glaucous gull chicks raised in captivity. The pilot study of adult gulls gave us enough blood and tissue samples to develop the methods needed for immune system analysis in the laboratory experiment. In the experimental study a total of 39 glaucous gull chicks were hatched and raised in captivity in Svalbard, Norway. The chicks were divided into two groups. One experimental group (20 chicks) was given food that mimicked the “natural” food found in the marine environment. The control group (19 chicks) was given “clean” food. After 56 days the chicks were sacrificed in order to collect samples for analyses of organochlorines (OCs) and immunocompetence measurements. The experimental group had 2.8, 3.9, 5.0, and 6.1 time’s higher concentrations of HCB, Oxychlordane, ?DDT, and ?PCB, respectively, compared to the control group at day 56. All chicks used in the experiment were immunised with various vaccines and sera in order to test their ability to respond against foreign antigens. The experimental chicks produced low levels of virus neutralising antibodies when tested against the herpes virus and reovirus. They produced higher levels of neutralising antibodies when tested to tetanus toxoid. There was, however, no difference between the experimental groups with regard to the mean antibody titres. The chicks in both groups also responded to the influenza virus by increasing the production of specific antibodies. However, the mean antibody titre in the exposed group was significantly lower than in the control group. The mitogen-induced response of blood lymphocytes to PHA and LPS was significantly higher in the exposed group compared to the control group. The specific response of blood lymphocytes to Con A, PWM, KLH, TET, and PPD was higher in the exposed group compared to the control group. However, do to high variance in the exposed group there was no significant difference between groups with regard to the lymphocyte response to these mitogens. The results from the present study indicate a toxic effect of OCs on the glaucous gull chicks, which induced a systematic activation of the immune system. Further work on data will be performed.