English
norskInstitutt for arktisk og marin biologi: Nye registreringer
Viser treff 1621-1640 av 2078
-
Energetic consequences and implications for food consumption models when feeding on various sizes of cod in harp seals (Phoca groenlandica)
(Master thesis; Mastergradsoppgave, 2016-05-16)The current population-based food consumption models assume that harp seals are swallowing fish whole. However, behaviours such as belly-biting and rejection of fishes’ heads has been observed, possibly biasing diet analysis based on hard parts such as otoliths, and consequently underestimating the total food consumption of fish by harp seals. The purpose of this study was to examine whether individual ... -
Fate of production in the Arctic seasonal ice zone. An investigation of suspended biomass, vertical export and the impact of grazers during the onset of the spring bloom north of Svalbard
(Master thesis; Mastergradsoppgave, 2016-05-15)In the Arctic Ocean, biological productivity is largely determined by sea ice, making the seasonal sea ice zone (SSIZ) its most productive region. The current study is a combined investigation of the suspended biomass, vertical export of organic material, and potential retention processes by zooplankton, during a crucial period of bloom development in the Eurasian SSIZ north of Svalbard, where few ... -
Comparison of gillnet and trap in relation to retention of salmon lice (Lepeophtheirus salmonis), size selection of sea trout (Salmo trutta) and catch efficiency
(Master thesis; Mastergradsoppgave, 2016-05-15)Salmon lice (Lepeophtheirus salmonis) are marine ectoparasites commonly found on salmonid species, where the infection levels on wild salmonids have dramatically increased the latest decade. Sea trout (Salmo trutta) is being used in salmon lice monitoring studies (e.g. NALO) where different sampling gears are used. The interaction between sea trout and lice is complicated, and therefore methodology ... -
A first insight into the fecal microbiota of the high Arctic muskoxen (Ovibos moschatus)
(Journal article; Tidsskriftartikkel, 2016-07-11)The faecal microbiota of muskoxen (n=3) pasturing on Ryøya (69° 33′ N 18° 43′ E), Norway, in late September was characterized using high-throughput sequencing of partial 16S rRNA gene regions. A total of 16 209 high-quality sequence reads from bacterial domains and 19 462 from archaea were generated. Preliminary taxonomic classifications of 806 bacterial operational taxonomic units (OTUs) resulted ... -
Cyclic nucleotide dependent ATPase activity in inside out vesicles from human erythrocytes
(Master thesis; Mastergradsoppgave, 2015-01-27)The transport of cyclic nucleotides out of the cell is energy requiring, dependent on ATP- hydrolysis. The ability to stimulate this ATPase is a hallmark of substrates for ABC-transporters e.g. ABCC5, ABCC4. It is believed that ABCC5 transporter has selective high affinity for cGMP. Previous studies support the idea that ABCC5 contribute to cGMP transport by human erythrocytes. Human erythrocyte ... -
The impact of different size herbivores on plant biomass in Yamal (Russia)
(Master thesis; Mastergradsoppgave, 2016-05-19)Tundra ecosystems are changing environments that are greatly affected by plant-herbivore relationships. Many herbivores of different sizes eat, trample or clip plants. However they can also act as support through nutrient addition by faeces. In this study I look at the impact of three sizes of herbivores (large, medium and small) on ten functional groups of plants (nitrogen-fixing forbs, erect ... -
An assessment of survey methods to estimate spring density of two ptarmigan species in arctic Norway
(Master thesis; Mastergradsoppgave, 2016-05-17)Both Willow ptarmigan (Lagopus lagopus) and Rock ptarmigan (Lagopus muta) are important game species in mainland Norway, but were recently added to the Norwegian Red List due to long-term population declines. Yet the knowledge about the population dynamics and the underlying drivers of both species is limited, especially for L. muta. Developing robust methods for long-term monitoring of population ... -
Hyperbenthic Food-Web Structure in Kongsfjord: A Two-Season Comparison using Stable Isotopes and Fatty Acids.
(Master thesis; Mastergradsoppgave, 2016-04-21)Current knowledge of the Arctic marine ecosystem is based primarily on studies performed during the polar day on the pelagic and benthic realms. Both the polar night and the hyperbenthic layer remain substantial knowledge gaps in the understanding of the marine system at high latitudes. To help address these knowledge gaps, this project investigates the hyperbenthic food web structure in Kongsfjord, ... -
Soft-bottom communities in Balsfjord. Stable over time of under change?
(Master thesis; Mastergradsoppgave, 2015-12-15)The soft-bottom macrofauna (>1 mm) was investigated at three different locations in Balsfjord; Andersdal, Svartnes and Tennes. The Svartnes data was then merged with Eivind Ougs long-term series from 1977-1994. The data showed that there were large variation between the three different stations in number of taxa and individuals found. A total of 59 taxa and 1514 (0.7 m2) individuals were found. The ... -
Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-17)Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although much progress has been made in understanding ... -
Herding conditions related to infectious keratoconjunctivitis in semi-domesticated reindeer: a questionnaire-based survey among reindeer herders
(Journal article; Peer reviewed; Tidsskriftartikkel, 2016-04-12)Background: Infectious keratoconjunctivitis (IKC) in Eurasian semi-domesticated reindeer (Rangifer tarandus tarandus) is a multifactorial disease, associated to infectious agents such as Cervid herpesvirus 2 (CvHV2) and various species of bacteria, but environmental factors may also be necessary to initiate the disease. Little effort seems to have been invested in addressing the herder`s experience ... -
Marine Mammal Brucella Reference Strains Are Attenuated in a BALB/c Mouse Model
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-09)Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in ... -
Under the snow: a new camera trap opens the white box of subnivean ecology
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-14)Snow covers the ground over large parts of the world for a substantial portion of the year. Yet very few methods are available to quantify biotic variables below the snow, with most studies of subnivean ecological processes relying on comparisons of data before and after the snow cover season. We developed a camera trap prototype to quantify subnivean small mammal activity. The trap consists of a ... -
Breeding persistence of Slavonian Grebe (Podiceps auritus) at long-term monitoring sites: predictors of a steep decline at the northern European range limit
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-10)The Slavonian Grebe (Podiceps auritus) has its European northern range limit in northern Norway, and is a species of national conservation concern due to its small population size and unknown population trend. Long-term monitoring at the range limit suggests breeding site use is in decline. We used annual occupancy data from 104 breeding lakes monitored since 1991 in northern Norway to investigate ... -
Reindeer and tundra in a changing world: threats and opportunities (språk: engelsk og samisk)
(Conference object; Konferansebidrag, 2015-10-15) -
Mapping species distributions: a comparison of skilled naturalist and lay citizen science recording
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-27)To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UK’s national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. ... -
Anthocyanin Profile in Berries of Wild and Cultivated Vaccinium spp. along Altitudinal Gradients in the Alps
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-16)Vaccinium spp. berries provide some of the best natural sources of anthocyanins. In the wild bilberry (Vaccinium myrtillus L.), a clear increasing trend in anthocyanin biosynthesis has been reported toward northern latitudes of Europe, but studies related to altitude have given contradictory results. The present study focused on the anthocyanin composition in wild bilberries and highbush blueberry ... -
Adaptive flexibility in the feeding behaviour of brown trout: optimal prey size
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-18)Background Brown trout, Salmo trutta Linnaeus, 1758, is a species of significant conservation and socio-economic importance. A consequence of this importance is the enormous amount of literature that has been published on the species in the last few decades. In general terms, brown trout has been considered as a size-selective predator, even though it is able to feed on a wide range of prey sizes. ... -
Genetic diversity and population structure of an important wild berry crop
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)The success of plant breeding in the coming years will be associated with access to new sources of variation, which will include landraces and wild relatives of crop species. In order to access the reservoir of favourable alleles within wild germplasm, knowledge about the genetic diversity and the population structure of wild species is needed. Bilberry (Vaccinium myrtillus) is one of the most ... -
Light and temperature effects on bioactivity in diatoms
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-05)Isolates of five pelagic North Atlantic marine diatoms (Bacillariophyceae): Attheya longicornis, Chaetoceros socialis, Chaetoceros furcellatus, Skeletonema marinoi and Porosira glacialis were cultivated in large photobioreactors at two light and two temperature regimes to test if this affected bioactivity. We screened for bioactivity in assays representing five different therapeutic areas: ...
