The highly rhythmic environment caused by the rotation of the earth has driven the evolution of an intrinsic timekeeping mechanism in most organisms known as circadian clocks. As climate change drives the expansion of southern species into northern latitudes, their circadian clocks are challenged by the novel light conditions they encounter. In contrast to the clear day and night in southern latitudes, ...

The transfer of smolt from freshwater (FW) to seawater (SW) is a critical stage in the farming of Atlantic salmon (Salmo salar) with mortalities of up to 15 % after transfer. One of the reasons for this loss is suboptimal smolt quality. It is therefore important to ensure that the fish are fully SW adapted before transfer to SW. Traditionally, smoltification is stimulated by exposing the fish to a ...

Klimaendringer påvirker arktis mer en andre områder i verden. Isfjorden på Svalbard utgjør et et utmerket modellsystem for å måle endringer i zooplanktonsammfunnet. IMOS tidserien ved Janne Søreide med kolleger har samlet in data i over 20 år, og konsekvent for flere stasjoner i de siste 8 årene. I denne master oppgaven ser jeg på hvordan zoogeografisk relativ abundans har endret seg de siste 12 ...

Knowing the metabolic rate of marine mammals is often important as baseline knowledge of their biology and physiology, e.g., to allow ecosystem assessments and estimation of their resource needs and use, and prey requirements. However, our current knowledge of energetics of large cetaceans is limited compared to many smaller cetaceans. Determining the energy expenditure of large free-ranging whales ...

The deep sea is the largest biome on Earth, albeit it is the least studied. Among the complex ecosystems and habitats that form the deep sea, submarine canyons and open slope systems are regarded to be potential hot-spots of biodiversity. The Mediterranean Sea hosts the 8.86% of the inventoried submarine canyons in the global ocean, like the Blanes Canyon, located in its Northwestern section. We ...

Many studies have been done on grandparental investment, asking why grandparents distribute their resources skewered. Maternal grandmothers invest most, and parental grandfathers invest least in their grandchildren. Here resemblance is used as an indicator of kin, asking if grandparents feel their grandchildren resemble them and looking at how they invest in these grandchildren. Daughters do not ...

Many artificial nest studies that goes over several years place the nests in the same location each placement. Over the years there is a chance that the predators learn where the nests are placed and that can give skewed results. The goal of my study is to see if the predators learn where the nests are located. This was done over three study sites on the Yamal peninsula. In two of the study sites ...

Barents Sea capelin (Mallotus villosus) year class strength is thought to be determined during the first months after egg hatching. The now widely accepted Hamre’s hypothesis states that young herring (Clupea harengus) present in the southern Barents Sea potentially may cause poor capelin recruitment. This hypothesis was presently tested through model scenarios, by simulating a realistic spatio-temporal ...

Southern elephant seals are abundant top trophic predators with a circumpolar distribution in the Southern Ocean. They spend up to 80% of their life at sea on long-ranging migrations to remote foraging grounds. During breeding and moulting they haulout on subantarctic islands. During these migrations they dive continuously to great depth, encountering various environmental conditions. They ...

The impact of Remote Piloted Aircraft Systems (RPAS, or drones) on marine mammals remains poorly documented despite their increasing use by hobbyists and scientists. In the High-Arctic Archipelago of Svalbard, where marine mammals are facing increasing pressure from the coupled effects of climate modification and an expanding tourism industry, the use of RPAS remains largely unregulated to date. In ...