Bioluminescence commonly influences pelagic trophic interactions at mesopelagic depths. Here we characterize a vertical gradient in structure of a generally low species diversity bioluminescent community at shallower epipelagic depths during the polar night period in a high Arctic fjord with in situ bathyphotometric sampling. Bioluminescence potential of the community increased with depth to a peak ...

Due to severe nutrient and light limitation, the central Arctic Ocean has been characterized as a region of low primary productivity, with high retention of carbon in the surface waters. Using an in-depth analysis of published and new measurements of turbulent microstructure and high-resolution profiles of nitrate concentration, we reassess the vertical supply of nitrate to the Polar Mixed Layer and ...

Why dominant males experiencing intense sperm competition sometimes show low investments in sperm production is not always obvious. One well-documented example is that of the external fertilizing teleost, the Arctic charr (Salvelinus alpinus), where individuals becoming dominant reduce sperm production and sperm swimming speed in water compared to subordinates. Here, we report how ovarian ...

Increasing temperatures, with pronounced effects at high latitudes, have raised questions about potential changes in species composition, as well as possible increased importance of small-celled phytoplankton in marine systems. In this study, we mapped out one of the smallest and globally most widespread primary producers, the picocyanobacterium Synechococcus, within the Atlantic inflow to ...

The arctic Adventfjorden (78°N, 15°E, Svalbard) used to be seasonally ice-covered but has mostly been ice-free since 2007. We used this ice-free arctic fjord as a model area to investigate (1) how the vertical fl ux of biomass (chlorophyll a and particulate organic carbon, POC) follows the seasonality of suspended material, (2) how sink- ing particle characteristics change seasonally and ...

Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels, Mytilus spp., are ecosystem engineers in the coastal zone globally. To improve knowledge of distribution and genetic structure of ...

Empirical data on the behavior of radionuclides in aquatic ecosystems are needed for radioecological modeling, which is commonly used for predicting transfer of radionuclides, estimating doses, and assessing possible adverse effects on species and communities. Preliminary studies of radioecological parameters including distribution coefficients and concentration ratios, for 90Sr and 137Cs were not ...

The projected alterations to climate in the High Arctic are likely to result in changes to the short growing season, particularly with varying predicted effects on winter snowfall, the timing of summer snowmelt and air temperatures. These changes are likely to affect the phenology of interacting species in a variety of ways, but few studies have investigated the effects of combined climate drivers ...

A new device based on the Raspberry-Pi to monitor the locomotion of Arctic marine invertebrates and to analyze chronobiologic data has been made, tested and deployed. The device uses infrared sensors to monitor and record the locomotor activity of the animals, which is later analyzed. The software package consists of two separate scripts: the first designed to manage the acquisition and the evolution ...