Artikler, rapporter og annet (arktisk og marin biologi): Nye registreringer
Viser treff 201-220 av 1607
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Spring phytoplankton distributions and primary productivity in waters off northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-13)The distributions of phytoplankton, zooplankton and hydrographic features off the coast of northern Norway were assessed in late April – early May 2019 using ship-based observations (CTD casts and Moving Vessel Profilers) and autonomous vehicles. A satellite chlorophyll climatology was generated to place our in-situ observations within a longer temporal sequence. Substantial spatial and temporal ... -
Limited predatory effects on infaunal macrobenthos community patterns in intertidal soft-bottom of Arctic coasts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-24)Predation shapes marine benthic communities and affects prey species population dynamics in tropic and temperate coastal systems. However, information on its magnitude in systematically understudied Arctic coastal habitats is scarce. To test predation effects on the diversity and structure of Arctic benthic communities, we conducted caging experiments in which consumers were excluded from plots at ... -
Salmon-lice as a potential threat to anadromous Arctic charr populations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-25)Salmon-lice have the potential to change the behaviour and growth of their salmonid host species. Here, the baseline infection levels of salmon-lice of post-smolts (n = 815) and veteran migrants (n = 875) of sea-run Arctic charr (Salvelinus alpinus Linnaeus, 1758) were monitored over two successive years in a sub-Arctic Norwegian fjord without farming of salmonids. All Arctic charr were collected ... -
Quantitative fatty acid signature analysis reveals a high level of dietary specialization in killer whales across the North Atlantic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-13)Quantifying the diet composition of apex marine predators such as killer whales (Orcinus orca) is critical to assessing their food web impacts. Yet, with few exceptions, the feeding ecology of these apex predators remains poorly understood. <p>Here, we use our newly validated quantitative fatty acid signature analysis (QFASA) approach on nearly 200 killer whales and over 900 potential prey to model ... -
Modelling the control of bovine brucellosis in India
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-08)Brucellosis imposes substantial impacts on livestock production and public health worldwide. A stochastic, age-structured model incorporating herd demographics was developed describing within- and between-herd transmission of Brucella abortus in dairy cattle herds. The model was fitted to data from a cross-sectional study conducted in Punjab State of India and used to evaluate the effectiveness of ... -
Ecological effects of mosquito control with Bti: evidence for shifts in the trophic structure of soil- and ground-based food webs
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-08)The microbial control agent <i>Bacillus thuringiensis</i> var. <i>israelensis</i> (Bti) has been successfully used worldwide to reduce abundances of biting Nematocera (Diptera), often with little direct impact on non-target organisms observed. However, the potential for additional indirect effects on other ecosystem properties, including on trophic linkages within food webs, is poorly known. We ... -
A semi-automatic workflow to process images from small mammal camera traps
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-05)Camera traps have become popular for monitoring biodiversity, but the huge amounts of image data that arise from camera trap monitoring represent a challenge and artificial intelligence is increasingly used to automatically classify large image data sets. However, it is still challenging to combine automatic classification with other steps and tools needed for efficient, quality-assured and adaptive ... -
A retrospective investigation of feather corticosterone in a highly contaminated white-tailed eagle (Haliaeetus albicilla) population
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-16)Exposure to persistent organic pollutants (POPs), such as organochlorines (OCs) and polybrominated diphenyl ethers (PBDEs), is associated with adverse health effects in wildlife. Many POPs have been banned and consequently their environmental concentrations have declined. To assess both temporal trends of POPs and their detrimental impacts, raptors are extensively used as biomonitors due to their ... -
Spatiotemporal distribution of Arctic herbivores in spring: Potential for competition?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-23)Biotic interactions are important to the structure and dynamics of food webs and may affect the spatial and temporal distribution of species. In the Arctic, spring snow-cover limits food availability at a critical time for herbivores, potentially leading to resource competition. This study investigates the potential for competition over forage resources during spring in a high-Arctic herbivore ... -
Life-cycle analysis of an endangered migratory goose to assess the impact of conservation actions on population recovery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-29)Evaluating the effectiveness of conservation actions is challenging for migratory species because a population can be impacted anywhere along its route. Conservation actions for the critically endangered Fennoscandian lesser white-fronted goose population include culling of red foxes in the breeding area and habitat improvements and reduction of illegal hunting in the non-breeding areas. One goal ... -
Home-field advantage effects in litter decomposition is largely linked to litter quality
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-03)Climate change and associated environmental alterations affect plant communities, potentially decoupling links between plants and their associated soil microbial communities. This may in turn affect processes like litter decomposition, an important function that controls nutrient and carbon cycling as well as many other ecosystem processes. Microbial decomposers have been proposed to specialize, ... -
Tracing basal resource use across sea-ice, pelagic, and benthic habitats in the early Arctic spring food web with essential amino acid carbon isotopes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-09)A rapidly warming Arctic Ocean and associated sea-ice decline is resulting in changing sea-ice protist communities, affecting productivity of under-ice, pelagic, and benthic fauna. Quantifying such effects is hampered by a lack of biomarkers suitable for tracing specific basal resources (primary producers and microorganisms) through food webs. We investigate the potential of δ<sup>13</sup>C values ... -
Isotopic turnover of polar cod (Boreogadus saida) muscle determined through a controlled feeding experiment
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-30)Polar cod (Boreogadus saida) is an important trophic link within Arctic marine food webs and is likely to experience diet shifts in response to climate change. One important tool for assessing organism diet is bulk stable isotope analysis. However, key parameters necessary for interpreting the temporal context of stable isotope values are lacking, especially for Arctic species. This study provides ... -
Evidence of separate influence of moon and sun on light synchronization of mussel's daily rhythm during the polar night
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-09)Marine organisms living at high latitudes are faced with a light climate that undergoes drastic annual changes, especially during the polar night (PN) when the sun remains below the horizon for months. This raises the question of a possible synchronization and entrainment of biological rhythms under the governance of light at very low intensities. We analyzed the rhythms of the mussel <i>Mytilus</i> ... -
Reduced efficiency of pelagic–benthic coupling in the Arctic deep sea during lower ice cover
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-25)Pelagic–benthic coupling describes the connection between surface-water production and seafloor habitats via energy, nutrient and mass exchange. Massive ice loss and warming in the poorly studied Arctic Chukchi Borderland are hypothesized to affect this coupling. The strength of pelagic–benthic coupling was compared between 2 years varying in climate settings, 2005 and 2016, based on δ<sup>13</sup>C and ... -
Seasonal plankton dynamics in Kongsfjorden during two years of contrasting environmental conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-24)Seasonal plankton time-series data are presented from Kongsfjorden from two years with contrasting environmental conditions. Kongsfjorden (west coast of Spitsbergen – 79°N) integrates inputs from Atlantic and Arctic waters, and glacier run-off, and is thus a prime location to study impacts on ecosystem dynamics of key environmental drivers that are relevant across the Arctic. Despite extensive ... -
Impact of Microsetella norvegica on carbon flux attenuation and as a secondary producer during the polar night in the subarctic Porsangerfjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-13)It is known that Microsetella norvegica feed on phytoplankton and provide an important link to higher trophic levels in Arctic fjords, such as fish sprat (Sprattus sprattus) and three-spined stickleback (Gasterosteus aculeatus). It has recently been suggested that M. norvegica may also contribute substantially to carbon flux attenuation during periods of high abundance. However, we still know very ... -
Under-ice observations by trawls and multi-frequency acoustics in the Central Arctic Ocean reveals abundance and composition of pelagic fauna
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-18)The rapid ongoing changes in the Central Arctic Ocean call for baseline information on the pelagic fauna. However, sampling for motile organisms which easily escape vertically towed nets is challenging. Here, we report the species composition and catch weight of pelagic fishes and larger zooplankton from 12 trawl hauls conducted in ice covered waters in the Central Arctic Ocean beyond the continental ... -
A Dynamic Occupancy Model for Interacting Species with Two Spatial Scales
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-10)Occupancy models have been extended to account for either multiple spatial scales or species interactions in a dynamic setting. However, as interacting species (e.g., predators and prey) often operate at different spatial scales, including nested spatial structure might be especially relevant to models of interacting species. Here we bridge these two model frameworks by developing a multi-scale, ... -
Photoperiod and dietary treatment in freshwater modulate the short-term intestinal response to seawater in Atlantic salmon (Salmo salar)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-02)Stimulation and timing of smoltification are essential for successful Atlantic salmon (Salmo salar) aquaculture. This study investigated intestinal responses during dietary and photoperiod manipulation in freshwater (FW) and after a subsequent seven days residence in seawater (SW). “Small” and “large” Atlantic salmon parr (~40 g and ~ 130 g respectively) were treated in FW for 12 weeks and ...