English
norskBlar i forfatter "Vihtakari, Mikko"
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The amphipod scavenging guild in two Arctic fjords : seasonal variations, abundance and trophic interactions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)Scavenging amphipods are important for the circulation and dispersal of organic material in the marine environment. Despite their dominance in the scavenging guild and importance in the food web, little is known about Arctic amphipods and their feeding preferences. We studied the amphipod scavenging guild using baited traps for one full year to increase our understanding of its seasonal variations. ... -
Bivalves as indicators of environmental perturbations related to climate and ocean acidification
(Doctoral thesis; Doktorgradsavhandling, 2015-03-13)The aims of this thesis were to increase knowledge on 1) susceptibility of bivalves to environmental perturbations and 2) usage of bivalve shells as sub-annual environmental proxy archives. These objectives were addressed using two experimental settings: 1) an ocean acidification (OA) experiment on bivalve gametes and early larval stages, and 2) year-long bivalve deployments on oceanographic moorings ... -
Black-legged kittiwakes as messengers of Atlantification in the Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-19)Climate warming is rapidly altering marine ecosystems towards a more temperate state on the European side of the Arctic. However, this “Atlantification” has rarely been confirmed, as long-term datasets on Arctic marine organisms are scarce. We present a 19-year time series (1982–2016) of diet samples from black-legged kittiwakes as an indicator of the changes in a high Arctic marine ecosystem ... -
Changes in Sea-Ice Protist Diversity With Declining Sea Ice in the Arctic Ocean From the 1980s to 2010s
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-06)The large declines in Arctic sea-ice age and extent over the last decades could have altered the diversity of sea-ice associated unicellular eukaryotes (referred to as sea-ice protists). A time series from the Russian ice-drift stations from the 1980s to the 2010s revealed changes in community composition and diversity of sea-ice protists from the Central Arctic Ocean. However, these observations ... -
Effects of Ocean Acidification and Warming on Sperm Activity and Early Life Stages of the Mediterranean Mussel (Mytilus galloprovincialis)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Larval stages are among those most vulnerable to ocean acidification (OA). Projected atmospheric CO2 levels for the end of this century may lead to negative impacts on communities dominated by calcifying taxa with planktonic life stages. We exposed Mediterranean mussel (Mytilus galloprovincialis) sperm and early life stages to pHT levels of 8.0 (current pH) and 7.6 (2100 level) by manipulating pCO2 ... -
Feeding at the front line: Interannual variation in the use of glacier fronts by foraging black-legged kittiwakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-28)Tidewater glacier fronts can represent important foraging areas for Arctic predators. Their ecological importance is likely to change in a warmer Arctic. Their profitability and use by consumers are expected to vary in time, but the underlying mechanisms driving such variation remain poorly known. The subglacial plume, originating from meltwater discharge, is responsible for the entrainment and ... -
Geographic variation in the life history of lane snapper Lutjanus synagris, with new insights from the warm edge of its distribution
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-20)Research on life-history variations in widely distributed fish species is needed to understand global warming impacts on populations and to improve fisheries management advice. The lane snapper Lutjanus synagris (Linnaeus, 1758) is commercially important to fisheries in the Western Central Atlantic, where spread information on its life-history traits is available. We studied growth, age, reproduction ... -
Ice-Associated Amphipods in a Pan-Arctic Scenario of Declining Sea Ice
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-13)Sea-ice macrofauna includes ice amphipods and benthic amphipods, as well as mysids. Amphipods are important components of the sympagic food web, which is fuelled by the production of ice algae. Data on the diversity of sea-ice biota have been collected as a part of scientific expeditions over decades, and here we present a pan-Arctic analysis of data on ice-associated amphipods and mysids assimilated ... -
Migration patterns of Greenland halibut in the North Atlantic revealed by a compiled mark-recapture dataset
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-18)Marine fisheries are often allocated to stocks that reflect pragmatic considerations and may not represent the species’ spatial population structure, increasing the risk of mismanagement and unsustainable harvesting. Here we compile mark–recapture data collected across the North Atlantic to gain insight into the spatial population structure of Greenland halibut (Reinhardtius hippoglossoides), an ... -
Pan-Arctic suitable habitat model for Greenland halibut
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-08)Deep-sea marine fishes support important fisheries but estimates of their distributions are often incomplete as the data behind them may reflect fishing practices, access rights, or political boundaries, rather than actual geographic distributions. We use a simple suitable habitat model based on bottom depth, temperature, and salinity to estimate the potential distribution of Greenland halibut ... -
Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current from Rijpfjorden, Svalbard, to the Arctic Ocean during Summer (2010-2014)
(Journal article; Peer reviewed, 2019-04-09)The northern coast of Svalbard contains high-arctic fjords, such as Rijpfjorden (80°N 22°30′E). This area has experienced higher sea and air temperatures and less sea ice in recent years, and models predict increasing temperatures in this region. Part of the West Spitsbergen Current (WSC), which transports relatively warm Atlantic water along the continental slope west of Svalbard, bypasses these ... -
Sea ice meiofauna distribution on local to pan-Arctic scales
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-29)Arctic sea ice provides microhabitats for biota that inhabit the liquid‐filled network of brine channels and the ice–water interface. We used meta‐analysis of 23 published and unpublished datasets comprising 721 ice cores to synthesize the variability in composition and abundance of sea ice meiofauna at spatial scales ranging from within a single ice core to pan‐Arctic and seasonal scales. Two‐thirds ... -
Tidewater glaciers and bedrock characteristics control the phytoplankton growth environment in a fjord in the arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-31)Meltwater discharge from tidewater glaciers impacts the adjacent marine environment. Due to the global warming, tidewater glaciers are retreating and will eventually terminate on land. Yet, the mechanisms through which meltwater runoff and subglacial discharge from tidewater glaciers influence marine primary production remain poorly understood, as data in close proximity to glacier fronts are scarce. ... -
Variable individual- and population- level responses to ocean acidification
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-29)Population responses to marine climate change are determined by the strength of the selection pressure imposed by changing climate, the genetic variability within the population (i.e., among individuals), and phenotypic plasticity within individuals. Marine climate change research has focused primarily on population-level responses, yet it is at the level of the individual that natural selection ...
