Trond Kristiansen

Norwegian Institute for Water Research | NIVA · Oceanography and Biogeochemistry

We review recent trends and projected future physical and chemical changes under climate change in transition zones between Arctic and Subarctic regions with a focus on the two major inflow gateways to the Arctic, one in the Pacific (i.e. Bering Sea, Bering Strait, and the Chukchi Sea) and the other in the Atlantic (i.e. Fram Strait and the Barents...

Datareport from the FerryBox monitoring of Inner Oslofjord 2019 for "Fagrådetfor vann- og avløpsteknisk samarbeid i indre Oslofjord"

The survival of fish eggs and larvae, and therefore recruitment success, can be critically affected by transport in ocean currents. Combining a model of early life stage dispersal with statistical stock‐recruitment models, we investigated the role of larval transport for recruitment variability across spatial scales for the population complex of No...

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoya...

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoya...

Following rapid cooling in the 1960s, much of the North Atlantic Ocean was characterized by a cold period during the 1970s and 1980s. This cold period was part of the multidecadal variability in sea surface temperatures known as the Atlantic Multidecadal Oscillation or AMO, which has a period of 60–80 years. During this cold period, below average a...

In a warming environment, permafrost thawing can play a significant role in the chemical composition of coastal waters in the Arctic region. It is a potential source of organic and inorganic forms of nutrients, as well as heavy metals and pollutants. To estimate the permafrost thawing influence on the chemical properties of the sea water, an experi...

https://meetings.pices.int/publications/presentations/2018-Climate-Change/S05-1420-Drinkwater_R.pdf

Climate impacts in Northeast Atlantic sub-arctic and Arctic.

Transport with ocean currents affects the spatial distribution and survival of fish eggs and larvae and thereby population connectivity. Biophysical models are commonly used to understand these dynamics. Advancements such as implementing vertical swimming behaviour and higher resolution ocean circulation models are known to improve model performanc...

Changes in structural connectivity as it can affect functional connectivity, the biological and behavioural responses of an organism, has been examined here over 2 contrasting years when the spatial distribution of larval and juvenile cod and their prey shifted from the flank to the crest on Georges Bank. New data on the gut contents of pelagic juv...

The exploitation status of marine fisheries stocks worldwide is of critical importance for food security, ecosystem conservation, and fishery sustainability. Applying a suite of data-limited methods to global catch data, combined through an ensemble modeling approach, we provide quantitative estimates of exploitation status for 785 fish stocks. Fif...

Geographic redistribution of living natural resources changes the access and thereby harvesting opportunities between countries. Internationally shared fish resources can be sensitive to shifts in the marine environment and this may have great impact on the economies of countries and regions that rely most heavily on fisheries to provide employment...

Abstract The North Atlantic Ocean contains diverse patterns of seasonal phytoplankton blooms with distinct internal dynamics. We analyzed blooms using remotely-sensed chlorophyll a concentration data and change point statistics. The first bloom of the year began during spring at low latitudes and later in summer at higher latitudes. In regions wher...

MyOcean Project initiated the first generation of regional physical and biogeochemical reanalysis products covering all European marginal seas and the first attempt of a coordinated and shared validation methodology. An overview of the principal characteristics of all regional physical and biogeochemical reanalyses is presented with the objective t...

Buoyancy acting on plankton, i.e. the difference in specific gravity between plankton and the ambient water, is a function of salinity and temperature. From specific gravity measurements of marine fish eggs salinity appears to be the only determinant of the buoyancy indicating that the thermal expansions of the fish egg and the ambient seawater are...

Environmental conditions during the pelagic juvenile cod period determine their fitness to survive settlement as demersal juveniles (0-group) and recruitment. This study examines the potential growth of pelagic juvenile cod in five areas of the New England Shelf based on time series of zooplankton and ocean temperature from surveys. An individual-b...

A gigantic light experiment is taking place in the Arctic. Climate change has led to substantial reductions in sea ice extent and thickness in the Arctic Ocean. Sea ice, particularly when snow covered, acts as a lid hindering light to reach the waters underneath. Less ice will therefore mean more light entering the water column, with profound effec...

We used remote sensing chlorophyll a concentration data, spring copepod abundance, and individual fish condition information to understand the annual recruitment variability of two neighboring haddock (Melanogrammus aeglefinus) stocks in the Gulf of Maine region. When we considered the full range of recruitment variability, the abundance of the cop...

Sea surface temperature (SST) anomalies are often both leading indicators and important drivers of marine resource fluctuations. Assessment of the skill of SST anomaly forecasts within coastal ecosystems accounting for the majority of global fish yields, however, has been minimal. This reflects coarse global forecast system resolution and past emph...

An extensive data series of salinity, nutrients and coloured dissolved organic material (CDOM) was collected in the Skagerrak, the northern part of the Kattegat and off the Jutland west coast in April each year during the period 1996-2000, by the Institute of Marine Researchin Norway. In this month, after the spring bloom, German Bight Water differ...

Arctic and Antarcticmarine systems have incommon high latitudes, large seasonal changes in light levels, cold air and sea temperatures, and sea ice. In other ways, however, they are strikingly different, including their: age, extent, geological structure, ice stability, and foodweb structure. Both regions contain very rapidly warming areas and clim...

Variability in walleye pollock (Gadus chalcogrammus) growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included lo...

The ability of larval fish to find food successfully after hatching is critical for their growth and survival during the early life stages. However, the feeding ecology of larval fish is strongly dependent on prevailing physical and biological conditions. Small changes in the prey distribution, turbulence, light, and ocean temperature can affect la...

Stock status is a key parameter for evaluating the sustainability of fishery resources and developing corresponding management plans. However, the majority of stocks are not assessed, often as a result of insufficient data and a lack of resources needed to execute formal stock assessments. The working group involved in this publication focused...

Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically i...

Understanding the biophysical mechanisms that shape variability in fisheries recruitment is critical for estimating the effects of climate change on fisheries. In this study, we used an Earth System Model (ESM) and a mechanistic individual-based model (IBM) for larval fish to analyze how climate change may impact the growth and survival of larval c...

Arctic and Antarctic marine systems have in common high latitudes, large seasonal changes in light levels, cold air/sea temperatures, and sea ice. In other ways they are strikingly different, including: geological structure; ice stability; and food webs. Both regions contain rapidly warming areas; reported climate impacts and future projections are...

Coupling an oil drift and fates model (Oscar) in an offline environment with an individual-based model (IBM) for Northeast Arctic cod (Gadus morhua) eggs and larvae enables us to quantify the exposure of eggs and larvae to oil from various oil spill scenarios. Oscar describes the spatio-temporal dispersal and fate of hydrocarbons, whereas the egg a...

Several factors lead to expectations that the scale of larval dispersal and population connectivity of marine animals differs with latitude. We examine this expectation for demersal shorefishes, including relevant mechanisms, assumptions and evidence. We explore latitudinal differences in (i) biological (e.g. species composition, spawning mode, pel...

The united States is an ocean nation—our past, present, and future are inextricably connected to and dependent on oceans and marine resources. marine ecosystems provide many important services, including jobs, food, transportation routes, recreational opportunities, health benefits, climate regulation, and cultural heritage that affect people, comm...

The United States is an ocean nation—our past, present, and future are inextricably connected to and dependent on oceans and marine resources. Marine ecosystems provide many important services, including jobs, food, transportation routes, recreational opportunities, health benefits, climate regulation, and cultural heritage that affect people, comm...

Considerable progress has been made in understanding physiological responses of marine organisms to climate change (Pörtner and Farrell, 2008; Somero, 2011) and in projecting future responses of individual species (Chown and Gaston, 2008; Helmuth, 2009). Key to this understanding are findings that indicate that multiple climate-related and non-clim...

Understanding how climate change may impact important commercial fisheries is critical for developing sustainable fisheries management strategies. In this study, we used simulations from an Earth System Model (NOAA GFDL ESM2.1) coupled with an individual-based model (IBM) for larval fish to provide a first assessment of the potential importance of...

Background: Individual-based biophysical larval models, initialized and parameterized by observations, enable numerical investigations of various factors regulating survival of young fish until they recruit into the adult population. Exponentially decreasing numbers in Northeast Arctic cod and Norwegian Spring Spawning herring early changes emphas...

Day-length variation as a function of geographical location and time of the year. Day-length shown at the surface (a) and at 20 meters depth (b) for four locations in the North Atlantic: Georges Bank, North Sea, Iceland, and Lofoten. (TIF)

Detailed methodology for individual-based model. (DOC)

Fisheries exploitation, habitat destruction, and climate are important drivers of variability in recruitment success. Understanding variability in recruitment can reveal mechanisms behind widespread decline in the abundance of key species in marine and terrestrial ecosystems. For fish populations, the match-mismatch theory hypothesizes that success...

Coupled biological-physical models of larval fish have become a widely used tool for studying recruitment variability. Within these models, foraging components include prey selection as a determinant of food availability but have not yet considered species-specific escape behaviors of prey, which can be important in determining capture success. Fur...

Environmental variation can cause significant fluctuations in the survival of larval fish and plankton. Understanding these fluctuations is critical for developing more accurate fisheries models, which are needed for both scientific and socioeconomic research. Growth, survival, and dispersal of marine planktonic larvae rely strongly on their behavi...

Understanding larval fish survival dynamics is essential to determining variability in future adult population structure. Realistic modeling of larval fish feeding ecology depends on incorporating both the biotic and abiotic conditions that affect predator–prey interactions. We used an individual-based model (IBM) to test which variables drive Atla...

The spawning strategy of cod has evolved through natural selection to give larvae a good start in life. Therefore, larval drift, growth, and survival are key processes to understand spawning strategies. Spawning of Northeast Arctic (NA) cod stretches from late February to early May over 1500 km along the Norwegian coast. Hatching occurs from late M...

Highly resolved general circulation models (GCMs) now generate realistic flow fields, and have revealed how sensitive larval drift routes are to vertical positioning in the water column. Sensible representation of behavioural processes then becomes essential to generate reliable patterns of environmental exposure (growth and survival), larval drift...

Due to vertical variations in ocean circulation, larval Northeast Arctic cod Gadus morhua may influence their own drift routes by migrating vertically. By coupling a larval individualbased model and a general circulation model, we simulated larval vertical positioning according to simple rules based on individual risk sensitivity. This enabled us t...

Individual-based models (IBMs) integrate behavioural, physiological, and developmental features and differences among individuals. Building on previous process-based models, we developed an IBM of larval Atlantic cod (Gadus morhua) that included foraging, size-, temperature-, and food-limited growth, and environmental factors such as prey-field, tu...

An individual based model with a mechanistic foraging routine was used to simulate growth rates and prey selection on Georges Bank in May 1993 and 1994. Extensive observations of the zooplankton field, and the hydrography were used as forcing of the model, and the results were compared to field data and earlier modeling results. The observed growth...

Altogether 163 observations of the Sechi disk depth, collected from April to October in the Nordic Seas, are presented together with salinities, other environmental parameters and positions. The Sechi disk depth ranges from 2 to 28 m, and the surface salinity from 25.4 to 35.2. There is no apparent correlation between Secchi disk depth and salinity...