•The central Arctic Ocean is not isolated, but tightly connected to the northern Pacific and Atlantic Oceans.•Advection into the Arctic Ocean forms lengthy contiguous domains that connect subarctic ...with the arctic biota.•The Arctic Ocean ecosystems are net biomass beneficiaries through advection.•Advective transport can be thought of as trails of life and death in the Arctic Ocean.•As compared to the Pacific gateway the advective supply of zooplankton biomass through the Atlantic gateways is 2–3 times higher.•The Arctic Ocean will more and more rely on an increasing local primary production while the advection of zooplankton will cease.
The central Arctic Ocean is not isolated, but tightly connected to the northern Pacific and Atlantic Oceans. Advection of nutrient-, detritus- and plankton-rich waters into the Arctic Ocean forms lengthy contiguous domains that connect subarctic with the arctic biota, supporting both primary production and higher trophic level consumers. In turn, the Arctic influences the physical, chemical and biological oceanography of adjacent subarctic waters through southward fluxes. However, exports of biomass out of the Arctic Ocean into both the Pacific and Atlantic Oceans are thought to be far smaller than the northward influx. Thus, Arctic Ocean ecosystems are net biomass beneficiaries through advection. The biotic impact of Atlantic- and Pacific-origin taxa in arctic waters depends on the total supply of allochthonously-produced biomass, their ability to survive as adults and their (unsuccessful) reproduction in the new environment. Thus, advective transport can be thought of as trails of life and death in the Arctic Ocean. Through direct and indirect (mammal stomachs, models) observations this overview presents information about the advection and fate of zooplankton in the Arctic Ocean, now and in the future. The main zooplankton organisms subjected to advection into and inside the Arctic Ocean are (a) oceanic expatriates of boreal Atlantic and Pacific origin, (b) oceanic Arctic residents and (c) neritic Arctic expatriates. As compared to the Pacific gateway the advective supply of zooplankton biomass through the Atlantic gateways is 2–3 times higher. Advection characterises how the main planktonic organisms interact along the contiguous domains and shows how the subarctic production regimes fuel life in the Arctic Ocean. The main differences in the advective regimes through the Pacific and Atlantic gateways are presented. The Arctic Ocean is, at least in some regions, a net heterotrophic ocean that – during the foreseeable global warming trend – will more and more rely on an increasing local primary production while the advection of zooplankton, as revealed by models, will cease.
The gross primary (GPP) and secondary production in the Arctic Basin, Eurasian shelves and the Barents Sea were investigated through the physically–biologically coupled, 3D SINMOD model with 20km ...grid size. The model was applied in an experimental setting where a control run had atmospheric forcing from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data. In order to test the effect of how retreating ice cover in the forthcoming century may affect the productivity through physical processes in the Arctic Ocean we added a latitude dependent air temperature starting at 1°C at 40°N increasing to +2,+4,+6 and +8°C at 90°N to the temperature forcing taken from ECMWF data. The model indicates that gross primary production (GPP) increases along the temperature gradient both in the Arctic Basin and along the Eurasian shelves from approximately 10 to 40 and 30 to 60gCm⁻²y⁻¹, respectively. In contrast, GPP in the Barents Sea was more or less constant (ca. 100gCm⁻²y⁻¹). For secondary production (key mesozooplankton species Calanus finmarchicus and Calanus glacialis) the results of the experimental runs are more complex. With an air temperature increase towards +8°C secondary production of C. glacialis in the Barents Sea dropped from about 3.9 to 0.3gCm⁻²y⁻¹, while that of the Arctic Basin and Eurasian shelf increased from approximately −0.1 to 1.5 and 1.4 to 2.4gCm⁻²y⁻¹, respectively. Secondary production changes are unevenly distributed spatially during future warming with the most significant increases occurring along the Eurasian shelves and the Chukchi Sea. Reductions are predicted for the Kara Sea and northern Baffin Bay. During warming and among the key mesozooplankton species the distribution of C. finmarchicus is constrained to the Barents Sea and eastern Fram Strait while C. glacialis almost disappears from the northern Barents Sea, the western Fram Strait and northern Baffin Bay. In contrast, this typical Arctic species expands to the Arctic Basin and on and off the Eurasian shelf, in particular the Chukchi and East Siberian Seas.
•Remote sensing and coupled physical–biological NPP models in Arctic Ocean.•Need to improve the parameterization of phytoplankton growth models in both.•One should take into account their fundamental ...differences in comparisons.
Over the last decade, several studies have reported a significant increase in marine primary production of the Arctic Ocean due mainly to a decrease in the extent of the icepack. Given the lack of in situ measurements, these studies were either based on prognostic models that use time series of remote sensing measurements of clouds, ice concentration and, most importantly, phytoplankton biomass at ocean surface (ocean colour remote sensing, OCRS), and coupled physical–biological ice–ocean (CPBO) dynamic models. In this paper, we review the strengths and limitations of these two approaches when applied in the Arctic Ocean. More specifically, we examine how they compare in terms of phytoplankton growth modelling and parameterisation, including relative to the current literature on measured Arctic phytoplankton growth parameters.
A 3-dimensional hydrodynamic−ecological model system (SINMOD) was used to estimate the full-scale cultivation potential of the brown alga Saccharina latissima in integrated multi-trophic aquaculture ...(IMTA) with Atlantic salmon Salmo salar. A previously developed model for the frond size and composition (carbon and nitrogen content) of S. latissima sporophytes was adjusted to data from an outdoor mesocosm growth experiment and then coupled and run online with the 3-dimensional model system. Results from simulations were compared with data from an IMTA field experiment, providing partial validation of the hydrodynamic–ecological–kelp model system. The model system was applied to study the large-scale cultivation potential of S. latissima in IMTA with salmon and to quantify its seasonal bioremediation potential. The results suggest a possible yield of 75 t fresh weight S. latissima ha⁻¹ in 4 mo (February to June) and about 170 t fresh weight ha⁻¹ in 10 mo (August to June). The results further suggest that the net nitrogen consumption of a 1 ha S. latissima installation in the vicinity of a fish farm producing approximately 5000 t salmon in a production cycle is about 0.36 (0.15) t NH₄⁺-N, or a removal of 0.34% (0.41%) of the dissolved inorganic nitrogen effluent with a cultivation period from August (February) to June. Due to the differing seasonal growth patterns of fish and kelp, there was a mismatch between the maximum effluent of NH₄⁺-N from the fish farm and the maximum uptake rates in S. latissima.
The impacts of oceanic CO2 uptake and global warming on the surface ocean environment have received substantial attention, but few studies have focused on shelf bottom water, despite its importance ...as habitat for benthic organisms and demersal fisheries such as cod. We used a downscaling ocean biogeochemical model to project bottom water acidification and warming on the western Eurasian Arctic shelves. A model hindcast produced 14–18 year acidification trends that were largely consistent with observational estimates at stations in the Iceland and Irminger Seas. Projections under SRES A1B scenario revealed a rapid and spatially variable decline in bottom pH by 0.10–0.20 units over 50 years (2.5%–97.5% quantiles) at depths 50–500 m on the Norwegian, Barents, Kara, and East Greenland shelves. Bottom water undersaturation with respect to aragonite occurred over the entire Kara shelf by 2040 and over most of the Barents and East Greenland shelves by 2070. Shelf acidification was predominantly driven by the accumulation of anthropogenic CO2, and was concurrent with warming of 0.1–2.7°C over 50 years. These combined perturbations will act as significant multistressors on the Barents and Kara shelves. Future studies should aim to improve the resolution of shelf bottom processes in models, and should consider the Kara Sea and Russian shelves as possible bellwethers of shelf acidification.
Key Points
Downscaling ocean model reproduces observed 14–18 year acidification trends (0.015–0.025 per decade) at high northern latitudes
Shelf bottom acidification and warming under SRES A1B is rapid and spatially variable (0.10–0.20 pH and 0.1–2.7°C over 50 years)
Acidification and warming may stress benthic and demersal organisms on the Norwegian, Barents, Kara, and East Greenland shelves
Pedersen, O. P., Pedersen, T., Tande, K. S., and Slagstad, D. 2009. Integrating spatial and temporal mortality from herring on capelin larvae: a study in the Barents Sea. – ICES Journal of Marine ...Science, 66: 2183–2194.Barents Sea herring and capelin are commercially very important fish stocks. We investigate the spatial and temporal mortality rate of capelin larvae in 2001 as a function of herring predation. Our methods are based on Lagrangian modelling, field surveys, and experimental data. The impact of juvenile herring predation on capelin recruitment is corroborated, in particular the importance of the integrated spatio-temporal overlap between the two stocks. Capelin larvae were reduced to 20–50% in two weeks in accordance with different simulation scenarios. Hamre advanced a hypothesis in 1994 that juvenile herring are important predators of capelin larvae and a main cause of poor capelin recruitment in years when herring are very abundant in the Barents Sea. This hypothesis is supported through the results of this work.
This paper addresses the ongoing invasion of Red King Crab (RKC) along the coast of North Norway, and the specific objective is to study larval drift, locations of settlement and interannual ...variation for 1998, 1999 and 2000. Through this study, we have established that the coastal region seems to be the most main settling region. We have also shown the effect of wind regimes and the Ekman drift on the larval trajectories. Our study has further demonstrated that the general direction of advection of larvae is to the east, and this is a persistent feature. There is also a dispersion of larvae in westbound direction along the coast. However, the net westbound distance advected is less compared to those advected eastbound.
The Barents Sea capelin stock is, potentially, the largest capelin stock in the world, with a maximum biomass in the range of 6–8 million tonne. The main spawning grounds for this capelin stock are ...along the coast of northern Norway. By modeling and fieldwork, this study addresses the interaction between mesoscale physical process and newly hatched capelin larvae. The study documents a close relationship between selected spawning location, advection, retention, mortality windows and dispersal patterns.
During winter 2003 and 2004, zooplankton and hydrographic data were collected in the northern parts of the Norwegian Sea (68–72° N, 8–17° E) west of the Norwegian shelf break at depths down to 1800 ...m. The results cover both inter and intra annual changes of hydrography and distribution of Calanus spp. For the whole survey area, average seawater temperature down to 1000 m was higher in 2004 than in the same period in 2003. For the upper 500 m the difference was ca. 1°C. Calanus finmarchicus dominated at ca. 75% of the total copepod abundance. Typical abundance of C. finmarchicus in the survey area was 30 000–40 000 m−2. C. hyperboreus was found deeper than C. finmarchicus while other copepods were found at the depth of C. finmarchicus or shallower. From January to February 2004, the peak of abundance of C. finmarchicus and C. hyperboreus shifted approximately 300 m upwards indicating that ascent from overwintering depth took place at a speed of 10 m d−1 during this period. In general, high abundance of copepods was found adjacent to the shelf slope while oceanic areas had low and intermediate abundance. In the southern part of the survey area, location of high and low copepod abundance shifted both between and within years. In the northern part of the survey area where the shelf slope is less steep, copepods was present at intermediate and high abundance during all surveys.
To investigate the seasonal carbon flux and the interannual variabilitiy, an upgraded and revised physically-biologically coupled, nested 3D model with 4 km grid size was applied. The model was ...validated using field data from the years for which the carbon flux was modelled, focussing on its precision in space and time, the adequacy of the validation data, suspended biomass and vertical export. Meteorological forcing had a strong impact on the vertical stratification of the regions dominated by Atlantic water and this resulted in significant differences in seasonal variability in primary production. The spatially integrated primary production in the Barents Sea was 42-49% greater during warm years than the production during the coolest and most ice-covered year.
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