scholarly journals Krill, climate, and contrasting future scenarios for Arctic and Antarctic fisheries

2014 ◽  
Vol 71 (7) ◽  
pp. 1934-1955 ◽  
Author(s):  
Margaret M. McBride ◽  
Padmini Dalpadado ◽  
Kenneth F. Drinkwater ◽  
Olav Rune Godø ◽  
Alistair J. Hobday ◽  
...  
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Open Water ◽  
Geological Structure ◽  
Climate Impacts ◽  
The Arctic ◽  
Life History Strategies ◽  
Future Scenarios ◽  
Zooplankton Species ◽  
Commercial Fish

Abstract Arctic and Antarctic marine systems have in common 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 climate impacts have been reported, as have dramatic future projections. However, the combined effects of a changing climate on oceanographic processes and foodweb dynamics are likely to influence their future fisheries in very different ways. Differences in the life-history strategies of the key zooplankton species (Antarctic krill in the Southern Ocean and Calanus copepods in the Arctic) will likely affect future productivity of fishery species and fisheries. To explore future scenarios for each region, this paper: (i) considers differing characteristics (including geographic, physical, and biological) that define polar marine ecosystems and reviews known and projected impacts of climate change on key zooplankton species that may impact fished species; (ii) summarizes existing fishery resources; (iii) synthesizes this information to generate future scenarios for fisheries; and (iv) considers the implications for future fisheries management. Published studies suggest that if an increase in open water during summer in Arctic and Subarctic seas results in increased primary and secondary production, biomass may increase for some important commercial fish stocks and new mixes of species may become targeted. In contrast, published studies suggest that in the Southern Ocean the potential for existing species to adapt is mixed and that the potential for the invasion of large and highly productive pelagic finfish species appears low. Thus, future Southern Ocean fisheries may largely be dependent on existing species. It is clear from this review that new management approaches will be needed that account for the changing dynamics in these regions under climate change.

scholarly journals Diagnosing CO2 emission-induced feedbacks between the Southern Ocean carbon cycle and the climate system: A multiple Earth System Model analysis using a water mass tracking approach

2021 ◽  
pp. 1-62
Author(s):  
Tilla Roy ◽  
Jean Baptiste Sallée ◽  
Laurent Bopp ◽  
Nicolas Metzl
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Water Mass ◽  
Buffering Capacity ◽  
Climate Impacts ◽  
System Model ◽  
Earth System ◽  
Local Climate ◽  
Mode Waters ◽  
Ocean Carbon

AbstractAnthropogenic CO2 emission-induced feedbacks between the carbon cycle and the climate system perturb the efficiency of atmospheric CO2 uptake by land and ocean carbon reservoirs. The Southern Ocean is a region where these feedbacks can be largest and differ most among Earth System Model projections of 21st century climate change. To improve our mechanistic understanding of these feedbacks, we develop an automated procedure that tracks changes in the positions of Southern Ocean water masses and their carbon uptake. In an idealised ensemble of climate change projections, we diagnose two carbon–concentration feedbacks driven by atmospheric CO2 (due to increasing air-sea CO2 partial pressure difference, dpCO2, and reducing carbonate buffering capacity) and two carbon–climate feedbacks driven by climate change (due to changes in the water mass surface outcrop areas and local climate impacts). Collectively these feedbacks increase the CO2 uptake by the Southern Ocean and account for one-fifth of the global uptake of CO2 emissions. The increase in CO2 uptake is primarily dpCO2-driven, with Antarctic intermediate waters making the largest contribution; the remaining three feedbacks partially offset this increase (by ~25%), with maximum reductions in Subantarctic mode waters. The process dominating the decrease in CO2 uptake is water mass-dependent: reduction in carbonate buffering capacity in Subtropical and Subantarctic mode waters, local climate impacts in Antarctic intermediate waters, and reduction in outcrop areas in circumpolar deep waters and Antarctic bottom waters. Intermodel variability in the feedbacks is predominately dpCO2–driven and should be a focus of efforts to constrain projection uncertainty.

scholarly journals Differing marine animal biomass shifts under 21st century climate change between Canada’s three oceans

FACETS ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 105-122
Author(s):  
Andrea Bryndum-Buchholz ◽  
Faelan Prentice ◽  
Derek P. Tittensor ◽  
Julia L. Blanchard ◽  
William W.L. Cheung ◽  
...  
Keyword(s):  
Climate Change ◽  
Marine Ecosystem ◽  
Trophic Relationships ◽  
The Arctic ◽  
Marine Animal ◽  
Polar Regions ◽  
Adaptive Planning ◽  
Commercial Fish ◽  
Marine Biomass ◽  
Emissions Scenarios

Under climate change, species composition and abundances in high-latitude waters are expected to substantially reconfigure with consequences for trophic relationships and ecosystem services. Outcomes are challenging to project at national scales, despite their importance for management decisions. Using an ensemble of six global marine ecosystem models we analyzed marine ecosystem responses to climate change from 1971 to 2099 in Canada’s Exclusive Economic Zone (EEZ) under four standardized emissions scenarios. By 2099, under business-as-usual emissions (RCP8.5) projected marine animal biomass declined by an average of −7.7% (±29.5%) within the Canadian EEZ, dominated by declines in the Pacific (−24% ± 24.5%) and Atlantic (−25.5% ± 9.5%) areas; these were partially compensated by increases in the Canadian Arctic (+26.2% ± 38.4%). Lower emissions scenarios projected successively smaller biomass changes, highlighting the benefits of stronger mitigation targets. Individual model projections were most consistent in the Atlantic and Pacific, but highly variable in the Arctic due to model uncertainties in polar regions. Different trajectories of future marine biomass changes will require regional-specific responses in conservation and management strategies, such as adaptive planning of marine protected areas and species-specific management plans, to enhance resilience and rebuilding of Canada’s marine ecosystems and commercial fish stocks.

scholarly journals Present and future aerosol impacts on Arctic climate change in the GISS-E2.1 Earth system model

2021 ◽  
Vol 21 (13) ◽  
pp. 10413-10438
Author(s):  
Ulas Im ◽  
Kostas Tsigaridis ◽  
Gregory Faluvegi ◽  
Peter L. Langen ◽  
Joshua P. French ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Impacts ◽  
Earth System Model ◽  
System Model ◽  
The Arctic ◽  
Earth System ◽  
Anthropogenic Aerosols ◽  
Emission Reductions ◽  
Air Temperatures ◽  
Arctic Surface

Abstract. The Arctic is warming 2 to 3 times faster than the global average, partly due to changes in short-lived climate forcers (SLCFs) including aerosols. In order to study the effects of atmospheric aerosols in this warming, recent past (1990–2014) and future (2015–2050) simulations have been carried out using the GISS-E2.1 Earth system model to study the aerosol burdens and their radiative and climate impacts over the Arctic (>60∘ N), using anthropogenic emissions from the Eclipse V6b and the Coupled Model Intercomparison Project Phase 6 (CMIP6) databases, while global annual mean greenhouse gas concentrations were prescribed and kept fixed in all simulations. Results showed that the simulations have underestimated observed surface aerosol levels, in particular black carbon (BC) and sulfate (SO42-), by more than 50 %, with the smallest biases calculated for the atmosphere-only simulations, where winds are nudged to reanalysis data. CMIP6 simulations performed slightly better in reproducing the observed surface aerosol concentrations and climate parameters, compared to the Eclipse simulations. In addition, simulations where atmosphere and ocean are fully coupled had slightly smaller biases in aerosol levels compared to atmosphere-only simulations without nudging. Arctic BC, organic aerosol (OA), and SO42- burdens decrease significantly in all simulations by 10 %–60 % following the reductions of 7 %–78 % in emission projections, with the Eclipse ensemble showing larger reductions in Arctic aerosol burdens compared to the CMIP6 ensemble. For the 2030–2050 period, the Eclipse ensemble simulated a radiative forcing due to aerosol–radiation interactions (RFARI) of -0.39±0.01 W m−2, which is −0.08 W m−2 larger than the 1990–2010 mean forcing (−0.32 W m−2), of which -0.24±0.01 W m−2 was attributed to the anthropogenic aerosols. The CMIP6 ensemble simulated a RFARI of −0.35 to −0.40 W m−2 for the same period, which is −0.01 to −0.06 W m−2 larger than the 1990–2010 mean forcing of −0.35 W m−2. The scenarios with little to no mitigation (worst-case scenarios) led to very small changes in the RFARI, while scenarios with medium to large emission mitigations led to increases in the negative RFARI, mainly due to the decrease in the positive BC forcing and the decrease in the negative SO42- forcing. The anthropogenic aerosols accounted for −0.24 to −0.26 W m−2 of the net RFARI in 2030–2050 period, in Eclipse and CMIP6 ensembles, respectively. Finally, all simulations showed an increase in the Arctic surface air temperatures throughout the simulation period. By 2050, surface air temperatures are projected to increase by 2.4 to 2.6 ∘C in the Eclipse ensemble and 1.9 to 2.6 ∘C in the CMIP6 ensemble, compared to the 1990–2010 mean. Overall, results show that even the scenarios with largest emission reductions leads to similar impact on the future Arctic surface air temperatures and sea-ice extent compared to scenarios with smaller emission reductions, implying reductions of greenhouse emissions are still necessary to mitigate climate change.

scholarly journals Spring partitioning of Disko Bay, West Greenland, by Arctic and Subarctic baleen whales

2012 ◽  
Vol 69 (7) ◽  
pp. 1226-1233 ◽  
Author(s):  
Kristin L. Laidre ◽  
Mads Peter Heide-Jørgensen
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Satellite Telemetry ◽  
Open Water ◽  
The Arctic ◽  
Interspecies Interactions ◽  
Baleen Whales ◽  
West Greenland ◽  
Bowhead Whales ◽  
Departure Date

Abstract Laidre, K. L., and Heide-Jørgensen, M. P. 2012. Spring partitioning of Disko Bay, West Greenland, by Arctic and Subarctic baleen whales. – ICES Journal of Marine Science, 69: . Movements of co-occurring bowhead (Balaena mysticetus) and humpback (Megaptera novaeangliae) whales in Disko Bay, West Greenland, were examined using satellite telemetry. Data on movements, habitat use, and phenology were collected from tagged 49 bowheads and 44 humpbacks during the transition from sea-ice breakup to open water between 2008 and 2010. Bowhead whales began their northward spring migration around 27 May (median day-of-the-year departure date = 147, interquartile range 141–153) and were distributed broadly in northern and central Disko Bay in water depths between 100 and 400 m. Humpback whales arrived in Disko Bay no later than 2 June and were located in shallow water (<100 m) along the coasts of the mainland or Disko Island. Trends in departure date from Disko Bay were significant for bowhead whales (∼15 d later, p < 0.001) between two periods: 2001–2006 and 2008–2010. Many species are predicted to arrive earlier in the Arctic and to expand their range northwards with reduced sea ice and increasing temperatures under climate change. Quantifying the spatial and temporal relationships between co-occurring Arctic and Subarctic top predators allows for baseline insight to be gained on how climate change might alter interspecies interactions.

Future Scenarios for Arctic Shipping

2020 ◽  
Author(s):  
Martin Bergström ◽  
Bernt J. Leira ◽  
Pentti Kujala
Keyword(s):  
Climate Change ◽  
Global Economy ◽  
The Arctic ◽  
Future Scenarios ◽  
Fuel Prices ◽  
Multiple Factors ◽  
Regulatory Changes ◽  
International Policies ◽  
Arctic Shipping ◽  
Improved Technology

Abstract Maritime activity in the Arctic is on the increase, driven by multiple factors including the development of Arctic natural resources, climate change, regulatory changes, improved technology and operations, national and international policies, infrastructure developments, fuel prices, and the global economy. This article aims to identify and analyze such change drivers and to discuss how these might influence the future of three specific segments of Arctic shipping: destination-Arctic shipping (operation between Arctic and non-Arctic locations), trans-Arctic shipping (operation between non-Arctic locations through Arctic waters), and Arctic cruising. The study finds that each considered segment of Arctic shipping is subject to a unique set of significant change drivers.

scholarly journals Wild and Farmed Arctic Charr as a Tourism Product in an Era of Climate Change

2021 ◽  
Vol 5 ◽  
Author(s):  
Guðrún Helgadóttir ◽  
Hans Renssen ◽  
Tom Robin Olk ◽  
Tone Jøran Oredalen ◽  
Laufey Haraldsdóttir ◽  
...  
Keyword(s):  
Climate Change ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Ecological Factors ◽  
Freshwater Ecosystems ◽  
Tourism Industry ◽  
The Arctic ◽  
Future Scenarios ◽  
Subarctic Region ◽  
Tourism Product

The topic investigated is the social-ecological system of Arctic charr (Salvelinus alpinus) fishing and aquaculture as a tourism product in an era of climate change. Arctic charr is a resilient salmonid species that was traditionally an important part of the sustenance economy in Arctic and Subarctic communities as a source of fresh food throughout the year. Arctic charr populations have declined in recent years, in part due to climate change. These changes in the freshwater ecosystems in turn affect the cultural and economic traditions of freshwater fishing and consumption. This development has consequences for the tourism industry as hunting, fishing and consuming local and traditional food is important in branding tourism destinations. Fisheries are no longer the source of this important ingredient in the Nordic culinary tradition, instead aquaculture production supplies nearly all the Arctic charr consumed. In this paper, we pool the resources of an interdisciplinary team of scholars researching climate change, freshwater ecology, aquaculture and tourism. We integrate knowledge from these fields to discuss likely future scenarios for Arctic charr, their implications for transdisciplinary social ecosystem approaches to sustainable production, marketing and management, particularly how this relates to the growing industry of tourism in the Nordic Arctic and Subarctic region. We pose the questions whether Arctic Charr will be on the menu in 20 years and if so, where will it come from, and what consequences does that have for local food in tourism of the region? Our discussion starts with climate change and the question of how warm it is likely to get in the Nordic Arctic, particularly focusing on Iceland and Norway. To address the implications of the warming of lakes and rivers of the global north for Arctic charr we move on to a discussion of physiological and ecological factors that are important for the distribution of the species. We present the state of the art of Arctic charr aquaculture before articulating the importance of the species for marketing of local and regional food, particularly in the tourism market. Finally, we discuss the need for further elaboration of future scenarios for the interaction of the Arctic charr ecosystem and the economic trade in the species and draw conclusions about sustainable future development.

scholarly journals Regional impacts of climate change in the Arctic and Antarctic

1998 ◽  
Vol 27 ◽  
pp. 543-552 ◽  
Author(s):  
Gunter Weller
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Climate Impacts ◽  
Indigenous Populations ◽  
The Arctic ◽  
Future Climate Change ◽  
Greenhouse Warming ◽  
Polar Regions ◽  
Sea Ice Extent ◽  
The Past

Regional assessments of impacts due to global climate change are a high priority in the international programs on global-change research. in the polar regions, climate models indicate an amplification of global greenhouse warming, but there are large differences between the results of various models, and uncertainties about the magnitude and timing of the expected changes. Also, the observed high-latitude climate trends over the past few decades are much more regional and patchy than predicted by the models. As a first step in assessing possible climate impacts, model results are compared with observations of changes in temperature, precipitation, sea-ice extent, the permafrost regime and other cryospheric parameters. While considerable uncertainties remain in the long-term prediction of change, there is some agreement between model results and observed trends by season on shorter time-scales, The warming observed over the land masses of the Arctic over the past few decades is matched by corresponding observed decreases in snow cover the glacier mass, balances, by thawing of the permafrost, and to a lesser degree by reductions in sea-ice extent. in Antarctica, warming in the Antarctic Peninsula and Ross Sea regions is associated with large decreases in ice-shelf areas and reduced ice thicknesses on the lakes in the McMurdo Dry Valleys. Major future impacts due to global greenhouse warming are likely to include permafrost thawing on and and its consequences for ecosystems and humans; changes in the productivity of marine ecosystems in the Arctic and Southern Ocean: economic impacts on fisheries, petroleum and other human activities; and social impacts on northern indigenous populations. Some of these impacts will have positive ramifications, but most are likely to be detrimental. While uncertainties exist about the future, climate change in the polar regions during the past few decades can be shown to have had major impacts already which will become much mole pronounced if present trends continue.

scholarly journals Regional Dynamic and Steric Sea Level Change in Response to the IPCC-A1B Scenario

2007 ◽  
Vol 37 (2) ◽  
pp. 296-312 ◽  
Author(s):  
Felix W. Landerer ◽  
Johann H. Jungclaus ◽  
Jochem Marotzke
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Sea Level ◽  
North Atlantic ◽  
Climate Change Scenario ◽  
The Arctic ◽  
Change Scenario ◽  
Sea Level Changes ◽  
The North ◽  
The North Atlantic

Abstract This paper analyzes regional sea level changes in a climate change simulation using the Max Planck Institute for Meteorology (MPI) coupled atmosphere–ocean general circulation model ECHAM5/MPI-OM. The climate change scenario builds on observed atmospheric greenhouse gas (GHG) concentrations from 1860 to 2000, followed by the International Panel on Climate Change (IPCC) A1B climate change scenario until 2100; from 2100 to 2199, GHG concentrations are fixed at the 2100 level. As compared with the unperturbed control climate, global sea level rises 0.26 m by 2100, and 0.56 m by 2199 through steric expansion; eustatic changes are not included in this simulation. The model’s sea level evolves substantially differently among ocean basins. Sea level rise is strongest in the Arctic Ocean, from enhanced freshwater input from precipitation and continental runoff, and weakest in the Southern Ocean, because of compensation of steric changes through dynamic sea surface height (SSH) adjustments. In the North Atlantic Ocean (NA), a complex tripole SSH pattern across the subtropical to subpolar gyre front evolves, which is consistent with a northward shift of the NA current. On interannual to decadal time scales, the SSH difference between Bermuda and the Labrador Sea correlates highly with the combined baroclinic gyre transport in the NA but only weakly with the meridional overturning circulation (MOC) and, thus, does not allow for estimates of the MOC on these time scales. Bottom pressure increases over shelf areas by up to 0.45 m (water column equivalent) and decreases over the Atlantic section in the Southern Ocean by up to 0.20 m. The separate evaluation of thermosteric and halosteric sea level changes shows that thermosteric anomalies are positive over most of the World Ocean. Because of increased atmospheric moisture transport from low to high latitudes, halosteric anomalies are negative in the subtropical NA and partly compensate thermosteric anomalies, but are positive in the Arctic Ocean and add to thermosteric anomalies. The vertical distribution of thermosteric and halosteric anomalies is highly nonuniform among ocean basins, reaching deeper than 3000 m in the Southern Ocean, down to 2200 m in the North Atlantic, and only to depths of 500 m in the Pacific Ocean by the end of the twenty-first century.

Polar marine ecosystems: major threats and future change

2003 ◽  
Vol 30 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Andrew Clarke ◽  
Colin M. Harris
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Marine Ecosystems ◽  
The Arctic ◽  
Polar Regions ◽  
Fishing Activity ◽  
Sea Ice Extent ◽  
Cumulative Impact ◽  
Sources Of Pollution ◽  
Large Populations

This review of polar marine ecosystems covers both the Arctic and Antarctic, identifying the major threats and, where possible, predicting their possible state(s) in 2025. Although the two polar regions are similar in their extreme photoperiod, low temperatures, and in being heavily influenced by snow and ice, in almost all other respects they are very different. The Arctic Ocean is a basin surrounded by continental landmasses, close to, and influenced by, large populations and industrial activities. In contrast, the Southern Ocean is contiguous with all the other great oceans and surrounds a single land mass; Antarctica is remote from major centres of population and sources of pollution. Marine environments in both polar regions have been highly disturbed by fishing activity, but, in terms of pollution, some areas remain among the most pristine in the world. There are, however, both local and global pressures. Over the 2025 time horizon, the greatest concern for the Arctic is probably the ecological implications of climate change, particularly insofar as sea ice extent and duration are likely to be affected. Such changes are not expected to be as pronounced in the Southern Ocean over this time period, and concerns are related more to direct threats from harvesting of marine living resources, and the ability to manage these fisheries sustainably. In both polar regions, the capacity of marine ecosystems to withstand the cumulative impact of a number of pressures, including climate change, pollution and overexploitation, acting synergistically is of greatest concern.

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