scholarly journals Sea ice and substratum shape extensive kelp forests in the Canadian Arctic

2021 ◽  
Author(s):  
Karen Filbee-Dexter ◽  
Kathleen A MacGregor ◽  
Camille Lavoie ◽  
Ignacio Garrido ◽  
Jesica Goldsmit ◽  
...  
Keyword(s):  
Sea Ice ◽  
Coastal Zone ◽  
Environmental Changes ◽  
Canadian Arctic ◽  
Open Water ◽  
Saccharina Latissima ◽  
Kelp Forests ◽  
Coastal Habitat ◽  
Potential Productivity ◽  
Eastern Canadian Arctic

The coastal zone of the Canadian Arctic represents 10% of the world’s coastline and is one of the most rapidly changing marine regions on the planet. To predict the consequences of these environmental changes, a better understanding of how environmental gradients shape coastal habitat structure in this area is required. We quantified the abundance and diversity of canopy forming seaweeds throughout the nearshore zone (5 - 15 m) of the Eastern Canadian Arctic using diving surveys and benthic collections at 55 sites distributed over 3000 km of coastline. Kelp forests were found throughout, covering on average 40.4 % (± 29.9 SD) of the seafloor across all sites and depths, despite thick sea ice and scarce hard substrata in some areas. Total standing macroalgal biomass ranged from 0 to 32 kg m‑2 WW and averaged 3.7 kg m‑2 (± 3.2 SD) across all sites and depths. Kelps were less abundant at depths of 5 m compared to 10 or 15 m and distinct regional assemblages were related to sea ice cover, substratum type, and nutrient availability. The most common community configuration was a mixed assemblage of four species: Agarum clathratum (14.9% ± 12.0 SD), Saccharina latissima (13% cover ± 14.7 SD), Alaria esculenta (5.4% ± 1.2 SD), and Laminaria solidungula (3.7% ± 4.9 SD). A. clathratum dominated northernmost regions and S. latissima and L. solidungula occurred at high abundance in regions with more open water days. In southeastern areas along the coast of northern Labrador, the coastal zone was mainly sea urchin barrens, with little vegetation. We found positive relationships between open water days (e.g., without sea ice) and kelp biomass and diversity, suggesting kelp forests could increase, and their species composition could shift, as sea ice diminishes in some areas of the Eastern Canadian Arctic. Our findings demonstrate the high potential productivity of this extensive coastal zone and highlight the need to better understand the ecology of these systems and the services they provide.

scholarly journals Sea-ice edge is more important than closer open water access for foraging Adélie penguins: evidence from two colonies

2020 ◽  
Vol 640 ◽  
pp. 215-230
Author(s):  
C Michelot ◽  
A Kato ◽  
T Raclot ◽  
K Shiomi ◽  
P Goulet ◽  
...  
Keyword(s):  
Sea Ice ◽  
Environmental Changes ◽  
Early Stage ◽  
Open Water ◽  
Gps Tracking ◽  
Ice Edge ◽  
Sea Ice Edge ◽  
Study Sites ◽  
The Impact ◽  
Adélie Penguins

Sentinel species, like Adélie penguins, have been used to assess the impact of environmental changes, and their link with sea ice has received considerable attention. Here, we tested if foraging Adélie penguins from 2 colonies in East Antarctica target the distant sea-ice edge or take advantage of closer open waters that are readily available near their colony. We examined the foraging behaviour of penguins during the incubation trips of females in 2016 and males in 2017, using GPS tracking and diet data in view of daily sea-ice data and bathymetry. In 2016-2017, sea-ice cover was extensive during females’ trips but flaw leads and polynyas were close to both study sites. Sea ice receded rapidly during males’ trips in 2017-2018. Despite close open water near both colonies in both years, females and males preferentially targeted the continental slope and the sea-ice edge to forage. In addition, there was no difference in the diet of penguins from both colonies: all penguins fed mostly on Antarctic krill and males also foraged on Antarctic silverfish. Our results highlight the importance of the sea-ice edge for penguins, an area where food abundance is predictable. It is likely that resource availability was not sufficient in closer open water areas at such an early stage in the breeding season. The behaviours displayed by the penguins from both colonies were similar, suggesting a common behaviour across colonies in Terre Adélie, although additional sites would be necessary to confirm this hypothesis.

scholarly journals Multiproxy evidence of the Neoglacial expansion of Atlantic Water to eastern Svalbard: Does ancient environmental DNA complement sedimentary and microfossil records?

2019 ◽  
Author(s):  
Joanna Pawłowska ◽  
Magdalena Łącka ◽  
Małgorzata Kucharska ◽  
Jan Pawlowski ◽  
Marek Zajączkowski
Keyword(s):  
Sea Ice ◽  
Dna Sequences ◽  
Environmental Changes ◽  
Environmental Dna ◽  
Open Water ◽  
Ice Cover ◽  
Atlantic Water ◽  
Ice Coverage ◽  
Ice Conditions ◽  
Multiproxy Approach

Abstract. The main goal of this study was to reconstruct the paleoceanographic development of Storfjorden during the Neoglacial (~ 4 cal ka BP). A multiproxy approach was applied to provide evidence for interactions between the inflow of Atlantic Water (AW) and sea-ice coverage, which are the major drivers of environmental changes in Storfjorden. The sedimentary and microfossil records indicate that a major reorganization of oceanographic conditions in Storfjorden occurred at ~ 2.7 cal ka BP. A general cooling and the less pronounced presence of AW in Storfjorden during the early phase of the Neoglacial are prerequisite conditions for the formation of an extensive sea-ice cover. The period after ~ 2.7 cal ka BP was characterized by alternating short-term cooling and warming intervals. Warming was associated with pulsed inflows of AW and sea-ice melting that stimulated phytoplankton blooms and organic matter supply to the bottom. The cold phases were characterized by heavy and densely packed sea ice resulting in a decrease in productivity. The ancient environmental DNA (aDNA) records of foraminifera and diatoms reveal the timing of the major pulses of AW (~ 2.3 and ~ 1.7 cal ka BP) and the variation in sea-ice cover. The AW inflow was marked by an increase in the percentage of DNA sequences of monothalamous foraminifera associated with the presence of fresh phytodetritus, while cold and less productive intervals were marked by an increased proportion of monothalamous taxa known only from environmental sequencing. The diatom aDNA record indicates that primary production was continuous during the Neoglacial regardless of sea-ice conditions. However, the colder periods were characterized by the presence of diatom taxa associated with sea ice, whereas the present-day diatom assemblage is dominated by open-water taxa.

scholarly journals Kelp in the Eastern Canadian Arctic: Current and Future Predictions of Habitat Suitability and Cover

2021 ◽  
Vol 18 ◽  
Author(s):  
Jesica Goldsmit ◽  
Robert W. Schlegel ◽  
Karen Filbee-Dexter ◽  
Kathleen A. MacGregor ◽  
Ladd E. Johnson ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Canadian Arctic ◽  
Environmental Data ◽  
Saccharina Latissima ◽  
Suitable Habitat ◽  
Percent Cover ◽  
Arctic Ecosystems ◽  
Modeling Approaches ◽  
Eastern Canadian Arctic ◽  
Occurrence Records

Climate change is transforming marine ecosystems through the expansion and contraction of species’ ranges. Sea ice loss and warming temperatures are expected to expand habitat availability for macroalgae along long stretches of Arctic coastlines. To better understand the current distribution of kelp forests in the Eastern Canadian Arctic, kelps were sampled along the coasts for species identifications and percent cover. The sampling effort was supplemented with occurrence records from global biodiversity databases, searches in the literature, and museum records. Environmental information and occurrence records were used to develop ensemble models for predicting habitat suitability and a Random Forest model to predict kelp cover for the dominant kelp species in the region – Agarum clathratum, Alaria esculenta, and Laminariaceae species (Laminaria solidungula and Saccharina latissima). Ice thickness, sea temperature and salinity explained the highest percentage of kelp distribution. Both modeling approaches showed that the current extent of arctic kelps is potentially much greater than the available records suggest. These modeling approaches were projected into the future using predicted environmental data for 2050 and 2100 based on the most extreme emission scenario (RCP 8.5). The models agreed that predicted distribution of kelp in the Eastern Canadian Arctic is likely to expand to more northern locations under future emissions scenarios, with the exception of the endemic arctic kelp L. solidungula, which is more likely to lose a significant proportion of suitable habitat. However, there were differences among species regarding predicted cover for both current and future projections. Notwithstanding model-specific variation, it is evident that kelps are widespread throughout the area and likely contribute significantly to the functioning of current Arctic ecosystems. Our results emphasize the importance of kelp in Arctic ecosystems and the underestimation of their potential distribution there.

scholarly journals Space-use strategy affects energy requirements in Barents Sea polar bears

2020 ◽  
Vol 639 ◽  
pp. 1-19 ◽  
Author(s):  
MA Blanchet ◽  
J Aars ◽  
M Andersen ◽  
H Routti
Keyword(s):  
Energy Expenditure ◽  
Sea Ice ◽  
Environmental Changes ◽  
Barents Sea ◽  
Open Water ◽  
The Arctic ◽  
Polar Bears ◽  
Gps Collars ◽  
The Barents Sea ◽  
High Caloric Diet

Polar bears Ursus maritimus are currently facing rapid environmental changes with loss of sea ice and shifts in their prey distribution. Two distinct ecotypes exist in the Barents Sea, where sea ice is decreasing at the highest rate in the Arctic. Coastal bears remain within the Archipelago of Svalbard year-round, whereas offshore bears follow the marginal ice zone (MIZ). We explored these 2 ecotypes’ habitat use, activity and energy needs as well as seasonal variation within these parameters. During the period from 2011-2018, adult female polar bears were equipped with GPS collars and activity sensors (n = 84); 46 of these were equipped with conductivity switches to record aquatic behaviour. Offshore bears travelled longer distances at a higher speed on land and at sea away from land and had a higher activity rate compared to coastal bears. This translated into higher overall energy expenditure. Offshore bears also undertook more distant and energetically costly trips from land to the MIZ, swimming in open water. Both ecotypes showed similar seasonal patterns of activity and movement consistent with their life history linked to sea ice phenology. Despite higher energy expenditure, the offshore strategy seemed to be as profitable as the coastal one as females had marginally better spring body condition, likely due to their specialized high caloric diet of seals throughout the year. However, both ecotypes are currently experiencing habitat changes. Future studies should aim to predict how rapidly declining sea ice in the Barents Sea may challenge polar bears energetically during the coming decades.

Diet and foraging ecology of Black Guillemots in northeastern Hudson Bay

1987 ◽  
Vol 65 (5) ◽  
pp. 1257-1263 ◽  
Author(s):  
D. K. Cairns
Keyword(s):  
Foraging Ecology ◽  
Canadian Arctic ◽  
Open Water ◽  
Hudson Bay ◽  
Boreogadus Saida ◽  
Foraging Habitat ◽  
Decapod Crustaceans ◽  
Cepphus Grylle ◽  
Landfast Ice ◽  
Eastern Canadian Arctic

I examined diet and foraging habitat selection by Black Guillemots (Cepphus grylle) in the eastern Canadian arctic. Birds fed on fish (Boreogadus saida, Stichaeus punctatus, Eumesogrammus praecisus) and mysid, amphipod, and decapod crustaceans. Guillemots concentrated at landfast ice edges early in the breeding season. Open-water foraging occurred principally in waters 10–30 m deep within 13 km of breeding colonies. Guillemots were aggregated on the water, but their distributions were not correlated with those of schooling prey. Guillemots feeding in open water obtained much of their food on the bottom, but some prey was likely taken during transit to and from the bottom.

Increased Arctic Ocean sea ice loss through the Canadian Arctic Archipelago under a warmer climate

2020 ◽  
Author(s):  
Stephen Howell ◽  
Mike Brady
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Canadian Arctic ◽  
Open Water ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Nares Strait ◽  
The Arctic Ocean ◽  
Important Pathway

<p>The ice arches that ring the northern Canadian Arctic Archipelago have historically blocked the inflow of Arctic Ocean sea ice for the majority of the year. However, annual average air temperature in northern Canada has increased by more than 2°C over the past 65+ years and a warmer climate is expected to contribute to the deterioration of these ice arches, which in turn has implications for the overall loss of Arctic Ocean sea ice. We investigated the effect of warming on the Arctic Ocean ice area flux into the Canadian Arctic Archipelago using a 22-year record (1997-2018) of ice exchange derived from RADARSAT-1 and RADARSAT-2 imagery. Results indicated that there has been a significant increase in the amount of Arctic Ocean sea ice (10<sup>3</sup> km<sup>2</sup>/year) entering the northern Canadian Arctic Archipelago over the period of 1997-2018. The increased Arctic Ocean ice area flux was associated with reduced ice arch duration but also with faster (thinner) moving ice and more southern latitude open water leeway as a result of the Canadian Arctic Archipelago’s long-term transition to a younger and thinner ice regime. Remarkably, in 2016, the Arctic Ocean ice area flux into the Canadian Arctic Archipelago (161x10<sup>3</sup> km<sup>2</sup>) was 7 times greater than the 1997-2018 average (23x10<sup>3</sup> km<sup>2</sup>) and almost double the 2007 ice area flux into Nares Strait (87x10<sup>3</sup> km<sup>2</sup>). Indeed, Nares Strait is known to be an important pathway for Arctic Ocean ice loss however, the results of this study suggest that with continued warming, the Canadian Arctic Archipelago may also become a large contributor to Arctic Ocean ice loss.</p>

scholarly journals Multiproxy evidence of the Neoglacial expansion of Atlantic Water to eastern Svalbard

2020 ◽  
Vol 16 (2) ◽  
pp. 487-501 ◽  
Author(s):  
Joanna Pawłowska ◽  
Magdalena Łącka ◽  
Małgorzata Kucharska ◽  
Jan Pawlowski ◽  
Marek Zajączkowski
Keyword(s):  
Sea Ice ◽  
Dna Sequences ◽  
Environmental Changes ◽  
Environmental Dna ◽  
Open Water ◽  
Ice Cover ◽  
Atlantic Water ◽  
Arctic Water ◽  
Ice Coverage ◽  
Ice Conditions

Abstract. The main goal of this study is to reconstruct the paleoceanographic development of Storfjorden during the Neoglacial (∼4 cal ka BP). Storfjorden is one of the most important brine factories in the European Arctic and is responsible for deepwater production. Moreover, it is a climate-sensitive area influenced by two contrasting water masses: warm and saline Atlantic Water (AW) and cold and fresh Arctic Water (ArW). Herein, a multiproxy approach was applied to provide evidence for existing interactions between the inflow of AW and sea ice coverage, which are the major drivers of environmental changes in Storfjorden. The sedimentary and microfossil records indicate that a major reorganization of oceanographic conditions in Storfjorden occurred at ∼2.7 cal ka BP. The cold conditions and the less pronounced presence of AW in Storfjorden during the early phase of the Neoglacial were the prerequisite conditions for the formation of extensive sea ice cover. The period after ∼2.7 cal ka BP was characterized by alternating short-term cooling and warming intervals. Warming was associated with pulsed inflows of AW and sea ice melting that stimulated phytoplankton blooms and organic matter supply to the bottom. The cold phases were characterized by heavy and densely packed sea ice, resulting in decreased productivity. The ancient environmental DNA (aDNA) records of foraminifera and diatoms support the occurrence of the major pulses of AW (∼2.3 and ∼1.7 cal ka BP) and the variations in sea ice cover. The episodes of enhanced AW inflow were marked by an increase in the percentage of DNA sequences of monothalamous foraminifera associated with the presence of fresh phytodetritus. Cold and less productive intervals were marked by an increased proportion of monothalamous taxa known only from environmental sequencing. The diatom aDNA record indicates that primary production was continuous during the Neoglacial, regardless of the sea ice conditions. However, the colder periods were characterized by the presence of diatom taxa associated with sea ice, whereas the present-day diatom assemblage is dominated by open-water taxa.

scholarly journals Sea ice thickness in the Eastern Canadian Arctic: Hudson Bay Complex & Baffin Bay

2017 ◽  
Vol 200 ◽  
pp. 281-294 ◽  
Author(s):  
Jack C. Landy ◽  
Jens K. Ehn ◽  
David G. Babb ◽  
Nathalie Thériault ◽  
David G. Barber
Keyword(s):  
Sea Ice ◽  
Canadian Arctic ◽  
Ice Thickness ◽  
Hudson Bay ◽  
Sea Ice Thickness ◽  
Baffin Bay ◽  
Eastern Canadian Arctic
Sign in / Sign up

Export Citation Format

Share Document