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 ◽  
...  

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.

FACETS ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 432-454 ◽  
Author(s):  
Aimee Huntington ◽  
Patricia L. Corcoran ◽  
Liisa Jantunen ◽  
Clara Thaysen ◽  
Sarah Bernstein ◽  
...  

Microplastics are a globally ubiquitous contaminant, invading the most remote regions, including the Arctic. To date, our understanding of the distribution and sources of microplastics in the Arctic is limited but growing. This study aims to advance our understanding of microplastics in the Arctic. Surface water, zooplankton, sediment, and snow samples were collected from Hudson Bay to north Baffin Bay onboard the CCGS Amundsen from July to August 2017. Samples were examined for microplastics, which were chemically identified via Raman spectroscopy for surface water and zooplankton and Fourier transform infrared spectroscopy for sediment. We found that 90% of surface water and zooplankton samples, and 85% of sediment samples, contained microplastics or other anthropogenic particles. Mean anthropogenic particle concentrations, which includes microplastics, were 0.22 ± 0.23 (per litre) for surface water, 3.51 ± 4.00 (per gram) for zooplankton, and 1.94 ± 4.12 (per gram) for sediment. These concentrations were not related to the human populations upstream, suggesting that microplastic contamination in the Arctic is from long-range transport. Overall, this study highlights the presence of microplastics across the eastern Canadian Arctic, in multiple media, and offers evidence of long-range transport via ocean and atmospheric currents. Further research is needed to better understand sources, distribution, and effects to Arctic ecosystems.


2011 ◽  
Vol 68 (9) ◽  
pp. 1511-1527 ◽  
Author(s):  
Andrew S. Medeiros ◽  
Roberto Quinlan

An examination of the Chironomidae, the dominant aquatic invertebrate taxa found in Arctic lakes and ponds, was conducted to determine the environmental gradients that may limit their geographical distribution in the eastern Canadian Arctic. Subfossil chironomid head capsules, comprising 86 taxa, were sampled from surficial sediments of 63 lakes that spanned from tree line (northern Manitoba) across multiple regions within the eastern Canadian Arctic. Water chemistry and environmental data were then compared with chironomid assemblages using multivariate analysis. The distribution of chironomids was found to primarily follow a temperature gradient, but additional significant relationships were also found along a nutrient–productivity gradient. Several species of the Tribe Chironomini, which generally represent warm-water adapted taxa, were also found far beyond tree line in the southern Kivalliq region of Nunavut, indicating a more northerly range than previously known. While temperature and trophic status were found to strongly influence the distribution of some taxa, partially constrained gradient analysis indicates that specific chironomid taxa could be used to indicate a primary response to climate regardless of trophic status. This may allow for more holistic inferences of how aquatic communities may respond to climate change as the range of temperature dependant species expand into Arctic systems.


2021 ◽  
Author(s):  
Karen Filbee-Dexter ◽  
Kathleen A MacGregor ◽  
Camille Lavoie ◽  
Ignacio Garrido ◽  
Jesica Goldsmit ◽  
...  

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.


2019 ◽  
Vol 374 (1788) ◽  
pp. 20190215 ◽  
Author(s):  
Sophie Monsarrat ◽  
Peter Novellie ◽  
Ian Rushworth ◽  
Graham Kerley

Setting appropriate conservation measures to halt the loss of biodiversity requires a good understanding of species' habitat requirements and potential distribution. Recent (past few decades) ecological data are typically used to estimate and understand species’ ecological niches. However, historical local extinctions may have truncated species–environment relationships, resulting in a biased perception of species' habitat preferences. This may result in incorrect assessments of the area potentially available for their conservation. Incorporating long-term (centuries-old) occurrence records with recent records may provide better information on species–environment relationships and improve the modelling and understanding of habitat suitability. We test whether neglecting long-term occurrence records leads to an underestimation of species’ historical niche and potential distribution and identify which species are more vulnerable to this effect. We compare outputs of species distribution models and niche hypervolumes built using recent records only with those built using both recent and long-term (post-1500) records, for a set of 34 large mammal species in South Africa. We find that, while using recent records only is adequate for some species, adding historical records in the analyses impacts estimates of the niche and habitat suitability for 12 species (34%) in our dataset, and that this effect is significantly higher for carnivores. These results show that neglecting long-term biodiversity records in spatial analyses risks misunderstanding, and generally underestimating, species' niches, which in turn may lead to ill-informed management decisions, with significant implications for the effectiveness of conservation efforts. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’


2019 ◽  
Author(s):  
Sophie Monsarrat ◽  
Peter Novellie ◽  
Ian Rushworth ◽  
Graham Kerley

ABSTRACTSetting appropriate conservation measures to halt the loss of biodiversity requires a good understanding of species’ habitat requirements and potential distribution. Recent (past few decades) ecological data are typically used to estimate and understand species’ ecological niche. However, historical local extinctions may have truncated species-environment relationships, resulting in a biased perception of species’ habitat preferences. This may result in incorrect assessments of the area potentially available for their conservation. Incorporating long-term (centuries-old) occurrence records with recent records may provide better information on species-environment relationships and improve the modeling and understanding of habitat suitability. We test whether neglecting long-term occurrence records leads to an underestimation of species’ historical niche and potential distribution and identify which species are more vulnerable to this effect. We compare outputs of species distribution models and niche hypervolumes built using recent records only with those built using both recent and long-term (post-1500) records, for a set of 34 large mammal species in South Africa. We find that, while using recent records only is adequate for some species, adding historical records in the analyses impacts estimates of the niche and habitat suitability for fourteen species (41%) in our dataset, and that this effect is significantly higher for carnivores. These results show that neglecting long-term biodiversity records in spatial analyses risks misunderstanding, and generally underestimating, species’ niche, which in turn may lead to ill-informed management decisions, with significant implications for the effectiveness of conservation efforts.


2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1604
Author(s):  
Sun Hee Hong ◽  
Yong Ho Lee ◽  
Gaeun Lee ◽  
Do-Hun Lee ◽  
Pradeep Adhikari

Predicting the distribution of invasive weeds under climate change is important for the early identification of areas that are susceptible to invasion and for the adoption of the best preventive measures. Here, we predicted the habitat suitability of 16 invasive weeds in response to climate change and land cover changes in South Korea using a maximum entropy modeling approach. Based on the predictions of the model, climate change is likely to increase habitat suitability. Currently, the area of moderately suitable and highly suitable habitats is estimated to be 8877.46 km2, and 990.29 km2, respectively, and these areas are expected to increase up to 496.52% by 2050 and 1439.65% by 2070 under the representative concentration pathways 4.5 scenario across the country. Although habitat suitability was estimated to be highest in the southern regions (<36° latitude), the central and northern regions are also predicted to have substantial increases in suitable habitat areas. Our study revealed that climate change would exacerbate the threat of northward weed invasions by shifting the climatic barriers of invasive weeds from the southern region. Thus, it is essential to initiate control and management strategies in the southern region to prevent further invasions into new areas.


1989 ◽  
Vol 26 (10) ◽  
pp. 1880-1903 ◽  
Author(s):  
Alexander D. McCracken ◽  
Godfrey S. Nowlan

Carbonate and petroliferous carbonate units ("oil shales") on Southampton, Baffin, and Akpatok islands have yielded a total of 2277 conodonts, the more biostratigraphically useful of which indicate not all units are correlative. The Boas River "shale", the lower of the two petroliferous units on Southampton Island, overlies the Bad Cache Rapids Group and contains a diverse fauna, including elements of Amorphognathus ordovicicus Branson and Mehl. Previous reports have indicated the presence of Culumbodina penna Sweet, a species whose range only barely overlaps that of A. ordovicicus in the middle Maysvillian. Carbonate beds and bedding-plane surfaces of the higher Red Head Rapids Formation at Sixteen Mile Brook yielded A. ordovicicus faunas containing Aphelognathus cf. A. divergens Sweet. These beds are likely Richmondian, since A. divergens is known elsewhere only from Richmondian strata. A metasicula of "Glyptograptus" hudsoni Jackson, several natural conodont assemblages, and fused enigmatic coniform elements were also found at Sixteen Mile Brook.The petroliferous unit in unnamed strata at Amadjuak Lake on Baffin Island contains Belodina area Sweet, which is indicative of a late Edenian to early Maysvillian age. Conodonts from the petroliferous strata at Jordan River on Baffin Island suggest a Trentonian to early Maysvillian age. The conodonts recovered from unnamed strata on Akpatok Island are not very diagnostic but indicate an age range from Shermanian to Gamachian.


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