1
|
St Louis VL, St Pierre KA, Emmerton CA, Serbu JA, Talbot CH, Szostek L, Lehnherr I, Muir DCG, Criscitiello A. Winter Dust Storms Impact the Physical and Biogeochemical Functioning of a Large High Arctic Lake. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7415-7424. [PMID: 38578215 DOI: 10.1021/acs.est.4c00705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
We found that a winter of abnormally low snowfall and numerous dust storms from eolian processes acting on exposed landscapes (including a major 4-day dust storm while onsite in May 2014) caused a cascade of impacts on the physical, chemical, and ecological functioning of the largest lake by volume in the High Arctic (Lake Hazen; Nunavut, Canada). MODIS imagery revealed that dust deposited in snowpacks on the lake's ice acted as light-absorbing impurities (LAIs), reducing surface reflectance and increasing surface temperatures relative to normal snowpack years, causing early snowmelt and drainage of meltwaters into the lake. LAIs remaining on the ice surface melted into the ice, causing premature candling and one of the earliest ice-offs and longest ice-free seasons on record for Lake Hazen. Meltwater inputs from snowpacks resulted in dilution of dissolved, and increased concentration of particulate bound, chemical species in Lake Hazen's upper water column. Spring inputs of nutrients increased both heterotrophy and algal productivity under the surface ice following snowmelt, with a net consumption of dissolved oxygen. As climate change continues to alter High Arctic temperatures and precipitation patterns, we can expect further changes in dust storm frequency and severity with corresponding impacts for freshwater ecosystems.
Collapse
Affiliation(s)
- Vincent L St Louis
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Kyra A St Pierre
- Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Craig A Emmerton
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Jessica A Serbu
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Charles H Talbot
- Canada Centre for Inland Waters, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Lisa Szostek
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto-Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Derek C G Muir
- Canada Centre for Inland Waters, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Alison Criscitiello
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| |
Collapse
|
2
|
Rühland KM, Evans M, Smol JP. Arctic warming drives striking twenty-first century ecosystem shifts in Great Slave Lake (Subarctic Canada), North America's deepest lake. Proc Biol Sci 2023; 290:20231252. [PMID: 37727085 PMCID: PMC10509573 DOI: 10.1098/rspb.2023.1252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/14/2023] [Indexed: 09/21/2023] Open
Abstract
Great Slave Lake (GSL), one of the world's largest and deepest lakes, has undergone an aquatic ecosystem transformation in response to twenty-first-century accelerated Arctic warming that is unparalleled in at least the past two centuries. Algal remains from four high-resolution palaeolimnological records retrieved from the West Basin provide baseline limnological data that we compared with historical phycological surveys undertaken on GSL between the 1940s and 1990s. We document the rapid restructuring of algal community composition ca 2000 CE that is consistent with recent increases in regional air temperature and declines in ice cover and wind speed, that collectively altered habitats for aquatic biota. This new limnological regime initiated the first observation of scaled chrysophytes and favoured the rapid proliferation of small planktonic cyclotelloid diatoms which replaced the long-established dominance of large filamentous Aulacoseira islandica in West Basin sedimentary records. Such abrupt transformations in the primary producers of this socioecologically valuable 'northern Great Lake' may have widespread implications for the entire food web with unknown consequences for aquatic ecosystem functioning and fisheries, which First Nations, Métis and other northern communities depend upon, pointing to the need for new studies.
Collapse
Affiliation(s)
- Kathleen M. Rühland
- Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, 116 Barrie St., Kingston, Ontario, Canada K7L 3N6
| | - Marlene Evans
- Environment and Climate Change Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 3H5
| | - John P. Smol
- Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, 116 Barrie St., Kingston, Ontario, Canada K7L 3N6
| |
Collapse
|