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With solar radiation being a primary driver of melting glacial ice and snow, glaciers and high-elevation mountain snowpacks are especially sensitive to even small changes in the concentration of light absorbing particles. Surface melt of snow and glacial ice is substantially higher if impurities such as mineral dust and organic matter are present in significant quantities. Bacteria and algae further promote darkening of the glacial surface and melting by aggregating these impurities in the form of biofilm. Like many mountain glaciers of the Alaskan region, the Juneau Icefield has seen extensive mass loss. Black carbon released by human and natural activities has become a major contributor to reducing snow and ice albedo. Microbes can affect the dynamics of black carbon on glacial surfaces, with biodegradation having profound implications on its residence time, light absorbance, and output to adjacent and downstream aquatic ecosystems. This NSF Rapid Response Research (RAPID) project funded the field work necessary for the acquisition of samples from the Gilkey Glacier, Alaska in July 2024. This dataset includes sample collection types, coordinates and stream flow data.
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Ecophysiological Responses of the Intertidal Seaweed Fucus Distichus to Temperature Changes and Reduced Light Driven by Tides and Glacial Input
Abstract Climate change is influencing the performance and distribution of macroalgae in the marine environment. Although intertidal seaweeds successfully adapt to extreme and rapid abiotic changes, exposure to persistent or prolonged potentially stressful conditions can affect their vitality and productivity. Rapid glacial melt can severely alter seawater physicochemical characteristics for shallow and intertidal seaweed communities on the Alaskan coasts. Understanding how intertidal macroalgae respond to this complex mosaic of stressors is key to assessing their ability to adapt to a climate change scenario. This study assessed whether specific stress responses and acclimation mechanisms were exhibited by the intertidal brown seaweed Fucus distichus subsp. evanescence may enable it to cope with changing temperatures and reduced light availability linked to tides and glacial inputs. We analyzed its physiological performance, including photobiological variables, nutrient content, nitrate uptake, and oxidative stress descriptors under strictly controlled laboratory conditions. Results show that this subspecies of Fucus distichus may be relatively unaffected by changes in light and temperature driven by glacial melt due to the presence of pre-adapted strategies that collectively express wide physiological tolerances. Outcomes provide insights into some of the mechanisms of stress tolerance of this major structuring seaweed across the Alaskan coast. Nonetheless, glacial melt would also lower salinity in coastal water, potentially resulting in osmotic stress and other physiological effects not explored here.
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- Award ID(s):
- 1757348
- PAR ID:
- 10423989
- Date Published:
- Journal Name:
- Estuaries and Coasts
- Volume:
- 46
- Issue:
- 5
- ISSN:
- 1559-2723
- Page Range / eLocation ID:
- 1269 to 1279
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s12237-023-01207-9
