Roundup: Glacier-Fed Lakes, Remote Sensing, and Glacial Succession

Roundup: Glacier-Fed Lakes, Remote Sensing, and Soil

 

Global Warming and Glacier-Fed Lakes

From Freshwater Biology: “Climate warming is accelerating the retreat of glaciers, and recently, many ‘new’ glacial turbid lakes have been created. In the course of time, the loss of the hydrological connectivity to a glacier causes, however, changes in their water turbidity (cloudiness) and turns these ecosystems into clear ones. To understand potential differences in the food-web structure between glacier-fed turbid and clear alpine lakes, we sampled ciliates (single-celled animals bearing ciliates), phyto-, bacterio- and zooplankton in one clear and one glacial turbid alpine lake, and measured key physicochemical parameters. In particular, we focused on the ciliate community and the potential drivers for their abundance distribution.”

Learn more about how global warming affects lakes here:

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A glacier-fed lake (Source: Rodrigo Soldon/Creative Commons).

 

Glacier Remote Sensing Using Sentinel-2

From Remote Sensing: “Mapping of glacier extents from automated classification of optical satellite images has become a major application of the freely available images from Landsat. A widely applied method is based on segmented ratio images from a red and shortwave infrared band. With the now available data from Sentinel-2 (S2) and Landsat 8 (L8) there is high potential to further extend the existing time series (starting with Landsat 4/5 in 1982) and to considerably improve over previous capabilities, thanks to increased spatial resolution and dynamic range, a wider swath width and more frequent coverage.”

Read more about remote sensing here:

Test region 1 in the Kunlun Mountains in northern Tibet using a S2A image from 18 November 2015 (Source: Remote Sensing).
Test region 1 in Tibet using a S2A image from 2015 (Source: Remote Sensing).

 

The Impact of Soil During Glacial Succession

From Journal of Ecology: “Plant–soil interactions are temporally dynamic in ways that are important for the development of plant communities. Yet, during primary succession [colonization of plant life in a deglaciated landscape], the degree to which changing soil characteristics (e.g. increasing nutrient availabilities) and developing communities of soil biota influence plant growth and species turnover is not well understood. We conducted a two-phase glasshouse experiment with two native plant species and soils collected from three ages (early, mid- and late succession) of an actively developing glacial chronosequence ranging from approximately 5 to <100 years in age.”

Learn more about the impact of soil during glacier succession here:

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A photo of Lyman Glacier with different plants growing on its face (Source: Marshmallow/ Creative Commons).

 

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Roundup: Bacteria Are Doing Well; Zooplankton, Dams Are Not

Each week, we highlight three stories from the forefront of glacier news.

Project Forecasts India’s Hydrological Future in a Changing Climate

Pangong River in India. How will climate change affect the Indian region's water? (Photo: Pankaj Kaushal/Flickr)
Pangong River in India. How will climate change affect the Indian region’s water? (Photo: Pankaj Kaushal/Flickr)

From Earth & Space Science News:

“The Indian subcontinent is particularly vulnerable to climate change because of its diversified socioeconomic and climatic conditions. Changes in monsoon variability and glacier melt may lead to droughts over the Indian plains as well as extreme rains and abrupt floods in the neighboring Himalayas…Through our work with the NORINDIA project, we found that there is a risk of 50% glacier melt in the Beas River basin, which covers northwest India and northeast Pakistan, by 2050.”

Learn more about NORINDIA and its work in India.

 

Chilly Conditions No Match for Methane-cycling Microorganisms

Microorganisms in the soil of the Austrian Alps have been found to produce methane according to a new study. (Photo: image_less_ordinary/Flickr)
According to a new study microorganisms in the soil of the Austrian Alps have been found to produce methane. (Photo: image_less_ordinary/Flickr)

From FEMS Microbiology Ecology:

“Alpine belt soils harbored significantly more methane-cyclers than ––those of the nival belt, indicating some influence of plant cover. Our results show that methanogens are capable of persisting in high-alpine cold soils and might help to understand future changes of these environments caused by climate warming.”

What are the implications of this study? Find out here.

 

Preliminary Study Looks at Relationship Between Glacial Lakes and Zooplankton

 Study looks to find why glacial lakes may be low in Zooplankton. (Photo: Macroscopic Solutions/Flickr)
Study looks to find why glacial lakes may be low in zooplankton. (Photo: Macroscopic Solutions)

From Polish Journal of Environmental Studies:

“Zooplankton communities can be affected by glacial influence. In marine environments zooplankton mortality, mainly associated with the chemical properties of the ice, has been found in areas close to ice fields.”

Find out which characteristic of glacial lakes is affecting zooplankton.

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Glaciers Influence Marine Invertebrates in Chile

Bivalves larvae – Swimming Manila Clam. The width of the picture is slightly over 1mm (Source: Dick/Flickr).
Bivalves larvae – Swimming Manila Clam. The width of the picture is slightly over 1mm (Source: Dick/Flickr).

Zooplankton are tiny creatures that drift in water bodies. A recent study by Meerhoff et al. in Progress in Oceanography describes linkages which connect them with glaciers. The researchers observed meroplankton—organisms which have planktonic features in their larval stages, but live sessile in the bottom as adults. They worked in the fjords of the Baker River, which is located between the Northern and Southern Patagonian ice fields in Chile. Physical and chemical conditions vary widely in these fjords, due to tides and to seasonal fluctuations in glacier meltwater and other contributions to river flow. These varying conditions, in turn, influence the dynamics of zooplankton communities, including productivity patterns, biomass, and community structure (the distribution and interactions of different species).

Zooplankton community dynamics in fjords are influenced by the strong vertical and horizontal gradients in hydrographic structure, such as freshwater discharge and tides. Studies have shown that temporal and spatial distributions of zooplankton are controlled by environmental conditions. Temperatures influence temporal scale by influencing metabolic rates and swimming behaviors of zooplankton. The salinity of water constrains the spatial distribution of estuarine zooplankton because each species can tolerate only certain levels of salinity. These two environmental factors also influence food availability and predation stress, which also affects the community structure of zooplankton.

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A fjord from the southern Patagonian in Chile (Source: NASA/Flickr).

The input of freshwater from glacial meltwater can change salinity, generate internal tides and reshape the circulation pattern in estuarine systems. Moreover, the turbidity of the water is influenced by glacial input. Even though the glaciers are virtually pristine, the meltwater is able to carry sediments along its way, known as rock flour. These finely ground particles, formed by the interaction of glaciers with their beds, are so small that they remain in suspension, making the water less transparent. This increase in turbidity limits light penetration and thus restricts primary production through photosynthesis by phytoplankton—the minute plants which float in the water column.

The study area of Baker river fjord in Chile (Source: Meerhoff et al./Progress in Oceanography).
The study area of Baker river fjord in Chile (Source: Meerhoff et al./Progress in Oceanography).
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CTD profiling for hydrographic measurements by the research group (Source: Erika Meerhoff).

Using vertical tows, Meerhoff and her associates collected samples in three sites close to the river mouth, during the Baker river minimum outflow season (October 2012) and during the maximum outflow season (February 2013). They observed strong hydrographic gradients, both horizontal and vertical, in early spring (October) and late summer (February). They have also found that these two seasons are significantly distinct in water-column conditions. Such variations are largely caused by freshwater discharges from nearby glaciers.

This study found a number of kinds of meroplankton in these fjords; the dominant organisms are larval forms of barnacles, squat lobsters, crabs, snails and bivalves. The study also indicated that zooplankton community shows seasonal variations. Specifically, barnacle larvae are favored in spring, when river outflow is at its minimum, while its food sources, phytoplankton, are more abundant. In contrast, bivalve larvae are dominant in summer due to higher surface water temperature. At this time, river outflow is at its maximum and phytoplankton availability is much lower than in spring, reflecting the greater turbidity of the water that carries glacier rock flour. Studies are needed to demonstrate whether bivalve larvae in this estuary feed on bacteria when phytoplankton are unavailable, as they do in other regions.

Adult stage of barnacles (Source: Abraham Puthoor/Flickr).
Adult stage of barnacles (Source: Abraham Puthoor/Flickr).

This study shows how freshwater input, along with other factors, affects zooplankton composition and distribution. It is remarkable to think of the numerous marine invertebrate larvae whose populations respond to glaciers located well inland of their estuarine home.

Look here for other stories about invertebrate life near and on glaciers.

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