Roundup: Mercury in Meltwater, Fish in Himalayas, and Black Flies in Colombia

Mercury Deposited as Snowfall Incorporated into Meltwater

From the Journal of Environmental Sciences: “The Tibetan Plateau (TP) is recognized as the ‘Water Tower of Asia.’ Yet our understanding of mechanisms influencing incorporation of mercury (Hg) into freshwater in mountain glaciers on the TP remains quite limited. Extensive sampling of environmental matrices (e.g., snow/ice) were conducted on the East Rongbuk glacier on Mt. Everest and Zhadang glacier on Mt. Nyainqentanglha for Hg speciation analysis. Speciated Hg behaved quite different during snowmelt: a preferential early release of DHg (dissolved Hg) was observed at the onset of snowmelt, whereas PHg (particulate-bound Hg) and THg (total Hg) become relatively enriched in snow and released later.”

Map of sampling locations.
Map showing the study’s sample sites and glacier locations (Source: Sun et al.).

 

Fish Diversity in Himalayan Streams Varies in Glacial and Rain-fed Streams

From Environmental Biology of Fishes: “Assessment of headwater biodiversity is essential for maintaining upstream downstream ecosystem services of rivers. Fish biodiversity assessment was conducted in the headwater tributaries of the glacial-fed Tamor River and rain-fed Kamala River in eastern Nepal. A total of eight sites were sampled… A total of 8940 fishes belonging to four orders, 10 families, 26 genera and 34 species were enumerated. Significant variation in Shannon-Weiner Diversity Index (p = 0.015) and Species Richness (p = 0.005) between the glacial fed and rain fed streams with higher values of these indices in the rain fed tributaries… These findings indicate that fish assemblages reflect the different ecological regimes of the glacial-fed and rain-fed headwaters.”

Map of study area
Map of study area (Source: Jha et al.).

 

Glacial Areas in Colombia Have Fewer Black Flies

From Acta Tropica: “Vector ecology is a key factor in understanding the transmission of disease agents, with each species having an optimal range of environmental requirements. Scarce data, however, are available for how interactions of local and broad-scale climate phenomena, such as seasonality and the El Niño Southern Oscillation (ENSO), affect simuliids. We, therefore, conducted an exploratory study to examine distribution patterns of species of Simuliidae along an elevational gradient of the Otún River in the Colombian Andes, encompassing four ecoregions… Species richness and occurrence in each ecoregion were influenced by elevation, seasonality, and primarily the warm El Niño and cool La Niña phases of the ENSO.”

Photo of Fly species examined by the study
Fly species examined by the study (Source: Mantilla et al.)

 

Roundup: Zinke, Wilkes Island, and Black Flies

Increased Ice Mass Loss in Wilkes Island

From Nature.com: “An increased mass discharge (53 ± 14 Gt yr−1) was found in the East Indian Ocean sector since 2008 due to unexpected widespread glacial acceleration in Wilkes Land, East Antarctica, while the other five oceanic sectors did not exhibit significant changes. However, present-day increased mass loss was found by previous studies predominantly in West Antarctica and the Antarctic Peninsula. The newly discovered increased mass loss in Wilkes Land suggests that the ocean heat flux may already be influencing ice dynamics in the marine-based sector of the East Antarctic ice sheet (EAIS).”

Learn more about the find here.

Antarctic ice velocity in 2015 and the velocity change between 2008 and 2015 (Source: Nature.com).

Zinke Seeks to Restore Glacier National Park’s Sperry Chalet

From Missoulian: “As part of a wide-ranging press conference here Saturday, Zinke said public comments overwhelmingly support rebuilding the popular backcountry chalet’s dormitory, burned in last summer’s Sprague Fire, as close as possible to its original state while making some upgrades. He proposes using a mix of public and private dollars to complete the work, adding that he is prepared to commit ‘whatever it takes in federal funding to restore the structure.”

Read the news here.

From left: Glacier National Park Superintendent Jeff Mow, Glacier National Park Conservancy Executive Director Doug Mitchell and Secretary of the Interior Ryan Zinke discuss the future of Sperry Chalet, along with other national park issues, during a wide-ranging press conference on Saturday in Columbia Falls. (Source: Eve Byron/Missoulian)

 

Black Flies and Interactions with Climate Phenomena

From ScienceDirect: “The lack of simuliids near the glacier might be associated with the low temperature, low discharge, and reduced particulate organic matter of the meltwater. Our results are consistent with studies of simuliids in other mountains of Colombia, which document a lack of Simulium species above the páramo (i.e., in the super páramo) (Muñoz and Miranda, 2000)… Our results emphasize the dynamic nature of simuliid communities over space and time. Studies of how simuliids respond to El Niño and La Niña can provide a window into the effects of global climate change (Finn and Adler, 2006)”

Find out more about this disease transmitting vector and its environmental stimuli here.

Adult Simulium trifasciatum(Source: British Entomology by John Curtis/ WikiCommons)