Inside the Gut of the Patagonian Dragon

The stonefly is the largest animal inhabiting the glaciers of Patagonia. What the inch-long insect eats and excretes on the ice is central to the overall glacier ecosystem. Also known as the Patagonian Dragon, the stonefly occupies a near-apex position in the truncated glacier food chain. Stonefly larvae develop in glacial meltwater pools, where the larvae spends most of its life as a waterbound nymph, consuming algae, fungi, and other small inhabitants found in cryoconite sediments. The wingless adults wander the ice surface in search of food and mating opportunities. Despite their significant influence on glacier biogeochemical cycles, glacier invertebrates like the stonefly and their associated bacteria remain understudied. New research published in the journal Environmental Microbiology provided the first look at the genetics underlying the gut microbiome of stonefly nymphs.

The research team, comprised of Japanese and Chilean scientists, traveled by horseback and camped at Tyndall Glacier in Chile, collecting samples for analysis in a Tokyo laboratory. The team were surprised to find some bacteria in the stonefly gut were not present on the glacier surface. Not only was the bacteria absent from the surface of the Tyndall Glacier, but they were also distinct from bacteria catalogued in other glacier environments, indicating a symbiotic relationship between the Patagonian stonefly nymph host and its gut bacteria. The stonefly nymph provides an enriching gut environment and in turn the bacteria aids in the insect’s nutrition and material cycle of the glacier environment.

The Tyndall Glacier is one of the largest glaciers in the Southern Patagonian Ice Field (Source: Takumi Murakami).

 

Insects and animals, including humans, host a variety of microorganisms in their digestive tracts. These microorganisms and other bacteria, called gut flora, help perform a variety of functions critical to the health of their host. For example, humans lack enzymes necessary to break down certain fibers, starches, and sugars. Our gut flora keeps us healthy and enables us to ingest a wide range of foods we would otherwise be unable to digest. Similarly, the stonefly’s gut community enables it to benefit from seemingly nutritionless cryoconite sediments.

According to Takumi Murakami, from Japan’s National Institute of Genetics and principal author of the study, glacier stonefly nymphs and their gut bacteria likely drive the decomposition of organic materials on the glacier. The gut bacteria-invertebrate symbiosis may even be a common phenomenon in glacier ecosystems beyond Patagonia. Understanding the role of high trophic level invertebrates, like the stonefly, and their bacteria in glacier ecosystems is key to understanding the big picture of glacier nutritional networks.

Stonefly nymphs and cryoconite sediment in a meltwater pool (Source: Takumi Murakami).

 

Japanese scientists have compiled a significant body of research on invertebrates and their gut flora, particularly those inhabiting glaciers. In 1984, Japanese researcher Shiro Kohshima documented a novel discovery on a visit to the Yala Glacier in Nepal; a cold-tolerant midge. Later he visited Patagonia to examine the glacier-indigenous insects of the region. Kohshima enlisted collaborators, who in turn brought their students, which has resulted in the present day team of glacier-insect specialists, including Murakami. Their diligence in studying glacier ecosystems has produced a prolific body of published work, helping fill knowledge gaps at the headwaters of organic decomposition.

(Source: Nicolas Ferrier/Instagram)

 

Further underscoring the importance of the research, Murakami told GlacierHub, “Recent studies suggested that glacier ecosystems are the source of nutrition for downstream soil, river, and ocean ecosystems.” Were it not for the bacteria inhabiting the gut of the Patagonian Dragon, the organic matter would not be processed, and thus would not contribute to the glacier or downstream ecosystems.

Murakami adds, “Since glacier environments are susceptible to climate change, it is essential to accumulate the knowledge on the current glacier ecosystems for future studies, otherwise we will lose the opportunity.” Murakami’s concern is not unfounded. In the U.S., the stonefly is the poster child of understudied species that are quickly disappearing due to rapidly changing habitats. Petitions listing two species of stonefly under the Endangered Species Act are under consideration.

Please follow, share and like us:
error

Roundup: Karakoram Glaciers, Comparing Bacteria, and Carabid Beetles

Anomalous Stable Glaciers in the Karakoram Mountains

From Climate Dynamics: “Glaciers over the central Himalaya have retreated at particularly rapid rates in recent decades, while glacier mass in the Karakoram appears stable. To address the meteorological factors associated with this contrast, 36 years of Climate Forecast System Reanalyses (CFSR) are dynamically downscaled from 1979 to 2015 with the Weather Research and Forecasting (WRF) model over High Mountain Asia at convection permitting grid spacing (6.7 km). In all seasons, CFSR shows an anti-cyclonic warming trend over the majority of High Mountain Asia, but distinctive differences are observed between the central Himalaya and Karakoram in winter and summer.”

Read more about the climatic differences between the central Himalaya and Karakoram here.

Payu peak (6610 m), Pakistan Karakoram Mountains (Source: Robert Koster/Flickr).

Microbial Differences of Two Andean Lakes

From Aquatic Microbiology: “The limnological signatures of Laguna Negra and Lo Encañado, two oligotrophic Andean lakes which receive water from Eucharren Glacier and are exposed to the same climatic scenario, were driven by the characteristics of the corresponding sub-watersheds. The abundance of phototrophic bacteria is a significant metabolic difference between the microbial communities of the lakes which is not correlated to the Chla concentration.”

Read more about microbial differences of two Andean lakes here.

Laguna Negra (Source: PoL Úbeda Hervàs/Flickr).

Carabid Beetles in Norway

From Norwegian Journal of Entomology: “Nine species of carabid beetles (Coleoptera, Carabidae) were pitfall-trapped during two years in an alpine glacier foreland of southern Norway. A two-year (biennial) life cycle was documented for Nebria nivalis (Paykull, 1790), N. rufescens (Ström, 1768), and Patrobus septentrionis Dejean, 1828. This was based on the simultaneous hibernation of larvae and adults. In P. septentrionis, both larvae and adults showed a considerable activity beneath snow. A limited larval material of Amara alpina (Paykull, 1790) and A. quenseli (Schönherr, 1806) from the snow-free period indicated larval hibernation. A. quenseli was, however, not synchronized with respect to developmental stages, and its life cycle was difficult to interpret.”

Read more about the ecology of carabid beetles in an alpine glacier foreland here.

Seven carabid beetles from the glacier foreland of Southern Norway (Source: Norwegian Journal of Entomology).

 

Please follow, share and like us:
error

Roundup: Decaying Matter, Glacial Bacteria, and CO2 Uptake

Transport of Nutrients and Decaying Matter by Rivers and Streams

From “Intermittent Rivers and Ephemeral Streams”: “The hydrological regimes of most intermittent rivers and ephemeral streams (IRES) include the alternation of wet and dry phases in the stream channel and highly dynamic lateral, vertical, and longitudinal connections with their adjacent ecosystems. Consequently, IRES show a unique ‘biogeochemical heartbeat’ with pulsed temporal and spatial variation in nutrient and organic matter inputs, in-stream processing, and downstream transport. Given that IRES are widespread, their improper consideration may cause inaccurate estimation of nutrient and carbon fluxes in river networks… Our purpose is to contribute to the flourishing knowledge and research on the biogeochemistry of IRES by providing a comprehensive view of nutrient and organic matter dynamics in these ecosystems.”

Read more about the findings here.

Photo of intermittent river in Boliva
An intermittent river in Bolivia (Source: Thibault Datry‏/Twitter).

 

Glacial Bacteria Originated on Slopes Near Alaskan Glacier

From Microbiology Ecology: “Although microbial communities from many glacial environments have been analyzed, microbes living in the debris atop debris-covered glaciers represent an understudied frontier in the cryosphere. The few previous molecular studies of microbes in supraglacial debris have either had limited phylogenetic resolution, limited spatial resolution (e.g. only one sample site on the glacier) or both. Here, we present the microbiome of a debris-covered glacier across all three domains of life, using a spatially-explicit sampling scheme to characterize the Middle Fork Toklat Glacier’s microbiome from its terminus to sites high on the glacier. Our results show that microbial communities differ across the supraglacial transect, but surprisingly these communities are strongly spatially autocorrelated, suggesting the presence of a supraglacial chronosequence… We use these data to refute the hypothesis that the inhabitants of the glacier are randomly deposited atmospheric microbes, and to provide evidence that succession from a predominantly photosynthetic to a more heterotrophic community is occurring on the glacier.”

Learn more about glacial bacteria here.

Topographic map of bacteria sample sites
Topographic map of bacteria sample sites on the Middle Fork Toklat Glacier (Source: Darcy et al.).

 

Simulated High Alkalinity Glacial Runoff Increases CO2 Uptake in Alaska

From Geophysical Research Letters: “The Gulf of Alaska (GOA) receives substantial summer freshwater runoff from glacial meltwater. The alkalinity of this runoff is highly dependent on the glacial source and can modify the coastal carbon cycle. We use a regional ocean biogeochemical model to simulate CO2 uptake in the GOA under different alkalinity-loading scenarios. The GOA is identified as a current net sink of carbon, though low-alkalinity tidewater glacial runoff suppresses summer coastal carbon uptake. Our model shows that increasing the alkalinity generates an increase in annual CO2 uptake of 1.9–2.7 TgC/yr. This transition is comparable to a projected change in glacial runoff composition (i.e., from tidewater to land-terminating) due to continued climate warming. Our results demonstrate an important local carbon-climate feedback that can significantly increase coastal carbon uptake via enhanced air-sea exchange, with potential implications to the coastal ecosystems in glaciated areas around the world.”

Read more about the study here.

Photo of the Gulf of Alaska from space
The Gulf of Alaska from space (Source: NASA Goddard Images/Twitter).

 

Please follow, share and like us:
error

Roundup: New Bacteria, Poetic Shasta, and Glacial Melt

New Bacteria Discovered at Tibetan Glacier

From Microbiology Society: “A cold-tolerant, translucent, yellow-pigmented, Gram-stain-positive, non-motile, rod-shaped bacteria was isolated from snow of the Zadang Glacier on the Tibetan Plateau, PR China. 16S rRNA gene sequence similarity analysis indicated that the isolate was closely related to Conyzicola lurida KCTC 29231 and Leifsonia psychrotolerans DSM 22824 at a level of 97.72 and 97.49 %, respectively. Other close relatives had a 16S rRNA gene sequence similarity of less than 97 %… Based on phenotypic and chemotaxonomic characteristics, strain ZD5-4 was considered to represent a novel species of the genus Conyzicola, for which the name Conyzicola nivalis sp. nov. is proposed.”

Read more about the new species of bacteria here.

An aerial image of the Tibetan Plateau where a new species of bacteria was discovered (Source: NASA/Creative Commons).

U.S. Geologist Clarence King’s Poetic Mount Shasta

From Project MUSE: “But, for all his complexities, King’s recorded observations of wilderness places rise above his life’s convolutions. Unfortunately, what escapes many scholars is the remarkableness of King’s writing, an irony considering its salience; in fact, King’s brilliance is best illustrated in his lexical finesse, poetic flights of language, and artistic verisimilitude of nature’s beauties.”

Learn more about the poetic perceptions and mastery of language of the late geologist Clarence King here.

Sunrise over Mount Shasta (Source: Michael Zanger/Creative Commons).

New Insights on Glacier Meltwater

From Geophysical Research Letters: “Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%)… Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.”

Read more about the new research here.

The Tanana River, Alaska (Source: Ron Reiring/Creative Commons).
Please follow, share and like us:
error

Roundup: Karakoram, Dust and Prokaryotes

Roundup:  Karakoram, Ice Core, and Chile

 

Karakoram Glaciers in Balance

From the Journal of Glaciology: “An anomalously slight glacier mass gain during 2000 to the 2010s has recently been reported in the Karakoram region. We calculated elevation and mass change using Digital Elevation Models (DEMs) generated from KH-9 (a series of satellites) images acquired during 1973–1980… Within the Karakoram, the glacier change patterns are spatially and temporally heterogeneous. In particular, a nearly stable state in the central Karakoram (−0.04 ± 0.05 m w.e. a−1 during the period 1974–2000) implies that the Karakoram anomaly dates back to the 1970s. Combined with the previous studies, we conclude that the Karakoram glaciers as a whole were in a nearly balanced state during the 1970s to the 2010s.”

Read more about this study here.

Karakoram's glaciers were in a nearly balanced state between 1970-2010 (Source: mtzendo / Creative Commons)
Karakoram’s glaciers were in a nearly balanced state between 1970-2010 (Source: mtzendo/Creative Commons).

 

Dust in Ice Core Reflects the Last Deglaciation

From Quaternary Science Reviews: “The chemical and physical characterization of the dust record preserved in ice cores is useful for identifying of dust source regions, dust transport, dominant wind direction and storm trajectories. Here, we present a 50,000-year geochemical characterization of mineral dust entrapped in a horizontal ice core from the Taylor Glacier in East Antarctica. Strontium (Sr) and neodymium (Nd) isotopes, grain size distribution, trace and rare earth element (REE) concentrations, and inorganic ion (Cl and Na+) concentrations were measured in 38 samples, corresponding to a time interval from 46 kyr before present (BP) to present… This study provides the first high time resolution data showing variations in dust provenance to East Antarctic ice during a major climate regime shift, and we provide evidence of changes in the atmospheric transport pathways of dust following the last deglaciation.”

Read more about the findings here.

An ice core from Taylor Glacier reveals changes in dust composition during the last deglaciation (Source: Oregon State University / Creative Commons).
An ice core from Taylor Glacier reveals changes in dust composition during the last deglaciation (Source: Oregon State University/Creative Commons).

 

Prokaryotic Communities in Patagonian Lakes

From Current Microbiology: “The prokaryotic (microscopic single-celled organisms without a distinct nucleus with a membrane or other specialized organelles) abundance and diversity in three cold, oligotrophic Patagonian lakes (Témpanos, Las Torres and Mercedes) in the northern region Aysén (Chile) were compared in winter and summer…Prokaryotic abundances, numerically dominated by Bacteria, were quite similar in the three lakes, but higher in sediments than in waters, and they were also higher in summer than in winter… The prokaryotic community composition at Témpanos lake, located most northerly and closer to a glacier, greatly differed in respect to the other two lakes. In this lake was detected the highest bacterial diversity… Our results indicate that the proximity to the glacier and the seasonality shape the composition of the prokaryotic communities in these remote lakes. These results may be used as baseline information to follow the microbial community responses to potential global changes and to anthropogenic impacts.”

Read more about the results here.

Prokaryotic diversity is greatest in Témpanos lake, near a glacier (Source: Cuorogrenata / Creative Commons)
Prokaryotic diversity is greatest in Témpanos lake, near a glacier (Source: Cuorogrenata/Creative Commons).
Please follow, share and like us:
error

Photo Friday: Studying Microbes on Glacier

Any avid hiker or mountaineer would agree life as a scientist studying microbes on glaciers is not too bad. Just look the business trips they get to make. Italian scientists Dr. Andrea Franzetti, environmental microbiologist, and his colleague Dr. Roberto Ambrosini, ecologist, took a trip to Baltoro Glacier in Pakistan to collect data and bacteria samples for their latest work on supraglacial microbes.

[slideshow_deploy id=’9805′]

Please follow, share and like us:
error

Roundup: Midges, Rotifers, and Iron-Eating Bacteria

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

 

Diversity of Midge Flies Near Italian Glaciers

From Insect Conservation and Diversity:

A winter-emerging midge. Courtesy of Flickr user thepiper351.
A winter-emerging midge. Courtesy of Flickr user thepiper351.

“A collection of approximately 100 000 chironomids (Diptera; Chironomidae) inhabiting glacial areas of the Southern Alps that were collected over a period of approximately four decades from 1977 to 2014 were analysed to evaluate the impact of environmental traits on the distribution of chironomid species. Although the list of species has not substantially changed over time, some rare species captured in the 1970s have not been collected in recent years, while other species have only been collected recently.”

Read more here.

Rotifers Colonize Maritime Glacier Ice

From Molecular Phylogenetics and Evolution:

Bdelloid rotifer, the species studied. Courtesy of Flickr user Ian Sutton.
Bdelloid rotifer. Courtesy of Flickr user Ian Sutton.

“Very few animal taxa are known to reside permanently in glacier ice/snow. Here we report the widespread colonization of Icelandic glaciers and ice fields by species of bdelloid Rotifera. Specimens were collected within the accumulation zones of Langjökull and Vatnajökull ice caps, among the largest European ice masses. Rotifers reached densities up to ∼100 individuals per liter-equivalent of glacier ice/snow, and were freeze-tolerant. ”

Read more here.

 

Bacteria Turn Iron into Food Under Glaciers

“Geochemical data indicate that protons released during pyrite (FeS2) oxidation are important drivers of mineral weathering in oxic and anoxic zones of many aquatic environments including those beneath glaciers.

Bacteria, courtesy of Flickr user AJ Cann.
Bacteria, courtesy of Flickr user AJ Cann.

Subglacial meltwaters sampled from Robertson Glacier (RG), Canada over a seasonal melt cycle reveal concentrations of S2O32- that are typically below detection despite the presence of available pyrite and several orders of magnitude higher concentrations of the FeS2 oxidation product sulfate (SO42-). Here we report the physiological and genomic characterization of the chemolithoautotrophic facultative anaerobe Thiobacillus sp. RG5 isolated from the subglacial environment at RG. The RG5 genome encodes pathways for the complete oxidation of S2O32-, CO2 fixation, and aerobic and anaerobic respiration with nitrite or nitrate.”

Read more here.

Please follow, share and like us:
error

Bacteria From the Sahara Desert Found on Swiss Glaciers

Bacteria living among dust particles from the Sahara have been found trapped in ice and snow on the Swiss Alps at an altitude of over 11,000 feet, according to a December article in Frontiers in Microbiology. The samplings collected from the Jungfraujoch region of Switzerland contained bacteria originally from northwest Africa, meaning these bacteria survived a remarkable wind-blown journey of over 1000 miles. These bacteria are particularly adapted to cope with UV radiation and dehydration stress, say authors Marco Meola, Anna Lazzaro, and Josef Zeyer.

GH7p2
Example of dust plume from North Africa over the Mediterranean Sea (Photo: Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC)

In February 2014 there was a strong Saharan dust event. According to the NASA Earth Observatory, dust events occur when powerful African winds uplift sand and dust into the atmosphere. Reaching high altitudes, clouds of dust are then transported across the globe through high altitude wind patterns. Initial uplift events are difficult to predict. In the past researchers collected dust samples via air capture, snatching the particulates, also called bioaerosols, straight out of the air before they landed. But it is difficult to grab enough dust using this method to have a sample size large enough for microbiological analyses, and the act of gathering particulates from the air often damages the samples that are captured. By collecting samples from snowpack in the European Alps, the researchers were able to obtain a pure sample without damaging the integrity and the potential viability of the particulates.

Bioaerosols are airborne particles that contain biological matter, according to the Centers for Disease Control and Prevention. This includes fungi, bacteria, and even viruses. Charles Darwin first discovered bioaerosols on his famous journey across the Atlantic with the crew of the Beagle. He describes them in his 1846 An account of the fine dust which often falls on vessels in the Atlantic Ocean as “67 different organic forms in fine dust particles.”

GH7p3
Section of one vertical snow profile sampled at Jungfraujoch.(Courtesy of :Meola M, Lazzaro A and Zeyer J )

Saharan dust events that travel toward Europe are rare. Because these events are monitored in real-time at the Jungfraujoch meteorological station, researchers are able to connect samples to specific dust events. For their research, Meola, Lazzaro, and Zeyer used samples taken from a depth of 220 cm from an excavated vertical trench in June 2014.

The particulates collected and attributed to the February 2014 Saharan dust event were tracked back to Algeria. Surrounding countries like Niger, Mali, and Morocco may have also contributed dust particles. Until they landed on the snow in Jungfraujoch, the bioaerosols stayed high in the upper atmosphere, where they were free from any risk of contamination. Three days after landing, the Sahara Dust particles were covered with fresh snow, preserving them by keeping them cold, insulated, and safe from UV radiation.

Meola, Lazzaro, and Zeyer were surprised that one phylum of bacteria, Proteobacteria, was the most common in both the clean-snow control sample and in the Sahara dust sample. What they did discover in the Sahara dust snow samples was an abundance of pigment-producing bacteria from Africa, absent from the clean-snow samples, including the pigment-producing Gemmatimonadetes. These are bacteria that have adapted to cope with high amounts UV radiation, very low temperatures, stress from dehydration, and nutrient deficient conditions. These unique adaptations allow them to survive the long journey from Africa to Europe.

It is remarkable that these tiny organisms, adapted to the desert conditions in the Sahara, can survive high in the atmosphere and as well as under the snow.

Please follow, share and like us:
error

Antarctic Bacteria Prove Resilient

Peptide Sequencing and Identification of Proteins in an Antarctic Bacterium Pseudomonas Syringae. Courtesy of Libertas Academica/Flickr.
Peptide Sequencing and Identification of Proteins in an Antarctic Bacterium Pseudomonas syringae. Courtesy of Libertas Academica/Flickr.

Surviving in Antarctic conditions takes more than cold-resilience for bacteria, recent research from the Center for Cellular and Molecular Biology found.

Using six different stressors in lab conditions, from temperature stress to pH change stress to salt and oxidative stress, the researchers were able to test bacterial resistance in the environments they are likely to encounter in Antarctica. In Antarctic glaciers, bacteria are likely to experience extreme cold, in thermal vents extreme heat, and in dried up lakes high levels of salinity. Often, bacteria experience more than one stress factor at a time.

Tests were carried out on ten different bacteria strains, which were grown separately and exposed to different conditions. A number of mutant bacteria developed from a strain of Pseudomonas syringae Lz4w, were also tested so that researchers could identify some of the genetic factors that allowed bacteria to develop stress resilience.

Researchers found that of all the stress conditions, the bacteria strains were better able to tolerate alkaline conditions. The bacteria did not fare so well under acidic conditions, which bacteria can face in Antarctic glaciers that contain some mineral acids.

Other stress tolerance levels varied depending on the bacteria strain. For example, Arthrobacter kerguelensis survived oxidation stress better than Pseudomonas meridiana. Under Ultra-Violet radiation, most of the bacteria strains died.

Antarctica - Gerlache strait. Photo courtesy of Rita Willaert/Flickr.
Antarctica – Gerlache strait. Photo courtesy of Rita Willaert/Flickr.

“Our investigation on tolerance of cold-adapted Antarctic bacteria to other environmental stressors fills the void in the present state of knowledge on the stress-adaptability of Antarctic bacteria,” the authors wrote. “The alkali-tolerance of all of the cold-tolerant Antarctic strains reveals their similarity with some other cold-tolerant bacteria isolated some time back from the Himalayan glacier.”

Researchers also found that bacteria that were exposed to multiple stress factors developed multi-stress protective molecules from proteins, lipids or other types of molecules which allowed them to be more resilient.

By looking into some of these proteins, the researchers were able to begin developing an understanding of the genetic elements that allowed bacteria to develop a tolerance for multiple stressful conditions. The findings could provide insights in the development of resilient  bacteria strains through genetic engineering.

“The multistress-protective potential of a metabolic enzyme, as evidenced in this study, reveals intricacy in the mechanism involved in stress adaptation of bacteria,” the authors concluded.

Please follow, share and like us:
error