The divide

River head waters may be separated by only a few meters along the Continental Divide of North America. Consider the Columbia River that flows into the Pacific Ocean and the Missouri River that flows into the Atlantic Ocean. Although they begin very close to each other, they eventually flow through different landscapes, through different cultures, making them very different rivers.


This series is a photo essay on these two major watersheds. Here we begin with head water springs. Water that flows up from below ground to form the start of a river.

Some rivers begin with head water lakes.

Small streams flow into larger streams.

Larger streams flow into rivers and lakes.

Eventually into the large, main stem of the river.

Before flowing into the ocean.


Tethysphere will profile parts of each watershed over the weeks to come in a celebration of rivers!

A land without fences

Yak Painting 2016.jpg

Faraway, so close. Sometimes I seek the far horizons, those wide-open steppes of Central Asia, only to look around the corner and find the open grasslands of the High Plains of North America. What is the difference between these ecologically similar but geographically distant landscapes? One answer is three thousand years of cultural history.

Open Mongolia 3
This steppe landscape in Mongolia is reminiscent of the pine clad ridges of North Central Wyoming in North America.

Open range. I was born and raised in the western US, both in the steel, concrete, and glass of large cities and the open landscape of the front range of the Rocky Mountains. Fields of prairie grasses interspersed with creosote and sage were common and from my young perspective these systems were the natural way the steppe country of the High Plains should look. We take for granted the landscape of our mind’s eye as the way the landscape has looked backward into the past, but this is often not true, particularly today with rapidly changing land uses. In the case of the western US, cattle and sheep, non-native grazers made their way to the high steppes of the Rocky Mountain region in the mid to late 1800s. The settlers and ranchers who brought cows and sheep to this surprisingly fragile landscape also brought their European land ethic. This land ethic was based on millennia of herding in a different world. The new world was full of people, native grazers, and prairie ecosystems that had evolved in ways unknown to the new arrivals.  Once let free to graze, these herds laid waste to much of the ecosystem, opening the way for aggressive species such as creosote and sage to out compete the dwindling biodiversity of short and mixed-grass prairie plant species. In other words, the landscape of my youth was a relatively recent scape that heralded the extirpation and extinction of native species.

Open herds. My first expedition to Mongolia was in the mid-1990s, not long after the dissolution of the Soviet hegemony. Mongolia was its own country for the first time in 70 years. Shortly after arriving, my eyes feasted on Northern Mongolia’s wide-open valleys, Gers (also called Yurts), mixed herds of yaks, sheep, goats, camels, and horses, and landscapes without fences. Try it sometime, go to an open range without any fences, it will take you a while to identify what is so different, so foreign. Our expedition could travel anywhere, a feature of our research that facilitated sampling biodiversity from Lake Hövsgol and then, over the years, sampling from lakes and streams of a large proportion of the country. A land without fences allows herders to move their herds to good pasture, to move them away from stream bottoms where their hooves may destroy the riparian system lining lotic systems. A land without fences makes neighbors out of all of us, makes us all caretakers of our common natural resources. This system of open range herding with herds moved seasonally is called pastoral nomadism. The herders were not nomads, but rather were connected to a set of lands they would frequent for the betterment of their herds and thus for their own welfare. This form of livelihood and land use may go back as far as 3000 years before present. Yes, this means that during the years when Genghis Khan and his people ruled the largest empire on Earth most people of those lands now called Mongolia were pastoral nomads, herders in a landscape without fences.

Open Mongolia 2
Open landscape, steppes, central Mongolia
Fencing Sandhills
Closed landscape, steppes, western North America

Don’t fence me in. Three thousand years ago the grassland steppes of the North American High Plains did not have fences either. In fact, this region was not fenced in any comprehensive sense until the invention of barbed wire fencing in the 1870s. Fencing and land ownership is not a cultural constant but rather varies by group. Prior to European settlement, the High Plains were inhabited by at least eight tribes who had many different cultures and types of land ethics, although most were not herders. Many tribes did manage the dominant grazer in the region, the North American Bison. Bison cut wide swaths across the landscape, grazing, drinking from streams and rivers before moving on in a small and large cycles across space and time. These large herds were dominant until relatively recently with the last large herds decreasing rapidly by the 1870s and through the 1880s. Until that time, the grassland ecosystem was driven by bison herds in conjunction with human burning of prairies and other land management that marks the prairies even today. In comparison, as recently as 200 years ago the North American steppe and the Central Asia steppe existed without fences, but each region differed in how grazers were managed, differentially affecting the landscape.

North American bison, Yellowstone National Park

Along came the settler. The loss of cultural and ecological diversity in North America resulting from the advent of the European land use practice cannot be overstated. In rapid succession, the High Plains lost most Bison, tribes, and ecological integrity. Overgrazing of sheep followed by cattle changed the landscape, in some cases drastically. Overgrazing can lead to open areas of soil that are susceptible to drying, increased albedo and these regions can spread leading to localized drying, accelerating the decline of the prairie ecosystem. These changes have been altering the High Plains for over a century, albeit with some better conservation, natural resource management, and ranching practices stemming the loss and, in some cases restoring ecosystems in minor ways. More recently, overgrazing has been impairing grassland ecosystems in Mongolia. Changes in the proportion of Cashmere producing goats in herds, an increase in cattle relative to yaks and sheep have intensified grazing to levels that damage the prairies. Soil compaction, increased albedo, destabilized stream banks are all exacerbated by increasingly severe whether such as violent summer storms and dzuds (severe winter storms). If you live off the land such as a rancher or a pastoral nomad does, these changes, whether self-inflicted or not, are the harbinger of change and loss. These changes also link land use from one side of the world to the other.

Save Winter Sandhills 2014
An increase in strong storms in both Mongolia and North America is leading to increased mortality of domesticated grazers.

Convergence. Strangely, land use and management of steppes in both North America and Mongolia are converging. At one time, both lands were characterized by culturally diverse groups of people who managed their grazers in different ways. Their land use diverged and now is becoming similar again. Perhaps North American natural resource managers can learn by studying the function of Mongolian steppe prairie and river ecosystems, those that have not been overgrazed and can still serve as reference to a time when ecosystems were less impaired by human activities. Perhaps Mongolian herders can learn from the mistakes North American ranchers made in the past when allowing for the overgrazing of short and mixed grass prairies. Perhaps there is a reason that when seeking those faraway places, we need to just look around our own landscapes to find the common beauty and convergent history between geographically disparate places.

Highland grasses grazed to the ground primarily by goats in Western Mongolia Altai region.

Further reading.

Lkhagvadorj, Dorjburegdaa, Markus Hauck, Ch Dulamsuren, and Jamsran Tsogtbaatar. “Pastoral nomadism in the forest-steppe of the Mongolian Altai under a changing economy and a warming climate.” Journal of Arid Environments 88 (2013): 82-89.

Fernández‐Giménez, M.E., 1999. Sustaining the steppes: a geographical history of pastoral land use in Mongolia. Geographical Review89(3), pp.315-342.

Sternberg, T., 2008. Environmental challenges in Mongolia’s dryland pastoral landscape. Journal of Arid Environments72(7), pp.1294-1304.

Goulden, C.E., Mead, J., Horwitz, R., Goulden, M., Nandintsetseg, B., McCormick, S., Boldgiv, B. and Petraitis, P.S., 2016. Interviews of Mongolian herders and high resolution precipitation data reveal an increase in short heavy rains and thunderstorm activity in semi-arid Mongolia. Climatic Change136(2), pp.281-295.

Speth, J.D., 2017. 13,000 years of communal bison hunting in western North America. In The Oxford Handbook of Zooarchaeology.

The Art of Conservation

IKES Lake is a small lake in northeastern Nebraska

To conserve. Conscious acts of conservation-works toward conserving natural resources and cultural heritage for today and for posterity are important and brave acts conducted by the few for the many. This is not conservatism or the wish to stay in place in the flow of time, rather to conserve is to find value in this world and to seek ways of keeping places, ecosystems, art, and structures for people to use, to enjoy, and to learn from in ways books or electronic resources cannot provide. In a world with dwindling natural and cultural resources, one may fall into despair, but hope can be found in organizations that seek to conserve. Conservation groups range in size from large, international organizations such as the World Wildlife Fund and the Nature Conservancy to national organizations such as the Izaak Walton League to regional and local organizations. Some conservation groups seek funds to work in policy and politics while others empower people to volunteer and help conserve the resources nearest them. No effort is too small. In fact, some conservation groups working closest to the community within which they serve have the greatest impact.

IKES storm
Storm over the Wayne IKES Lake

The power of small. The Wayne Chapter of the Izaak Walton League (IKES for short) manages a small lake located just northwest of the town of Wayne, Nebraska. IKES Lake is nestled among the dense rows of corn that characterize northeastern Nebraska and northwestern Iowa. In a region of sparse natural resources, it serves as a small oasis where people can fish or picnic. The mission of the Izaak Walton League is to conserve, restore, and promote the sustainable use and enjoyment of our natural resources, including soil, air, woods, waters, and wildlife.  This mission is made manifest by the Wayne Chapter through environmental education. Members of the Wayne IKES have collaborated with local and regional researchers, teachers, conservationists, natural resource managers, and astronomers to make the Lake a focal point of school programs and community outreach. In 2008, members of the A. Jewell Schock Museum of Natural HistoryA. Jewell Schock Museum of Natural History (AJSMNH) located in the nearby Wayne State College initiated a long-term and large-scale project to bring third grade students from area schools to the Lake for round robins of environmental activities.

Building partnerships. These activities complimented long running programs such as the annual Fishing Derby and Youth Mentor Hunt. Other partners such as the Nebraska Department of Education came together to reach out to the Junior High School students in the region. The Director of AJSMNH at WSC worked with teaching faculty to have in-service teachers lead the round robin environmental activities. Meanwhile, science faculty from WSC Fred G. Dale Planetarium worked with Wayne IKES to create programs such as the Star Party while members of the Biology Faculty collaborated on the IKES Family Outdoor Day, programs designed to provide exceptional experiences for the regional community while teaching college students about science and conservation. Collectively, a few dreamers and a few conservationists created a network of enthusiastic collaborators including researchers from two projects funded by the National Science Foundation: MAIS and MACRO Rivers. These dreamers worked toward creating a better world in this small part of the Great Plains of North America.

Clouds IKES
The edge of the small Wayne IKES Lake is bordered by corn and soy, seen through prairie forbs as a flat landscape.

Creating a better world. This small conservation movement began with a few individuals who donated their time as members of the Wayne IKES Chapter. They meet monthly and spend considerable time caring for the lake and maintaining the surrounding land. Their work creates an oasis for those in the region to find some solace in nature. The Izaak Walton League is a membership organization with fees going towards local, regional, and national conservation efforts. But the collaborations between the Wayne Chapter and their partners has made this resource available for community members during outreach events throughout the year. Who knows, perhaps the many school students and community members who have participated in IKES events over the years will learn to be conservationists too, spreading a love for this land and these waters.

For more information and a partial list of partners

Wayne Chapter of the Izaak Walton League

A Jewell Schock Museum of Natural History

Fred G. Dale Planetarium

Nebraska Game and Parks Commission

Wild Turkey Federation

Logan Creek Pheasants Forever

Wayne Community Schools

Wakefield Community Schools

Wayne State College, School of Natural and Social Sciences

Wayne State College, School of Education

Wayne State College, Service Learning

The Nebraska Department of Education

The National Science Foundation

Frisbee photo IKES





Birds and Macrosystems: Three

marce profile flathead lake 2018
Humans, like migratory birds, travel the world, connect ecosystems

Macrosystems are ecological systems that are studied at large spatial scales (greater than 10^2 km2 ) and large temporal scales (measured in decades to millennia). The macrorivers project studies rivers at these large geographic and temporal scales. Birds often migrate, connecting disparate regions of watersheds in ways no other type of animal has until humans began long-distance travel. The birds and macrosystems series provides digital tours on aquatic birds, on their biology, ecosystem, and the biomechanics of flights. The tours are produced by students from Embry Riddle Aeronautical Universitywho worked under the direction of Dr. Sally Blomstrom in collaboration with Dr. Barbara Hayford of Tethysphere. Here is an overview of Macrosystems:

Scale interaction
Macrosystems are studied are large scales but the interactions within and between scales my affect birds as they migrate

The third bird profiled in this series is the western grebe.

Western grebe
Photo by Dominic Sherony, via creative commons

As the western grebe flies along is migration path, it may carry algae and macroinvertebrates from one part of a watershed to another or across many different watersheds. Why is this important? Well, the birds mix biota at different interactive scales. Something that more researchers study today, as ecosystem science becomes global.

For more information:

Cornell Ornithology Lab

Heffernan, James B., Patricia A. Soranno, Michael J. Angilletta Jr, Lauren B. Buckley, Daniel S. Gruner, Tim H. Keitt, James R. Kellner et al. “Macrosystems ecology: understanding ecological patterns and processes at continental scales.” Frontiers in Ecology and the Environment12, no. 1 (2014): 5-14.



Birds and Macrosystems. Two


Macrosystems are ecological systems that are studied at large spatial scales (greater than 10^2 km2 ) and large temporal scales (measured in decades to millennia). The macrorivers project studies rivers at these large geographic and temporal scales. Birds often migrate, connecting disparate regions of watersheds in ways no other type of animal has until humans began long-distance travel. The birds and macrosystems series provides digital tours on aquatic birds, on their biology, ecosystem, and the biomechanics of flights. The tours are produced by students from Embry Riddle Aeronautical University who worked under the direction of Dr. Sally Blomstrom in collaboration with Dr. Barbara Hayford of Tethysphere. Here is an overview of Macrosystems:


Here is some information on the Sandhill Crane.

Tethysphere birds

As the sandhills crane flies along is migration path, it may carry algae and macroinvertebrates from one part of a watershed to another or across many different watersheds. Why is this important? Well, the birds mix biota at different interactive scales. Something that more researchers study today, as ecosystem science becomes global.

For more information:

The Cornell Lab of Ornithology

Heffernan, James B., Patricia A. Soranno, Michael J. Angilletta Jr, Lauren B. Buckley, Daniel S. Gruner, Tim H. Keitt, James R. Kellner et al. “Macrosystems ecology: understanding ecological patterns and processes at continental scales.” Frontiers in Ecology and the Environment12, no. 1 (2014): 5-14.


Birds and Macrosystems. One

Tethysphere birds

Macrosystems are ecological systems that are studied at large spatial scales (greater than 10^2 km2 ) and large temporal scales (measured in decades to millennia). The macrorivers project studies rivers at these large geographic and temporal scales. Birds often migrate, connecting disparate regions of watersheds in ways no other type of animal has until humans began long-distance travel. The birds and macrosystems series provides digital tours on aquatic birds, on their biology, ecosystem, and the biomechanics of flights. The tours are produced by students from Embry Riddle Aeronautical University who worked under the direction of Dr. Sally Blomstrom in collaboration with Dr. Barbara Hayford of Tethysphere. Here is an overview of Macrosystems:

Overview of Macrosystems scale from the Macrorivers project.

The first bird profiled in this series is the Black-Crowned Night Heron.

Photo from Charles Homler, via creative commons

As the black-crowned night heron flies along is migration path, it may carry algae and macroinvertebrates from one part of a watershed to another or across many different watersheds. Why is this important? Well, the birds mix biota at different interactive scales. Something that more researchers study today, as ecosystem science becomes global.

For more information:

Cornell Lab of Ornithology—Home

Heffernan, James B., Patricia A. Soranno, Michael J. Angilletta Jr, Lauren B. Buckley, Daniel S. Gruner, Tim H. Keitt, James R. Kellner et al. “Macrosystems ecology: understanding ecological patterns and processes at continental scales.” Frontiers in Ecology and the Environment12, no. 1 (2014): 5-14.





A Midge by Any Other Name Is Still A Midge

Midge, Missouri River, Nebraska, 2011. Also known as a chironomid and non-biting midge. The common name of midge is shared with other families of flies.

What is in a name? Recently, I have observed a push back against jargon in specialized professions. For example, The Center for Plain Language began as a group of advocates for plain and clear language in government communications and has spread to advocate clear communications in many different disciplines. This came to my attention via an article posted on my news feed that was a few years old, published in The Atlantic and written by Victoria Clayton, “The Needless Complexity of Academic Writing“. I found the message important, timely, necessary and agreed with much of the article. Some papers I read are boring and strife with needless jargon while others are well-written, engaging, and fun to read. However, I was disturbed by two items that came up in the article. First, the idea that academicians should write for an audience other than their peers. In fact, the target audience for our published works is our peers. Second, the idea that academicians’ use of jargon is elitist, a ploy to exclude those outside of our specific discipline. Perhaps some academicians do this, but most use very exact language for very exact purposes, to convey concise and accurate results from our research and scholarship. Each word has meaning.

This midge has long legs but is not called a daddy long legs.

Daddy Long Legs. For example, entomologists, those who study insects, use the scientific jargon of Latin names and classification systems to communicate explicit information on specific taxa. I have decades of experience in teaching what a species is, what a taxon is, what a classification system is, what binomial nomenclature means, all to students who do not want to know this information. At all. Why is this all so important? Well, each term and concept listed above conveys a wealth of information to entomologists. The application of this information is important, it allows us to calculate biodiversity, analyze patterns in nature, and tell one species that vectors a deadly disease from another that does not. We may be tempted to use language such as common names so that non-experts understand this research. But common names are misleading. Take the example of daddy long legs. The common name has been applied to daddy long leg spiders, daddy long leg spiders (again), and daddy long legs flies. In one case, daddy long legs are a group otherwise known as cellar spiders in the family Pholcidae, in the other case, daddy long leg spiders are not spiders, but another type of arachnid called Opiliones. The daddy long legs fly also goes by the common names crane flies and mosquito hawks, all of which are flies in the family Tipulidae. Common names are misleading and use of scientific nomenclature is clear for those in the discipline and who understand the terms.

Slippery slope. That is not to say that we don’t have room for improvement. But people outside of our discipline are not the ones to provide it. Especially in a world where once commonplace words and phrases are no longer understood. I first realized this problem when I began teaching twenty years ago. Students indicated that I used too much jargon. However, in class I explained all the scientific terms in great detail, provided resources and lists with definitions (You know, kind of the idea of teaching). So, what were the students writing about in my evaluations? It turns out they were upset with my use of non-scientific words. For example, I used the word inundate (see below). This is a word I learned as a teenager while reading some pulp science fiction book. Inundate means to fill to over flowing. I had used the word in my plain speech for so long that it did not occur to me to define it. These were college students after all. Today the problem is much greater. Some students do not know what is meant when they are asked to perform simple tasks such as summarize or paraphrase. At what point does plain speech become ineffective speech? And sometimes even common word substitutes for jargon are not understood.

For example, the river inundated the valley.

Solutions. Admittedly, an impenetrable realm of academia exists, protected by obscure words, obtuse language. Sure, those of us in this realm spend an immense amount of time and energy getting into the realm and then must feed the jargon dragon to get published so we can remain. The problem is that our work is losing relevance in the world outside our realm. This creates a real danger, the loss of our realm and all that it produces such as space shuttles, 3-D printed hearts, and biodiversity estimates, methods in logic and reason. Perhaps the greatest output from our realm is reason. So, how do we solve this conundrum? We need discipline-specific jargon to communicate effectively, but we need to effectively communicate with non-experts. Well, the solution is simple. We need a new world of experts who work directly on communications with the public. These are people who are trained as the historians, philosophers, lawyers, literary critics, and scientists but who are devoted to translating the works of the disciplines they love for lay audiences. Although the field of translational communications is growing, it needs much more support, more positions within and outside the academy. Given the over production of academics relative to the declining number of jobs, perhaps departments, schools, colleges, and universities need to invest in the growth of this relatively new area of outreach for the good of us all.

How is it that this midge head is not relevant in today’s society?

The Rise and Fall of Rivers: A Photo Essay


Missouri River. The Missouri River is one of the longest rivers in the world, especially if you trace its flow all the way to the Gulf of Mexico. This large, muddy river is also a large sandy-bottom river. Its watershed covers the middle and part of the southern Great Plains of North America. The large, shifting river bed was treacherous, with sudden subsidence sending once stable banks tumbling into the river. Large strands of cottonwoods, burr oaks, willows and other trees lined the banks in gallery forests, open and savannah-like. The Missouri headwaters are near Helena, Mt, but these photos are of the lowest, unchannelized reaches of the river near Vermillion, South Dakota. I include high and low flow of the Missouri during the 2011 flood and 2012 drought.

Clark Fork River. This river drains the northern Rocky Mountains, with headwaters on the west side of the continental divide from the Missouri River Headwaters. The Clark Fork flows west, then northwest before joining the Columbia River eventually reaching the Pacific Ocean. The watershed geology is made up of Precambrian and Pre-Belt rocks that date back to over a billion years before present in same reaches . The rugged shores are lined with larch, ponderosa pine, fur, and willow, often in narrow riparian bands. During winter, snow storms may drop several feet of snow on the river, but the river continues flowing beneath the ice and snow. Tributaries of the Clark Fork and the river itself offer some of the best fly fishing in the world. I include photos of the river during high and low flow in spring, summer, and winter.

Bitterroot River. The Bitterroot River is one of the few rivers in the United States that flows due north. It drains the Bitterroot and Sapphire Mountains of the southern reaches of western Montana before flowing into the Clark Fork. The Bitterroot Mountains are rugged, characterized by many steep sided, deep canyons from which streams flow down to the valley floor to join the main stem of the river. These mountains are also composed of Precambrian and Pre-belt rock formations. The Sapphire Mountains are less rugged, with only a few tributary streams flowing into the river. The Bitterroot valley is wide, and the riparian zone is characterized by gallery forests of cottonwoods, willows, pines, and other trees. Like the Clark Fork River, the Bitterroot is well known for fly fishing. I include photos of the river during high and low flow in spring, fall, and winter.

Bulgan River. The Bulgan River, or Bulgan Gol, is a river that drains the southern Altai Mountains of western Mongolia before flowing into China where it is known as the Ulungur River. This river differs in that it flows into an endorheic basin, otherwise known as an evaporative basin. Rivers that enter endorheic basins often flow into large lakes that have no outlets, thus they evaporate and the rivers never make it to the sea. The Altai Mountains comprise one of the largest mountain chains in Asia, with elevations of over 4000 meters or 13,0000 feet in Mongolia. The northern part of the Altai in Mongolia has many glaciers, but the southern regions of the Altai are dryer, with sand dunes abutting the base of the mountains. The Bulgan watershed is characterized by rugged mountains with little riparian vegetation. Some willow shrubs and grasses dominate the shoreline. Large boulders hem in the river in its mid to upper reaches, making access difficult. I include photos of different parts of the Bulgan watershed with low and high flow.

Mighty Midge: Midges in Space

Rock pools_Clark Fork_Thompson Falls_Sept 2018a.jpg

Rock Pools. We start with a small point, a small place in space and time, a rock pool. Perhaps you have seen a pool of water standing on a boulder after a summer rain. Most of us have seen puddles in roads after a downpour or standing in garden fountains. These ephemeral pools have a short life span, they may exist for a few hours or a few days, perhaps for a month and then they evaporate until the next rain. In drylands, the monsoon season delivers enough precipitation to create rock pools that last a month or more, but then the pools dry up and will not be seen again until the following year. In times of drought, the pools may not appear again for years.

Drought and desiccation. If you take the time to look, you will find that these pools are alive with a community adapted to the brief time span of ephemeral pools. Garden fountains host microbes, mosquitos, frogs, in some cases fish. Puddles in the middle of the road host fairy shrimp and tadpole shrimp. Rock pools support communities of biting and non-biting midges. Some of these species are just taking advantage of an available water resource, but others have their entire life cycle, their very lives dependent on the wax and wane of the temporary pool. They have very short life spans and must spend part of their life cycles in a stage that can exist in the absence of water, a stage that can resist or persist through desiccation.

Semi-arid lands and rocks similar to those where Polypedilum vanderplanki are found. Photo from Wikipedia commons.

Water bears and all. Some species survive months, years, even decades encysted in a protective covering that will allow them to resume development only in the presence of water. More rarely, some species survive desiccation in other developmental stages. The larvae of the African sleeping midge, Polypedilum vanderplanki Hinton 1951 go through the process of anhydrobiosis, a process through which they shrivel up and become inactive to survive long periods of heat and drought. These larvae were first described from rock pools in northern Nigeria and likely live in rockpools across the semi-arid regions of Africa, habitats that include periods of extensive drying and heat. Water bears or Tardigrades are relatively well known for the process of anhydrobiosis, but microbes, fungi, and some plants also survive drought this way. The African sleeping midge is notable because it is the largest animal that can go through complete desiccation via anhydrobiosis.

Generalized illustration of a Polypedilum larvae

Sugar and glass. Amazingly, these larvae convert their tissues to a form of glass to survive the low water and high temperature conditions. First, their tissues accumulate high concentrations of a type of sugar called trehalose. These sugars then become glass via the process of vitrification. The result is a shriveled, small, vitreous individual that can remain in this state for long periods of time. Once the rains return to rehydrate the pools, the larvae convert back to their original forms and continue on to the rest of their life cycles: metamorphosis to the pupal stage followed by metamorphosis to the adult stage, mating, and laying eggs. One important aspect of their life cycles is that they may require a period of drying out or desiccation. In other words, they are so adapted to this strategy that they cannot live without it.

Ground control to major midge. Given the protection that vitrification provides, scientists began testing the environmental limits of these larvae, the point to which they can still survive, rehydrate, and continue on with their lives. Upper and lower temperature limits have been tested (-270°C to over 100°C). Length of time in the desiccated stage has been tested (at least 3 years). Tolerance to radiation has been tested (rehydration observed after doses as high as 3500 Gy). And finally, tolerance to the vacuum of space has been tested. Polypedilum vanderplanki survived 13 months in the vacuum of space in an experiment on the International Space Station, with 80% of the exposed larvae viably rehydrated.

International Space Station. Open share photo from NASA.

Implications. It was not clear from the study whether the specimens exposed to space were viable after long periods of time or successfully reproduced, but they did survive these harsh conditions initially. As the largest animals exhibiting anhydrobiosis, they make excellent candidates for long term space voyages. They can serve as part of hydroponic ecosystems, a food source for humans, or a food source for any fish. We will not be keeping them out in the vacuum of space for these purposes, but their ability to withstand high radiation and temperature extremes in their shriveled up, glass-like state will provide an extra buffer should specimens ever be exposed to these conditions. Then they simply need be rehydrated and added to the environment to play their role in human exploration and colonization of space.

Rock pool

An afterthought.  I am fascinated by the idea that these midges may be part of space exploration in the decades to come, but I am more excited by the role they play on Earth. My imagination was first captured by the discovery of tadpole shrimp jumping in a pool in the middle of a road in Colorado. Later I discovered midges living in muddy pools in Panama, observed fairy shrimp in road puddles in Mongolia as part of the MAIS research team, and found midges in garden fountains wherever I have lived. Some of the species in these habitats are uniquely adapted to the short life cycles and extreme conditions. They themselves are unique and are important parts of global and local biodiversity.

Further Reading

Crowe, J.H., Carpenter, J.F. and Crowe, L.M., 1998. The role of vitrification in anhydrobiosis. Annual review of physiology60(1), pp.73-103.

Hinton, H.E., 1951, August. A new Chironomid from Africa, the larva of which can be dehydrated without injury. In Proceedings of the Zoological Society of London (Vol. 121, No. 2, pp. 371-380). Oxford, UK: Blackwell Publishing Ltd.

Hinton, H.E., 1960. A Fly Larva that tolerates Dehydration and Temperatures of− 270° to+ 102° C. Nature188(4747), p.336.

Novikova, N., Gusev, O., Polikarpov, N., Deshevaya, E., Levinskikh, M., Alekseev, V., Okuda, T., Sugimoto, M., Sychev, V. and Grigoriev, А., 2011. Survival of dormant organisms after long-term exposure to the space environment. Acta Astronautica68(9-10), pp.1574-1580.

Sakurai, M., Furuki, T., Akao, K.I., Tanaka, D., Nakahara, Y., Kikawada, T., Watanabe, M. and Okuda, T., 2008. Vitrification is essential for anhydrobiosis in an African chironomid, Polypedilum vanderplankiProceedings of the National Academy of Sciences105(13), pp.5093-5098.

Watanabe, M., Kikawada, T. and Okuda, T., 2003. Increase of internal ion concentration triggers trehalose synthesis associated with cryptobiosis in larvae of Polypedilum vanderplankiJournal of Experimental Biology206(13), pp.2281-2286.

Watanabe, M., Nakahara, Y., Sakashita, T., Kikawada, T., Fujita, A., Hamada, N., Horikawa, D.D., Wada, S., Kobayashi, Y. and Okuda, T., 2007. Physiological changes leading to anhydrobiosis improve radiation tolerance in Polypedilum vanderplanki larvae. Journal of insect physiology53(6), pp.573-579.

Wełnicz, W., Grohme, M.A., Kaczmarek, Ł., Schill, R.O. and Frohme, M., 2011. Anhydrobiosis in tardigrades—the last decade. Journal of insect physiology57(5), pp.577-583.


Hot Springs: An Introduction


Cold. Spring freshwater environments hold a place in literature, song, and art, serving as a metaphor for a source, a point of origin. Springs have been studied by naturalists, geologists, ecologists, microbiologists, and taxonomists. Springs are defined as water emerging from the ground. The source of that ground water, the depth of the source, the chemistry of the rocks through which the water flows all create unique spring environments. Nearly all springs emerge at temperatures more constant than found in surface water. Cold springs are not cooled by any particular process, rather they simply retain the relatively cold temperatures of the earth during warmer seasons. Deep cool springs are inviting on the hottest of summer days, promising relief from the heat. However, during winter, the water emerges at temperatures warmer than surrounding environment. Springs and spring fed streams rarely freeze during winter. They let off steam, often being mistaken for warm or hot springs.

Hot spring, Yellowstone National Park, observe the microbial mats along the edge of the spring

Hot.  Some springs are heated by subterranean magma or other heat sources and emerge at temperatures much greater than the surrounding ambient water and atmospheric temperatures. These hot or thermal springs are unique to the point of rarity, but are found throughout the world, mostly near fault and tectonic zones and near volcanoes. Thermal spring water may emerge from the ground at temperatures approaching boiling or may emerge at warm temperatures ranging from 35 to 40°C, cool enough for safe contact with the skin.

Fountain Geyser 2
Hot springs surround Fountain Geyser, Yellowstone National Park

Variety. Hot springs are as varied as the ground chemistry and heat sources that define them. Some are acidic, characterized by sulfur fumes and low productivity. Others are basic, characterized by high concentrations of salts and precipitates. Many thermal springs support large colonies of algae and bacteria that mesh together to form extensive mats (See the review by Castenholz 1969). A small set of these microbes survive, even thrive in the highest temperatures.

Yeroogiin Khaluun RashaanA
Yeroogiin Khaluun Rashaan, Mongolia (Photo: John Morse)

Extremophiles. Brock (1985) and others studied the microbes, those thermophilic algae and bacteria, in Yellowstone National Park for at least ten years. They identified several species, extremophiles, living at temperatures in excess of 100°C. One species, Thermus aquaticus, has important uses in biotechnology. The enzyme that strings together nucleotides, the building blocks of DNA, can break apart or denature at high temperatures for most species. Yet, since Thermus aquaticus is adapted to the hottest temperatures on Earth, its DNA polymerase enzyme is not denatured by high temperatures. Researchers use this feature to create copies of DNA from small original concentrations of sample DNA in the process called the Polymerase Chain Reaction or PCR.

Ponca Hot Spring, Colorado, USA

Diversity in the heat. The temperature is greatest at the source of hot springs, but it cools as a function of distance from that source, along the spring runoff. A succession of life is found along this thermal gradient. Species of algae and bacteria occupy niche spaces defined by temperature, chemistry, and competitive exclusion, sometimes in a predictable pattern. Invertebrates also may vary along the thermal gradient, sometimes moving up or down the runoff as the temperatures change to exploit the best temperature ranges for the species, their thermal optimum.

Firehole River
Firehole River, Yellowstone National Park. This thermally influenced river exhibits a thermal gradient.

Of pools and parks. When I first started studying hot springs, I envisioned the clear, colorful springs of Yellowstone National Park. In fact, what I found when I went searching for hot springs were pools crowded with happy people soaking in the heat and watching the golden sun set over mountain peaks. Most hot springs are not protected in North America, rather they have been modified as pools or spas. Some thermal water is harnessed and sent by pipes to hot springs swimming pools. The majority of research has focused on those few springs on conservation lands. Microbes have been studied extensively in Yellowstone National Park while thermophilic invertebrates have been studied in hot springs in Iceland, Japan, and New Zealand.  However, few studies of thermal springs have consisted of surveys of large geographic areas. Such studies could answer whether thermophilic species of blue green algae or cyanobacteria are truly cosmopolitan with only a few species found at the extreme limits of life worldwide.  Or the research could find new species of invertebrates.

Future topics. The world of thermal springs is fascinating and beautiful. Future topics will include microbial mats, thermal Diptera, and the geophysical environment.

Spring source, Ponca Hot Springs

Further Readings

Brock, T.D., 1985. Life at high temperatures. Science230(4722), pp.132-138.

Castenholz, R.W., 1969. Thermophilic blue-green algae and the thermal environment. Bacteriological Reviews33(4), p.476.

Lamberti, G.A. and Resh, V.H., 1985. Distribution of benthic algae and macroinvertebrates along a thermal stream gradient. Hydrobiologia128(1), pp.13-21.

Hayford, H. and Herrmann, S.J., 1998. Migration patterns of four macroinvertebrates along a rheocrene thermal spring. Studies in crenobiology: the biology of springs and springbrooks. Backhuys Publishers, Leiden7584.

Polymerase Chain Reaction.

Pielou, E.C. 2000. Freshwater. University of Chicago Press. 256 pp.

Tüxen, S.L., 1944. The hot springs of Iceland. Zoology of Iceland.

Pritchard, G., 1991. Insects in thermal springs. The Memoirs of the Entomological Society of Canada123(S155), pp.89-106.

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