The McMurdo Dry Valleys in Antarctica lie among the Transantarctic Mountains near McMurdo Sound. Together they form the largest ice-free area on the continent and are one of 26 sites in the National Science Foundation’s Long Term Ecological Research Network (LTER). Underlain by continually frozen permafrost, aboveground the valleys contain glaciers, perennially ice-covered lakes, ephemeral streams fed by summertime glacial meltwater, and vast expanses of exposed soils. They comprise an extreme cold desert and end member ecosystem in the LTER and provide an unusual opportunity to study an ecosystem dominated by microorganisms, algal mats, some occurrences of lichen and mosses, and relatively few groups of invertebrates. Higher forms of life are essentially absent.
CWEST Participants: Mike Gooseff (lead investigator), Karen Cozzetto, Josh Koch, Sarah Spaulding
USGS and INSTAAR researchers have been collaborating in the Dry Valleys since the establishment of the McMurdo Dry Valleys LTER (MCMLTER) project in 1993. A wide variety of MCMLTER research takes place including research on: glacier hydrology and mass balance, lake chemistry and geochemical evolution, paleolimnology, lake ecosystems, and soil ecosystems. However, much of the USGS-INSTAAR joint research has involved the study of stream hydrology and ecology. Stream Teams, initially comprised of USGS and then later joined by INSTAAR researchers, have been conducting field work in the Valleys since 1987. To learn more about Stream Team research and monitoring, visit the Stream Team's home page.
Collaborative research: reactivation of a cryptobiotic stream ecosystem
Center director and INSTAAR researcher Diane McKnight collaborated with USGS researchers, Cathy Tate and Ned Andrews, to study the persistence of cyanobacterial mats in the Dry Valleys. To do this, they constructed a sandbag wall to divert glacial meltwater to an abandoned channel that had not received substantial flow for approximately two decades. Within one week they found abundant cyanobacterial mats in the channel indicating that the mats had been preserved in a cryptobiotic state over the 20 year time period and had, in effect, been “waiting for water” to thrive.
McKnight, D. M., Tate, C. M., Andrews, E. D., Niyogi, D. K., Cozzetto, K., Welch, K., ... & Capone, D. G. (2007). Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: a long-term geomorphological experiment. Geomorphology, 89(1), 186-204. DOI: 10.1016/j.geomorph.2006.07.025
Collaborative research: hyporheic zone preferential FlowFormer INSTAAR student and now USGS researcher Josh Koch and INSTAAR researcher, Karen Cozzetto, participate in a subsurface tracer injection experiment in Von Guerard Stream in the Dry Valleys. USGS Wyoming Water Center hydrologists Kirk Miller and Ray Woodruff helped with the tracer injection preparations. The conservative tracer was injected into what is known as the hyporheic zone, which consists of the near stream sediments through which stream water flows in and out. The experiment provided evidence for hyporheic zone preferential flow, a newly forming area of stream research.
Cozzetto, K. D., Bencala, K. E., Gooseff, M. N., & McKnight, D. M. (2013). The influence of stream thermal regimes and preferential flow paths on hyporheic exchange in a glacial meltwater stream. Water Resources Research, 49(9), 5552-5569. DOI: 10.1002/wrcr.20410