Project Description:
We are conducting Martian planetary analog studies at the Flashline Mars Arctic Research Station on Devon Island, Nunavut in support of both a biological and geological field research programme.
Biology: Comparative microbial ecology of extreme environments in deserts and Polar Regions conducted with Mars mission simulation techniques.
Summary: A research team on a simulated mission to Mars will compare soil ecology, microbial ecosystems, lichen diversity and hypolithic cyanobacteria in two extreme environments: the deserts of southeastern Utah and the area near Haughton Crater on Devon Island, Nunavut. Comparing the microbial communities of these Martian-analog sites should yield insights into the success of microbial communities in these environments and ecological and genetic factors contributing to their local abundance and fitness. Comparing these two environments using the same team and the same analytical methods will test the biological similarity of far-separated Martian analogues.
Project Rationale: Martian analog sites are locations on Earth selected as testbeds for Martian planetary exploration based on their remoteness and geological and meteorological similarities to Mars (Sokoloff et al. 2016). Microbial organisms, such as lichens and cyanobacterial hypoliths, are ecologically important in these environments due to their resistance to UV radiation and desiccation, characteristics that make them particularly interesting to astrobiologists (Sokoloff et al. 2016). Comparing the microbial communities of these Martian-analog sites, using a single team and the same techniques at both stations, should yield insights into the success of microbial communities in these environments and ecological and genetic factors contributing to their local abundance and fitness.
Lichens
Lichens are one of the best known extremophiles. Although lichens are found in temperate settings they are also present in extreme deserts and in Polar Regions. Lichens are a composite organism with a multicellular fungus (mycobiont) providing structure and environmental protection while a photosynthetic component (photobiont) provides carbon sources via photosynthesis. Many lichens can survive on atmospheric humidity only. Indeed, lichens define the lower limit of survival at low water activity (eg. Palmer and Friedmann 1990).
At MDRS and FMARS these species grow in rock and soil, and exchange photobionts with endolithic colonies of algae and biological soil crusts (Sokoloff et al. 2016). Characterizing the biodiversity and substrate ecology of lichens at Haughton Crater will provide information valuable to ongoing planetary analogue research at both Mars Society stations, and the search for these organisms is analogous to the future manned search for biomarkers on Mars. To date, 182 lichen species have been reported from the locally-rich Truelove Lowlands on Devon Island (Barrett and Thomsen 1975), 61 species have been recorded from eastern Wayne and Emery counties, Utah, and 16 species have been recorded from the vicinity of MDRS (Sokoloff et al. 2016). Further work will undoubtedly add new species records for both Mars Society stations and for the western half of Devon Island, which is underexplored for lichens.
A recent major discovery in lichen science was the identification of Cyphobasidium yeasts (unicellular fungi) as a third component (Spribille et al. 2016) in what has heretofore been assumed to be a binary symbiosis of an alga (or cyanobacterium) and a multi-cellular fungus. The presence of this yeast is confirmed by sequencing a variety of lichen species from temperate ecosystems in Montana and in northern Europe and in herbarium specimens representing a global distribution. The discovery of this third partner opens up the question of its role in lichen survival in extreme dry and cold environments. It would be interesting to determine if the yeasts are present in the lichens in these two extreme environments. This can be determined by DNA sequencing lichens in the field using a MinIon DNA Sequencer. If this third symbiont is present, the prevalence of the yeast, and its presence or absence in different species in these extreme environments may help elucidate the ecological role of these yeast in Lichen survival.
Methods: We will undertake research in the vicinities of each site by foot, complete plant inventories of all lichens, and collect data on conservation status, ecology, distribution, and population variation as appropriate. All of these data will be useful for long-term monitoring of potential changes in species diversity in the future.
Approximately 300 specimens will be collected, photographed, and studied. Collections will be deposited at the National Herbarium of Canada (Canadian Museum of Nature), and duplicate specimens will be distributed to national and international herbaria, all contributing to the permanent scientific record documenting the distributions of Arctic lichen species in time and space. As time permits we will make occasional collections of vascular plants, algae, fungi and bryophytes.
Lichen specimens are collected from the environment by hand, using a small knife, or by using a hammer and chisel for crustose (rock-growing) specimens. These lichens are dried in the field in paper bags.
For each collection event we:
Collect one to several individuals of a species (depending on the size of an individual, and how common the species is locally). If a species is not common, we collect only enough material to properly document its occurrence at the site. If a species is rare, we do not collect any specimens, and document its occurrence only with photographs.
Record detailed notes on the location of the species, its local growing conditions, and other species that grow at the site. In a subset of instances we take photographs of the species growing in its natural state.
Hypoliths
Microbial communities dominated by cyanobacteria of the genus Chroococcidiopsis are found below the surface of translucent rocks in the most arid regions of deserts throughout the world (Cockell and Stokes, 2004; Warren-Rhodes et al., 2006, 2013; Pointing and Belnap 2012, Pointing et al., 2009). They are typically found under quartz (Nienow, 2009). They are present under suitable stones at the MDRS desert site and at the FMARS polar site.
It is known that Chroococcidiopsis is tolerant of radiation, long periods of desiccation, and limited water availability (Billi et al. 2000) and this has made them of particular interest to astrobiology (Billi et al. 2011). In this study we propose to compare the sequences between Chroococcidiopsis from the temperate desert site at MDRS with FMARS polar site to determine there are any common genes that form part of the tool-box used by organisms to survive in extreme environments. We hypothesize that genetic analysis will show that cyanobacteria of the genus Chroococcidiopsis which are found below the surface of translucent rocks at the MDRS desert site and the FMARS polar site share comment genes that enable their survival in extreme environments.
Methods: photosynthetic hypoliths (algae and cyanobacteria that grow on the underside of rocks) are of particular interest to astrobiologists due to the extreme environments they inhabit. We will collect rocks with hypolith colonization from sites around the operational area of the Flashline Mars Arctic Research station and record the following accompanying data:
1. Precise coordinates of where sample was collected.
2. A habitat description for each sample location
3. Rock type
4. Soil type where rock was found.
5. % colonization of each site
6. Colonization measurement of each rock
7. Soil moisture, and pH, and EC
In addition we will take field photographs of each specimen as required. The samples will be returned to the lab at the Flashline Mars Arctic Research Station where selected samples will be DNA sequenced using a portable minION DNA sequencer.
Geology: Patterned Ground Research
The Haughton Impact Structure has been identified as the furthest north meteor impact crater in the world. Its unique location in the Canadian arctic has exposed it various physical and weathering processes not seen on other impact structures on Earth. It has experienced several periods of glaciation throughout its history and presently hosts a number of periglacial landforms that are of particular interest to planetary geoscientists.
There are a number of locations around the crater floor that host patterned ground features that are the result of the ground swelling and contracting due to seasonal temperature changes that cause the top layer of permafrost to melt and re-freeze. Over time, this process creates patterned ground landforms, also called polygons, which can provide additional insight into the nature of the permafrost in the area while also serving as an analogue for similar features that have been identified in periglacial environments on Mars.
The proposed scope of patterned ground research to be conducted over the summer months of 2017 will include three distinct phases as outlined below.
Phase 1 will involve site characterization activities including but not limited to: measuring individual patterned ground features using surveying equipment and GPS units, aerial photography using a line-of-sight ground-operated drone, and the placement of temporary markers or flags to identify points of interest that will be removed and packed out at the conclusion of field activities.
Phase 2 will involve the installation of several temperature and moisture dataloggers to measure subsurface conditions in selected patterned ground features. These dataloggers are about 1 cm wide by 2 cm long and will be installed to the permafrost/soil contact, not expected to exceed 1 meter below ground surface. They will be installed to this depth using a battery-operated handheld drill with an auger-bit attachment. The dataloggers will be connected to a cable running to the surface and identified using a pin-flag and left in the ground over a period of approximately 80 days to record subsurface conditions over that period of time. At the conclusion of field activities, the dataloggers will be retrieved and their holes back filled, returning surface conditions to those observed at the time of arrival.
Phase 3 involves collecting confirmation grab samples at the time of datalogger retrieval to understand the ambient physical conditions they were situated in over the monitoring period. Additional grab surface samples will also be collected as a part of Phase 3 to support observations made as a part of Phases 1 and 2 as needed. Each collected sample volume is expected to fit inside of a standard-sized sandwich bag.
References
1. Barrett, P.E. and Thomson, J.W., 1975. Lichens from a High Arctic Coastal Lowland, Devon Island, NWT. Bryologist, pp.160-167.
2. Billi, D., Friedmann, E.I., Hofer, K.G., Caiola, M.G., Ocampo-Friedmann, R., 2000. Ionizing-radiation resistance in the desiccation-tolerant cyanobacterium Chroococcidiopsis. Appl. Environ. Microbiol. 66 (4), 1489–1492.
3. Billi, D., Viaggiu, E., Cockell, C.S., Rabbow, E., Horneck, G., Onofri, S., 2011. Damage escape and repair in dried Chroococcidiopsis spp. from hot and cold deserts exposed to simulated space and Martian conditions. Astrobiology 11 (1), 65–73.
4. Cockell, C.S., Stokes, M.D., 2004. Ecology: widespread colonization by polar hypoliths. Nature 431 (7007), 414–414.
5. Nienow, J.A., 2009. Extremophiles: Dry Environments (including Cryptoendoliths). In: Encyclopedia of Microbiology, Elsevier, Oxford, pp. 159–173.
6. Pointing, S.B., Belnap, J., 2012. Microbial colonization and controls in dryland systems. Nat. Rev. Microbiol. 10 (8), 551–562.
7. Pointing, S.B., Chan, Y., Lacap, D.C., Lau, M.C., Jurgens, J.A., Farrell, R.L., 2009. Highly specialized microbial diversity in hyper-arid polar desert. Proc. Natl. Acad. Sci. 106 (47), 19964–19969.
8. Palmer, R.J., Friedmann, E.I., 1990. Water relations and photosynthesis in the cryptoendolithic microbial habitat of hot and cold deserts. Microb. Ecol. 18, 111–118.
9. Sokoloff, P.C, Freebury, C.E., Hamilton, P.B., and Saarela, J.M. (2016) The "Martian" flora: new collections of vascular plants, lichens, fungi, algae, and cyanobacteria from the Mars Desert Research Station, Utah. Biodiversity Data Journal 4: e8176. doi: 10.3897/BDJ.4.e8176
10. Spribille, T., Tuovinen, V., Resl, P., Vanderpool, D., Wolinski, H., Aime, M.C., Schneider, K., Stabentheiner, E., Toome-Heller, M., Thor, G. and Mayrhofer, H., 2016. Basidiomycete yeasts in the cortex of ascomycete macrolichens. Science, 353(6298), pp.488-492.
11. Warren-Rhodes, K.A., McKay, C.P., Boyle, L.N., Wing, M.R., Kiekebusch, E.M., Cowan, D.A., et al., 2013. Physical ecology of hypolithic communities in the central Namib Desert: The role of fog, rain, rock habitat, and light. J. Geophys. Res.: Biogeosci. 118 (4), 1451–1460.
12. Warren-Rhodes, K.A., Rhodes, K.L., Pointing, S.B., Ewing, S.A., Lacap, D.C., Gómez-Silva, B., et al., 2006. Hypolithic cyanobacteria, dry limit of photosynthesis, and microbial ecology in the hyperarid Atacama Desert. Microb. Ecol. 52 (3), 389–398.