Zuni Salt Lake - Research Paper Example

Zuni Salt Lake Nichole Herrera Bio 495-001 This paper reviews the limnology of Zuni Salt Lake in the of New Mexico. It is a saline lake, although it is fed by freshwater, both from underwater springs and from rainfall and tributary streams. The lake is located inside a crater and, therefore, has a very self-reliant system for which it only needs the fresh water system replenishment that comes through seasonal changes in climate. The vegetation grows according to the level of the salinity of the lake at different times of the year and also in different locations of the lake. There is not much mammal life here except for the migratory birds that pass through the area Insect life is also minimal. This is a self-sustaining ecological system that continues to replenish itself very efficiently, so long as there are no disruptions from severe climate changes or man-made intrusions that would permanently affect it. Introduction Limnology is the study of inland waters such as lakes, rivers, streams, wetlands, reservoirs and groundwater. These bodies of water interact with the atmosphere and their own drainage basins, and through these interactions, provide their own ecosystem of growth in biological cellular activities, such as plant life, basin organisms, and any other physical and chemical interactions that can take place. Each body of water has its own environmental composition, based on the varied and specific interactions that take place in a certain area and also dependent on what is around the body of water. HISTORICAL OVERVIEW Zuni Salt Lake is situated 42 miles southeast of the Pueblo of Zuni and is known as a salt lake, about a mile wide, set within a depression, with two volcanic cinder cones in the center. While the depression is not necessarily a volcanic crater, the steep walls (or cliffs) of the crater contain sandstone from the Cretaceous Era which is capped by a lava sheet and volcanic ejection residual (Darton 1905). The lake is a religious symbol to the native Zuni Indians (and other tribes) and also provides salt to them, particularly during the dry season. At other times of the year, it is about four feet deep. Another area with similar geological expressions in New Mexico, but without a lake, is the Quemado or Red Hill volcanic field (Hoffer and Corbitt 1989). In 1905, when N.H. Darton visited the lake, it produced about three tons of salt a day and the Indians would sell it to earn a living. The salt, at that time, was presumed to be from springs which rose from the underlying ‘Red Beds’ and fresh water also constantly flowed into the lake from a small eastern shore spring, especially during rainy sessions, of which there were very few. There was also a drainage area from the southern higher slopes. The Cretaceous sandstone cliffs on the south side and the valley floor also contain Cretaceous sandstone, along with the lava composite. Zuni Salt Lake Fig.1 (sites.coloradocollege.edu) View of Zuni Salt Lake, N.M., looking south from the northern end of the lake, to the mounds located inside the lake. The lake is known as the ‘Old Lady Salt’ or ‘Salt Woman’ to the Indians and is a pilgrimage destination for many Indians. Collecting the salt is part of a ceremony and used in religious rituals aside from its daily use (Colorado College web 2013). Aside from its historical position, Zuni Salt Lake has also been part of battles over mineral and water rights, including the Salt River Project electrical company in 1986, when the company attempted to put in a new coal strip mine about 12 miles away from the lake. Along with the proposal made for the coal mine, a railroad line would also be installed and this would cross over several of the Indians’ pilgrimage trails and graves in that area. There would also be new wells dug to pump water at about 85 gallons per minute near the Zuni Salt Lake aquifers, thus depleting the supply to the lake and ultimately seriously damaging the ecosystem of the lake irreparably. After a protest, the project was finally dropped (Colorado College web 2013). Methods The methodology for conducting this research was to do a number of keyword searches through Google Scholar first regarding limnology of Zuni Salt Lake to see what came up. For the most part, the research offered observations made by early scientific observers who did not have the advanced tools to do specific testing of the environmental and ecological factors found at the lake. Some efficient reports were found later in more scientific journals from later years, but they were also scarce, and it would seem that the lake is perhaps not so important for scientific studies, although it is very interesting. As we become more environmentally conscious, this may change over time and more efficient studies will be done. Basic background research was also done on the historical value of the lake which turned up what Zuni Salt Lake represented to the Indians of the area and their religious observations of the lake. This turned out to be pretty interesting as to how they used the salt, not only for living purposes but also for religious ceremonies. Research was also done on keywords from the resources used to make sure the terminology was fully understood within the context of the research so as to interpret this research correctly. Results A historical background was first researched to find out about how the lake was formed, and it appears that the lake is very old. However, the history of the Indians and their religious relationship to the lake proved to be very important and the lake is now part of the National Register of Historic Places, a most important listing (Colorado College web 2013). The next part was to find out what types of testing had been done in the area for the ecosystem and any parts that were of particular notice. There was some interesting literature from the first part of the last century which is included in this report but the paper only gives observational data, consistent with the available tools at that time (Darton 1905). There was also a report from the 1970s with a better overview on plant life in the area along with soil description. Consequently, based on the research found, much of this paper focuses on soil composition and the plant life found in the area, particularly in the basin itself. Brief references to water composition and sources are also mentioned. The results of the research were that there were not a whole lot of research studies done on this lake. There were more articles on background information of historical importance and only a few scholarly or scientific reports that were applicable to this specific research. That seemed fairly surprising because of the varied life found here. The reasons may be two-fold: 1) it is rather far out from mainstream traffic; 2) the varied life is more on a minute scale, not easily visible to the eye unless closely studied as in a scientific review. Discussion LAKE COMPOSITION Bradbury (1971) determined that Zuni Salt Lake was formed during the late Pleistocene Era when volcanic and phreatic eruptions and explosions penetrated the Paleozoic and Mesozoic strata. Terrain Map of Zuni Salt Lake Fig. 2 (Darton 1905) Sketch map and sections of Zuni Salt Lake, N.M. with countour intervals at 50 feet. The lake sits closer to the north side of the depression as mud and dust carried by the wind has deposited on the southern side of the depression as the lake has regressed over the centuries. The northern ridge of the depression is stratified, fine-grained and is relatively cross-bedded, containing scoria as well as fragments of sedimentary rocks and Carboniferous limestones with characteristic fossils (Darton 1905). The sides of the depression slope downwards for about 150 feet and the two prominent cones in the bed of the basin, rise nearly as high as the sides of the crater walls. The larger cone also carries a depression in which there is a smaller lake that is slightly less salty than the main lake. The second cone, however, does not have a crater and also appears older than the cratered cone. Both cones also consist of scoria and other volcanic residue (Darton 1905). The assumption for how these two cones were made, as proposed by Darton (1905) is that there was a great ejection of hot water rather than a volcanic eruption, and that this water also spewed scoria and rock fragments, including fossiliferous limestone, from underground. The depression was most likely made when a depressed area occurred, made by the solution of salt and also by the spewing of various rocks (Darton 1905). Lake Inside Larger Cone Fig. 3 (Darton 1905) Looking into the crater in the larger cinder cone which shows interior salt water pool at lake level. The alternative, as he puts it, is that there was lava which extruded up but that the volcanic ejections occurred before the subsidence of the basin. Once the subsidence had occurred, then a later eruption pushed up the cones. Water continues to be fed from the aquifers underneath, along with any water that comes down through rivulets and from rainfall. Therefore, while the lake itself is saline, it is fed by freshwater sources (Darton 1905). VEGETATION In more up-to-date data, Bradbury (1971) states that the dominant organisms in both the Zuni Salt Lake and the Cinder Cone Pool are composed of Artemia salina and Hydropyrus hians. The Cone Pool bed is also covered with a blue-green algal matting of Anacystis sp.. Sediments differ slightly in both water formations: Zuni Salt Lake has salt crusts which contain halite, calcite and gypsum, mixed with clay and organic matter; the Cone Pool contains watery sapropel, algal materials, calcite and gypsum. These all fluctuate during heavy rainfalls in the late summer and early autumn, affecting the ecology conditions (especially salinity) of the waters (Bradbury 1971). Pinyon and juniper woodlands are found on the mesas and buttes, which reside along the Carrizo Valley next to the lake formation. Juniper is also found in the rough volcanic residue that surrounds the rise. Grass and small shrubs grow in the fine-grained alluvial soils. Plants which dominate the region are: Pinus edulis on the north-facing slopes of Cretaceous sandstone mess; Juniperus monosperma on well-drained ejecta-soil mesas; Bouteloua gracilis on finer soils that have runoff; Sporobolous cryptandra on fine soils; Chrysothamnus greenei found almost everywhere; Atriplex canescens on areas with fine but poorly drained soils; Lycium pallidum, which can occasionally be found on rocky soils; and Artmeisia tridentate, which is more prevalent to the southern end (Bradbury 1971). The valley floor shows an abundance of Atriplex canescens, Sacobatus vermiculatus and Sporabolous cryptandra. Where there is a fresh-water spring on the south wall, mesic plants are found such as Forstiera neomexicana and Parthenocisus inserta. On the northeast and eastern sides of the lake, marsh flora is found such as Juncus mexicanus, Distichlis stricta, Scirpus americansu, Zygadenus gramineus, Ramunculus cymbalaria, Kochi scoparia and Salsosa kali (381). No vegetation grows wherever there are saline seeps (Bradbury 1971). HYDROLOGY As noted before, water is replenished by a freshwater spring at the northern end of a fault which intersects the maar walls, and the second source of water is from saline springs which come from fractures in the floor of the maar that extend down to subsurface Permian formations. These ground waters move from underlying aquifers along the fractures into the lake. Fresh water is found more at the top while the saline water flows in from below. During dryer months, salinity increases because of less fresh water input, which causes the water gravity to rise, giving evidence that water loss occurs only with evaporation at 119 cm between March and July (Bradbury 1971). Evaporation Chart by Month Fig. 4 (Bradbury 1971) Evaporation at Zuni Salt Lake, extrapolated from surrounding stations. Ultimately, variation does occur, although it is safe to say that when the weather is dry and hot, evaporation occurs until the end of summer and the rainfalls begin. Variances are due to changes in the weather and to dikes and dams that are built that prevent or reduce freshwater runoff that normally replenishes the lake (Bradbury 1971). It is also important to mention that the salinity of the water changes the type of algae that can be found. ALGAE When fresh water is routed into the lake and the salinity drops, algae begins to bloom and turns the water a yellowish green. However, in the early spring weeks, algae begin to decline in abundance as salinity increases, until there is little life left in the water. Those algae that are commonly found are Oscillatoria, Chlamydomonas, Dunaliella salina and Platymonas (Bradbury 1971). Additionally, brine shrimp (Artemia salina) can be found during the high salinity periods, as water is typical to levels found in coastal waters at that time. Brines are freshened by summer rains and algae, which begins to come back around then, is the food of choice. Most of the Artemia salina population resides in the southern part of the lake, and once the water begins to rise, they repopulate the whole lake (Bradbury 1971). OTHER LIFE Other life which resides outside the water are the shore flies (Hydropyrus sp.), which occur in saline environments, dragonflies and damselflies which hover over the lake and are considered to be there to oviposit in the brines. These insects, however, are not affected in any real way by the chemical composition of the water, although they may end up as food for birds that stop there. Birds most often seen by the lake are the Eared Grebe (Podiceps caspicus) and Killdeer (Charadrius vociferous), a common wading bird that feeds on brine shrimp and insects (Bradbury 1971). There are no mammals that are directly associated with living in the lake. Conclusion This was a very interesting subject to research, particularly Zuni Salt Lake, as the water in the lake strongly affects the plant life and ecology in general that occurs in the area. What was most notable about the ecology was the different types of plants that would occur in different parts of the lake on the sides of the walls, due to the salinity level in that part of the lake. Where fresh water flowed in, different vegetation would occur than in another part of the lake, which had more saline content in the water. This also included the life cycle for algae and for brine shrimp, and how the presence of one was essential for the other to feed on for survival. In turn, the presence of brine shrimp also provided food for the birds who would be in a migrating pattern at that time and would stop to rest and feed at the lake at just the right time. This also included insects that were present because brine shrimp were present and, therefore, were also available for the birds to eat. The lake is actually its own little ecological system deposited inside a crater, providing its own world and life cycle that is dependent most heavily on the water that is provided from underground and from the rainfall above. Without that water replenishment, there would be almost no ecological system at all. Literature Cited Bradbury, J.P. “Limnology of Zuni Salt Lake, New Mexico.” Geographical Society of America Bulletin, 82. (1971). pp. 379-398. Colorado College. ‘The Old Salt Woman: Zuni Salt Lake, New Mexico.’ Colorado College Online: Indigenous Religious Traditions. 2013. < https://sites.coloradocollege.edu/indigenoustraditions/sacred-lands/the-old-salt-woman-zuni-salt-lake-new-mexico/> accessed April 26, 2013. Cummings, D. ‘Geological map of the Zini Salt Lake volcanic crater.’ Miscellaneous Geologic Investigations Map 1-544. Catron County, New Mexico: U.S. Geological Survey. 1968. Darton, N.H. “The Zini Salt Lake.” Journal of Geology, 13.3 (1905): 185-193. Hoffer, J.M. and L.L. Corbitt. ‘A preliminary note on some unusual explosion-collapse craters, Quemado basalt field.’ 40th Field Conference Guidebook. Catron County, N.M.: New Mexico Geological Society. 1989. pp. 157-158. Johnson, Gordon V. and Larry L. Barton. Trophic Status of Selected Northern New Mexico Lakes. New Mexico: New Mexico Water Resources Institute. 1976. accessed April 23 2013. Read More