. Yellowstone National Park has over 3,000,000 visitors annually. This high tourism level appears to have a negative effect on conservation, especially of its hot springs. It is located in Wyoming but also extends to Montana and Idaho. The U.S. Congress established it and President Ulysses S. Grant signed it into law on March 1 1872.. The discovery of how visitors have affected the colors of hot springs in the park was made by researchers at Montana State University, Germany’s Brandenburg University of Applied Sciences. Researchers discovered that hot spring chemicals have been altered by tourists over time. They also found other pollutants in the water. Joseph Shaw (co-author) of the research at Montana State University’s Electrical and Computer Engineering Department created a simulation of Morning Glory Pool, which is currently a mixture of blue, yellow and green. This was done between the 1880s and the 1940s before temperatures reached the highs of today and tourists began flocking to it. The pool’s water was a deep, uniform blue before they arrived. Coins and trash have accumulated at the bottom, which has blocked the heat vent, decreasing the temperature to where microbes are able to thrive and survive. The pool’s “mats”, which are large colonies of microbes, have caused the water to change color. Morning Glory Pool in Yellowstone National Park wasn’t always like this. Paul Nugent (a Montana State University computer engineer researcher), said that it is now clear that the mats contain complex microbe communities, including thermophilic and blue-green algae, and other thermophilic bacteria, and archaea. The study found that blue-green algae (or thermophilic Cyanobacteria) is the most prevalent type of algae within these pools. This gives the pool its greenish to yellow hue. In their paper published in the journal Applied Optics, the researchers stated that color observed in shallow water features is primarily due to the spectral characteristics of the microbial matrix, which are related to water temperature. Colors observed in deeper waters result primarily in wavelength-dependent absorption or scattering in water.
