Ecology of a Hot Spring

[Music] across the surface of the Earth is a dynamic biosphere of Life plants and animals interacting with their physical environments to understand his environment man studies the conditions of light moisture and temperature that determine the survival of organisms by proving extreme Environ man discovers the physical limits of Life Dr Thomas Brock has for many years investigated the tolerance of life to extreme high temperature what he is learning is extending our understanding of the evolution of life and the effects of thermal pollution in Aquatic and environment steam rises from Soil and Water heated by molten lava deep in the Earth at first this thermal area seems hostile to life yet this is an ideal natural laboratory for the study of organisms that live at high temperatures it is an area preserved and protected in Yellowstone National Park here the soil is soft and porous a condition induced by gas and steam Rising through [Music] it sulfur crystals in the soil are formed from the hot gases the soil is highly acid conditions are not conducive for higher forms of life the most limiting of environmental factors here is temperature a few inches below the surface of the soil the temperature is 91° Centigrade indicating much higher temperatures at greater depth the tremendous Heat heat and pressure created deep in the earth propels boiling hot water to the surface spectacular guises are formed when the buildup of steam pressure drives the water High into the air there are over 100 geysers at yellower but Hot Springs are even more common than geysers water in runoff channels cools as it flows away from the source of the spring though water stays hot in the center of the channel and cools near the edges forming a v-shaped temperature gradient the v-shaped pattern traces the upper temperature limits at which various organisms can grow in an attempt to collect specimens cover slips are mounted on a specially designed rack the rack is placed at the source of the hot spring where the temperature is highest microscopic organisms if they are present in the water will adhere to the glass and begin to grow the rack will remain in the the hot water for several days because of the High Altitude water boils at 93° centigrade in Yellowstone compared to 100° at sea level the temperature of the water at this source is 91° CRA much higher than that at which fish and other animals can survive in the outflow channel near the spring the water has cooled slightly to 88° Pink toughs of material not seen at higher temperatures are collected for later study down the channel the water continues to cool to 75° C the pink material is replaced by yellow another sample is collected further down the channel the first signs of photosynthetic life appear blue green algae where the water has cooled to below 70° Centigrade a thick blue green Alo mat appears to determine the composition of the mat a core sample is taken the sample reveals layers of different colored material beneath the green surface of the map 2 Days Later Dr Brock returns to complete the sampling he has obtained specimens from temperature ranges in the channel where organisms are conspicuous now the sampling of the source will be [Applause] completed under a high powerered microscope the cover slip is examined surprisingly filamentous and rod-shaped bacteria have grown on the glass A few species that are able to withstand the stress of boiling water sample from the channnel are now examined the pink and yellow materials are also bacteria long filaments growing profusely in water 3° cooler than the Boiling Spring the core sample shows the blue green alga only on top where light energy is available for photosynthesis unlike the bacterial samples the blue green algae do not grow above 70° beneath the Alo layer orange bacteria form thin layers the bacteria are held together by a gelatinous material that gives the mat its thick consistency these samples show that there are distinct upper temperature limits for different groups of organisms the runoff channels from the geysers and hot springs end at the fire Hole River a large cool Mountain stream the hot water forms a natural thermal pollution Source raising the river's temperature 17° in some places the hot springs runoff channels and River provide a natural Laboratory for the continuing study of the effect of high temperature on ecosystems in addition to heat another factor causing stress in the hot springs environment is water acidity hydrogen sulfide from deep in the earth is converted to sulfuric acid some hot springs have a higher acid content than others the acidity of the water is measured with a pH meter a pH of two is a strong acid condition similar to that of gastric fluid since acid is a common industrial pollutant an understanding of this environment may help us predict the consequences of a ID pollution these spherical shaped bacteria require a hot acid environment to thrive where the highly acid water has cooled to 55° Centigrade a thick mat is formed of an algae which require acid for growth this algae is quite different from those found in neutral Waters organisms of the hot spring communities are adapted to changes in environmental conditions most readily observed is the response of alga to changing light intensity as can be demonstrated with this filter the algae beneath the filter receive less light than those in the surrounding area a week later the alga in dimlight have increased their chlorophyll content as is shown by the green coloration several days of cloudiness will cause a similar change in color in summer the large mineral Terraces that surround some hot springs are brilliant oranges and yellows during winter the same Terraces appear dark green steam increased cloudiness and fewer hours of sunlight cause a decrease in light intensity this decrease causes an increase in alal chlorophyll with more chlorophyll the algae can gather increased amounts of the dimmer light the ability to adapt to changing light intensity enables algae to maintain growth and photosynthesis at Peak efficiency through all seasons inches above the Terrace the air temperature is far below freezing yet the water temperature in thermal areas remains unchanged the constant water temperature has a profound effect on the ecosystems created by the thermal area animals remain active all winter idate FES feed on the alal mat in both laral and adult stages large masses of eggs are common during the winter months the adult flies seldom Venture more than a few inches from the M as the subfreezing temperature would be fatal the thermal area attracts larger animals elk feed in the ice free River of the thermal area where aquatic plants and alga grow the snowf free thermal area provides relief for these large mammals during the long harsh winter the knowledge gained from the studies in Yellowstone could not be gained elsewhere and is of great importance for our understanding of environmental pollution and of the nature of life itself Yellowstone in winter or summer is a unique Natural Area of enormous interest for science it provides an undisturbed outdoor laboratory of unparalleled Beauty and excitement it must remain this way so that all generations of mankind can enjoy and study it [Music]