Research About lakes

Posted On: Filed Under: Biological Research

Changes in the lakes within the Mount St. Helens blast zone

We will study changes in two lakes (Meta and Ryan) since the blast. Analysis will consist of analyzing physical and chemical properties of soils and entering these data into a GIS to model the amount of runoff in each watershed. The other focus will look at nutrients and plankton within each lake and conducting experiments to determine the effects of different levels of nutrients and predation on the plankton.

 

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Posted On: Filed Under: Biological Research

Limnological monitoring of some lakes of the Mount St. Helens National Volcanic Monument.

The monitoring program will sample the phytoplankton and zooplankton communities of Castle and Coldwater Lake. The sampling program will also include water samples which will be analyzed for soluble reactive phosphorus, total phosphorus, nitrate, major ions, dissolved oxygen, and conductivity. Temperature and water transparency will also be observed. The data will be analyzed to determine the structure of phytoplankton and zooplankton communities in these two lakes and the possible impacts of fish introduced into Coldwater Lake.

 

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Posted On: Filed Under: Biological Research

The herpetofauna of Mount St. Helens: survival and colonization following the 1980 eruption.

This study documents the survival and colonization of reptiles and amphibians in areas impacted by the 1980 eruption of Mount St. Helens. Surveys were conducted at 15 locations, with representative sites in three distinct volcanic impact zones, 1) ashfall, 2) blowdown, and 3) blast, during spring and summer from 1980 through 1991. Twelve species of herptiles (9 amphibians, 3 reptiles) are considered to have survived volcanic influences ranging from the directed blast to the accumulation of ash in otherwise unaltered habitats. These survivors represent most of a hypothetical list of 16 species considered to have occurred in the area before the eruption. Generally, surviving species were characterized by being more aquatic than those not found and this was attributed to the thermal buffering capacity of cool ice and snow covered aquatic systems where individuals were protected from the hot volcanic gases.

 

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Blast zone lakes and organic geochemistry

The objective of the research is to describe the processes controlling dissolved organic material in the lake water following the 1980 eruption of Mt. St. Helens. The concentrations of DOC (dissolved organic carbon) increased 50-fold after the eruption and these increases influenced the chemistry and biology of the lakes for several years. We have shown that most of this DOC was comprised of organic acids classified as either fulvic or hydrophilic acids, similar to those in typical natural waters. We found that between 1980 and 1983, these organic acid fractions underwent oxidative changes in their chemical characteristics. Similar changes may occur in more typical lakes.

 

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Recovery of riparian vegetation at Mount St. Helens

This study documents rates and patterns of vegetation recovery at lakes and streams in the blast zone of the May 1980 eruption. Recovery of streamside vegetation was dominated by plants that resprouted from below ground parts that survived the blast. Depending upon frequencies and intensity of secondary disturbances, revegetation from seeds has become increasingly important. Flooding, battering, and deposition of reworked tephra have extremely important effects on streamside revegetation. Recovery rates are more rapid at greater distances from the volcano where blast effects were less devastating.

 

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Post eruption studies of ecological recovery of lakes and rivers in the blast zone of Mount St. Helens

This study concentrates on the effects of the May 1980 eruption on Spirit Lake. During and subsequent to the eruption, Spirit Lake received debris avalanche material, timber and other forest vegetation, pyroclastic flows, mudflows, ashfall, and geothermal waters.

 

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Posted On: Filed Under: Biological Research

Lakes and thermal environments in the blast zone of Mount St. Helens

Approximately 20 lakes exist in the blast zone of Mount St. Helens. The degree to which they were disturbed on May 18, 1980 ranges from slight to a complete physical, chemical, and biological restructuring. Initially, our research focused on the physical, chemical, and microbial conditions within the lakes. Heavily devastated lakes were markedly changed chemically and all plants and animals eliminated. Recovery took the form of dramatic physical and chemical changes within the lakes which were linked to microbial activity. Rapid recovery occurred the first two years. Once the physical and chemical conditions were ameliorated, further biological succession was possible. Presently, we continue to track these changes.

 

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Observations on the floating log raft in Spirit Lake.

Observations on Spirit Lake and its log raft have been conducted since 1982. At that time a significant number (close to 20%) of the stumps (not the broken flotsam) had settled into an upright position in the water. This number included some that had floated into shallow water and had grounded lightly on the bottom (Coffin, 1983).

 

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