Wednesday, May 15, 2013

Stream Health Blog

Stream Health Blog

Nitrates: usually does not have a direct effect on aquatic insects or fish, but excess levels of nitrates in water can create conditions that make it difficult for aquatic insects or fish to survive, can be a source of food,  it can interfere with the ability of your red blood cells to transport oxygen in humans, amount of nitrates in water is determined by both natural processes and human intervention, essential for all living things: animals and plants. Nitrogen forms a part of the proteins and DNA that are found in cells. Animals get nitrogen by eating plants and other animals.

Conductivity: a measure of the ability of water to pass an electrical current. Conductivity in water is affected by the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, and phosphate anions or sodium, magnesium, calcium, iron, and aluminum cations,  also affected by temperature: the warmer the water, the higher the conductivity, Conductivity in streams and rivers is affected primarily by the geology of the area through which the water flows, Streams that run through areas with granite bedrock tend to have lower conductivity, streams that run through areas with clay soils tend to have higher conductivity, Studies of inland fresh waters indicate that streams supporting good mixed fisheries have a range between 150 and 500 µhos/cm. Conductivity outside this range could indicate that the water is not suitable for certain species of fish or macro-invertebrates, useful as a general measure of stream water quality, Significant changes in conductivity could then be an indicator that a discharge or some other source of pollution has entered a stream


Turbidityis a measure of water clarity how much the material suspended in water decreases the passage of light through the water, Turbidity can affect the color of the water, Higher turbidity increases water temperatures because suspended particles absorb more heat & this Higher turbidity increases water temperatures because suspended particles absorb more heat, also reduces the amount of light penetrating the water, which reduces photosynthesis and the production of DO, Sources of turbidity include:

Soil erosionWaste dischargeUrban runoffEroding stream banksLarge numbers of bottom feeders (such as carp), which stir up bottom sedimentsExcessive algal growth. regular monitoring of turbidity can help detect trends that might indicate increasing erosion in developing watersheds, Turbidity often increases sharply during a rainfall, especially in developed watersheds, which typically have relatively high proportions of impervious surfaces, Turbidity can also rise sharply during dry weather if earth-disturbing activities are occurring in or near a stream without erosion control practices in place.

Dissolved Oxygenis typically a limiting factor in aquatic ecosystems. Dissolved oxygen (DO) concentrations are expressed as milligrams of oxygen per liter of water (mg/L). The amount of DO affects what types of aquatic life are present in a stream, physical factors that influence DO are temperature, altitude, salinity, and stream structure. Temperature inversely controls the solubility of oxygen in water; as temperature increases, oxygen is less soluble, biological processes of photosynthesis and respiration also affect dissolved oxygen concentrations in streams, must be measured directly in the stream, since concentrations change quickly once a sample is collected. A DO probe allows several measurements to be taken in a short period of time, allowing quick comparisons for different physical characteristics within the stream reach


Temperaturewater temperature determines the kinds of animals that can survive in a stream. If the temperature gets too hot or too cold for some organisms, they die. Temperature also can affect the chemistry of the water. For example, warm water holds less oxygen than cold water, temperature increase as small as 1 or 2 Celsius degrees can kill native fish, shellfish, and plants, can possibly kill plants and animals.


Alkalinity is the water's capacity to resist changes in pH that would make the water more acidic. This capacity is commonly known as "buffering capacity.", The pH of the buffered solution would change when the buffering capacity of the solution is overloaded, It essentially absorbs the excess H+ ions and protects the water body from fluctuations in pH, determined  by the soil and bedrock through which it passes. The main sources for natural alkalinity are rocks which contain carbonate, bicarbonate, and hydroxide compounds. Borates, silicates, and phosphates also may contribute to alkalinity, is important for fish and aquatic life because it protects or buffers against rapid pH changes


E.coli: is an emerging cause of food-borne and waterborne illness. Although most strains of E. coli are harmless and live in the intestines of healthy humans and animals, this strain produces a powerful toxin and can cause severe illness








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