WREC

Wildcat Creek Spring 2013 Sample Results

Volunteers sampled 231 stream sites on Friday,  April 11 between 2 and 5 p.m. Results of their efforts are presented below.

 

 Temperature - Samplers measured temperature in the field directly from the stream at the time of sample collection. Temperature is an important parameter as it is the regulator for aquatic communities - all plankton, bug, and fish species have a preferred temperature. Temperature also controls the amount of dissolved oxygen present in the water - cooler temperature waters hold more dissolved oxygen. Finally, temperature controls the rate at which chemical reactions occur, such as the conversion of nitrate-nitrogen to ammonia-nitrogen. Higher temperatures are shown in orange and red. Several factors affect temperature including riparian buffers or shading, watershed inputs, and surrounding land uses. Compared to Spring 2013, temperatures across the majority of the subwatershed were found to be much cooler. Throughout the western, southern, and eastern portions of the subwatershed, stream samples suggested colder temperatures anywhere from 2 - 9 degrees C difference.

 

 

pH - Samplers measured pH from water samples at the staging location. Water pH is a measure of the amount of hydrogen ion available in the water. Water pH determines the solubility and biological availability of chemicals, including nutrients such as nitrogen and phosphorus, and metals, like copper or lead. Typical pH levels in streams measure between 6.5 and 8.5. pH levels are indicative of the geological materials in the drainage area. Additionally, the amount of photosynthesis occurring in the stream can affect pH levels. Higher pH levels are shown in red, while lower pH levels are displayed in blue. pH levels below 6 are of concern for biotic communities. Compared to Spring 2013, average pH levels between 6.5-8.5 were found mainly in the eastern and northeastern areas of the subwatershed. pH levels that are a cause for concern were found mainly in the western and southwestern areas of the subwatershed.

 

 

 

Transparency - Samplers measured water transparency using transparency tubes. Water transparency in streams reflects the distance downstream that you can see through the water. Tubes measured 114 centimeters, so any values greater than 114 centimeters exceed our ability to detect a change in water transparency. Low numbers (10 cm) indicate poor transparency while those in the 70 centimeter (2 foot) range indicate good transparency. Compared to Spring 2013, transparency in the Wildcat Creek subwatershed had decreased in quality. Transparency readings of 30 cm. and below were much more common, especially in the eastern portion of the subwatershed. This could be due to the recent rainfall the area experienced days before the sampling took place, as transparency is affected by recent precipitation events rather than a general increase in precipitation levels.

 

 

  

 Orthophosphate - Phosphorus is typically the nutrient which limits the productivity in aquatic communities. Phosphorus can be measured in many forms including orthophosphate or soluble reactive phosphorus. This form of phosphorus is the soluble, organic, readily available form of phosphorus. Higher phosphorus concentrations typically lead to higher levels of productivity. Increased productivity can result in increased concentrations of algae or plants, which can result in decreased dissolved oxygen concentrations, taste and odor problems, and create poor habitat for aquatic communities. These results are from field test strips; while these strips are useful for in the field measurements they do not always provide accurate results. Compared to Spring 2013, the east most portion of the Wildcat Creek subwatershed has experienced an increase of orthophosphate in the system, with samples measuring over 7.5 ppm (shown in red).

 

 

Nitrate/Nitrite - Nitrate-nitrogen and nitrite-nitrogen, like orthophosphate, represent the available nitrogen in an aquatic system. Nitrogen is also available in the atmosphere and can move from the air into the water by nitrogen-fixers. Nitrogen can readily convert between different forms, especially nitrate and nitrite. Conversion to and from ammonia also occurs when dissolved oxygen is available in the system. Nitrate and nitrite concentrations are displayed below with orange and red representing higher concentrations. Nitrate-nitrogen concentrations measuring higher than 2 ppm can inhibit aquatic communities. Concentrations higher than 10 ppm violate the state water quality standards. Compared to Spring 2013, nitrate/nitrogen concentrations have remained fairly stable, if not decreased by a small amount. This could be due to delayed tilling of farm land caused by exceptionally wet soil conditions from this past winter’s precipitation.

 

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