WREC

Great Bend Region Fall 2011 Sample Results

204 volunteers sampled 206 stream sites in the Region of the Great Bend and 52 sites on the Middle and South Forks Wildcat Creek drainage on Friday, September 16th between 1:45 and 5:46 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 darker colors. Several factors affect temperature including riparian buffers or shading, watershed inputs, and surrounding land uses. Highest temperatures were measured in the Wabash River and in relatively shallow, slow flowing streams. This is to be expected in the fall when small streams are receiving runoff from groundwater, while water in the Wabash River is being heated by sunlight. Comparing fall 2011 temperatures with temperatures measured during previous sampling blitzes indicates that temperatures were generally lower this year. Cooler air temperatures and overcast skies over the week prior to sampling may account for lower instream temperatures.

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 6.5 to 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. This means that streams where high levels of algae occur result in higher pH levels. Higher pH levels are shown in darker colors, while lower pH levels are displayed in lighter colors. Further observation is necessary in those tributaries where low pH levels were measured.

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.

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 darker orange colors 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. Nitrate-nitrogen concentrations mimic those found during earlier sampling blitzes. Generally, sites which exhibited high nitrate-nitrogen concentrations in 2009 also exhibited high nitrate-nitrogen concentrations in 2010 and again in 2011.

E. coli - E. coli is an indicator organism used to monitor pathogen concentrations with surface waters. E. coli is present in the intestines of all warm-blooded mammals and can survive and reproduce outside of the body. Untreated sewage, combined sewer overflows, polluted discharges, input from animals, and source populations can all contribute E. coli to surface waters. In Indiana, concentrations measuring greater than 235 colonies/100 mL are deemed non-supporting of their designated use. In the figure below, those watersheds which do not meet water quality standards are shown in darker colors.

Back to Blitz