Marsh Report

San Joaquin Marsh Report

Abstract

Marsh reserves provide supports to many plant and animal species, which become field ecologists' study target. In this comparative study of the two "sister" ponds, devices such as YSI 55 Dissolved Oxygen meter and Extech ExStik II stick meter, along with the HACH Test Kit, were used to study the dissolved oxygen, temperature, % DO saturation salinity, conductivity, and the presence of orthophosphate and/or nitrate in pond water. From the targeted Pond 9 and Pond 7 of the San Joaquin Marsh Reserve, orthophosphate and nitrate was tested to be present with time and temperature being factors for changes in several measurements.

Introduction

The UCI Natural Reserve System's San Joaquin Marsh Reserve houses a wide diversity of wetland habitats that includes marshlands, shallow ponds, and channels, in addition to dry upland habitats. There has been over 100 migratory bird species making their stops over the years, adding up to over 200 bird species sighted altogether. The marsh becomes a crucial living space for many plants and animals (Bretz, 2010).

With 11 pond locations in phase 1 restoration area of the San Joaquin Marsh Reserve, each one of these ponds were designed so that about 60% of the surface area is shallow shelf habitat and the other 40% being deeper channels to holds water all year long. After each year's nesting season in the fall, the shallow shelves are mowed and filled with water coming all the way San Diego Creek through a pumping system, which attracts fall migratory birds. When spring arrives, the ponds gradually dry up and the new growth of plants such as coastal bulrush (Bolboschoenus robustus) and coastal bulrush (Bolboschoenus robustus), whose underground bulbs survived the mowing done in the fall, fill the shallow shelves (Bowler, April 20, 2012).

For this study purpose, two "sister" Pond 9 and Pond 7 from the marsh was examined and tested within a two-week time frame for comparative observations. Several devices were used to test for the ponds' water temperature, dissolved oxygen (DO), % DO saturation, salinity, conductance, and for the presence of orthophosphate and/or nitrate in each pond.

Materials and Methods

To begin this comparative study, Pond 9 was first examined. The YSI 55 Dissolved Oxygen (DO) meter was used to measure DO near surface and near bottom in mg/L, surface and near bottom temperatures in degrees Celsius, and % DO saturation in mg/L. The Extech ExStik II stick meter, on the other hand, was used to measure salinity in parts per thousand (ppt) and conductivity in micro-Siemens (mS).

A HACH Test Kit (0 - 50 mg/l, Model PO-19) was used to measure orthophosphate using the water samples taken from Pond 9 in the region where the water is most clear. Before any testing was done, all the viewing tubes were rinsed with the sample water. One viewing tube, which can be called the blank, was filled up with the sample water to the top line. The tube was then placed in the top spot on the left of the color comparator. Meanwhile, a second tube was filled with the sample water to the 20-mL mark. A phosphate reagent powder pillow was then poured into the second sample tube and swirled to mix the product. We waited for about eight minutes after the addition of the powder to see full color development and 10 minutes for the final rest result to be read. A blue-violet color indicates the presence of phosphate. The second tube was then places on the top right opening of the color comparator. Holding the comparator towards the sunlight, we looked through the openings of the two tubes while rotating the color disc until the colors from the windows match. The number found on the scale after the two colors match was divided by 50 to obtain the final result in mg/L phosphate.

A HACH Test Kit (0-10 mg/l, Model NI-14) was used to measure nitrate. For the nitrate nitrogen test, one of the coloring tubes was filled up to the top mark, strongly shook with the sample water inside, and the tube was then emptied before the process was repeated. A nitrate reagent powder pillow was added to the sample to be tested and mixed by shaking for three minutes; then, it was left rested for 30 more seconds. Next, one nitrite reagent powder pillow was then added to another water sample tube and shook for only 30 seconds. A red color indicates the presence of nitrate. It was then placed in the right tube side holder with the control on the left side after a 10-20 minute wait. The comparator was once more used to compare the samples in the present of a light source. The disc was rotated until the colors match, which represents the amount of mg/L nitrate nitrogen found in the pond water sample. The final result could be calculated by multiplying the mg/L nitrate nitrogen by 4.4.

Finally, a 5-gallon water pour was done by filling the bucket with water from the pond and pouring it out into a tight net filter for observation. The same procedures was repeated for Pond 7 the following week.

Results

From Table 1, notice that dissolved oxygen, % saturation with DO, and temperature for both Pond 9 and Pond 7 showed a positive correlation with time. After about an hour gap in between each measurement, the data for all the retested categories experienced an increase in number. Some results saw a smaller increase and others saw a larger difference. Temperature, though experienced an increase, result in a difference of no more than 1 degree Celsius. Although the number appears rather consistent between the two ponds, the % DO saturation near the surface and near the bottom for Pond 9 appeared greater in mg/L than the dataset of Pond 7 (Table 1).

Salinity, conductance, orthophosphate, and nitrate were only measured once for each pond. Pond 9 salinity was measured at 5.24 ppt while Pond 7 was measured to be lower at 4.97 ppt. Conductance for Pond 9 was then 2.5 uS and higher at 7.0 uS for Pond 7. In addition, the amount of orthophosphate for Pond 9 was measured to be 0.13 mg/L and 1.3 mg/L for nitrate; whereas, the amount of orthophosphate for Pond 7 was measured to be 0.2 mg/L and 0.44 mg/L for nitrate (Table 1).

The 5-gallon water sample pour for Pond 9 saw 4 water