Queenstown Creek: Land Use Vs. Water Quality (continued)

The Secchi disc is a marked disc that is used to determine water clarity. Secchi disc readings, from 1985 through 1999, showed a very gradual decline in clarity ranging from a high reading of 1.75 meters to .9 meters. The cause of this decline is unknown. It is possibly due to algae but my experiment did not test for that.

Nitrogen measures the amount pollution or chemicals harmful to marine life. Over the years, nitrate levels increased. The highest point was 0.46 ppm. It started off as .25 ppm.

Salinity, which is the level of salt in the water, remained between 6.5 ppt and 12.6 ppt. The first and last readings of the two end years (1985 and 1999) were 11.5 ppt and 12.6 ppt.

Dissolved oxygen is the measurement of oxygen in the water measured in parts per million. The results ended up saying that all averages of dissolved oxygen were just very slightly decreasing. The lowest and highest levels were 6.4 ppm and 8.1 ppm.

The next and final test was pH. pH is actually a logarithm to find how much acid is in the water. 7.0 is called the base that divides the acidic water from the alkaline water. Fish can’t live in water with acid. The values stayed above 7.4 but under 7.8. The last reading was 7.67.

My second set of data consists of land use percentages. The two places in Queenstown Creek were the point and creek head. The photographs used were taken in 1985 and 2000. There have been many physical changes in the environment.

First is the point. In 1986, half the land was forest, and near half was agriculture. The rest of it was marsh and residential area. In 2000, forest stayed the same with golf course trading places with agriculture. Ponds, marsh, and residence took over what was left.

Second is the creek head. 47% used to be agriculture and forest and meadow made up the rest. The year 2000 was totally different. There is no sign of agriculture, yet forest pretty much stayed the same, and so did meadow. Finally, 29% was made up of residential area.

As you can see, Queenstown Creek has definitely showed a large change over the past fifteen years. Both land use and water quality are certainly not the same.