Blackwater River Lab

Madison Powers
Stephen Harris
Tyler Graf
November 8th, 2011

Introduction

    The purpose of this lab was for the 2011 AP Environmental Science E Block class to determine the health of the Blackwater River shed during the months of October and November. Data was to be collected using new methods to the students. After gathering this data and learning new scientific processes, the data was to be analyzed to determine the health of this specific section of the Blackwater River.

Materials & Methods

    A vast array of materials were used in the study. The chemical tests that were used were pH, nitrogen, phosphate, turbidity, coliform bacteria, and dissolved oxygen. Many of these were tablets that were mixed with a specific amount of the sample water. Other materials include nets, wooden boards, plastic buckets, plastic cups, thermometer, white plastic trays, marking ribbons, magnifying glasses, bark covers, glass vials and tubes, spoons, a shovel, and identification sheets for macro invertebrates.
    A pit trap was set up to collect invertebrates. General observations were first taken that day, observing the weather conditions, temperatures, and any changes in the area. To set up the pit trap, first an area for the trap had to be selected. This area, known as site 4, was located south east of the swinging bridge on the Blackwater River. The site was under a large dead tree, surrounded by tall grasses and shrubs, bordered by a small area with standing water. Once the area had been selected, a wooden board, two plastic cups, shovel, and colored marking ribbons were collected. Next, a hole large enough for the cup to sit in and be even with the ground was dug with the shovel, right next to the large dead tree. The cup was placed inside the hole, and the second cup was placed inside the first one for easier data collection. Next, a wooden board was pushed into the ground so that it was perpendicular to the ground but also touching the edge of the cup. Two sticks were used to hold the board in place, and brush and grasses were spread around it to make the area look and seem like it was natural. The reason for the board was so that when animals run into the board, they crawl along it, get to where the cup was on the board, and fall into the cup. Lastly, a piece of bark was placed over the cup to keep out rain water and debris.
    When data was collected, the first thing that was done at the site was a general observation of the weather, wind, and landscape. The wind speed was done using the Beaufort Scale and was a general guess. The temperature was done using an electronic thermometer. To test the air temperature, the thermometer was dried and held up in the air, away from any disturbances, and the temperature was recorded. Next, the probe of the thermometer was put into the soil next to the pit trap, and the temperature was recorded. The thermometer was also placed in the water, after having been dried off and cleaned of debris, and the water temperature was recorded. Next, the pit trap was checked. The bark was removed, and the top cup was taken out. The contents of the cup were emptied into a white tray and magnifying glasses were used to observe the contents. Any invertebrates were recorded.
    At a nearby tributary site a method involving a net and disturbances upstream was used to capture invertebrates. An area was assigned, site 4. Site 4, where the data was collected, was about 40 feet downstream from the road under which the tributary crossed. A net was placed perpendicular to the stream bottom, allowing for nothing to flow underneath the net. Next, disturbances were made upstream by stirring the water and organic matter at the bottom of the tributary with a stick. The organic matter floated into the net. The net was removed from the stream and the contents were put into a white plastic tray that had about an inch of water in it. The contents of the tray were allowed time to settle. Once settled, the contents were observed. Macro invertebrate identification sheets and magnifying glasses were used to figure the different organisms in the tray. These organisms were recorded in a spreadsheet. The contents of the tray were then poured back into the tributary. Chemical tests were also done on site 4. These tests included pH, nitrogen, phosphate, dissolved oxygen, coliform, and turbidity. The procedure for these tests was included in the packaging and the directions were followed to gather the most accurate results. The soil, air, and water temperature were also taken again, using the previously mentioned method.

General Narrative on Observations

Figure 1.1 The Site Locations

    On the first day, October 17th, 2011, at around 12:05 AM, arrival was made at the site. The ground in the floodplain was very wet, due to the recent heavy rains. There were large puddles everywhere, and the ground seemed to be thoroughly soaked. The weather was overcast. There was very little sun, lots of dark gray clouds. The area that made up all of the smaller study sites was very grassy and had many small shrubs including goldenrod in the areas that got flooded by the river. Areas that were not flooded by the river tended to have larger shrubs and small to medium sized trees. These trees included maples and ash trees. These trees were no more than 4-6 inches in diameter. A site was selected for the set up of a pit trap, this being site 4. The area around the pit trap had one large dead stump in the immediate area of the trap. The site was covered by the shade of some maple trees, one a foot in diameter, and the rest 4-6 inches in diameter. On the ground around the trap, there was a mix of dead leaves, dead grasses, and dead branches. The soil here was very wet and compost like. Much of the debris on the ground had been packed down by the rain, including the grass. There were a few ferns and vines surrounding the dead stump. To the immediate left right of the trap was depression filled with water.

Figure 1.2 The Pit Trap Locations

    On October 18th, 2011, at 11:10 AM, the site was very similar to  the way it had been the day before. The weather was overcast, again, and it was still fairly cloudy, with the sun trying to break through every once in a while. The ground was still very damp from the recent rains, though it had dried out a bit from the previous day. The wind had been the same as the previous day, and the temperatures were similar. The air temperature on this day was 58 degrees Fahrenheit, and the ground temperature was 51.9 degrees Fahrenheit. The wind speed was rated at Beaufort Scales Force 2 Intermittent. The cup had filled halfway with water, and there were no visible organisms in it. There were no organisms in the cup on this day. The only major change in the area surrounding site 4 was that the grass had been matted down very flat, possibly due to the rain or animals.

Figure 1.3 The Tributary Site Locations

    On October 25th, 2011, at 11:10 AM, a new site was used for data collection. The weather this day was much different from the previous days. There were fewer clouds in the sky, and the sun was trying to break through, but the wind was faster and the temperature colder. The air temperature on this day was 54.8 degrees Fahrenheit and the ground temperature was 47.8 degrees Fahrenheit. The wind speed was rated a Beaufort Scales Force 5. Pit trap 4 had only 1 slug and 1 worm in it. The ground had dried out a lot, no longer soaking wet with puddles but almost dry to the touch. The new site, the tributary site, was located along the road that headed west from where the bus had been parked at the base of the ski area. There was a culvert that ran under this road that the tributary flowed through. Site 4 was the assigned site. This site had a large amount of dead leaves on the ground, and many deciduous trees overhanging the tributary. These trees were over similar size to the ones at the pit trap. Much of the vegetation was small shrubs on either side of the tributary, along with the small and medium sized deciduous trees. The bottom of the tributary at site 4 had a large amount of sediment. The water was no deeper than 6-8 inches and there was a large amount of leaf litter in the water. Some small grasses were growing in the water as well. Chemical data and invertebrates were gathered for site 4. The pH was 5, the nitrogen was 0 PPM, the phosphate was 1 PPM, the turbidity was 0 JTU and the water temperature was 49.3 degrees Fahrenheit. The invertebrates gathered were 2 cagebuilding caddisflies, 10+ scuds, 4 beetle larva, 1 stonefly nymph, and 2 mayfly nymphs.

Data

Figure 2.1 General Observations/Data of the Site

Figure 2.2 The Chemical Data for the Tributary Sites

Figure 2.3 The Pit Trap Invertebrate Data

Figure 2.4 The Tributary Invertebrate Data

Analysis

    From interpreting the data, much can be said about the Blackwater River. The tributary had a large amount of indicator species, which are species that have a low tolerance for polluted waters. Caddisflies, stoneflies, and mayflies are all indicator species.  Coliform also is an indicator of how good the water quality is. 20 coliform per 100 ml, what was found at the tributary, is very low on the coliform spectrum. Anything under 200 coliform is good for swimming in, and 0 is good for drinking. 20 coliform is very low on this scale, so the water is relatively clean at site 3 of the tributary. The pit traps show a large majority of the gathered invertebrates to be beetles or slugs, which means there could be high abundances of each in the area, though there is not enough data to make a strong conclusion on. Also, from sites 1 to 4 the number of invertebrates descended. The vegetation in these sites varied greatly, one being open and grassy, and the other being wooded and covered with dead leaves.
    The chemical data also proved to be interesting for such a small amount of data. An interesting trend in the data is that the pH descends from 7 to 5 from site 1 to site 4. This could be due to the different organic matter at the different sites, and also the different sediment at each site. The turbidity at almost every site was 0 JTU, which means the water is very clear and the plants and organisms aren’t being blocked of too much sunlight. Another interesting piece of data is the dissolved oxygen. On the upstream side, it was 4 ppm. On the downstream side of the road, there were 0 ppm dissolved oxygen. This may be due to the culvert, the change in the tributaries flow speed, or the depth of the water. Nitrogen and phosphate levels are relatively low, which means there is not a large amount of runoff from outside sources into the tributary. What is interesting though is that the phosphate levels fluctuate from 4 ppm to 1 ppm to 4 ppm to 1 ppm in descending order of the sites. There is also 2 ppm nitrogen at site 2, which could be due to student error or by coincidence in this part of the tributary. The rest of the sites had 0 ppm nitrogen so site 2’s measurement seems out of the ordinary.  Either way, there are very low nitrogen and phosphate levels in the water, which means there is very little runoff of fertilizers and dead matter into the river, which is good for its health.
    Due to there being very little temperature and wind data, no trends can be determined for temperatures and wind speeds through the 3 days of testing.

Conclusion

    Based on the data that was gathered, the health of the Blackwater River is good. The data shows this, because there are relatively low levels of chemicals that indicate that the river health is bad, such as excessive nitrogen and phosphate levels. There also was also a good amount of indicator species, and because they were able to survive in the tributary, that must mean that the water was of good quality. Because there was presence of indicator species, it can be assumed that the water of the tributary is relatively clean and free of pollutants, which means that the water quality is good. Not much can be said about temperature and wind trends because not enough data was able to be collected. Based on visual observations, it does not seem like eutrophication is happening, and the low chemical levels support this. There did not seem to be a large amount of plant life in the water, and there was a reasonable amount of indicator species. All in all, the water quality and the health of the Blackwater River was good.
    There are numerous ways that this experiment could have been improved. One thing could have created variations in the data would be that numerous people collected the chemical and invertebrate data. Different people could have used different methods to gather data. Because of this, the data that was collected may not be accurate. A way to fix this in the future would be to have one person collect all the data, or make sure that every person used to exact same method. Another thing that changed the study was that there were only 3 days where data was collected. If there had been more days to collect data, more data could be collected and the study would have been more accurate.



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