The Hunt for PBDEs

Ben Charleston

January 14th, 2019

The Hunt for PBDEs in both the Day Student Lounge (DSL) at Proctor Academy, and my home in Belmont, New Hampshire

Results for the Day Student Lounge:

Results for my house:

Examples of products and their tags that contain PBDEs:















Examples of products and their tags that do not contain PBDEs:













Concluding Questions:

A) Where (what kind of room) did you find most of the (PBDE) flame retardant products?

I found most of the flame retardant products in my living room. I think this is because my living room contains a lot of furniture from before 2008, and it was made when TB-117 still required flame retardants. In the more modern rooms of my house, such as my bedroom, I found fewer items that contained flame retardants


B) What was the most abundant product found to be dosed in flame retardants?

The most abundant product found to be dosed in flame retardants were couches and chairs. While most of these products that I found at Proctor in the Day Student Lounge were flame-retardant free, nearly all the couches and chairs in my house were doused in PBDEs.


C) Examining your charts, which product do think gets the most use from people?

Examining my charts, I believe the product that gets the most use from people is mattresses. While couches are also heavily used, I typically lay on my mattress for a minimum of 8-10 hours per day, while I only sit on couches for a couple of hours. I think many other people in America also use their mattress far more than any other piece of furniture.


D) Knowing that exposure rate, route of exposure and age of exposure are keys to determining the toxic impact, which product generates the highest health risk? Which product has the lowest health risk? Explain why.

I think that mattresses generate the highest health risk because people are exposed to their mattresses every night. Since one’s head is only inches from the mattress while sleeping, the route of exposure is inhalation. When something is inhaled, it can reach the bloodstream in a matter of seconds. Also, since young people sleep longer, they are exposed to the toxins in their mattresses for an extended period of time. This is dangerous because children under the age of six have an extremely fast metabolism, and the chemical can be absorbed into the body with ease. I think the rug under my Christmas tree at my house has the lowest health risk for two reasons. One is because it is only present in my living room for three months of the year, meaning that the exposure rate is very low. The second reason is because the rug is on the floor, it is unlikely that people will be inhaling the PBDEs from the carpet unless they are laying on the floor, which is an uncommon occurrence.


E) After watching TOXIC HOT SEAT what would you suggest are some appropriate means to address the concerns of PBDE exposure?

Educating the public, especially parents, about what PBDEs are and the possible risks associated with them could prevent people from buying furniture with PBDEs in it. In addition, I would suggest better labeling of furniture. When I was searching for these labels at home and at Proctor, the labels were hidden in obscure places which made the very hard to locate. Then, once I located the tag, it was challenging for me to tell whether or not the product contained flame retardants. I think every piece of furniture should explicitly state whether or not it contains PBDEs or not. Also, I know it is hard to test the effects of chronic exposure to a chemical, but I think the scientific community needs to make a considerable effort to identify specific diseases associated with PBDEs and attempt to find ways to prevent and maybe even cure those diseases. One of the major problems put forth in the movie was that the scientific community was not speaking up about the dangers of PBDEs, and this must change if we ever want to live in a world that is free of flame retardants.


F) Reflect on the movie, this activity and what you have learned. Share your thoughts, concerns, and impressions.

My biggest concern after watching the movie and doing the activity is that it is tough to tell whether or not a product contains PBDEs. When I looked at the tags, I knew exactly what I was looking for, and sometimes I still could not figure it out. This makes me wonder if the average consumer, who probably knows very little about TB-117 or flame retardants would be knowledgeable enough to decipher whether or not a product had PBDEs. I am also concerned about the effects that PBDEs will have on the people who were exposed to them, especially at a young age. For me, this concern is personal because when flame retardants started to become popular. I grew up surrounded by flame retardants, and no science explains the health problems I could face later in life due to my exposure to PBDEs as a child. Lastly, I am concerned that even though we are starting to phase out PBDEs, they will never become completely eradicated from the environment. This could lead to adverse health due to PBDEs for many generations to come.




Proctor Pond Final Blog Post


The purpose of studying the pond is “to understand if the pond is healthy or not by measuring biodiversity”(Alan McIntyre). It is important to study the pond because the recent addition of the artificial turf fields could disrupt the biotic and abiotic interdependence within the pond. As Alan stated, “Artificial turf may create an artificial die-off” (Alan McIntyre). Also, the data collected will be important because the pond is being dredged in December, and the data from this year can be compared to the data from next year and determine whether or not dredging improved pond health. On the dates October 19th, October 23rd, and October 25th, E Block AP Environmental science investigated and gathered data on the Proctor Pond.


The pond should be healthy with significant biodiversity because it is located in a protected area away from anything environmentally hazardous or threatening. Even though the turf fields are within proximity, drains divert water from the turf away from the pond.


  • 1 Thermometer to test both the air and water temperature
  • 1 D-shaped net for collecting biotic samples
  • 1 iPhone 7 for taking pictures
  • 1 notebook for recording biotic and abiotic data, as well as making general observations about the site
  • 1 pencil to take notes
  • 1 Beaufort scale to identify the wind speed based on observations
  • 2 test tubes, each with 5 mL and 10 mL markings on them
  • 1 LaMotte phosphorus testing kit
  • 1 LaMotte pH testing kit
  • 1 LaMotte turbidity testing kit
  • 1 large bin for collecting samples
  • 1 small container with three compartments for identifying specific organisms
  • 1 magnifying glass
  • 1 pipette
  • 1 Spoon with holes in it
  • 1 biotic identification sheet for identifying indicator species, somewhat tolerant species, and very tolerant species.

Photo by Sarah Ferdinand

Sampling Methods:

Each day, Will Luskey, Joey Briggs, and I collected data using the same method. First, we collected biotic samples and then abiotic samples. Below is a procedure for collecting both biotic and abiotic samples.

Biotic Sampling:

  1. Pick up the D-shaped net, the large bin, and the small container and bring them over to the edge of the pond.
  2. While standing at the edge of the pond, place the D-shaped net into the water, and make sure it is touching the bottom.
  3. Next, move the net to the right, and then back to the left (this is called sweep netting) three times. At this point, the net should have an inch or two of abiotic material in it.
  4. Next, place the contents of the net into the large bin, and then fill the large bin halfway with water from the pond. Remove the large pieces of organic matter which will impede your vision (leaves or sticks), but leave the organic material that will not impede your vision (dead grasses) as they could be a home for an organism.
  5. Now, begin to sift through the contents of the bin and place any living organisms into the smaller container, where they can be identified. Begin to identify these organisms using the biotic identification sheet. Record the quantity of each species found in a notebook. (NOTE: WE DID THIS INSIDE ON OCTOBER 25TH SINCE IT WAS TOO COLD OUTSIDE)
  6. Repeat steps 1-5 as time permits
Original photo by Ben Charleston
Original photo by Ben Charleston

Abiotic Sampling:

  • Air temperature:
    • Hold the thermometer with an outstretched arm, and make sure the probe is not touching the ground. Observe the thermometer reading, and once the reading stays at one value for 60 seconds, record the air temperature in a notebook.
  • Water Temperature:
    • Place the probe into the water, ensuring it is completely submerged. Observe the thermometer reading, and once the reading remains at one value for 60 seconds, record the water temperature in a notebook.
  • Phosphate:
    • Fill one of the test tubes with pond water up to the 5mL line.
    • Take one of the tablets from the phosphate test kit and place it in the test tube, and shake the test tube until the tablet is completely dissolved.
    • Wait five minutes, and then compare the color of the solution in the test tube to the colors on the chart to get a numerical value (1-4) for the phosphate level.
Original photo by Ben Charleston
Original photo by Ben Charleston
  • pH:
    • Fill one of the test tubes with pond water up to the 10mL line.
    • Take one of the tablets from the pH test kit and place it in the test tube, and shake the test tube until the tablet is completely dissolved.
    • Compare the color of the solution to the colors on the chart to get a numerical value (1-11) for the pH.
Original photo by Ben Charleston
Original photo by Ben Charleston
  • Wind Speed:
    • Examine the Beaufort scale chart, and compare the surroundings to the description on the chart to get a numerical value (1-12) for the approximate speed of the wind.

Original photo by Ben Charleston

Original photo by Ben Charleston
  • Turbidity:
    • Fill the test tube from the turbidity testing kit to the specified amount.
    • Place the test tube over the center circle and look through the test tube, at the circle.
    • Approximate the turbidity (0-100 JTU) by comparing the appearance of the circle beneath the test tube to the surrounding circles, with corresponding numerical values.
Original photo by Ben Charleston
Original photo by Ben Charleston


  • Weather:
    • Simply pay attention to the weather for the entirety of the study
    • Classify each day as sunny, partly cloudy, cloudy, rainy, or snowy. (Also, note if there is extremely high wind)

Narrative on Sites, Observations, and Events

On Friday, October 12th, 2018, the class was split up into five groups containing three to four students in each group. My group of three people was assigned data collection from site three. Site three is in the back right corner of the pond, as seen in the map below. Also, there are two inflows to the pond at sites one and two, and one outflow at site five. The water in the pond comes from all the drains around campus (see map below) going all the way back to the hockey rink. We studied our site at different times of the day, on each day of study. On October 19th, the site was studied from 10:55 AM to 11:25 AM, On October 23rd, the site was studied from 11:45 AM to 12:30 PM, and on October 25th, the site was studied from 10:40 AM to 11:20 AM. On the last two days of the study, October 23rd and 25th, the wind was light, and these days earned a one and two, respectively, on the Beaufort scale. This approximates to winds speeds of 1-3 mph on October 23rd and 4-7 mph on October 25th. However, on the first day of the study, October 19th, the wind was much stronger, and was evaluated at a 5 on the Beaufort scale. This is significantly stronger than the other two days, and approximates to 19-24 mph. Also, there was a major rain event between October 19th and October 23rd, which could have brought sediment into the pond and affected the data. Site three is unique because it is the only site on the pond which has a significant amount of grass. This grass is important because it protects the surrounding area from wind and debris. However, as the study went on, I began to notice that the grass was dying, and by October 25th, the grass was still standing, but was 100% brown with no traces of green. This rapid death of the grass could be due to the temperature and weather on the three days which was 53.2°F and partly cloudy on the 19th, 46.6°F and cloudy on the 23rd, and 39.5°F and partly on the 25th. Despite the cold temperatures and overcast skies, the quantity of organisms observed increased each day we sampled. On the first day ten organisms were observed representing four different species, on the second day 44 organisms representing 9 species were recorded, and on the third day 39 organisms representing 6 species were observed.

Original photo by Ben Charleston
Original photo by Ben Charleston
Map by Zach Raye Steiner, Will Luskey, and Joey Briggs
Map from Sarah Ferdinand, made by Anna Krajewski




Annual Water Temperature: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Water Temperature (°F):

Year                                                                          Water Temperature (°F)

2007 52.1
2008 52.1
2009 N/A
2010 53.1
2011 N/A
2012 54.3
2013 55.6
2014 54.4
2015 50.5
2016 47
2017 56.6
2018 44.84
Overall Average 52.054

Dissolved Oxygen (mg/L) Over Time: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average (mg/L)
2007 2.5
2008 1.67
2009 N/A
2010 1.6
2011 N/A
2012 1.5
2013 N/A
2014 6.2-7.9
2015 6.65
2016 8.3
2017 1.39
2018 N/A
Graph by Ben Charleston, inspired by Sarah Ferdinand

This data set demonstrates that the water temperature this year is the coldest since 2007, 7.214°F below the average and 2.16°F colder than the next coldest year. The average air temperature during the study was also cold, measured at 45.9°F. The temperature of both the air and the water are important factors to consider. Colder water temperatures allow the water to hold more dissolved oxygen. Although the dissolved oxygen levels were not measured this year (due to technical failure of the DO measuring device), I would hypothesize that the DO levels this year are the highest of any year. This hypothesis is supported by the data because the next coldest year (2016) when the temperature was 47°F, the dissolved oxygen content was 8.3mg/L, higher than any other year. Also, the second coldest year, (2015) when it was 50.4°F, the dissolved oxygen content was 6.65mg/L, the second or third highest ever recorded. If this trend continues, than it is likely that this year had a dissolved oxygen content of at least 8.3mg/L. While dissolved oxygen is an important factor, it is clear that DO levels fluctuate more from temperature changes, than actual changes in the ecosystem’s health. For example, the study in 2007, when the temperature was 52.1°F, measured DO levels of 2.5mg/L, the fifth lowest ever, but a diversity index of 19.3 (See the data table below), the highest ever. This proves that while DO levels may represent changes in the ecosystem, scientists must be careful because DO levels are also a reflection of the temperature during the study.

Also, the cold air and water temperatures were a variable which prevented us from keeping our hands in the water for a long time. This could have prevented us from seeing some organisms which could possibly alter the data.

pH Over Time: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 6.77
2008 7.03
2009 NA
2010 6.88
2011 NA
2012 6.63
2013 7.25
2014 6.15
2015 6.42
2016 6.75
2017 6.68
2018 6.73
Overall Average 6.73

Mayfly Nymphs Over Time: Data Table Made By Ben Charleston

Year Number of Mayfly Nymphs observed
2007 11
2008 5
2009 N/A
2010 11
2011 N/A
2012 9
2013 30
2014 72
2015 7
2016 27
2017 24
2018 15
Overall Average 21.1

Stonefly Nymphs Over Time: Data Table Made By Ben Charleston

Year Number of Stonefly Nymphs observed
2007 5
2008 2
2009 N/A
2010 1
2011 N/A
2012 1
2013 22
2014 6
2015 2
2016 0
2017 6
2018 3
Overall Average 4.8
Graph by Ben Charleston, inspired by Sarah Ferdinand

This data is useful because Mayfly Nymphs and Stonefly Nymphs are indicator species, which means they require a very specific pH to survive. As Alan said, “Indicator species will not tolerate a pH less than 6.5 or greater than 7.5, or bad water quality” (Alan McIntyre). This proves that if there is an abundance of indicator species, the body of water is in good health. Throughout the years the pond has been studied, the year with the highest amount of stonefly nymphs and mayfly nymphs was 2013 when the pH was 7.25, the closest ever to neutral (7). In 2013, there were 22 stonefly nymphs and 30 mayfly nymphs observed. The almost neutral pH, and the abundance of mayfly nymphs and stonefly nymphs observed shows that the pond was in good health in 2013. One exception to this trend is the number of mayfly nymphs observed in 2014. In 2014 the pH was 6.15, too low for an abundance of indicator species, yet the class observed 72 mayflies. However, Alan explained that during this year, “There was one student who was exceptional at biotic sampling, and collected the vast majority of the organisms. I think this student had previous experience studying a body of water beforehand” (Alan McIntyre). Therefore, the reason for the high amount of mayfly nymphs in 2014 is not because the water quality was good, but rather because one student had experience with sampling, making this data hard to compare to other years.

Also, due to the cold temperatures, my group’s ability to identify mayflies and other smaller species was impaired. For example, on the third day, it was so cold that we were forced to go inside to do our biotic sampling, and on this day (October 25th) we found 7 mayfly nymphs compared to only 4 mayfly nymphs on the first two days combined. This supports the idea that if scientists are distracted (cold weather), the data can be impacted greatly.

Diversity Index: Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 19.3
2008 15.4
2009 N/A
2010 11.7
2011 N/A
2012 7.26
2013 12.2
2014 7.1
2015 6.3
2016 6.3
2017 7.4
2018 7.09
Overall Average 10
Graph by Ben Charleston, inspired by Sarah Ferdinand

This diversity index was calculated using the Simpson’s Diversity Index Formula:


In this equation, N is the total number of individuals, and n is the number of individuals observed from one species. This formula is designed to account for the richness and evenness of a species. This calculation is useful because the higher the number, the more species present. For example, in 2007, which recorded the highest diversity index ever, there were 25 different species observed. Also, in 2008, which recorded the second highest diversity index ever, there were 24 species present. However, in 2015 and 2016, the two lowest diversity indices ever, there were only 19 and 22 species observed. While this may seem like a lot, in 2015 only 10 of the species had more than 5 individuals observed, and in 2016 only 7 of the species had more than 5 individuals observed. Therefore, biodiversity isn’t only based on the pure number of species present, but also the how many individuals of each species are present.

Water Quality Pollution Index: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 59
2008 48
2009 N/A
2010 44.3
2011 N/A
2012 41.6
2013 66.4
2014 63.5
2015 37.9
2016 34.4
2017 48.1
2018 34.3
Overall Average 47.75
Graph by Ben Charleston, inspired by Sarah Ferdinand

The water quality pollution index was calculated by labeling each species as dominant (>100 organisms), common (10-99 organisms), and rare (1-9 organisms). After labeling each species, the species were split up into three categories with varying levels of pollution toleration. The species with low levels of pollution toleration, indicator species, were given more weight than species who cold tolerate higher levels of pollution. The values for each of the groups were then added up to get the water quality score. A water quality score of more than 40 signifies excellent water quality, a score of 30-40 signifies good water quality, a score of 15-30 signifies fair water quality, and a score less than 15 signifies poor water quality. Our water quality score was 34.3, meaning the pond water quality is good. This is the lowest water quality score ever recorded. However, the low water quality may not indicate that the pond is totally unhealthy, as the temperature could have affected this data. In 2016, the second coldest year ever recorded, the water quality pollution index was 34.4, only 0.1 higher than ours. Also, in 2017, the warmest year ever, the water pollution index was 48.1 which is significantly higher than this year, as well as the two previous years. Therefore, water temperature may decrease the water quality pollution index for two possible reasons: colder water decreases organisms’ activity, making them harder to catch, or the colder air and water temperatures make the scientists so uncomfortable that it becomes impossible to accurately identify all the organisms in the sample.

Turbidity (JTU): Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average (JTU)

























Overall Average


Graph by Ben Charleston, inspired by Sarah Ferdinand

This data and graph regarding the turbidity of the pond is useful because turbidity is indicative of how much sediment is in the water. While sediment can be harmful to a pond, it also brings in nutrients that promote population growth. For example, in 2013, the average turbidity was 20 JTU, the highest ever recorded. The high turbidity in 2013 can be attributed to the installation of the turf fields, which do not hold the sediment as well as the previous grass fields. However, in 2013, the in the diversity index went up from 7.26 in 2012 to 12.2 in 2013, and the water quality pollution index went up from 41.6 in 2012 to 66.4 in 2013. This trend is observed again in 2017 when the average turbidity was 13.3 JTU, and the diversity index was 7.4, which is 1.1 higher than the previous two years. The water quality pollution index was 48.1, significantly higher than in 2015 and 2016, which recorded water pollution indices of 37.9 and 34.4, respectively. Therefore, as the turbidity increases, the biodiversity and water quality increase as well.

Although turbidity increase water quality and biodiversity, high levels of turbidity are not a good sign for the pond. Higher turbidity levels mean there is an excess amount of sediment entering the pond, which means the pond is slowly getting shallower. This shallowing trend is one of the reasons why Proctor decided to dredge the pond in December.

One variable for collecting the turbidity is some groups did it before sweep netting, after sweep netting, or from their sampling bin. Taking the turbidity after sweep netting or from the sampling bin could give levels of turbidity that are too high because the benthic (bottom) region of the site had already been disturbed, which could make the water murky. Taking a sample for this murky water would give a turbidity reading that is higher than the actual turbidity at the site.

Phosphate (PPM): Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average (PPM)

























Overall Average


Graph by Ben Charleston, inspired by Sarah Ferdinand

The phosphate levels of the pond indicate how much ATP (Cellular Energy) is being produced through respiration by organisms in the pond. In a healthy system, the phosphate levels should be low because organisms are utilizing all phosphate for ATP production. This is reflected in the data from the pond, and years with high phosphate levels typically had lower biodiversity. For example, from 2007-2008, phosphate levels increased from 2.2PPM to 4.0PPM, and the diversity index decreased from 19.3 to 15.4. Also, the study in 2013 recorded phosphate levels of 0.4PPM, the lowest ever, and the diversity index of this year was 12.2, up 4.94 from the previous year. Therefore, the overall trend is that as phosphate levels decrease, biodiversity increases. However, in 2012, phosphate levels were low, but biodiversity was also low. The low diversity index in 2012 was not due to a lack of species, as 24 different species were observed, but it is because there were a handful of species which dominated the others in terms of individuals that were observed. This domination could be due to the construction happening in 2012, which could have put sediment in the pond that contained nutrients which favored the growth of only a few species.

This year, one possible source of error my group had is that we only measured phosphate levels for one out of the three days because our class ran out of tablets. This struggle was shared by many other groups, and could have impacted our classes overall average phosphate levels. Another variable in our study is that the phosphate levels were qualitatively measured on a color scale, and the interpretation of the color that signifies a certain value could vary from group to group. For example, our group approximated the phosphate levels as 1.5 because the color was in between one and two, but some groups only used whole numbers. This difference in the collection of data from group to group could have altered the data significantly.

Original photo by Ben Charleston


Throughout the study of the pond, there were many data points, both abiotic and biotic, that were observed or calculated. The reason for collecting this data is to determine the healthiness of the pond. Based off this year’s data, I would say that the pond is in decent, but declining health. I say this because the turbidity this year was 14.32 JTU, the second highest ever recorded. This means that there is a lot of sediment flowing into the pond from various places such as parking lots and construction sites. All of this sediment is slowly filling in the pond, and, as Alan said, “the pond has gotten significantly shallower over the years” (Alan McIntyre) and “Without dredging, it would turn into a wetland” (Alan McIntyre). Also, turbidity shows how deep sunlight can reach into the pond. If the sunlight can only reach a few feet below the surface, that means the compensation point of the pond is higher, making the pond less productive. The compensation point is the point where the amount of oxygen produced through photosynthesis is equal to the amount of oxygen required to perform cellular respiration. Essentially, the compensation point is the depth where the pond becomes productive, and the deeper the compensation point, the more productive the pond. Therefore, the fact that the turbidity was so high this year means that the compensation point of the pond is most likely shallow, meaning the pond is probably less productive than in previous years. Another concerning data point is the number of mayfly nymphs and stonefly nymphs observed. This year there were 15 mayfly nymphs compared to 24 in 2017, and there were 3 stonefly nymphs this year, compared to 6 in 2017. Indicator species are valuable because they have very specific niches, meaning they have very specific needs in order to survive. Since indicator species have very specific niches, if they are present in abundance, typically, the water quality is excellent. This year we found a total of 15 mayfly nymphs and 3 stonefly nymphs, which is a very low number and shows that the pond is in declining health. Also, the water quality pollution index was 34.3, the worst ever recorded, suggesting the pond is on a downward trajectory. However, there are two data points which show the pond is in decent health, phosphate levels and the diversity index. This year the diversity index was 7.09. Although this number is lower than last year (7.4), it is higher than the diversity index in 2015 (6.3) and 2016 (6.3). The diversity index from this year shows that the pond has, at most, lost a little of its biodiversity from last year. Also, the phosphate levels this year were 1.25 PPM, the fourth lowest ever, although phosphate was not measured in 2009, 2010, 2015, 2016, or 2017. Low phosphate levels are a good sign because it means that there are enough organisms respiring in the pond using the available phosphate to produce ATP (Adenosine Triphosphate).

Based off all of the data points collected, I conclude that the pond is mainanting decent health, but the health will continue to decline if nothing is changed. However, with the dredging of the pond this winter, I believe that the pond will recover. I think next year, the study will conclude that the pond is unhealthy, but in the years after that, the study of the pond will conclude the pond is healthy and yield similar result to the study in 2007 and 2008.

Despite the declining health of the pond, some symbiotic relationships were observed. One of these symbiotic relationships is predation between predaceous diving beetles and tadpoles. In this relationship, the predaceous diving beetle preys on tadpole populations. In addition to symbiotic relationships, competition between species was also witnessed. Since the pond does not have an unlimited amount of resources, there is competition for food. Two species that regularly compete over food are mayfly nymphs and stonefly nymphs. This competition is called interspecific competition. This competitive relationship is supported by the data because there is only one year, 2013, when there were a lot of mayfly nymphs and stonefly nymphs.

Although extensive measures were taken to ensure the accuracy of our study, there were many variables and possible sources of error. Of these variables, the ones that affected our study the most was the temperature, our method of biotic sampling, and the fact that some of the abiotic tests can be altered by interpretation. The cold air temperature, measured at 45.9℉, made it painful to keep my hands in the water for more than one minute at a time. This could have caused us to overlook many organisms that we would have seen in warmer conditions. However, on October 25th it was so cold that we had to do our biotic sampling inside. Sampling inside allowed my group to focus better, and therefore we found more organisms. Also, as the study progressed, picking organisms out of the bin became easier and easier. This suggests that many organisms could have gone undiscovered and unaccounted for on the first day. Another major variable was the fact that the measurements for phosphate, pH, and turbidity were all derived by comparing the color of a solution (or a circle for turbidity) to a chart. This is a source of error because each person may interpret the color differently, which could skew the data for the whole class.

When Alan first told us we were going to study the Proctor Pond, I was excited. During my sophomore year, I did a history project on the pond, so I know all of its history, but I have always wanted to know about its current health. Albeit, I must admit I was a bit nervous because I had no previous experience with biotic sampling or identifying species. However, after the first day, I immediately became comfortable with and enjoyed testing both the abiotic and biotic factors at my site. I learned how to sweep net and sift through the contents of our net and locate most of the living organisms. However, this study was not always easy, as it was extremely cold, windy, and, at times, rainy. Although I was able to push through these unfavorable weather conditions, I would like to do this study again when I don’t have to stick my hands under my armpits every five minutes to warm up my hands. All things considered, this study was fun, and every time I walk by the Proctor Pond, instead of staring at my phone, I will think about all the mayfly nymphs, scuds, copepods, and other species lurking below the surface.

Proctor Pond Study Post #1

Purpose: The purpose of studying the pond is “to understand if the pond is healthy or not by measuring biodiversity”(Alan McIntyre). It is important to study the pond because the recent addition of the artificial turf fields could disrupt the biotic and abiotic interdependence of the pond. As Alan stated, “Artificial turf may create an artificial die-off”. Also, the data collected will be important because the pond is being dredged in December, and the data from this year can be compared to the data from next year and determine whether or not dredging improved pond health.

Hypothesis: The pond should be healthy and have biodiversity because it is located in area that is protected and away from anything environmentally hazardous or threatening.  Even thought he turf fields are close, they have drains that divert water from going from the turf to the pond.

Materials: Thermometer, net, phosphorus testing tablet, pH indicator tablets, large bin for collecting samples, small container for identifying specific organisms, and a magnifying glass.

How to accomplish the study: Using the materials from above, we will examine and collect data on the abiotic and biotic factors of the pond for several class periods. Since all areas of the pond are different, the class was split up into groups to cover the whole pond. Each group was assigned a specific location on the pond, and at the end of the study, all the groups will combine their data to determine the health and resilience of the pond.

Method for Data Collection:  A net was placed in the pond near the edge and moved in a circular motion to stir up the bottom and collect small invertebrates. The invertebrates from the net were placed into a bin to examine the contents, identify organisms of special interest, and place those organisms into a separate container for further examination. The organisms of interest were examined to determine if they were indicator species (not tolerant to water pollution), somewhat tolerant to water pollution, or very tolerant to water pollution. After identifying these organisms, the pH and phosphorus levels of the water was tested using a pH and phosphorus test kit.

Observations: Upon arriving at the pond, I noticed that the lily pads and vegetation around the pond was beginning to die off. As Alan stated, “The vegetation will continue to die off every time the ground frosts over at night”. At my site,  in the corner of the pond with the most vegetation, I noticed that the tips grass in the pond were starting to turn brown, although the majority was still green. The air temperature at our site was 42.2°F , and the water temperature was 50.5°F. After measuring the temperature, a net used to collect biotic elements from the pond and begin identify organisms. In total 16 organisms identified from 7 different species.

The organisms we collected

Of the 16 organisms observed, only 3 were indicator species(all of them were mayfly nymphs), and the rest were tolerant of pollution to an extent. Next, the abiotic elements of the pond were analyzed. To test the pH of the pond, 10mL of water was placed in test tube, then a pH tablet was added and shook until the tablet was completely dissolved. The color of the water in the test tube was compared to a chart to determine the pH of the pond at our site. The pH of the pond was approximately 6.5, which is slightly acidic, as seen in the pictures below.

The scale to measure pH
The color of the pond water after adding the pH tablet

Next, the phosphorus levels of the water was tested by collecting 5mL of water in a test tube, then adding a tablet and shaking the solution until the tablet was dissolved. Also, it was necessary to wait five minutes after the tablet had dissolved to compare the color of the solution with the chart to determine the phosphorus levels. After five minutes, the color of the solution appeared to be between a 1 and a 2 on the phosphorus chart, as seen in the photos below.

The color of the pond water after adding the phosphorus indicating tablet
The scale to measure phosphorus levels












Location Air Temperature (Degrees Fahrenheit) Water Temperature (Degrees Fahrenheit)
Site #3 42.2 50.5


Abiotic Factors:

Element Measured Level Recorded
pH 6.5
Phosphorus 1-2


Biotic Factors:

Species Observed Number of Individuals observed
Mayfly Nymph 3
Scuds 5
Midge Larvae 2
Predaceous Diving Beetle 1
Damsel Nymph 1
Copepod 3
Backswimmer 1


The air temperature indicates that the vegetation inside and around the pond could soon be dead. A temperature of 42.2°F during the day means that temperatures are well below freezing at night, meaning the possibility of a frost or snow, which would kill the plants, is high.

The abiotic factors we recorded seem to indicate that the pond is healthy. A slightly acidic pH of 6.5 is almost neutral which means the pond can support a variety of species, leading to biodiversity. The phosphorus level in the pond are low, which means that nearly all the available phosphorus is being used by the organisms for energy in the form of ATP, which is “the energy for all living systems” (Alan McIntyre). Low levels of phosphorus in the water  indicate that there are many organisms in the pond, since almost all of the available energy is being used.

The biotic factors observed also support the conclusion that the pond is healthy. However, most of the organisms that were found are tolerant of pollution, indicating that the pond may be polluted a little bit, but not heavily. Test more location in the pond, for example locations much deeper and towards the middle may yield some different organisms.


Overall, the points of data that we collected today indicate that the pond is resilient and healthy. There is a wide variety of species in the pond, and these species are present in abundance. However, one point of data that could be incorrect is the temperature of the water. When I measured the temperature of the water I did so in only a couple inches below the surface, and the temperature in deeper water could have been different.

I really enjoyed the first day studying the pond. It was fun to catch and identify species on our own. After the watershed project I was familiar with the names of the invertebrates. I also enjoyed testing the abiotic factors, and I look forward to testing another abiotic factor in the future: nitrate levels. Having quantitative data of different components in the pond provides insight to factors that contribute to pond health. Testing the level of nitrates suggest how many amino acids are present in the pond. Ideally, in a healthy ecosystem, there should be no free nitrates, and all the nitrates will be used by organisms to synthesize proteins. Based on the data I collected today, I anticipate that the nitrate level of the pond is low, as the other tests have indicated the pond is in good health.

Swimming the Watershed

At 11:30 on Tuesday, October 9th, 2018, E Block AP Environmental Science set out to explore Proctor’s watershed. It was a partly cloudy day with temperatures around 70℉. The research adventure consisted of visiting and performing analytical tests at three different sites: The Proctor Access Point on the Blackwater River, Frazier Brook, and Pleasant Lake. Proctor’s watershed starts at Pleasant Lake, which collects runoff from the nearby mountains, then flows into the Blackwater River. Frazier Brook, also part of Proctor’s watershed, flows through Andover eventually joining up with the Blackwater.

Map of our journey, with red stars representing the sites we studied. Taken by me.

At each of these three locations, several quantitative tests were performed and observations of the abiotic, biotic, cycles, diversity, energy, and evolution (ABCDEEs) of each environment to produce a snapshot of the overall health of these three sites. I hypothesized that all three places would be healthy, however, Pleasant Lake would have more biodiversity than the rivers since lakes are typically warmer and more conducive to life. Lakes would also collect more nutrients/organic matter because there is less flowing water. More nutrients would mean a wide variety of food sources for a variety of living things.


The first stop was the Proctor access point on the Blackwater River. We arrived about 11:40, and engaged in a quick group conversation about living systems. During this discussion, Alan stated that, when assessing the health of a living system, it is important to remember “Living systems can self-repair and self-organize, whereas machines cannot.” This is important to consider because it explains that living systems can adapt and change to a variety of conditions put forth by nature and human influence. After this discussion, we walked about 500 feet to a clearing on the bank of the river to get a better view (shown in the picture).

The clearing where we observed the Blackwater River. Taken by me.
Walking back from the Blackwater River. Taken by me.


The water temperature of the Blackwater was 57℉, and the river appeared to be in good health, which Alan later confirmed. However, we did not bring any other quantitative tests, so we were unable to confirm the health of the river and relied on observations of the river and its surroundings. I noticed the several distinct abiotic and biotic components of the ecosystem: water, rocks, dirt, and several species of trees and grasses. However, Alan noted there was also sulfur, phosphorus, oxygen, nitrogen, and hydrogen dissolved in the river water. The presence of these elements makes sense because they are the building blocks of life, and without them, no organic matter would exist. In this situation, the river is playing a vital role in the nutrient cycle by transporting nutrients to areas farther down the river. Since tall trees are surrounding the river, little to no sunlight was able to reach the water. Therefore, the energy in the ecosystem is held by the large tall trees and the other producers. Although this spot is now surrounded by a diverse forest, only 10-12 thousand years ago, there was a 1-mile thick glacier that covered everything. This glacier eventually melted followed by primary succession. Slowly, soil was generated and increasingly complex plants appeared, and the excess of water in Pleasant Lake forced the creation of the Blackwater River. After learning about the evolution of the Blackwater River, we walked back to the bus and drove to our next stop, Frazier Brook.

Stirring up the riverbed at Frazier Brook. Taken by me.

After a five-minute drive and a 500-foot walk, we arrived at Frazier Brook. The Frazier Brook was much wider, although more shallow than the Blackwater. The flowing river water was very dark, almost black, making the bottom difficult to see. The first student to walk into the water, Will Luskey, stated: “the bottom is very rocky.” This statement made me curious how the rocks could make the water seem black? After stepping into the water, it felt cool. The temperature of the water was 61.7 ℉. I picked up one of the rocks and it was covered in thick layer of black algae, causing the water to appear black. The river bed was stirred up and we collected a variety of macroinvertebrates including stoneflies, mayflies, and dragonfly nymphs

Stonefly from Frazier Brook. Taken by me.

The presence of these organisms is significant because they are indicator species. This means that these species require a specific pH and a particular amount of sulfur, phosphorus, oxygen, nitrogen, and hydrogen for survival. The fact these organisms are present indicates the river is healthy. Since we observed multiple individuals of each species, Frazier
Brook is a healthy body of water that can support many organisms that feed on the macroinvertebrates observed in the river. Also, since the turbidity of the water is 0JTU, the water


Picture of the Turbidimeter at Frazier Brook. Taken by me.

is clear with little or no pollution. The macroinvertebrates were returned safely to the river before boarding the bus to the final location, Pleasant Lake.

After another ten minute drive, we arrived at Pleasant Lake. The first one to step into the water Julian stated, “This is way warmer,” and Alan added, “My feet aren’t numb.” However, despite these observations, the water temperature was 61.9℉, only 0.2 degrees warmer than Frazier Brook. This difference between the feel of the water and the actual temperature could be because when Jack measured the temperature of the lake, he did so in two feet of water, where the water is colder, and when the temperature was measured at Frazier Brook, it was measured in two inches of water, near the surface, where the water is warmer. Also, a lake should be warmer than rivers because water has a higher specific heat due to the lake’s large volume, meaning the lake holds the heat from the summer longer than the river. The lake was much more windy and wavy than the other two river locations. This makes sense because there are no obstructions to block or deflect the wind. Although the river does not have a continuous current like the river, I thought the waves could help circulate nutrients throughout the lake.

Picture from Pleasant Lake. Taken by me.

After a brief history of the lake, Alan informed us that Pleasant Lake has little biodiversity because of two invasive species: milfoil and rock bass. These two species are not native to Pleasant Lake, and unfortunately have no natural predators. Therefore, these species were able to easily take over the lake and prevent growth of other plant and animal species. The lack of biodiversity contradicted my initial hypothesis, which was surprising. It is possible that Pleasant Lake was diverse at one point, and the introduction of rock bass and milfoil out-competed many other species. Although the lake does not contain a variety of species, it is still reasonably clean, earning a turbidity score between 0JTU and 20JTU. Will also found a crayfish in the lake, and since crayfish require very high water quality to survive, it can be concluded that Pleasant Lake has clean and nutrient-filled water, despite its problem with invasive species. Alan also informed us that Pleasant Lake was the beginning of the watershed because it is surrounded by high mountains, created by glaciers 10-12 thousand years ago, which funneled water into the lake. After leaving Pleasant Lake, the water then flows through the Blackwater River to the Merrimack River, and eventually emptying into the Atlantic Ocean. After observing Pleasant Lake, we returned to the bus and drove back to Proctor.

Below are the data points we observed at each location:

Location Water Temperature (℉) Turbidity (JTU)
Blackwater River 57 n/a
Frazier Brook 61.7 0
Pleasant Lake 61.9 0-20

During the trip to Proctor’s watershed, I was introduced to new ways of measuring and observing. Using a thermometer and the turbidimeter, allowed for quantitative comparison of all three location tested. The trip provided an opportunity to experience the ecosystem on a deeper level by using a biotic factor, the indicator species, to describe water quality. Not only did we observe the body of water itself, but also the surrounding soil and vegetation. Examining the soil and vegetation around a body of water can reveal whether the water level is above or below normal, how much erosion has occurred, and other useful pieces of information.

The trip to Proctor’s watershed was informative and enjoyable. It was a beautiful day to be outside and explore the watershed.  It was a welcomed change collecting data outside verses in the classroom. This was the first time since freshman biology that I’ve had the opportunity to investigate the Proctor ecosystem.  Wading in the cold water of Frazier Brook gave me a new appreciation for all the organisms that call the icy water home. At times, taking notes outside while people are talking quickly was challenging, and it was a struggle to capture all the information. Although by our last stop, Pleasant Lake, I was able to take notes efficiently, by writing down keywords and then expanding upon the ideas on the way back to Proctor. However, one thing I would have liked to do is measure the pH at each of the sites. Measuring the pH at each of the sites would have allowed us to determine which organisms could live in that environment, and help to determine the overall health of the site. For example, if we measured the pH at the Blackwater River, which appeared healthy, and it was acidic (pH of 3 or 4), then these results would refute my original observation that the river is healthy. Overall, I enjoyed this trip, and I look forward to the study of the Proctor Pond.