Research Report for Science on Seneca

Research Question: Will the depth of the sampling locations affect the population of phytoplankton in Seneca Lake?

Independent Variable: Depth of the water.
Controlled Variable: All studies will be done in Seneca Lake.
Other Variables: Temperature, D.O. levels, overall plankton population, turbidity.

Context: Plankton population in marine ecosystems like Seneca Lake has many contributing factors that go into it, such as temperature of water, and current.  Plankton travel by flowing with the current, so any area with a high speed current will most likely have many plankton traveling through it.  Availability of nutrients can also be a limiting factor of plankton population, like any other living species.  According to a paper by David Thomas of Bangor University, the amount of sunlight entering the lake is also a limiting factor of plankton population, and is often considered the key factor that contributes to plankton population.  Light is necessary so the plankton can undergo photosynthesis, which is necessary for the survival of the plankton.  According to another article, dissolved oxygen and pH levels were key into limiting the population of plankton, just like they were in the Furnace Brook Lab Report.  The amount of plankton in the water will also tell us the quality of the water, since creatures like the plankton only live in water with high D.O. levels.

Sources:http://www.mathclimate.org/sites/default/files/DavidThomas-PhytoplanktonGrowth.pdf
              http://www.ncbi.nlm.nih.gov/pubmed/11757850
              http://extension.psu.edu/natural-resources/water/news/2013/macroinvertebrates-as-indicators-of-water-quality

Hypothesis: Temperature, sunlight, D.O and pH levels will have an impact on the population, but depth will have either very little impact or no impact.  According to all three of my sources, depth was not listed as a factor when it comes to limiting factors of population, while the others were.

Method: I will test for depth, water temperature, and dissolved oxygen levels, along with plankton population.  I will test all of these things the same way in each location, keeping all of them constant.

Procedures:
Dissolved Oxygen-
1.  Add 8 drops of manganese (II) sulfate solution and 8 drops of alkaline potassium iodide azide solution to the LaMotte sample bottle.
2.  Cap the bottle and carefully agitate the bottle by inverting for 3-4 minutes, allowing the solutions to mix. Allow a orange brown precipitate to form on the bottom of the bottle.
3. Add a 1-gram spoonful of sulfamic acid to the bottle, and agitate until white crystals form and mix with the brown crystals, making a clear brown solution.
4. Fill up the titration tube to 20mL with this solution.
5. Add 8 drops of starch solution to the tube, look for color change.
6. Fill the titrator up to the zero mark with the sodium thiosulfate solution.
7. Put the titrator in the hole of the cap of the titration tube and titrate the solution slowly.  Swirl around until the blue color is completely gone.  Refilling may be necessary.  Record the dissolved oxygen in ppm.
Location and Depth-
1. When the ship comes to a complete stop, use the GPS to find the exact location of the ship.
2. Use the depth finder aboard the ship to find the depth, again while at a complete stop.
Temperature-
1. Use the CTD on the ship to get a temperature reading.
Plankton Collection-
1. Twist end of rope around your hand two or three times and clench fist around it.
2. Make sure the bottom of the net is closed so you know the sample will be captured.
3. Put the net in the water (while holding onto it, of course) and walk from the back of the boat to the front, and then back again.  Keep your pace and the depth of the net constant as you walk.  Make sure the net doesn't hit the side of the boat.
4. From the back of the boat, gather up the line until the net is vertical and level with the railing.  Using tap water in the wash cup, wash the net so plankton fall into the cup at the bottom of the net.
5. Carefully bring the grey cup on board without spilling the plankton sample.
6. Have the sample from the grey cup flow to the beaker provided by using the attached tubing.
7. Take the beaker for lab analysis.  When done with the sample, make sure you clean the beaker properly.

Final Question: How many phytoplankton are projected to be in Seneca Lake?  And approximately how many are consumed by zebra mussels?

Data

Sample 1:

	Latitude	Longitude	Sample Temp.	Sample Depth	pH	Chloride	Dissolved Oxygen	Depth To Bottom
PM	42◦50’N	76◦58’W	7◦C	54 M	7.4	180ppm	10ppm	62.6 M
AM	Same	Same	13◦C	38.9 M	7.3	200ppm	30ppm	46.6 M

Sample 2:

	Latitude	Longitude	Sample Temp.	Sample Depth	pH	Chloride	Dissolved Oxygen	Depth To Bottom
PM	42◦51’N	76◦58’W	14◦C	10 M	7.4	143ppm	10ppm	22.7 M
AM	Same	Same	13◦C	10 M	7.4	300ppm	30ppm	22.3 M

Sample 3:

	Latitude	Longitude	Sample Temp.	Sample Depth	pH	Chloride	Dissolved Oxygen	Depth To Bottom
PM	42◦52’N	76◦58’W	13◦C	Surface	7.5	200ppm	10ppm	8 M
AM	42◦51’N	Same	13◦C	Surface	7.3	140ppm	10ppm	7.5M

            The six different locations were all within 2 minutes north of each other when it comes to latitude but actually all had the same coordinates when it comes to longitude.  This means that all of the locations were actually pretty close to each other, but far enough apart to make a significant difference in depth.  The AM and PM samples from the deeper location had identical coordinates, but the PM group experienced a much greater depth at their spot.  The AM group had a sampling depth of 38.9 meters, where the PM group had a depth of 54 meters, which is quite a significant difference.  Since the PM group had a deeper sample, they experienced a temperature of 7 degrees Celsius instead of 13 or 14 like the other groups, but had a pH of 7.4 which was right in line with the others.  The chloride samples were close at 180ppm for the PM group and 200ppm for the AM.  The dissolved oxygen was far off though, as the AM got a reading of 30ppm instead of 10ppm in the PM.  As you can tell, the medium sample depth numbers were in line with each other at both locations except for the chloride and dissolved oxygen numbers, which had pretty significant differences.  The chloride reading for the AM group in the second sample was 300ppm, which is higher than the salt content should be for water used as drinking water.  A number so high means that the salt can be tasted in the water.  The AM group had a dissolved oxygen reading of 6ppm, four lower than the PM group’s reading of 10ppm.  All the numbers in sample 3 were in line with each other except for the chloride readings.  The AM group collected a chloride reading of 200ppm, much higher than the reading of 140ppm collected by the afternoon group.  Human error could come into play while calculating chloride, but that will be discussed in the Evaluation section.  The weather on the day of the sampling could be considered gloomy, but not rainy.  There was constant cloud cover while my group was sampling, but not much rain fell.  Temperatures were not extremely cold or warm, about 45 degrees Fahrenheit.  My group’s dredge sample did not contain much plant or animal life, barely any at all actually.  The mussel content wasn’t extreme, either.  There were a few scattered Quagga mussels, but no Zebra mussels.  There was a decently large amount of sediment and rocks in my group’s sample, though.

 

Sample	Total Population	1	2	3	4	5	6	7	8
1A	9	2	2	2	3	X	X	X	X
2A	15	2	2	1	7	2	1	X	X
3A	9	1	1	3	1	1	1	1	X
1P	21*	1	1	1	16*	2	X	X	X
2P	17	1	1	1	2	5	2	4	1
3P	19	6	1	7	3	1	1	X	X

*16 may not have been the final count, only 16 were counted, but possibly more present.

Results

(All data above is in parts per million or ppm) My group was the AM group.

Discussion

            

Some trends that can be noticed in my data are that the PM group got significantly different readings than the AM group did.  Actually, both of the readings collected by the PM group were 20ppm lower than the ones that were collected by the AM group.  Now, according to the data logger graphs, the highest amount of dissolved oxygen that should be in the lake was 15ppm.  The AM group (the group I was in) got a reading of 30ppm when it comes to dissolved oxygen.  Another trend that can be noticed is that the chloride numbers are much higher than the dissolved oxygen levels.  This is supposed to be this way because oxygen is only present in water to provide life for certain beings, but high levels are not necessary for these plants and animals to survive.  The salt is in the water naturally, and will get its numbers from water brought in through rivers and streams that may connect to oceans when at their ends.

Evaluation

            

The activities done at Seneca Lake proved that my hypothesis was correct, and depth of water would not have a large effect on the population of phytoplankton and other organisms that may be present in the lake.  I hypothesized that factors like temperature, dissolved oxygen, pH, and sunlight would be better contributors to the population of phytoplankton.  Another factor I didn’t mention was the time of day, which actually seemed to be the biggest factor in the plankton collection.  All of the samples collected in the afternoon had higher numbers of plankton than the samples collected in the morning.  Sunlight may have something to do with this, since the cloud cover began to dissipate in the afternoon.  Plankton can only live with certain levels of light in the water, which is necessary for the plankton to undergo photosynthesis, so this was most likely the main cause for the major increase in plankton population in the afternoon.  Some weaknesses I found in this experiment were the amount of samples taken, and the time of year.  If more samples were taken during both times of day, more trends could be found to quite possibly predict future samples and trends.  The time of year played a major factor as well.  This experiment was originally supposed to be done in the second week of October, not the first week of November.  Two weeks can make a major difference here.  Temperature on the water and in the water can be totally different, which can affect how the plankton function in the water, and if they survive or not.  Human error played a major factor in this lab.  While trying to find readings for dissolved oxygen and chloride, the tests were left to be done by inexperienced students, not teachers or professors that know what they are doing.  I’m not calling anyone stupid, but human error might’ve been less of a factor if professionals conducted these tests.  Human error is the reason groups got numbers higher than what is tolerable by the lake. 

Conclusion

On this research trip I found out that my hypothesis was correct, being that the depth of the water is not a factor in what the population of the phytoplankton will be.  Sunlight is a major factor, since plankton need photosynthesis to survive, and without sunlight, there is no photosynthesis.  What i didn't find was how pH affected the population, since all of the locations had basically the same pH levels.  That was part of my hypothesis and I wanted to know if I was correct in that aspect as well.