Thursday, March 12, 2009

Lake Core Investigation

By Molly, Nicole, Taylor and Robert

Question: How do diatoms differ from 50 cm to 70 cm?

Data: We did about 5 different slides at 50 cm and also at 70 cm. The diatoms differed between the two observations.


Claim: Both were the same size but they were shaped differently. The diatoms at 50 cm were shaped like bricks and the diatoms at 70 cm were shaped like ladders.

Evidence: There were more diatoms at 70 cm than 50 cm.

Reasoning: At 50 cm we didn't see many diatoms, but at 70 cm we saw more than 20 diatoms

Further Questions:

1. Would've our results changed if we went deeper than 70 cm?

2. Would the moisture or dryness of the soil change the amount of diatoms?

Lake Adley Diatom Count

By: Ellen D. & Brittany M.

Question: If we look at 2 different cores at the same depth would there the same kinds of diatoms.

Procedure: First we will clean off a slide, then take a small sample of core A at 20cm from the top. Then we will mix it with a drop of water and place a slide cover on top. We will then place it under a compound microscope and find as many diatoms as possible. We will then repeat these steps two more times. After recording our data we will take another slide sample, but this time from core B but still at 20Cm from the top. We will then look for more diatoms. Then we will repeat these steps 2 more times. After recording our data we will compare the types of diatoms we found.

Variable changed: cores
Variable measured: kinds of diatoms
Controls: Depth, amount of sediment

Core A
Slide 1: Anomoeoneis, Navicula/Pinnularia, Aulacoseira, Cymbella
Slide 2:Aulacoseira, Cyclotella, Hantzchia/Nitzschia, Surirella
Slide 3:Cyclotella, Navicula/Pinnularia, Aulacoseria

Core B
Slide 1:NONE
Slide 2:NONE
Slide 3:NONE

Conclusion: We conclude that there is a big difference in the 2 different cores. We came to the this conclusion because in the first core we saw many different types of diatoms, but when we looked at the next core we did not find any. We think this is a logical conclusion because there might have been more diatoms in one spot in none in the other

Friday, March 6, 2009

lake core sample

We did oberservations on the lake core sample of adley.
Our question:How many diatoms are there at 2cm than
Data:first day of the observations we found 1 diatoms under 2cm.
and under 10cm we found 3 diatoms.
the secound day of observations we found 2 diatoms under 2cm.
and under 10cm we found 3 diatoms.
the third day of observations we found 2 diatoms under 2 cm.
and under 10cm we found 2 diatoms.
conclusion: The concluison to our lake core sample is the more the
lake core sample goes in the ground the more diatoms appeat on the
slides , when we look at 2cm we found f diatoms over all and when we
did 10cm we found 8 diatoms over all.
further questions: 1) can we find more diatoms at 50cm than 10cm?
2)when you look at 10cm for diatoms and go 10cm down each time how
many ditaoms will you find
BY: Mark Hewitt and Justin Thomas

mackenzie, shelby, and alex

Question: How many different diatoms are there at 10 cm down and 60cm down?

Variables change: depth
Variables measure: how many different diatoms
Controls: same core, same materials

lake core
compoud scope
tooth picks
slip cover
note book

1 clean slide
2 get sample from 10cm down and put on slide
3 put water on and spread
4 examine under a compound scope
5 repeat #1 and get a sample from 60cm down
6 repeat #3 and #4
7 record data in note book
8 when finished, clean slide and put stuff away

Slide #1 at 10cm down
asterionella tormosa-1
Slide #2 at 10cm down
Slide #3 at 10cm down
Slide #1 at 60cm down
Slide #2 at 60cm down
Slide #3 at 60cm down
fragilaria capucina-3

claim-at 10cm down we found 6 different kinds of diatoms and at 60cm down we found 9 different kinds of diatoms.
evidence-we made three slides from each depth and examined them from under the compound scope. of all the slides we took from 10 cm down we found five synedra, one asterionella formosa, ten melosiera, one amphora, one cyclotella, and one planothidium/achnanthes. of all the slides at 60cm down we found one epithemia, nine navicula/pinnularia, two cyclotella,14 melosiera, two gyrosigma, one rhopalodia, one synedra, three amphora, and three fragilaria capucina.
reason-we think there are more at 60cm down because it's older and maybe there were more diatoms at that time. it may have been at the end of the drought period so maybe the habitat would have been different. and we have a lot of benthic and they hangout towards the bottom of the lake. we believe that this was also before lake adley became polluted.

Diatom Investigation

Question: Are there different diatoms at 10 cm and at 90 cm?
By: Becky, Brianna, Hunter, and Jason

Procedure:Take a sample of the lake core from 10cm. Make a smear slide by putting the dirt on and adding some water. Put the smear slide under a compound microscope and record what diatoms we see in our notebook. Repeat these same steps 2 times. Take a sample of the lake core from 90 cm. Make a smear slide by putting the dirt on and adding a few drops of water. Put the smear slide under a compound microscope and record what diatoms we see in our notebook. Repeat 2 times.


  • toothpick

  • compound microscope

  • slide

  • slipcover

  • lake core


At 10 cm:

  • 2 Fragilaria Capucina

  • 2 Synedra

  • 2 pieces of Gyrosigma

  • 2 pieces of Asterionella Formosa

  • 1 Navicula/Pinnularia

At 90 cm:

  • 4 pieces of Asterionella Formosa

  • 3 Fragilaria Capucina

  • 7 synedra

  • 2 pieces of Gyrosigma

Claim/Evidence: We found out that there are different kinds of diatoms at 90 cm and at 10cm. At 90 cm there were 4 pieces of Asterionella formosa, there were also 3 Fragilaria Capucina, 7 synedra and 2 pieces of Gyrosigma. At 10 cm we found 2 fragilaria capucina, 2 Synedra, 2 pieces of Gyrosigma, 2 pieces of Asterionella Formosa and 1 Navicula/Pinnularia.

Reasoning: Maybe we incorrectly evaluated which diatoms were what. Maybe one of those areas of time were drier so only certain kinds of diatoms were able to survive. It could have been wetter one year so there were different diatoms.

Further Questions: What different kinds of pollen are there at different depths? When the sediment is larger are there more or less diatoms?

lake core investigation

zach sax, zach Question: What depth are the most diatoms found at. 10cm or at 80cm. Claim: we found more diatoms at 80cm. there were less diatoms at 10cm

Data: 80cm=16

Reasoning: The sediment that is deeper is older. Which gives more time to collect at the bottom.

Further question: how many more diotoms are at 20cm then 70cm
: what diatoms will you find the most

Thursday, March 5, 2009

Diatoms in the Lake Adley core sample

By Trent, Connor, Tyler and Dominic

Question: How many different kinds of diatoms are at 4cm and at 24cm?

1 take 2 samples one from 4 cm deep and one from 24 cm

2 put the samples on seprate glass slides

3 compare slides on a microscope

4 write down comparisins and differences between the diatoms on the slides

Variable Changed: Depth

Variables Measured: Number of Diatoms

Controls: Number of samples taken


With many slides at the correct depth of 4cm and 24cm our results were we did not find any diatoms at 4 cm at 24cm we found several cymbella and synedra for this maybe as the depth increases your diatoms may increase. Because they live on the bottom you will find more than the ones that float.

Wednesday, March 4, 2009

Osakis Diatom Study

Olivia, Avery, Taylor, Tyler

Question: Are there more Diatoms at two cm or at 80 cm?

I. Clean off slide
II.  Put two drops of water on the slide
III. Take one toothpick and put it in the mud about one-half cm
IV. Take it out
V. Take a circular motion to spread the mud around
VI. Look under a microscope
VII. Count all the Diatoms that can be identified

I. Slide
II. Toothpick
III. Cover Slide
IV. Microscope
V. Mud
VI. Water
VII. Water Dropper
VIII.  Notebook/Paper

Two cm deep five different Diatoms- 4 slides, types are: Melosira, Nitzchia, Diatoma, Stephanadiscus, and Cocconeis
Eighty cm deep six different Diatoms- 4 slides, types are: Cymbella, Melosira, Frustulia, Nitzchia, Surirella, Euontia 

Claim: Eighty cm deep had one more Diatoms that two cm.
Evidence: We took four slides of each and found that there was just one 
more Diatoms at two cm than at eighty cm.
Reasoning: The reasoning we came up with was that eighty cm could've 
settled so that they could've cross bred to make a different Diatom or they just be different conditions the farther they go.

Questions/Comments: Very interesting shape description in the experiment by Nick, Dylan, Eric, RC

Osakis Earth Science Investigations

Lake Core Investigation, Osakis High School

Names: Paul, Rachelle, Becka, John

Procedure: 1. Drop two drops of water on glass slide.
2. Smear the sample onto the slide with tooth picks.
3. Put the cover slip on.
4. Examine the samples under a microscope.

Materials: 1. Glass slides
2. Cover slips
3. Compound microscope
4. Pencils.
5. Science journal
6. Tooth picks
7. Water dropper
8. Core sample (at 1cm and 33cm).
Data/Result: Total Diatoms-166

Conclusion: We found that there are more diatoms at 33 cm that at 1 cm.  Three out of four of our people had more diatoms in 33 cm than in 1 cm.  We think that there are more diatoms at 33 cm because it had more time to develop. 

Do only certain diatoms live during a certain time or doesn't it matter when or where they lived.

Tuesday, March 3, 2009

Osakis Earth Science Investigations

Students from Osakis High School will soon be publishing their research from the Lake Adley sediment cores collected last February.  Eighth graders will be reporting their counts of diatoms at two separate depths of the 90 centimeter core sample.