Our group was in charge of the physical data section of this conference.
We consist of seven students; Mario, Kavy, Aimee, Jeremy Michele,
Anna, and Olly. Stephanie and Bob were our instructors. Each team
in this conference performed five tests at the dock. Our dock
is located in a protected area. It is called "Little Harbor",
it's a harbor inside a larger harbor. The seven tests performed
were, air temperature, water temperature, Salinity (ppt), dissolved
oxygen (ppm), turbidity, and tide height. We will explain each
test and the results of our data will be listed below in the graphs.
To take the temperature readings we used an alcohol thermometer
to take both the air temp., and the water temp. Anna, Michele,
and Aimee took these tests. (We are from the first group who performed
these tests). We took the air temp. by creating an area of shade
to keep the thermometer out of direct sunlight. Then we took the
water temp. from three places on the dock. We tied a string to
one end of the thermometer and held it just under the surface
of the water for one minute.
Our next test was to measure the amount of salt in the water,
otherwise known as salinity. We filled our hydrometer with salt
water from the harbor. Before doing this we made sure the needle
in the hydrometer was moving freely. After having been filled,
we set the hydrometer down on the dock to read the salinity reading.
The salinity reading comes from the number in which the needle
points to on the hydrometer.
We also conducted dissolved oxygen tests. It included taking two
samples of water (without any bubbles). In order to do this we
had to fill buckets of water over the edge of the dock, and then
submerge our hands in the freezing water in order to fill the
sample bottles. Each group did about six samples. Then it was
a race against time to get our samples fixed. Every moment they
were left out our results could be affected. So first we added
8 drops Manganous Sulfate Solution then we added 8 droops Alkaline
Potassium Iodide Azide solution, from our LaMotte dissolved oxygen
kits. Then we shook them and added 1 scoop of Sulfamic Acid Powder,
and we shook again, until it was an ugly orange color. Now our
sample fixation is complete. Next we needed to titrate. To do
this we added 20 ml of our stuff to a titration tube, then we
use Sodium Thiosulfate, in a direct read titrator to turn the
solution pale yellow. We added starch indicator, it turned blue/black
and continued to titrate until the sample was clear. We read the
ppm of dissolved oxygen off the titrator. Now our test is complete.
We took a turbidity test to document the clarity of the water.
To test this we took our black and white Secchi disk to the deep
end of the dock and lowered it over the edge. We continued to
lower the disk bottom. We pulled it out and measured it, it read
3.7 meters. All of the groups that did this test found that when
we lowered the Secchi disk that they could still see it when it
hit the bottom. We found that the water was very clear, we think
it was so because Eel Pond is a very small protected harbor so
it may be less disturbed because it doesn't have the ocean's currents.
To measure the tides we put up a long measuring stick on one of
the poles on the dock. We put 0 at the hightide mark. Each group
measured the tide mark when they were on the dock. We found that
the changes between low and high tides was very minimal. This
was due to many things. For one thing Little Harbor is a small
protective inlet and that lessens the difference between tide
heights. We are also in the middle of the moon cycle and that
lessens the gravitational pull of the moon and the differences
between the tide heights. Yesterday the 11 April 1996 the high
tide was at 3:39 pm and the low tide was at 8:39 pm. After accumulating
all the data we observed that the tidal change was approximately
26 cm between 12:15 pm and 8:30 pm.
In consequence of our inexperience in the marine biological field
our results may not have been totally accurate. We are still learning
how to take accurate tests. The inlet itself, where we took our
measurements effected our results as well. The inlet is very protected
and the tides heights are small, this created a special protected
environment which is not found often. But being perfectly accurate
in our experimental procedure was not the main point of going
to Woods Hole. The trip was to provide students with some hands-on
experience in marine biology and also to give the students an
insight into the life of a scientist. The experience of working
at Woods Hole was very unique, and we are very privileged to be
here.
Knowledge should be attained experimentally as well as theoretically.
Return to Tidepools to Telecommunications @ 2000 - 4 Archive Home
Page.