Methods*

This study was done in Nahant, MA at the Northeastern Marine Science Center's Canoe beach. (Please see map to your right.) Both field and laboratory methods were involved in conducting this experiment. This section will be divided into three sections; field methods, lab methods and statistical analysis.

Field Methods

The first day of the experiment involved selecting the tide pools. Six tide pools were randomly selected within the upper intertidal region. The six pools selected were in relatively close proximity to one another. (About a meter apart from each other.) The depth of each tide pool was measured using a meter stick in cm.

A diversity study was done on each tide pool using this template: DO NOT FORGET TO PUT LINK TO SHEEET to record the results. The following organisms were counted in each 0.25 meter quadrant; Littorina Obtusata, littorea, and saxatilis. Two quadrant samplings were taken per each pool during each visit. (Please see photo to the right.) During the three visits, the quadrant samplings were done in roughly the same area, the most northern and southern area of each tide pool.

In order to do the salinity and ph tests for each tide pool water samples had to be taken. Using a 100ml plastic, water samples were collected. The tubes were submerged in each pools and then capped immediately. Due to time constraints test results were not done on the samples immediately. Samples were frozen in a freezer within 6 hours of their collection. They stayed frozen until time allowed for extensive testing to be done. At which time they were taken out 3 hours prior to testing to defrost.

General observations of the tide pools and the surrounding environment were noted during the experiment. Qualitative information such as climate, recent rainfall, and human disturbance was noted during each visit. Please see the Field Notebook used for this project to see all observations written down.

Lab Methods

Two laboratory tests were performed to test the water samples for salinity levels and ph. These tests were performed on each of the 6 tide pools for all three days or a total of 36 experiments. The test kit used was the Salt Water Aquaculture Kit by Lamotte.

The salinity test is as follows:

1. Fill test tube to 10 mL line with demineralized water from the Demineralizer Bottle.

2. Fill the 0 - 1.0 Direct Reading Titrator to 0 line with sample water. Wipe any excess water off the Titrator.

3. Dispense 0.5 mL of sample water into titration tube by depressing plunger until tip is at 0.5 line. Discard remaining water in Titrator.

4. Add 3 drops of Salinity Indicator Reagent A . Cap and gently swirl to mix. Solution will turn yellow.

5. Fill the 0-20 Direct Reading Titrator with Salinity Titration Reagent B . Insert Titrator into hole of cap..

6. While gently swirling sample, slowly depress the plunger until color changes from yellow to pink-brown. Read test result where the large ring on the Titrator meets the Titrator barrel . Record as ppt Salinity.

7. If Titrator becomes empty before color change occurs, refill and continue titrating. Add original amount (20 ppt) to final result.

NOTE: Each minor division = 0.4 ppt Salinity

The ph test is as follows:

1.Fill a test tube to the 0.5ml line with sample water.

2.Add 10 drops of wide range pH indicator.

3.Cap and mix.

4.Insert wide range pH octa-slide bar into the Octa Slide Viewer.

Insert test tube into Octa-slide viewer.

Match sample color to a color standard record as pH.

The salinity test and ph test directions are copyright protected under lamotte llc. To see the manual in its entirety please go

here.

Statistics Used

ANOVA was used on the data collected. The data tested was the total number of snail per each tide pool per each day vs. salinity and ph per each tide pool per each day. In addition to that an ANOVA was done on each tide pools specific data to test significance for individual tide pools.








*The following methods are not the entirety of experiments done on these tide pools. This was a team project and many variables were tested. The above methods only relate to this sites hypothesis. To learn more about these tide pools please visit my team members sites: Paul studied O2 levels while on the other hand..Cait studied many factors within the tide pool