STEP 2b: Record Your Data
Before you begin collecting data, you need to gather the resources necessary
to record your data from the quadrat photos. You should do the following:
Print the Data Table
Print the Percent Cover Chart
Review the Tips for Collecting Data Data
Table - Open and print out the data
table (pdf, 47Kb).
 |
You'll use it to record your estimates of percent cover of Fucus, mussels, and barnacles in the Mearns Rock quadrats from 1990 to 2004. You will assume that the percent cover of each organism was 0 in 1989. To help you "calibrate" your estimates, we've included our estimates of percent cover for each organism in 1990. |
Percent
Cover Chart - Open and print the percent
cover chart (pdf, 58Kb).
You’ll use this chart as an aid for estimating the percent
cover of a particular form of marine life in the quadrat you are observing.
Think of the black areas in the chart as representing one of the three
marine life forms you saw earlier in the field guide.
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Tips
for Collecting Data
Because the Mearns Rock quadrat photos were taken at different times
of day and under different weather and light conditions, they vary
in their color and clarity.
Watch
for four color ranges to identify the marine life:
| Gray areas tend to be bare rock. | |||||||
| Black areas are often mussels. | |||||||
| Areas that range from green to gold to brown are often Fucus gardneri (rockweed or popweed). Young Fucus plants are more green in color, mature plants are more brown. | |||||||
| White or light gray regions tend to be barnacles. | |||||||
Establish Observation Criteria
As you look through the photos, you will note that algae or
seaweed sometimes covers much of the rock, possibly hiding barnacles
and mussels from view. Before making your estimates, first establish
the criteria that you'll follow. For example, consider basing your observations
on "what's visible" rather than on your best guess of what
might be living underneath something else. Also, consider the intense
competition for space that exists among marine life forms in the intertidal
region. For example, if sea otters clear mussels off a section of the
rock, that opens space for barnacles, Fucus, or other organisms to "move
in" to that space. You'll see several examples in these photos.
Time to Get Started!
You are now ready to open the series of high-resolution photos
of the same quadrat of Mearns Rock, taken each year from 1990 to 2004.
As you examine each quadrat photo, you will estimate how much of the quadrat
Fucus occupies (as a percent of the total area), how much of the quadrat
mussels occupy, and how much of it barnacles occupy. Record your estimates
in the data table you printed out earlier. Now,
go back to the quadrat photos in Step 2a to start recording your data!
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