STEP 1a: Read the Introduction
Want to try your hand at some marine biology? Then grab your raingear and follow steps 1, 2, 3 & 4 above to make a study of the marine life occupying a quadrat of Mearns Rock. A quadrat is a small sampling plot or area that is designed to represent a larger area that is being studied. Mearns Rock is a boulder in Prince William Sound, Alaska, that was oiled in 1989 by the Exxon Valdez oil spill. For your study, you'll use a series of close-up photos of the quadrat, each showing a different year from 1990 to 2004. Your goal will be to see how the percent cover of mussels, barnacles, and Fucus gardneri (a kind of seaweed, also called rockweed) in this study area has changed during those 15 years.
As you complete this project, you'll be using the same method used by
real marine biologists. To study how marine life abundance changes
from one year to the next, marine biologists sometimes section off a
small plot of land that's representative of the particular habitat they're
studying (for example, a rocky shoreline or a beach). They use a frame
(generally a 0.25 or 0.5 square meter of PVC pipe), known as a quadrat,
which they place on the ground to mark an area to study in depth. Each
year, the biologists return to count the organisms or plants that occupy
the area inside the quadrat. In most studies, many quadrat samples are
necessary to adequately represent the whole area. In the photo at the
left, a NOAA marine biologist is using a quadrat in his studies of the
Mearns Rock site. He's trying to find out how the abundance of Fucus,
barnacles, mussels, and other organisms has changed since the year before.
Abundancethe total number of individuals of a species present in an area.
Barnaclesmarine crustaceans with feathery appendages for gathering food that are free-swimming as larvae but permanently fixed (to rocks, boat hulls or whales) as adults.
Bouldera mass of rock greater than 256 millimeters in diameter.
Marinerelating to the seas and oceans.
Musselsa bivalve mollusk usually having a dark elongated shell.
Percent Coverthe proportion (in percent) of a certain species or group of species that is occupying a surface such as the ground, a rock, etc.
Quadrata small plot or sample of land that is representative of the particular habitat that is being studied. Often the plot of land is demarcated using a frame made of PVC pipe or other material.