  COOL Classroom 2.1 Print this Discovery

# Discover How to Calculate Where Seagrass May Grow

By combining the Bathymetry data of the Bay with the calculated Light Penetration Depth, scientists can predict where seagrass beds should grow in the Bay. To do this, scientists basically do algebra on a map.

First, scientists divide the bay up into a grid. They use this grid to calculate whether seagrass will grow in different areas (grid cells).

Second, each grid cell is assigned an appropriate Light Penetration Depth value based upon the data from that grid cell.

Third, each grid cell is assigned and appropriate Bathymetry value based upon the data from that grid cell.

Finally, the scientists (or really their computers) subtracts the Bathymetry value from the Light Penetration Depth value for each grid cell to calculate the probability of seagrass growing in that grid cell. If the value is positive than seagrass beds can grow in that grid cell, if the value is negative then seagrass beds cannot grow in that grid cell.  Map Algebra: Each number in the grid is subtracted by the corresponding number from the same grid cell in the second grid. This is how we do map algebra. 