Module 3 • Ecology: Dynamic Oceans
Student Page 3-6a
Step 4: Transect interpretation
Remember that the goal of this survey made in 2002 was to figure out whether at that time the
population of narwhals was growing or declining. In other words, we are going to determine the
trend of the population samples over a period of time. We do that by plotting the data for 2002 with
that of earlier surveys conducted in Inglefield Bredning in 1985, 1986, 2001—and from that draw a
trend line!
What we are going to plot is the calculated number of whales at the surface:
Survey number Area (km
2
) Number of Number of whales Whales at surface
and date pictures taken observed on the
pictures