Home Methods 1 | Photo Identification | Mark and Recapture Biopsy | Summer Feeding Areas, Wintering Grounds and Migration | Human Impact | Population Estimates

Activity 1: Questions about SPLASH | Activity 2: Interpreting Graphs | Activity 3: Mark and Recapture | Activity 4: Estimating Humpback Population Growth | Activity 5: Whale Tails: Photo ID | Activity Answers

Interpreting the Graphs

Graphs are an important tool that scientists use to illustrate their data. In the following activity, you will be asked to interpret what the graph is reporting:

Graph 1 Wintering and Summer Feeding Areas
Graph by Jay Barlow, NMFS

The brown text are wintering areas; the blue text are feeding areas.

1. How many humpbacks spend the winter at the Mexico mainland?

2. What is the total estimate for humpback whales on the feeding grounds?

3. Judging by the thickness of the migration line, which breeding area has the largest migration?

Graph 2 – Gear Entanglements –
Ed Lyman, Hawaiian Islands NMS

4. What type of gear entanglement is highest in the North Pacific?
5. What is the total amount of gillnet entanglements in the North Pacific?
6. What region had the highest rate of all types of entanglement?

Graph 3 – Cascadia Research

7. In 1992 what was the population estimate for humpbacks living on the West Coast of the U.S.?
8. What does the graph indicate about the humpback population in 1999 and 2000?

Graph 4 Population estimates for the N. Pacific –
Cascadia Research

9. What are the two main wintering areas in the North Pacific and how many whales are estimated to be in each area?
10. What are three main summer feeding areas and how many whales are estimated to be in those areas?
11. Why are population totals different for the wintering area and the feeding areas?

Graph 5 Serious injury to whales due to entanglements –
Cascadia Research

12. Off the Russian east coast, how many whales had two serious injuries?
13. What is the total number of whales that had entanglement scars in SEAK (South East