An investigation was carried out to study the physiological response to diving in two marine mammals: the Weddell seal (Leptonychotes weddellii) and the California sea lion (Zalophus californianus). The heart rate of both species was measured at regular intervals during a simulated dive.
The results are shown in the table and graph below.
| Diving duration (minutes) | Heart rate of Weddell seal (beats per minute) | Heart rate of California sea lion (beats per minute) |
|---|---|---|
| 0 (Pre-dive) | 65 | 92 |
| 5 | 22 | 45 |
| 10 | 14 | 38 |
| 15 | 11 | 37 |
| 20 | 10 | 38 |
| 25 | 10 | 37 |
Compare the effect of diving duration on the heart rate of the Weddell seal with that of the California sea lion.