Getting deep with the ocean’s master divers

This exercise is a part of Educator Guide: Whale’s Breathtaking Dive Impresses / View Guide

Directions for teachers: After your students read the online Science News article “A beaked whale’s nearly 4-hour-long dive sets a new record,” ask them to answer the following questions. A version of the story, “Whale’s breathtaking dive impresses,” can be found in the November 7, 2020 issue of Science News.

1. Why are Cuvier’s beaked whales considered master divers?

The whales hold records for deepest and longest dives by a marine mammal.

2. How long did the beaked whale highlighted in the story’s headline stay underwater without coming up for air? How does that new record compare with a 2014 dive made by another Cuvier’s beaked whale?

The whale spent 222 minutes, or 3 hours and 42 minutes, underwater. That is more than 80 minutes longer than the previous record-holder spent underwater.

3. What is anaerobic respiration?

Anaerobic respiration is a way cells generate energy without oxygen.

4. What do scientists think enables Cuvier’s beaked whales to stay underwater for such long periods of time? Explain.

Large stores of oxygen and a slow metabolism may help the whales dive for extended periods of time. The mammals even switch to anaerobic respiration when their oxygen runs out. The whales may have the ability to tolerate lactic acid building up in their bodies over time — a consequence of anaerobic respiration.

5. How long did scientists estimate the whales could dive before running out of oxygen? What data did they use to come up with this estimate?

About 30 minutes. They calculated the estimate based on data from seals.

6. How many whale dives did Nicola Quick and her team analyze? How long did the dives last?

The researchers analyzed 3,680 dives. Most dives lasted about an hour, but 5 percent lasted more than about 78 minutes.

7. What do the findings suggest about the whales?

It takes twice as long as thought for the whales to run out of oxygen and switch to anaerobic respiration.

8. What did researchers expect to find about the whales’ surface recovery time after a long dive?

The scientists expected to find that the whales spend more time at the ocean surface to recover from long dives.

9. What are two additional research questions related to this study that could be investigated?

What is the average surface recovery time after long dives? How does that time relate to average recovery time after short dives? How do beaked whales process lactic acid? Why can whales dive for longer periods of time than seals?