WhaleWorks: Student Booklet

Transcription

1 2009 SMILE Winter Teacher Workshop High School Club Activities : Student Booklet STATION A: Good Vibrations At this station, you will be using tuning forks to experiment how sound travels through, air, solids and water. Make sure every student in your group gets a chance to try each step. 1. Take a tuning fork from the station. Holding the handle of the tuning fork, strike it on a hard, solid surface. Gently move the fork toward the shallow pan of water and submerge the two tines (prongs). Question 1: What happens and why? Sound travels through air at about 340 m/s (~0.2 mile/s). However in seawater it travels at approximately 1600 m/s (~1 mile/s). Question 2: About how much faster does sound travel through seawater than it does in air? Question 3: Why would seawater be a better conductor of sound? Sound can also be conducted through bone and soft tissue. 2. Strike the tuning fork again and hold it a few inches from your ear. What you hear is your perception of the sound vibrations moving from the tuning fork. 3. Next you will test sound through your jawbone and the soft tissue on your chin. Discuss with your group whether you think this will change your perception of the sound?

2 Question 4: What is your group s hypothesis? 4. Strike the tuning fork again and hold the tip of the handle to your lower jaw. Question 5: What do you hear/feel? Question 6: Why do you think this is happening? Land mammals, such as elephants, can easily see 100 feet ahead of them across open ground. If you have ever opened your eyes underwater whilst swimming, you will know that vision underwater is much more limited. Question 7: Thinking about this and what you have discovered at this station, how are marine mammals most likely to communicate? Why would this benefit them? Give examples. A toothed whaleʼs fatfilled jawbone conducts sound through the jaw to bones in the middle ears.

3 STATION B: Blubber Gloves This station will help you investigate the role of whale blubber. 1. Discuss with your group a prediction for how cold the ice in the dishpan is. Now measure the temperature with a thermometer. Question 1: What is the temperature of the ice? The temperature of the North Pacific Ocean varies from 48 F to 64 F. Is the ice within this temperature range? Imagine the dishpan of ice as a representation of the North Pacific. 2. In your group, take turns putting a bare hand into the ice. Use a stopwatch to see how long the temperature of the ice can be tolerated by each person. Record these results on the observation sheet and calculate an average (in seconds) for the group. This average will be your control measurement. NB: This is not an endurance test! Think of your hand as your whole body; as soon as it becomes too chilled, take your hand out and stop timing! 3. Next, have your group repeat the experiment using the following to cover hands: a. A double-lined Ziploc bag (i.e. one bag inside another) b. A rubber glove c. A rubber glove lined with a cotton glove d. A rubber glove lined with a wool glove e. A blubber glove Record all your observations. If you have time, complete additional experiments using your own combination of hand coverings with available materials. Question 2: Which hand covering provides the most warmth? Question 3: What is your explanation for these outcomes?

4 Marine mammals, like humans, are warm blooded. A human being without any protection in water that is 32 F can lose consciousness in around 10 minutes, as heat loss is much greater in water than in air. Question 4: How do marine mammals survive in a cold ocean, such as the North Pacific? Experiment observation sheet: Hand Covering Time Until Chilled Group Average (Sec) Bare hand (control) Rubber glove Rubber glove lined with cotton glove Rubber glove lined with wool glove Blubber Glove Additional: Body blubber is a key feature of the Northern Elephant Seal

5 2009 SMILE Winter Teacher Workshop High School Club Activities STATION C: Eat Like a Whale At this station you will investigate different whale feeding strategies. Skimmers Bowhead and right whales are examples of mysticetes (baleen whales) that feed by skimming the surface of the water with their mouths open, using baleen combs to filter out food. Gulpers Some mysticetes, such as blue and fin whales, have pleats in their throat that help the throat to expand, allowing the whale to take in large quantities of both water and prey. Bubblers Bubble netting is a strategy for catching fish unique to humpback whales. In a group of 5-15 whales, one whale will submerge and shriek an eerie sound while blowing bubbles in a circle formation. The fish become frightened and move close together. Biters Ordontocetes (toothed whales), such as sperm whales and orca, are active hunters feeding on prey such as fish, squid and other marine mammals. 1. Assign each member of your group a feeding type: skimmer, gulper, bubbler or biter. Have each type simulate their feeding strategy using the instructions below: Skimmers: Move a comb through a pan of water filled with parsley. Remove the parsley by tapping it onto scrap paper. Gulpers: Hold a comb in front of the open end of a Ziploc bag. Move the bag through the parsley water and gently squeeze the water back out of the bag through the comb a little at a time. Tap the remaining parsley out onto scrap paper. Do this until all the water is drained from the bag. Bubblers: Using straws, 2 or more students blow bubbles through the parsley water, working as a group to move the food to the center of the dishpan. Another student then brings a ziploc bag up from the bottom of the pan, through the center of the concentrated food. Use a comb to strain the parsley from the water and tap it out onto scrap paper.

6 Biters: Using tongs and the water containing Styrofoam pieces, grasp prey out of the water. Place pieces onto scrap paper and record how much is captured per bite. In these simulations, the parsley represents krill, copepods and other zooplankton; the Styrofoam represents fish, squid and seals. 2. With each feeding simulation, observe amounts of food collected and record visual estimates on the table below. Weigh the amounts if scales are available. Try to repeat each simulation a number of times to work out an average amount of food per feeding type. Feeding Type Amount of Food Collected Average Amount Skimmers Gulpers Bubblers Biters Question 1: Using your results, which baleen feeding type is most efficient? Why? Question 2: Which prey should toothed whales concentrate on? Why?