Gray Whales in the Sanctuary Teaching Notes

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1 Gray Whales in the Sanctuary Teaching Notes Lesson Overview This lesson asks students to examine whale data from the Channel Islands National Marine Sanctuary and draw conclusions about Gray Whale migration through the Sanctuary. Objectives: California State Standards Addressed Grade(s): 7th Students know both genetic variation and environmental factors are causes of evolution and diversity of organisms (Life Sciences, 3a) Students know that extinction of a species occurs when the environment changes and that the adaptive characteristics of a species are insufficient for its survival. (Life Sciences, 3e) Grade(s): 9 th 12 th Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats. (Life Sciences, 6a) Students know how fluctuations in population size in an ecosystem are determined by the relative rates of birth, immigration, emigration, and death. (Life Sciences, 6c) Students use technology tools to enhance learning, increase productivity, and promote creativity. (Technology) Students use a variety of media and formats to communicate information and ideas effectively to multiple audiences. (Technology) Make informed choices among technology systems, resources, and services. (Social, Ethical, and Human Issues, Category 2) Student Learning Objectives Students will examine marine mammal data in the Channel Islands, drawing conclusions about where and why whales migrate through the sanctuary. Students will be able to identify the migratory patterns of California Gray Whales. Students will identify the feeding habits of California Gray Whales. Students will identify the reproductive habits of California Gray Whales. Students will determine how feeding and reproduction influence migratory patterns of California Gray Whales. Students will be able to communicate what they have investigated by creating a poster/presentation of their findings. Print Resources Simmonds, Whales and Dolphins of the World The MIT Press, Boston, MA. 6/26/2007 p. 1 of 9

2 Carwardine, Mark & Camm, Martin. Whales, Dolphins, & Porpoises. 1995, Dorling Kindersley Limited, New York, NY. Waller, Geoffrey ed., Burchett, Michael & Hull, Richard. Sealife: A complete guide to the Marine Environment Smithsonian Institute Press, Washington, D.C. Online Resources American Cetacean Society: American Cetacean Society Channel Islands Chapter s Gray Whales Count: Channel Islands National Marine Sanctuary Marine Mammal Sightings Database: NOAA Fisheries Marine Mammal Stock Assessment Report: Answers 1. Nineteen different species of marine mammals are seen around the Channel Islands. 2. Yes, bathymetry does affect the distribution of whales. Most of the whales are found in shallow waters. 3. The symbols representing the different whale species changed color. 4. Answers will vary depending upon which color scheme was applied. 5. Answers will vary depending upon what sighting was examined. Sample data provided: a) Type of Animal: Common Dolphin b) Date Seen (YYYYMMDD): c) Vessel Spotted: Condor Express d) Coordinates: ( , ) 6. Yes. Most gray whale sightings in Channel Islands National Marine Sanctuary (CINMS) occur during the spring and fall. During the spring, most of the gray whale sightings are near shore. During the winter, most the gray whale sightings occur offshore, close to the islands. Few gray whale sightings occur during the summer or fall. 7. Gray whales migrate over 12,000 miles annually. 8. Gray whales travel south to Mexico in the winter. 9. They return in the spring to their Northern feeding grounds. 10. Answers will vary. Gray whales stay close to shore in the spring as they return to the Artic Circle to feed with their young. It may be safer near the shore. 11. Although gray whales are primarily spotted in CINMS during the spring and winter, there are also a few summer sightings. These whales may be slow to migrate, have late births, or be lost. 12. The color of the summer gray whale sightings changed from red to yellow. 13. The summer sightings occurred during June, July and August. 14. Some of the sightings may have been the same animal, but not all. Several sightings occur on the same day and at different (distant) parts of the sanctuary. 6/26/2007 p. 2 of 9

3 15. Answers will vary. Students should note that the whales congregate near shore and seem to prefer soft sediments. 16. The gray whales are found primarily over soft substrates. 17. Gray whales feed by scooping up a mouthful of mud from the sea floor. It uses it tongue to push the mud through their baleen in order to filter out the food. 18. Answers will vary. It is easier for the whales to feed over soft sediments than hard (rocky) substrates. 19. They travel to Baja California during the winter so their young are born in warm waters. They return to the north for the rich feeding grounds. 20. The advantage of having calves in warmer waters is that the calves spend less energy staying warm and have more energy to grow. 21. They return to the north because the food supply is so abundant. The calves can grow and lay down fat stores for warmth and their annual migration. 22. Answers will vary. The gray whales stay close to shore in the spring because it s safer for the calves. 6/26/2007 p. 3 of 9

4 Gray Whales in the Sanctuary Student Lesson Lesson Overview In this activity, you will analyze the variable patterns in California Grey Whale Migrations throughout the Channel Islands Marine Sanctuary. As you investigate these patterns, you will explore Gray Whale feeding, migratory, and social behaviors, Channel Islands Marine Sanctuary substrate, kelp beds, and water temperature patterns; and analyze the variations in behavior between the different seasons and migratory patterns. GIS Activity Launch ArcView 3.2 or 3.3. Double click the ArcView icon on your computer s desktop or choose Start/All Programs from the Windows menu. If the Welcome to ArcView dialog appears, click Open an Existing Project and click OK. If it doesn t appear, choose File/Open Project from the ArcView program menus. Open the project file titled, Gray_Whales.apr. Navigate to the Gray_Whales folder on your hard drive. Choose Gray_Whales.apr, and click OK (Windows) or Open (Macintosh). The Gray_Whales.apr project opens showing the Channel Islands located off the coast of southern California (near the cities of San Barbara and Ventura). Click, the maximize button in the upper right corner of your ArcView window. Explore the distribution of marine mammals around the Channel Island. Turn on the CINMS Marine Mammals data layer by clicking the check box in front of the theme name. The marine mammal sighting data was collected by volunteer naturalists aboard commercial whale watching boats. Turn on the Bathymetry theme. Depth is measured in meters. Darker shades of blue represent deeper waters, lighter shades of blue represent shallower waters. You may need to turn the Marine Mammals theme on and off to see the impact of depth on the distribution of marine mammals. 1. How many different types of marine mammals are seen in the Channel Islands? 2. Does the bathymetry or water depth seem to influence where marine mammals are seen? If so, how? Zoom in on the Channel Islands. Choose 7, the Zoom-In tool from the tool bar. Click and drag a box around the Channel Islands National Marine Sanctuary. If you make a mistake, click 2, the Zoom-to-Previous-Extent tool, and try again. 6/26/2007 p. 4 of 9

5 If necessary, use 9, the Pan tool, to adjust or center the view (map) window without zooming in. Change the CINMS Marine Mammals legend. Activate the CINMS Marine Mammals theme by double-clicking on the theme name. It should appear raised or have a shadow around it. Open the Legend Editor window by double click on the theme s symbols. Update the Legend Editor window by choosing a different color scheme by first finding the Color Scheme: box near the bottom of the window, then using from the pull-down menu to select a different color scheme. Click Apply and close the Legend Editor window. 3. How did the view (map) change? 4. Do different species stand out than in the previous color scheme? The power of a GIS system such as ArcView is that the map you see is directly tied to the information used to create the map. You can explore the data tables for each theme and its attributes (information about the feature, such as the species name, behavior, reporting vessel, etc) by using 3, the Identify tool, or opening the theme s attribute table. Explore the information provided for each sighting point using 3, the Identify tool. Choose 3 from the tool bar. Click on one of the marine mammal data points. An Identify Results window will open showing all of the attribute information associated with the sighting point you click on. Study the information contained in the window. Record the relevant information on your Data Sheet. Note: If you click in a location where the symbols are overlapping, the Identify Results window will display the attribute information for all of the sightings. It may take a few minutes to display all of the attribute information. Be patient! 5. Record the following information for one of the sightings: a. What type of animal is represented? b. When was it seen? c. Which vessel spotted this animal? d. What are the coordinates (latitude and longitude values) for the sighting? Close the Identify Results window. Observe California Gray Whale Migratory Patterns. Turn off the CINMS Marine Mammals theme by clicking in the check box. Turn on the CI Gray Whales and click on the theme name to activate it. The theme name should appear raised. Using the 3 tool, click on one of the gray whale sighting. Try to pick a whale sighting that is located away from other sightings. What information is provided about each sighting? Use the scroll areas to see all the information provided for each sighting. 6/26/2007 p. 5 of 9

Notice that the date of the sighting and its season (spring, summer, etc.) are recorded. Explore seasonal differences in gray whale sightings by classifying the gray whale sightings by seasons.

6 Notice that the date of the sighting and its season (spring, summer, etc.) are recorded. Explore seasonal differences in gray whale sightings by classifying the gray whale sightings by seasons. First, close the Identify Results window. Next, open the Legend Editor by double clicking on the gray whale symbol under the theme name (on the left side of the window). Update it as shown on the right: o Change the Legend Type: to Unique Value. o Set the Values Field: to Season. o Choose a Color Schemes: from the drop-down list. o Click Apply. o Close the Legend Editor window. 6. Are there any patterns in Gray Whale migration during different seasons? Read more about gray whale migrations. Click on the Gray_Whales.apr project window to activate it. Click the Views icon, choose Gray Whale Migration from the list of views, and then click Open. A new window describing Gray Whale migration will appear. Study the information provided, then answer the following questions. 7. How long of a migration do Gray Whales make? 8. What time of year do they travel to Mexico? 9. What time of year do they return? 10. Why do the gray whales stay near shore in the Spring but not in the Winter? 11. Why do you think there are a few gray whale sightings in the summer? Close the Gray Whale Migration window. Build a query to view only the gray whale sightings that occurred during the summer. Open the query builder by clicking,, the Query Builder tool, or choosing Theme/Query from the menu bar. Update the CI Gray Whales Query window to select the summer sightings. o Under Fields:, double click on Season. o Single click once on the = sign. o Under Values:, double click on Summer. o Click the New Set button. Note: If you get a syntax error message, close the query window, re-open the query window and begin again. o Close the Query window. 12. What happened to the color of the Summer Gray Whale sightings? 6/26/2007 p. 6 of 9

7 Choose 3, the Identify button from the tool bar and then click on several of the yellow sightings. 13. When did these sightings occur? 14. Looking at the dates of the sightings in the information box, could these sightings all possible be of the same animal? Compare the bottom sediments found throughout the sanctuary with the location of whale sightings to identify any patterns. Turn on the CI Benthic Habitat theme. This theme shows the type of bottom sediments (soft or sandy versus hard or rocky substrate) and the water depth. 15. Do you see any patterns in the gray whale migration and substrate composition? 16. What types of substrate do the gray whales seem to prefer? Why? Open the Gray Whale Feeding view. If necessary, open the project window by choosing Window/Gray_Whales.apr from the ArcView program window. Click the Views icon to display a list of available views. Choose the Gray Whale Feeding view by clicking on it to activate it. Open the Gray Whale Feeding view by clicking Open or double clicking on the theme name. Study the image and read the description of gray whale feeding behavior. 17. How do the whales feed? 18. Is there any advantage to the substrate being harder or softer in their feeding behaviors? Close the Gray Whale Feeding view. Analyze information on Gray Whale behaviors. Open the Behaviors view and study it. Close it when you are finished. Open Calving view and study it. Close it when you are finished. 19. Why do the whales migrate so far? 20. What is the advantage of having calves in warmer waters? 21. Why do the whales return to the Artic? 22. Why don t the whales return to the Arctic on the same path they took to get to Mexico? Do you see any advantages to taking a different path? Close ArcView. When asked Save changes? choose No. 6/26/2007 p. 7 of 9

8 Background Information Classification: Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Cetacea Family: Eschrichtiidae Genus: Eschrichtius Species: robustus California Gray Whales Adult gray whales weigh between tons and average between feet long. Newborns are estimated to weigh 1/2 of a ton at birth and average between 1 17 feet in length. Fossil records indicate gray whales have ancestors dating 100,000 years ago, with relatively little change to the current species. Current global numbers of gray whales are estimated between 21,000-23,000 individuals. A small number of gray whales found of the California coast are a part of the Korean population while the majority of individuals are a part of the California population. The North Atlantic population was extinct, possibly due to over whaling, by the late 1800 s. Gray whales are a mottled gray color, often with encrusted barnacles, lice, and mites. Migration The California gray whale, Eshrichtius robustus, completes one of the longest known migrations of any mammal. Gray whales spend the summer in Arctic feeding grounds and the winter in breeding grounds off the coast of Baja California. The migration averages 12,400 miles annually. Calving usually occurs between January 5 and February 15. The gray whales return to the Arctic in the summer to feed. Feeding Patterns Gray whales are bottom feeders. They are capable of diving as deep as 345 feet to feed, but generally prefer shallower depths. While feeding, gray whales turn onto one side and fill their mouths with sediment, then use their tongue to push the water and sediment out of their mouths, through the baleen. The baleen traps small invertebrates and fish. Gray whales feed primarily on benthic amphipods, mollusks, crabs, and polychaete worms. Often individual whales prefer feeding on one side or the other. This causes noticeable differences between the two sides of the head; one side may appear damaged scraped, scarred, etc. The damage results from consistently feeding on one side and rubbing against the sea floor, or on the baleen from consistently using one side. Calving Gray whale mothers are extremely protective of their calves, and were nicknamed the devilfish by whalers for their aggressive protective behaviors of their calves. Mothers and calves remain in the lagoons until the calves are able to make the return voyage to the feeing grounds in the north. 6/26/2007 p. 8 of 9

9 Behaviors Gray whales are seen breaching, lifting 75% of their bodies out of the water, then pivoting and landing on their sides or backs, typically 2 or 3 times in a row. This behavior is seen in all waters, but primarily in the breeding grounds. Gray whales also are known for spy hopping, where the head is lifted vertically out of the water, raising the eye above the surface, sometimes turning. It is thought that the spy hopping behavior is used to help navigate throughout their migration. The gray whales blow is usually a V-shaped spray- due the two distinct blowholes. During migration, Gray whales breathe every 3-5 minutes before diving. On deep dives, whales raise their tail flukes above the surface of the water before taking a vertical stroke and heading into deep waters. 6/26/2007 p. 9 of 9

MARINE MAMMALS. Species: Feeding: Breathing adaptations? Seasonality: What species can be commonly seen locally? baleen or teeth?

MARINE MAMMALS. Species: Feeding: Breathing adaptations? Seasonality: What species can be commonly seen locally? baleen or teeth? MARINE MAMMALS The order Cetacea, which includes whales, dolphins, and porpoises is divided into two suborders: Mysticeti and Odontoceti. For the suborders below, list the species commonly sighted in Virginia