SHARKS AND SHORELINES - Nature Works Everywhere

1 | S h a r k s a n d S h o r e l i n e s – T e a c h e r G u i d e

© Janet Haas for The Nature Conservancy

SHARKS AND SHORELINES Subject: Science

Grade level: 6-10

Purpose and Overview:

This set of activities is divided into three parts. In Part 1, through a short video and reading, students learn about lemon sharks, their impact on the mangrove ecosystem, and the threats to sharks worldwide. In Part 2, students partake in a quest to learn about great white sharks and their prey through a series of interactive, online components including real-time data and visualizations. In this activity they identify a shark to track online and then examine the shark’s path and make inferences about where it goes and why. In Part 3, students engage in an outdoor activity designed to teach them about predator/prey relationships in a marine environment. Students assume the roles of predator and prey and through several iterations of the game; they will understand how populations of predators and prey are interconnected.

Time: • Part 1: One to two 45-minute class periods • Part 2: Two 45-minute class periods • Part 3: Two to three 45-minute class periods

Introduction: Through the use of tagging technologies, scientists have been able to track the paths of many marine predators like sharks, seals, and tuna. This information is vital in the conservation of marine animals because it allows scientists to understand potential threats to species where human activities like fishing may overlap migration routes, breeding grounds, and feeding grounds. Additionally, by collecting tracking data on marine animals, scientists can begin to build a picture of the whole marine ecosystem.

In the Sharks and Shorelines | EARTH A New Wild video associated with this set of activities, shark tracking data allowed scientists to identify one of the breeding grounds for the lemon shark: shallow, coastal waters. Scientists determined that these sharks return to the same place every year to give birth. The presence of the sharks controls grazing behavior and ultimately keeps marine herbivores like manatees and sea turtles from overgrazing the mangrove habitat. When the mangroves are intact, they have a role in protecting the coasts from storm surges and coastal erosion. This predator-prey relationship is vital to keeping the mangrove ecosystem strong, which in turn helps keep human habitats from being ruined in the event of a hurricane or powerful tropical storm.


Part 1: Lemon Sharks and Mangroves

Grades: 6-10

Subject: Science

Purpose: The purpose of this activity is to introduce students to the role that lemon sharks play as predators in a marine ecosystem and to relate the behavior of lemon sharks to the preservation of the mangrove forest and the protection of our coasts. Students will also learn about the threats to sharks worldwide and how tagging helps in conservation efforts.

Time: One to two 45-minute class periods

Materials: • Teacher - computer, internet access, LCD projector • Sharks and Shorelines | EARTH A New Wild video (3:56 min)

URL: https://vimeo.com/116273821 • Copies of student worksheet for Part 1 (located at the end of this document) • Small whiteboards or sheets of drawing paper and markers • Student copies of the National Geographic article “Blue Waters of the Bahamas”

URL: http://ngm.nationalgeographic.com/print/2007/03/bahamian-sharks/holland-text • Optional – student access to computers to explore interactive content for the shark ecosystem

URL: http://www.pbslearningmedia.org/resource/5aeed659-7f0b-417f-81d9-5f2e9c747644/ecosystem-explorer-earth-a-new-wild/

Objectives: The student will….

• List the ocean herbivores that can impact a coastal ecosystem. • Describe how sharks maintain the coastal ecosystem through intimidation behavior. • Identify how the tagging of sharks helps scientists to learn more about their behavior. • Relate how tagging data improves shark conservation efforts. • Describe how humans are impacted by the sharks’ presence. • Illustrate the threats to sharks worldwide. • Predict what would happen if sharks, an apex predator, were removed from an ecosystem. • Evaluate how humans can help conserve sharks.

Next Generation Science Standards: Disciplinary Core Ideas: • LS2A Interdependent Relationships in Ecosystems • LS2B Cycle of Matter and Energy Transfer in Ecosystems • LS2C Ecosystem Dynamics, Functioning, and Resilience • LS4D Biodiversity and Humans Crosscutting Concepts: • Cause and Effect • Stability and Change


Performance Expectations: Middle School • MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on

organisms and populations of organisms in an ecosystem. • MS-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple

ecosystems. High School • HS-LS2-6. Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain

relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.

Vocabulary: Bycatch: fish or other organisms caught while actually fishing for another species or target fish.

Ecosystem: a biological community of organisms interacting with the biotic (living) and abiotic (nonliving) components of their environment.

Finning: refers to the removal of shark fins while the remainder of the living shark is discarded into the ocean. Shark fins are in high demand in some parts of the world for use in shark fin soup and traditional cures, in which shark fins are an ingredient. Because fins are worth a lot of money compared to the rest of the shark, fishermen can collect more fins if they harvest them while at sea and throw the rest of the shark overboard. Sharks with their fins removed cannot swim and will eventually perish.

Herbivore: an animal that eats plants.

Longline fishing: a deep-sea, commercial fishing technique in which a really long line (often several miles long) with baited hooks spaced at intervals is used to catch fish; also called longlining. Longline fishing can have serious consequences for sea turtles and sharks when they are caught as bycatch. Sea birds are vulnerable when the longlines are set because they are attracted to the bait.

Mangrove: a tree or shrub that grows in coastal swamps that are flooded at high tide. Mangroves can protect coastlines from erosion and flooding.

Predator: an animal that preys on or eats others; sharks are predators.

Prey: an animal that is hunted and killed by another animal for food.


Suggested Flow for Part 1:

Section A: Video Viewing Guide

1. Distribute copies of the student worksheet for Part 1 so that students can answer the video viewing questions while they are watching the Sharks and Shorelines video. Go over the questions with students so they know what to look for during the video.

2. Show students the video and then give them time to complete any questions on the worksheet that they were unable to answer and then go over questions with the students.

3. Be sure to emphasize with students that the sharks’ presence in the mangrove acts as a deterrent to herbivores like sea turtles and manatees. This is called intimidation behavior. Simply by swimming around, the sharks discourage herbivory, which is what ultimately helps keep the mangrove forests and sea grass communities going strong and these healthy communities provide habitat for a wide variety of marine organisms. Humans benefit because the mangroves can help prevent coastal erosion and flooding.

4. Optional activity: If you have access to student computers, it may be useful to provide students with another opportunity to interact with the shark story. The “Ecosystem Explorer” was inspired by content from the EARTH A New Wild series and includes a “Shark World” where students can explore the shark ecosystem through interactive, multi-media content. You can find the interactive content here: http://www.pbslearningmedia.org/resource/5aeed659-7f0b-417f-81d9-5f2e9c747644/ecosystem-explorer-earth-a-new-wild/. If time doesn’t permit, you could assign this as homework.

Part 1 Student Worksheet - Video Viewing Questions Answer Key 1. In the video, scientists are shown tagging different ocean predators. What kinds of data can

scientists collect from the tags? Answer: The tags data can tell scientists when are where the sharks are moving. Scientists can determine key migration routes, breeding grounds, and feeding grounds.

2. How does the tagging help with conservation? Answer: It helps pinpoint the areas that might need to be protected. Tagging also shows movement and distribution patterns, as well as biological hot-spots, so that the culling of marine populations can be done with much more sustainable foresight.

3. What have researchers learned about lemon sharks through tagging? Answer: Lemon shark females return to their birth places to give birth to new young.

4. What does the mangrove ecosystem provide for organisms? Answer: It provides food and shelter for a variety of young marine organisms. An “underwater nursery.”

5. How do sharks maintain the mangrove ecosystem? Sharks regulate feeding behavior of prey. Herbivores are less likely to eat as much vegetation when they are on the lookout for sharks.


6. List some examples of marine herbivores. Answer: Manatees, sea turtles, some species of fish

7. How do the sharks help humans? Answer: The mangroves decrease powerful waves that hit the shores during storms. Just by swimming in coastal waters, sharks keep the mangroves and sea grass areas healthy by preventing overgrazing. By protecting these areas, we are protecting shark nurseries and the sharks help protect the mangrove, which in turn protects our vulnerable coasts.

Section B: Threats to Sharks 1. The purpose of this part of the activity is for students to read more about the sharks around Bimini

in the Bahamas and learn about some of the threats to the sharks there and elsewhere in the world. If you have time for students to read an article to learn more, they can do the following reading and white-boarding activity. If you want to introduce students to the threats that sharks face worldwide, but are short on time, you can show the video, “Collapse of Sharks” (3:05 minutes), which examines the demand for shark fins in the Far East and describes the resulting decrease in shark populations. URL: http://www.pbslearningmedia.org/resource/nat08.living.eco.humeco.collapse/collapse-of-sharks/

2. Distribute copies of the three-page National Geographic article “Blue Waters of the Bahamas” by Jennifer S. Holland and have students read the article. They can do this in class or for homework to save class time.

3. After students have read the article, assign them to small groups of three to four.

4. Distribute white boards or large sheets of drawing paper to each group.

5. Read off the first question and give students two to three minutes to do a very simple illustration for this topic. Emphasize that it does not need to be a work of art – stick figures will do. There should be no text accompanying their drawings. The groups can talk through what should be drawn and elect a student to do the drawing or they can all share the task. If you have access to small whiteboards, give one to each group for their drawings. If not, use large sheets of paper, or have students do this in their notebooks in small groups. If you have access to a document camera, students can project their drawings. The purpose behind using drawing for this activity is for students to synthesize the information from the text and not to copy from the reading when answering a question.

6. Once the time is up, have all of the students hold up their drawings and have the whole class look around and see what was drawn. Have each group elect a speaker to explain their illustrations. By having students hold up their drawings, you can quickly assess how the students have interpreted the reading and other students can check their answers against the rest of the class. Students may have drawn different things and that will allow the class to see the different interpretations of the article as well as the similarities.


7. Repeat this process for every topic in the list below.

Topics for illustrations:

• According to this article, what are the biggest threats that lemon sharks face? Drawings may include fishing, long-lining, finning, human development

• Why are mangroves being threatened in the Bahamas? Drawings may include buildings, boats, marinas, casinos

• How would the depletion or removal of an apex predator, like the lemon shark affect the marine ecosystem. Drawings may include sharks eating other fish that are eating algae on coral reefs.

8. After the rounds of drawings are complete, conduct a final discussion and ask the students to share

ideas about how humans can help sharks and marine ecosystems. Student answers may include managing the number of tourists and creating marine protected areas.

Other Resources for Part 1:

• Information on the biology of Lemon Sharks: http://www.elasmo-research.org/education/ecology/estuaries-lemon.htm

• Shark facts and information on how The Nature Conservancy is working to project sharks: http://www.nature.org/ourinitiatives/habitats/oceanscoasts/sharks.xml


Part 2: Track a Shark!

Grades: 6-10

Subject: Science

Purpose: The purpose of this activity is to give students a chance to investigate the life of a great white shark using real tracking data from an online source. Students will also analyze other data to determine the reasons behind shark migration.

Time: Two 45-minute class periods

Materials: • Teacher – computer, internet, LCD projector • Copies of student worksheet for Part 2 (located at the end of this document) • Internet with access to http://www.ocearch.org/ website • Computers (one per student is ideal for this activity, but you could also group students on

computers)

Objectives: The student will…

• Describe the movement of sharks using an online tracking tool. • Analyze the movement of sharks based on tracking data, sea surface temperature, and other

factors. • Relate shark movements to the geography the East Coast of the U.S. and the sea floor of the

Atlantic Ocean. • Identify areas where sharks and humans may come into contact. • List the threats to sharks and describe how tagging data can help shark conservation efforts. • Evaluate information and create a statement to explain the reasons behind shark migration.

Next Generation Science Standards: Disciplinary Core Ideas: • LS2A Interdependent Relationships in Ecosystems • LS2B Cycle of Matter and Energy Transfer in Ecosystems • LS2C Ecosystem Dynamics, Functioning, and Resilience • LS4D Biodiversity and Humans Crosscutting Concepts: • Patterns • Cause and Effect Science and Engineering Practices: • Asking questions • Analyzing and interpreting data • Constructing explanations • Engaging in argument from evidence


Performance Expectations: Middle School • MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on

organisms and populations of organisms in an ecosystem. • MS-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple

ecosystems. • MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological

components of an ecosystem affect populations.

Vocabulary: Bathymetry: the study of underwater depth of bodies of water. The word bathymetric relates to

measurements of the depths of oceans or lakes.

Sea surface temperature: is the water temperature close to the ocean’s surface. This temperature can be measured remotely by satellites.


Suggested flow for Part 2: 1. Distribute copies of the student worksheet for Part 2 to students. The teacher answer key is on the

next page.

2. Project the http://www.ocearch.org/ website and walk students through some of the basic functionality.

3. It may be useful to give students a background on some of the geographic features of the sea floor to give them some context for where the sharks go. If students can make connections between these features it will help them to understand how scientists use location clues as a starting point for asking more questions and conducting research. The tracked sharks tend to stay on the continental shelf of the United States. So it’s a little unusual to see a shark venture far out into the deeper waters beyond the continental shelf.

4. Use the websites below to show students what the ocean floor looks like and give them context for understanding the difference between the continental shelf and the deep ocean.

a. Use the link below to project the bathymetric map of the Atlantic Ocean floor created by the National Oceanic and Atmospheric Administration (NOAA). URL: http://www.nnvl.noaa.gov/MediaDetail.php?MediaID=572&MediaTypeID=1 Talking points for this image:

• Notice how the continental shelf of the East Coast gently drops off • The Mid-Atlantic ridge is the world’s longest mountain range that splits the Atlantic

Ocean into East and West. • The Puerto Rico Trench is the deepest part of the Atlantic

b. Use the link below to show an animated tour of the sea floor created by using a

combination of ship-based measurements and satellite data. Go to the link and click play on the video, which was created by the Environmental Visualization Laboratory at NOAA. URL: http://www.nnvl.noaa.gov/MediaDetail2.php?MediaID=662&MediaTypeID=3&ResourceID=104527

c. Click this link to view a collection of materials by NOAA on the ocean floor, including background information on the tectonic plates, trenches, canyons, volcanoes, and more: URL: http://www.education.noaa.gov/Ocean_and_Coasts/Ocean_Floor_Features.html

5. After this introduction, send students to computers to work through the tasks on their worksheet and move about the room to support them as questions arise.

6. When students have completed the worksheet, regroup and have a class discussion. Since students could track four different sharks, you may wish to have students who researched the same shark combine together to compare their description of their shark’s movement. Alternatively, you could group students together who researched different sharks so that they can compare and contrast the difference in shark movement.


SHARKS AND SHORELINES Student Worksheet – TEACHER ANSWER KEY Part 2: Track a Shark! Instructions:

• Go to http://www.ocearch.org/ and explore the site for a few minutes to understand how it works.

• After you have explored, in the left hand box under sharks, enter the names: Mary Lee, Betsy, Genie, and Katharine. Type the full name, hit enter, then type another name. If you try to select the name as it pops up below, it may be difficult to select more than one shark at a time. Once you have all four sharks selected, under tracking activity, select “last two years.” Under gender and stage of life leave it as the default “all”. Under tagged at, select “Cape Cod”. Then click “track shark.”

• For easier map viewing, close the social media box on the right side, and then your map should look approximately like the image to the right.

• When you mouse over one of the circles on the colored line, it indicates the time and date of the shark’s ping as shown in the image below on the left. If you click on a dot, you get the time and date AND the name of the shark. The large orange circles with the white center show the most recent location of the shark. When you click on the orange circle, you get detailed information about the shark (example in the image below on the right).

OCEARCH™ Screenshot

OCEARCH™ Screenshot OCEARCH™ Screenshot


Answer the questions below utilizing the OCEARCH™ website with the tracks for Mary Lee, Betsy, Genie, and Katharine displayed.

Questions:

1. What is a ping? Can sharks send a ping when they are underwater? (hint: mouse over the information “i” in the Global Shark Tracker box. Answer: A ping is when the shark’s dorsal fin breaks the surface of the water and transmits a signal to a satellite overhead. The satellite then transmits an estimated geo-location that is placed on the map. Sharks do not send a ping when they are underwater.

2. Some sharks have large gaps in tracking data, what might account for this? (hint: look at recent pings for a clue) Answer: If sharks don’t surface long enough for the location to be detected, there might a gap in the tracking data. The next time the shark surfaces, we will know where it is but we will not be able to tell where it went between pings.

3. Based on the map you have generated of the sharks’ movement over 2 years, what is one thing that all 4 sharks have in common at first glance? Answer: For the most part, all sharks stay in the Atlantic Ocean right off of the East Coast of the United States. Most of the pings don’t go farther north than Massachusetts and don’t go farther south than Florida.

4. What are some differences that you notice? Refer to sharks by name when describing the differences. Answer: In February and March 2013, Mary Lee went much farther out into the ocean than the other sharks. In December 2013, Betsy went the farthest out into the Atlantic Ocean and then the next ping wasn’t until April 2014 when she showed up in the Gulf of Mexico. Only Betsy and Katharine went into the Gulf of Mexico, but Betsy ventured the farthest into the Gulf, while Katharine stayed closer to Florida.

5. How can you tell which direction sharks are moving? Answer: Start by mousing over the dots to look at the dates. Then see which dates come first. For example, you can tell if a shark is moving south if the newer dates are all south of the first dot you examined.

6. Which island was Mary Lee near during February 2013? Answer: Bermuda

7. Zoom in on Cape Cod. In which months does it appear that Mary Lee, Betsy, Genie, and Katharine sharks are near Cape Cod? Answer: In general, it seems that they are there from August through December.

8. If the line between two dots (pings) goes across land, what can you infer about a shark’s path? Answer: Since sharks can’t move across land, it just means that the shark likely swam around a land feature but didn’t surface long enough to ping. So the map drew a line to connect the dots, but that’s not really accurate. Or if the shark did surface long enough, maybe there was a fault with the transmitter.


Now that scientists have access to shark tracking data, they are just beginning to get a picture of where sharks spend their time. However, there is still much research to be done before scientists know why sharks where go where they do. Betsy, Genie, Katharine, and Mary Lee are all the same species of shark – great white. Pick one of these sharks to track.

**Note for teacher: Genie and Betsy do not have as many pings, so if you have students that may need more time for activities need other modifications you might suggest that they choose one of these two sharks.

Once you have decided on the shark, delete the other three sharks from the map by clicking on the “x” next to their names in the Global Shark Tracker box.

Which shark will you track?_______answer key includes all 4 sharks___

Use the map on page 10 (page 19 of the teacher guide) of this worksheet to help you take notes about shark location. It may be useful to change the tracking activity time parameters, for example, you could track one year or just one week. By fine tuning your shark track, you might be able to get an idea of how long it stays in one location. At the very bottom of the map, you can click full screen to get rid of the control box for better viewing.

When you locate your shark, pay attention and make note of the underwater geographic features nearby on the map. Note that the darker the blue color, the deeper the water. The light blue areas are shallower waters and are usually located above a continental shelf. You can also see mid-ocean ridges and trenches on the OCEARCH™ map. The image below shows a 3-D version of the sea floor.

Image Credit: NOAA Environmental Visualization Lab


Use the hints and guiding questions below to help you get started with your research. The goal of your research is to establish a profile for your shark, which will serve as a starting point for trying to answer the question “why does my shark go where it goes?”

9. Under tracking activity select “past year” and then click track shark. Write a detailed description of what your shark did in the last year. Where does your shark go during the summer, fall, winter, and spring? Use cities, states, directions (N, S, E, and W), and geographic features in your answer. Use the map on page 10 (page 19 of the teacher guide) to write location notes to help you craft your answer.

**Teacher note: the answers to the following questions will vary since the data is real-time. If you use this lesson a year from when it was written, the shark track could be very different from the answers below. These example answers for Mary Lee and Katharine are based off of tracking data from the years 2014-2015.

Answers:

Mary Lee: Mary Lee spent some of Jan 2014 out in the deeper water off of the continental shelf, then for most of 2014 she stayed fairly close to the East Coast between the cities of Charleston, SC and Jacksonville, FL. In Dec 2014 she headed NE, nearly in the same direction as she was in Jan 2014, but this time not go past the edge of the continental shelf. In Jan 2015 she pinged back in the area where she spent most of 2014 and was directly off the coast from Savannah, GA.

Katharine: She pinged near Daytona Beach, FL in Jan 2014 and then headed north in Feb 2014. She swam around the area between Savannah, GA and Jacksonville, FL during the next few months. From May to June 2014 she went south around the tip of Florida, stopping at Key West on May 27th and then into the Gulf of Mexico. Between July 6th and July 17th she swam out of the Gulf and around the tip of Florida but didn’t ping between those dates. She then started heading north and was already to Daytona Beach by Jul 21, 2014. She was off the coast of NC in September 2014 and headed toward Cape Cod in Oct, Nov, and part of Dec 2014. In December 2014 she started to head away from the cape and by Jan 2, 2015 she was at the edge of the continental shelf west of NYC. By Jan 5, 2015 she was still off the continental shelf but had reached due east of Delaware. There were some weird pings that showed up on Jan 10th on land, but that was probably some kind of transmission error. Either way, she pinged several times on the 10th and she was very close to the Cape Hatteras National Sea Shore in NC. She continued moving south down the coast and on Jan 22, 2015 she pinged off of the coast of SC near Hilton Head Island.

Genie: In Jan 2014 Genie was near the coast by Savannah, GA and then she swam south toward Jacksonville, FL by the end of Jan. She pinged again in April 2014 off the continental shelf SE of Virginia Beach, VA. By May she had moved north, still off the continental shelf but this time east of the NJ coast. On May 25, 2014 she pinged off the coast of the Eastern Shore of VA and then headed south where she pinged again on July 21, 2014 near Savannah, GA. By Sept 2014 she was headed back north and pinged off of the coast of VA again. The next time she pinged she was near Cape Cod in Oct 2014.


Betsy: On April 18, 2014 Betsy was far out in the Gulf of Mexico directly south of Louisiana. Then on April 23, 2014 she pinged closer to FL near Cape Coral. She stayed in this area until at least the beginning of June. Her next ping wasn’t until Sep 27, 2014 off the island of Nantucket. She pinged near Nantucket a month later on Oct 22, 2014 and then headed directly south and pinged again near the continental shelf east of NJ on Nov 15, 2014. She headed south and then pinged right near Rehoboth Beach on the Delaware coast on Nov 21, 2014. Her last ping was the same day but she had headed out to sea and was due east of DE off the continental shelf.

10. Select “all activity” under tracking activity and then click track shark. If your shark took a surprising or unusual path, where did it go? Answers:

Mary Lee: Mary Lee has a lot of history and a lot of pings. In all of her activity dating back to her tag date of Sept 17, 2012 – the most unusual event was when she went headed due east from Long Island, NY in Jan 2013 and then went north a little bit near the edge of the continental shelf and then headed south and pinged at Bermuda in late Feb 2013. She then headed SW of Bermuda and didn’t start heading back to the US coast until March 2013. She pinged near the coast of NC in late March 2013.

Katharine: Katherine went into the Gulf of Mexico and spent a lot of time there just due south of Panama City, FL in June 2014. She also seems to surface a lot compared to the other sharks. She has a lot of pings! But from July 21-28 she has no pings and swims really far NE from Daytona Beach, FL in a northerly direction and pings again far off the coast of Charleston, SC.

Genie: Genie’s path was pretty consistent. She traveled north and south off the coast of GA and up to Cape Cod. The only real anomaly was when she was farther out in the ocean due east from Cape Hatteras in April 2014.

Betsy: Went far out into the Gulf of Mexico in April 2014. She also went very far out in the Atlantic past the continental shelf in Dec 2013.

11. Make a list of reasons that sharks might go to certain places (think about the things that every animal needs to do). Answer:

• Sharks need to find a mate and breed • They need to give birth to young • They need food


12. The article “Shark Spring Break: Florida Swarm Explained” (link below) says that sharks head south for spring break. Did your shark spend the spring near Florida? URL: http://news.discovery.com/animals/sharks/shark-spring-break-swarm-explained-130308.htm Answers: Mary Lee: in the last two years (2013-2014) Mary Lee did not swim to FL during the spring months Katharine: Was near the coasts of Georgia and Florida in the spring of 2014. Genie: In the spring of 2014 Genie was nowhere near Florida. In April 2014 she was off the coast of Virginia and North Carolina, far out in the water past the continental shelf. Betsy: Did head south for Spring Break and spent April 2014 in the Gulf of Mexico.

13. One thing that all 4 sharks had in common was they were originally tagged on Cape Cod in Massachusetts. Why do the sharks come to the Cape Cod area? A scientist recently tweeted this clue; can it help you answer the question?

“A weird concentration of black spots has been spotted in a satellite image. Where is this, what are the black spots? #beachmystery #sharkbait https://goo.gl/maps/2bTHA”

Open the map and see if you can identify where the black dots are (circled in red below), what they are, and explain why they are important to sharks.

Answer: The black dots are gray seals on the beach near the Monomoy National Wildlife Refuge on Cape Cod. Gray seals are food for the sharks and are a huge reason for the sharks return to this area.

**Teacher note: If students can’t figure out the relevance of the image, they could read this article about sharks returning to Cape Cod to eat gray seals.

URL: http://www.slate.com/articles/health_and_science/science/2013/07/sharks_return_to_cape_cod_gray_seals_are_the_bait.html

Google Maps Screenshot


Image credit: Tobey Curtis, NOAA Fisheries

In the image to the right, the green dots represent 649 verified white shark observations in the Northwest Atlantic Ocean from 1800-2010.

The white shark observation records that were used to make this graphic were compiled from a variety of sources including commercial fishery observer programs, scientific research surveys, commercial and recreational fisherman, newspaper articles, recreational tournaments, scientists, landings data (total number of species captures, brought to shore, and sold), and more.

Unfortunately, because the sightings only occur when human-shark interactions happen, this does not capture the whole picture of shark movement, however, this data set from a 2014 paper by Tobey Curtis et al. represents the most comprehensive information on great white shark location in the Northwest Atlantic Ocean so far. Continued shark observation and tagging data will only help to complete the picture and will be useful for shark conservation and management moving forward.

14. Describe the location of the Northwest Atlantic Ocean (see above image) shark observations with respect to the coastlines, continental shelf, and the deep ocean. Answer: In general, the observed sharks were in shallower waters on the continental shelf and close to the coastline. In rare occasions they have been spotted out in deeper waters.

15. Is it possible that sharks could occur in deeper waters past the continental shelf? Answer: Yes, because these data are limited to human-shark interactions, it is possible that we don’t know the whole story. There are a few sharks in the OCEARCH™ data and even in the image above that went farther out into the Atlantic (Bermuda). In fact, there are OCEARCH™ tagged sharks around the rest of the world that don’t always stay near coastlines.

**Teacher note: you may want to point students to the whole OCEARCH™ map since this activity restricted them to sharks that were tagged at Cape Cod and live in the Atlantic. This will help them see the behaviors of sharks that live in other parts of the world.

16. How can satellite tracking data help to give a better picture of shark movement compared to human observation alone? Answer: Sharks must have some interaction with humans in order to be captured and tagged, but after that the satellite picks up shark location when sharks surface. This location data doesn’t depend on human-shark interaction. This is drastically different from human observation alone, which might consist of only one location data point for one shark. The satellite tracking data helps to depict the whole journey of a single shark over several years, which is a far richer data set. In addition, when sharks are tagged, shark details like age and gender are recorded so researchers can combine this information with the track to start to help answer questions like “do female great white sharks have different migration patterns than male sharks?”


In the images above, shark sightings by season are overlaid on maps of sea surface temperature (SST). As shown in the key, the redder the color of the ocean, the hotter the SST. The darker blue ocean color indicates cooler SST.

In the diagram, CC stands for Cape Cod; NYB = New York Bight; CH = Cape Hatteras; FL = Florida; GOM = Gulf of Mexico; and CS = Caribbean Sea.

17. Based on the information in the sea surface temperature (SST) images above, make a statement that describes how shark location relates to SST. Be sure to use approximate locations and temperature values in your description. Answer: In the winter months when SST is cooler near Cape Cod, sharks were spotted off the coast of North Carolina and all the way down to Florida where it is warmer than approximately 20o C. In the summer months when SST rises significantly to around 35o C around Florida and all the way up to Delaware, the majority of shark sightings were around the NE coast from Delaware and north to Canada where the water is much cooler than approximately 30o C. In the fall and spring when SST is less extreme, the sharks were more evenly distributed along the coast compared to winter and summer. In the spring, there were a few more in around Florida than in the fall, but this is likely because the some sharks were still hanging around after the winter months. In the fall, there were a few more sightings in the NE, likely because not all of the sharks had started their southward migration for winter.

Image credit: CC by Tobey Curtis et al. (2014), NOAA Fisheries


18. Based on your findings so far, describe what you think are some of the major influencers of shark movement. Answer: Sharks appear to prefer swimming in waters near the coast and on the continental shelf. It also appears that they move where food is and they are influenced by sea surface temperature.

19. What are some unanswered questions you have at this point? These unanswered questions could form the basis of a scientific research project. Answers may vary but could include:

• Why do some sharks go way out into the deep ocean – like the one that showed up near Bermuda?

• Where do the sharks go to breed and have young? • How will climate change influence shark movement? • How does the population of gray seals affect the shark population?

20. Sharks are pretty fierce animals, but they are not immune to threats. What kinds of things or

activities might endanger sharks? Answer: Commercial fishing, finning.

21. Looking at the track of your shark, where are areas that you think the shark could potentially encounter humans? Mark them on your paper map on page 10 with the letter “x”. Answer: Will vary, but students should mark areas where their shark came very close to the coast where humans might be swimming, surfing, or doing other recreational activities.

22. How does have shark tagging data help us to conserve sharks and shark habitat? Answer: If we can see where sharks go, we can determine which areas might need more protection. For example, shark nursery areas might need to be protected. To ensure that sharks can reproduce and keep their populations going strong.

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SHARKS AND SHORELINES - Nature Works Everywhere