This multi-part activity really dives deep into the ‘super powers’ of sharks! To survive and dominate in their marine habitat as top predators, over the millennia sharks have developed several unique superpowers, or as they are most commonly known as, adaptations 😉 This activity is a dynamic, hands-on way for students to explore several of these adaptions. Rotating around stations, they will learn more about sharks’ sense of smell, their teeth, electrical detection, and encounters with people.
- Small, opaque jars each filled with a unique, fragrant scent with holes poked into the lids
- Set of cards with various shark species and the kind of food they eat.
- Set of cards with pictures of those same shark species’ teeth
- Container filled with small strips of crumpled paper, sand or sawdust
- Small metal objects to bury in container
- Small, hand held metal detector
- US Map with noted shark encounters from 1837 to 2016
- Print out comparing the visual silhouette of a surfer on a surfboard, a seal, and a sea turtle
For this activity, set your classroom up into different stations, each one centered on a different kind of shark adaptation. If you like, you can give your students a worksheet with questions they are to answer at every station. Additionally, each station will have information about the specific adaptation and materials for the students to use in exploring them. Divide your students into small groups, each starting at a different station. After 5-10 minutes, each group will rotate to the next station, continuing until each group has completed every station.
Station 1: Shark Scents!
How well can sharks smell? Sharks have an extremely acute sense of smell. Sharks have larger brains than most cold-blooded animals. With this larger brain comes a vast amount of sensory information. Nearly two thirds of a shark’s brain is devoted to the sense of smell. They also have odor-detecting cells inside their nostrils. They can smell odors in very low concentrations – in fact, a great white shark can smell one drop of blood in 100 gallons of water! Fish give off a certain odor when they are in distress, which is easily detected by sharks. They can detect odors up to one mile away. Sharks rely on all of these senses to locate food and to make them extremely effective at hunting down prey.
- Station will have printed hand out about shark’s ability to smell prey underwater when hunting.
- Station will also have multiple small, opaque jars. Each on should be filled with a unique fragrant scent with holes poked into the lids
- Make sure to choose strong scents that are easily detected, and ones that are familiar to the students
- Each jar will only be labeled with a number.
- After reading a handout about sharks’ adaptation for smelling, students will be asked to smell each jar carefully, and then attempt to identify each scent.
Station 2: Shark Teeth!
Sharks do not chew their food. They swallow food whole or in big chunks and rely on enzymes and hydrochloric stomach acids to break the food down. Different species of sharks have different shaped teeth. Sharks often lose their teeth. There are several rows of new teeth in a shark’s jaw to replace lost teeth. A replacement tooth can move into place in less than 24 hours. Some species of sharks may lose as many as 30,000 teeth in a lifetime. The shape of sharks’ teeth depends on the type of food they eat. They can have anywhere from 20 to several hundred teeth. Some sharks have one type of teeth in the upper jaw and another type in the lower jaw.
- Station will have a handout about how sharks eat, and what they use their teeth for.
- Station will also have note cards divided into two piles. One pile will have cards with various shark species and the kind of food they eat. The other pile will have note cards with pictures of those same species’ teeth.
- Each notecard with a tooth should be numbered.
- Students will be asked to read the descriptions of the shark’s food, and using that information, match each shark to their teeth.
Station 3: Sharks are Electric!
Sharks have larger brains than most cold-blooded animals. With this larger brain comes a vast amount of sensory information. In addition to the five senses used by humans, sharks possess a sixth, very unique sensory adaptation, electro-reception. They can detect electrical charges that are emitted by all living things as they breathe or move. This is called electroreception. Some sharks can actually use electricity to locate prey. A shark uses a system of small holes and canals located in the snout and head called the ampullae of Lorenzini to detect these impulses. This works best at close range, and can be used to locate animals that the shark may not be able to see. Sharks rely on all of these senses to locate food and to make sharks extremely effective at hunting down prey.
- Station will have printed hand-outs about sharks’ ability to use their ampullae of Lorenzini to sense prey hiding under sediment or in rock holes by detecting the electrical pulses created from beating hearts and moving muscles.
- Station will have a container filled with small strips of crumpled paper, sand or sawdust.
- Buried in the container will be various metal objects
- Students will carefully wave small hand-held metal detectors over container to detect the presence of objects
Station 4: Shark Encounters!
There are 470 different species of sharks, ranging from only a few centimeters long (dwarf lanternshark) to multiple meters long (whale sharks). Sharks do not kill for sport. They kill only when they are hungry. After a large meal, a shark may go for many days (or weeks!) without eating at all. A shark can eat an average of about 2% of its body weight per day. Sharks have a varied diet depending on their species, which can include plankton, fish, crustaceans, coral, sea urchins, horseshoe crabs, mollusks, sea turtles, seabirds, marine mammals, or even other sharks. Most prey on weak, injured, or dying animals, since they are easier to catch. Sharks do not eat humans, although there are some situations where people are mistaken for food and bitten. Only about 25 people are killed by sharks each year worldwide. Fatal shark encounters are extremely rare, which is why they usually make headline news. People are not a shark’s prey of choice. Generally, encounters are due to confusion, when humans enter sharks’ environment. However, due to fear of sharks, and the popularity of shark fin soup, over 100 million sharks are killed by people every year.
- Before looking at the pictures, have the students predict how many shark encounters they think there are every year.
- Station will have printed hand out of a map of shark encounters reported in the United States between the years of 1837 to 2016
- Station will also have print out comparing the visual silhouette of a surfer on a surfboard, a seal, and a sea turtle.
- Students will be asked to compare the different silhouettes and look at the map of recorded encounters.
- How accurate were their predictions? Is the number of recorded encounters surprising compared to how the silhouettes look?
- Be careful and make sure to NOT say ‘shark attack’ as it is not a term used anymore in professional science. Research by ecologists and zoologists now support the idea that sharks do not purposefully attack humans, but do so by mistake or in self-defense. Shark encounters is the term used most commonly.
- After every student completes each station, have them return to their normal seats.
- Do sharks have to see their prey to know where they are?
- What is unique about the shark’s brain that helps it smell?
- What is in the shark’s snout that helps it detect its prey?
- Are all shark teeth the same? Why not?
- Are sharks as dangerous to people as we think they are?