Use this slide as an ice breaker to talk about connections and relationships between sharks, the environment, and people. See what the kids or adults come up with on their own. Should only take 3 to 4 minutes to get their brains going in the direction you want for this lesson.
Sources: http://en.wikipedia.org/wiki/Carbon_dioxide Erik Brush, author of The Sixth Extinction: http://thesixthextinction.homestead.com/index.html Picture: http://images.wikia.com/green/images/2/2f/Carbon_cycle.png
Discuss the “cycle of life” by referencing other life cycles children are familiar with. Ask students why the diagram is shaped like a triangle? Read the information below, or go to the site: http://aquaviews.net/scuba-guides/visual-indicators-of-a-healthy-reef/ So you can further explain why the different types are important to a healthy reef. Summarize as you feel is proper for your group of students. Abundance of Herbivorous Fish – Parrotfish, Surgeonfish and Tangs The first good sign of a healthy coral reef is the abundance of Herbivorous Fish primarily Parrotfish and Surgeonfish. Herbivorous fish keep algae populations in check which often compete with the corals for sunlight, nutrients and space. While there are several species of algae eating herbivorous fish, the reason these two species are the ones to look out for is that Parrotfish usually eat the harder, calciferous algae which most species do not prefer. Surgeonfish and Tangs tend to graze on the softer algae allowing existing corals thrive. So spotting plenty of parrotfish and Surgeonfish on a dive would be a good indicator that the reef is doing. Sea Urchins Sea Urchins are a strange indicator of a healthy reef system as they can be both beneficial and harmful to a coral reef depending on their numbers on a reef. Urchins are often known as the lawnmowers of the sea as they feed on a wide variety of marine algae and sea grasses, which helps slow-growing corals to compete for limited reef space. Areas of coral reef that have seen the absence of sea urchins, have gradually gone into decline with uncontrolled algae growth. However the abundance of Sea Urchins can also cause the complete elimination of algae and sea weed robbing the nourishment that mollusks and herbivorous fish rely on also causing the destruction of the reef. Spotting a reasonable amount of sea urchins would signify a fit reef. The Presence of Large Fish & Apex Predators The largest fish on a coral reef in decline are usually the first to go. The presence of Barracuda, Jacks, Grouper, Snapper and large Potato Cod, Napoleon Wrasse which are the predators in the food chain, indicate that there is a healthy balance of fish in the reef. Even the Herbivorous fish should have a good number of large sized adults and not just juveniles which indicate poor reef conditions. Octopuses are primary predators on clams and shellfish and their presence in the reef also signifies a healthy shellfish population. If the reef has numerous smaller fish, and no larger pelagic, or adult carnivores, it is a sure sign that the reef is either in decline or recovering from a decline. Sharks Sighting sharks in a reef is a prime indicator that the ecosystem is thriving. Reef Sharks, black-tip, white tip or grey sharks, keep the larger fish populations in check and form the Apex predators of the reef ecosystem. The absence of large-bodied predators at the apex of marine food chains can result in large-scale changes in the abundances of other species and cause an imbalance in the reef. So sighting a shark is a good sign that things are well on the reef. Abundance of Giant Clams, Conches, and Molluscs What makes Giant Clams a good indicator of a healthy reef is the fact that these endangered creatures are highly sensitive to changes in the water acidity and temperature and perish were conditions are less than perfect. Giant Clams are of vital importance to the reef as they act as nurseries for a host of fish and invertebrates as well as shrimp. Clam shells provide the perfect substrates for attachment for several species of sponges, coral and algae which promote the development of the reef. Clams, conches and molluscs are also filter feeders – sifting plankton debris from the water for food, improving overall water quality in the reef. Smaller grazer molluscs like Abalone and snails also help keep algae growth in check.
This slide gives you a good chance to look and talk about different fish which live on a reef. Which fish have kids seen before? Eaten? What do they know about the different types of fish. Cool fact: Parrot fish can change from female to male or male to female. All parrot fish are basically born hermaphrodites. If, within there school there are not enough males or females, parrot fish will change their sex to ensure their species will survive. They usually live about 7 years.
The photo on the left shows a reef over run by algae.
The answer is number 1. Below are some quick facts about these sharks. Gray Reef Shark http://www.animalpicturesarchive.com/view.php?tid=3&did=25707 Size:Up to 2.5m Weight:200-300kg Food Sources:Reef fishes, squids, octopus Habitat:Warm shallow reefs Locations:From the Red sea to the easter islands Interesting Facts:Not an aggressive shark School Shark: Size:Up to 6ft long Weight:Unknown Food Sources:Bony fish Habitat:Deep waters 550 m (1,800 ft) Locations:Western Atlantic: southern Brazil to Argentina
http://aquaviews.net/scuba-guides/visual-indicators-of-a-healthy-reef/ http://www.ulike.net/Coral_Reefs Teacher can get students to read this slide, check for understanding, especially underline words and discuss the question at the bottom of the slide before moving on. There is a lot of information and room for discussion, gadging your
The pictures on this slide are meant to show a dying or dead Earth. With no oxygen, life on Earth will end as we know it.
Beautiful, Important Sharks
Beautiful, ImportantSharksBe cool and know the facts!
What would happen on Earth if sharksbecame extinct like the dinosaurs?Would life change or stay the same?
Why are sharks so important to Earthand people?• The ocean makes 70% of our O2(air/oxygen) and breathes 80% ofCO2 (carbon dioxide).• This O2 is made by ocean plantscalled algae and phytoplankton.• Algae and phytoplanktonbreathe CO2 ,and with sunlightand water, they make energy.They then breathe out O2 . This is acycle. It is called the carboncycle.• All life on Earth needs O2 to live.How many names of living things doyou know need air to live?
How do sharks protectphytoplankton andgreen algae?Sharks eat huge amounts ofsmall fish andcrustaceans. Theseanimals eatphytoplankton and greenalgae.The number of sharks in theworld is getting smallereach day. So the number ofanimals that eatphytoplankton and greenalgae gets bigger.This happens in the deepoceans and in shallow seas.How will this effect howmuch O2 is made on Earth?green algaeSatellite view of healthy build upphytoplankton and green algae.crustaceansphytoplanktonSheldon Plankton
What else do sharks do to help the oceans?Make Healthy ReefsMake Healthy Reefs• On reefs, sharks help keepthe number of different kindsof fish and sea life healthy.• Reefs are important becausethey have ocean plants.• Do you remember what oceanplants eat?• Reefs are only on 1% of theocean floor, but reefs are thehome to 25% of all marinespecies (ocean animals).• What are some differentthings that could happen ifall the reefs died?Sharks are needed for reefs to grow,survive and be healthy.
How do sharks’ diet make a reef healthy?How do sharks’ diet make a reef healthy?• Since sharks are the toppredator, they help keep thenumber of fish that eat algae andcoral at a healthy number. Thatway reefs stay healthy too.• Sharks also eat sick and weak fishso fish families can stay strong andhealthy.
What does a balanced reef lookWhat does a balanced reef looklike?like?Large Fish (TopLarge Fish (TopPredators)Predators)Phytoplankton andPhytoplankton andAlgae Eating FishAlgae Eating FishAlgae EatersAlgae EatersA balanced reef has a smallernumber of top predators, alarger number plant eating fish,and even a larger number algaeeating fish.
Look at these two pictures carefully.Can you tell which one is healthy which one is not?How do they look the same?How do they look different?Which one do you think has sharks living there?
Which one of these sharks do youthink lives near or on reefs?Gray SharkGray Shark School SharkSchool SharkWhich one of these sharks would like to go to English class?
Police Sharks: Watchingthe Oceans for ourHealthWhat are the names ofsharks which live aroundreefs?The cycle of life on a reefneeds larger fish (predators)to eat smaller fish and seacreatures (prey). Thesesmaller fish are larger innumber and eat algae andcoral. If there are too manyof these smaller fish thenreefs will eventually die,making our oceans sick.Without sharks, reefs are indanger!White TipBlackTipCaribbean Reef SharkGreyShark
1. Why is having abalanced amount ofphytoplankton andgreen algae importantfor life on Earth?2. How do sharks helpmake breathing possibleon Earth?What can youremember about whatyou just learned?3. Why is our O2 andsharks in dangertoday?4. What can you do tohelp sharks and ourair?
How people are killing sharks?- People cut the fins off sharksand throw their bodies into theocean.- Sharks are usually still alivewhen it is thrown back into thewater.- They can’t swim without finsand they can’t breath withoutswimming.- They usually sink to the bottomand get eaten by other fish or diefrom losing blood and air.- 100 million +/-sharks are killedeach year, mostly for soup.- This means almost 200 sharksa are being killed every minute.Fins are sold for a lot of money and madeinto soup.How many sharks have been killed since we begantalking about sharks?