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Algae that Kill

Algae that Kill. Mr. Bunn Lunch Lectures Spring 2014. Case Study. Atacama Desert – Chile 40 baleen whales 5 million years ago. What!?!. Why did all of these whales die in one place? What/Who is the culprit? Where to begin? What are the main causes of death?. Viruses.

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Algae that Kill

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  1. Algae that Kill Mr. Bunn Lunch Lectures Spring 2014

  2. Case Study Atacama Desert – Chile 40 baleen whales 5 million years ago

  3. What!?! • Why did all of these whales die in one place? • What/Who is the culprit? • Where to begin? • What are the main causes of death?

  4. Viruses • Scientists hypothesized that a virus was the cause • Analyzed the Chilean graveyard • Found fossil remains of seals, an extinct species of sperm whale, an aquatic sloth and a billfish • Marine viruses tend to be host specific • Ruled out virus or disease

  5. Where now? • What else could have caused the mass death of these baleen whales? • Scientists looked again at the graveyard • Mix of herbivores and carnivores

  6. History/Recurrences • Fossils found in four distinct layers • Indicates a recurring cause of death • Did some research… • Found that there was a mass killing of seabirds by a bloom of toxic dinoflagellates around the time of this mass killing

  7. Harmful Algal Blooms (H.A.B.) • Microscopic Algae • Oldest members of the plant kingdom • Grow in such large numbers… • Turn the ocean red= “red tides”

  8. So, why is this a bad thing? • Affects recreation and tourism • Species of algae produce toxins • Domoic Acid • Can cause paralysis and death in mammals and birds • How? Well, I’m glad you asked 

  9. So, back to our whales… • Odontocete • Toothed

  10. Types of Whales • Mysticete • Baleen

  11. Feeding How would you expect baleen whales to feed? Hint: Their baleen looks like a… FILTER FEEDING!

  12. What’s going on? Scientists propose that the baleen whales ingested high amounts of these H.A.B. and died from the toxins

  13. What about the carnivores? • How do we explain the death of these other animals that would be eating other animals? • Inhaling toxins, algae on seagrasses • Biomagnification • Animals eat other animals that have eaten the H.A.B.s that have the toxin (toxin gets concentrated)

  14. Facts about Algal Blooms Not all species of H.A.B.s produce toxins and not all toxic algae produce harmful substances each time Marine algae go through “boom and bust” cycles Blooms occur repeatedly

  15. Present Day Similarities • Sea lions, dolphins and seabirds today have been and are affected by H.A.B.s • This helps support the hypothesis • Background information that is tested

  16. Wrapping it Up This is a “hypothesis” Scientists do not have clear ideas about exactly what happened It’s ok to “not know”

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