Presentation on theme: "Toxic and Harmful Algal Blooms “You Are What You Eat”"— Presentation transcript:
1 Toxic and Harmful Algal Blooms “You Are What You Eat” Rudo Kashiri
2 Learning Objectives Understand food chains and food webs Recognize the importance of and need for primary producersAppreciate the interconnectedness and interdependence of organismsSo where does energy come from? The fundamental energy source for most of the environment is the sun. Photoautotrophs capture the sun’s energy and use it to make organic compounds through photosynthesis. The process of photosynthesis transforms carbon dioxide and water into simple carbohydrates. The photoautotrophs then use the simple carbohydrates to build other more complex organic molecules (proteins, lipids and starches) that are either used as building blocks for their cells or are stored for later use. Photoautotrophs are often also called primary producers because they establish the basis for most other production; they create organic material from inorganic, or non-living, sources.How do algae fit into the marine food web? The photoautotrophs with which we are most familiar are the trees and flowers that we see everyday on land. However, there are a substantial number of photoautotrophs in the marine environment as well – most of which we can’t see without a microscope! Despite their small size, these microscopic primary producers, marine algae and cyanobacteria, are vital to our planet's productivity since they are at the base of the marine food web.What happens further up the food web? Each level of a food web or a food chain is called a trophic or feeding level, and the organisms in the food web are classified by whether they are primary producers or consumers. The consumers in food webs are called heterotrophs and they consume the organic material made by the autotrophs. Heterotrophs cannot make their own food so they are dependent on the autotrophs for survival
3 ActivityIn this simulation, predators “eat” their prey by tagging their prey’s elbow.Once an organism is “eaten,” it relinquishes its food bag to its predator and sits down in the feeding area.During this time, the living krill can continue to graze on the algae.There has been an algal bloom in the areaDistribute the M&M’s in a grassy area or throughout classroom. Explain to them that there has been an “M&M” algal bloom in the area. The organisms that are able to eat the M&M algae are the krill. Distribute the appropriate “Life Card” to each student and explain that each “animal” is being given specific directions as to how they should respond to this bloom.Students are assigned a specific organism in an Ocean food webKrill, Fish, Seals and Killer WhaleTheir name tag tells them what to doex-the krill graze on M & M's for 30 seconds
4 Who is in the food web?KrillFishSealKiller Whale
5 Materials 1 pound of M&M regular candies Plastic sandwich bags markers cut out “life cards”Ropestopwatch or other timing device(http://www.bigelow.org/edhab/pdf/tracing_life_cards.pdf),
6 KrillYou came across an algal bloom and it’s a feeding frenzy! You only have limited time to graze before the current causes the bloom to dissipate. Grab everything that you can to get those needed nutrients!They should move around the area feeding on the algae (collecting M&M’s and placing them in their food bags).Remind the students to refrain from truly eating their food, since they will need to assess their feeding success at the end of the game. At the end of the timed period, the “krill” should remain where they are in the area, but stop collecting M&M’s.Step 1 – The Krill: The “krill” have seconds to “graze.” They should move around the area feeding on the algae (collecting M&M’s and placing them in their food bags). At the end of the timed period, the “krill” should remain where they are in the area, but stop collecting M&M’s.You have seconds to “graze
7 FishYou came across a swarm of krill feeding on an algal bloom. You have just finished eating a bunch of copepods along the coast, so you aren’t very hungry. You eat only 1 of the krill. Enter the feeding area and do what is indicated on your “Life Card.”The Fish: Tell the fish to enter the feeding area and do what is indicated on their “Life Card.” Explain to the class that in this simulation, predators “eat” their prey by tagging their prey’s elbow. Once an organism is “eaten,” it relinquishes its food bag toits predator and sits down in the feeding area. During this time, the living krill can continue to graze on the algae.
8 SealsYou came across a school of fish feasting on Krill. Do what is indicated on your “Life Card.”
9 Killer WhaleYou came across a group of seals feasting on a school of fish. You were successful at catching one of them for your afternoon meal. Enter the feeding area and accomplish what is indicated on the killer whale “Life Card.”At this time, inform the students that some of the algae that they ate were toxic! If the krill consumed red or orange M&M’s, they consumed toxic algae!
10 Share your “Life Cards” KrillFishSealkiller whaleThe participants will share what was on their life cards
11 Toxic algae All red and orange M&M’s are toxic algae! Count the total number of M&M’s collectedCheck and sort your food.Number of red and orange M&M’s collected.calculate the amount of toxic algae consumed as a percent of the total consumption.100 x [# red + # orange]/[total #]Some of the algae you ate was toxic. If the krill consumed red or orange, they consumed toxic algae!Students can then sort their food and count the total number of M&M’s they collected and the number of red and orange M&M’s they collected. Have them calculate the percentage of toxic algae they consumed. 100 x [# red + # orange]/[total #]
12 Who is aliveIf there are any krill still alive that “ate” ANY red or orange M&M algae, they are now dead.If there are any fish still alive that “consumed” 20% or more red and orange M&M algae, they are now dead.If there are any seals still alive that “consumed” between 20%- 30% red and orange M&M algae, they are now sick. If there are any seals still alive that “ate” over 30% red and orange M&M algae, they are now dead.If the killer whale “ate” between 20%-30% red and orange M&M algae, it is now sick. If the killer whale “ate” over 30% red and orange M&M algae, it is now dead.Discuss the conclusions that can be made from this activity. This can be accomplished through a group discussion, through individual reflective papers, or through individual journal entries.
13 Data collection toxic algae consumed Krill fish seals whale Organism
14 ConclusionsWhat can we do to reduce use of toxins, or keep them out of the food chains?How did you feel when you heard that the red and orange M&Ms were toxic?How can you use this activity with your students?What conclusions can you make from this activity.