Bling Bling the Fish Are Dead

Bling Bling the Fish Are Dead

Dinner time…Hg time?

International Baccalaureate Environmental Science and Systems Topics covered:

2.1.5 / Discuss how the pyramid structure affects the functioning of an ecosystem.
This should include concentration of non-biodegradable toxins in food chains, limited length of food chains, and vulnerability of top carnivores.
2.7.2 / Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem due to a specific human activity.
5.1.1 / Define the term pollution
5.1.2 / Distinguish between the terms point source pollution and non-point source pollution, and outline the challenges they present for management.
Point source pollution is generally more easily managed because its impact is more localized, making it easier to control emission, attribute responsibility and take legal action.

Also applicable for AP Environmental Science, AP Biology, Ecology, and Marine Biology

Activity / Time / Description
Day 1
Step 1- Introduction:
The hook (the story) / 10 min /
  • Play nice “restaurant” music as students walk into classroom
  • Pass out Seafood restaurant menu (SeafoodRestuarant.doc)
  • Ask students: What they would order and why (if they were not a vegetarian)? Each student circles their restaurant choice and quickly writes why it is their choice.
  • Choices: Shellfish (oysters), Tuna, Beef, Salmon, Swordfish, Tilapia, SF Bay Halibut, and crustacean (king crab)

KL on Hg / 15 min /
  • Ask Students: What have they heard about mercury? (do a K) Put ideas on board.
  • Hand out a KL sheet- students to add to it.

Re-evaluate menu choice / 10 min /
  • Ask Students: Based on what you know about mercury, what would you order on the menu and why.
  • Put ideas on back-side of KL sheet
  • (this is their hypothesis for the final project)

Step 2- Model:
Lecture/discussion / 45 min / Talk about how Hg gets into food
  • Ecosystem  bacteria  fish (lower on food chain) fish (higher on food chain)  human
  • Basic chemistry of Hg
  • Sources (natural and anthropogenic – mining, waste, CFLs, ewaste)
  • Where does Hg enter the food chain?
  • Anaerobic bacteria
  • Diet of Shellfish (oysters), Tuna, Beef, Salmon, Swordfish, Tilapia, SF Bay Halibut, and crustacean)
  • Bioaccumulation
  • Define bioaccumulation and contrast with biomagnifications
  • Why does tuna have such high levels of Hg?
  • Research concentration of Hg in plants and animals.

Homework / 30 min / Read: USGS Mercury Contamination of Aquatic Ecosystems
Add to the “L” column of KL chart
Day 2:
Step 3 - Coach:
Check-in / 15 min /
  • Quizlett on Hg in aquatic systems and bioaccumulation

Calculation / 15 min /
  • Amount of Hg in a can of tuna vs. body weight calculation

Step 4 - Fade:
Final activity
(make key) / 40 min / Rewrite menu (SeafoodRestuarant.doc) with amount of Hg in each food source based on a 150lb person and source of the Hg pollutant
  • Concentration of Hg in seafood:

If time: Can incorporate into step 3:

Bioaccumulation activity
(If time) / 30 min /
  • Bioaccumulation activity
  • Talk about results and how much Hg accumulated and why
  • Compare this with the organisms on the menu

Resources:

  • Video on teaching Hg:
  • Concentration of Hg in seafood:
  • KQED video on Hg in SF Bay:
  • SF Estuary institute:
  • SF Bay Fishing Report:

For ppm demonstration:

  • Becker Bottle – Fisher (for ppm)
  • Popcorn in a bottle (ppt) – build yourself by placing 1 blue corn kernels (glued to bottom or side of bottle) out of 1000 yellow popcorn kernels
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