Webquest

For this activity, you should allow approximately 3 days in the computer lab (standard class periods of 40 min).  Consider doing 1 task per day.  

Task 1

2 paragraphs - Students may click on the surf-your-watershed info for general info about each lake.  Chemical tests are also supplied for 2 lakes.  There was no chemical data available for Lake Lariat.  The Report the kids click over to will tell them the maximum limit for contamination is 0.1 ppm.  The averages for each lake show that they are all over the limit.  This should indicate that an advisory should be issued for each lake.  When asked for trends in the first graph, students should notice that Clopper lake has considerably less contamination than the others (but still too high).  Reasons for the differences may be found in the individual lake information or from the Factors link.  Reasons cited may be size of lake, age of lake, pH, Dossolved Organic Compounds, sulfate, and land use.  Any of these may make a difference.  Our study did not address these factors.  The second graph should illustrate that the smaller fish are in Clopper lake.  All fish contamination increases with the fish size.  The bigger the fish, the more mercury in the tissue.  This is because the size of the fish is connected to it's age and how long it has been consuming mercury.  Mercury never leaves the system so as a fish ages, it will accumulate more, and more, and more.

Task 2

3 Paragraphs - This task offers students a way to the determine maximum recommended number of fish meals they may eat per month for several different  fresh water and marine species. Students perform five different calculations outlined on the task worksheet.  A worksheet will need to be copied for each student.  Manipulation of this info was not possible on this website.  Click here to get the worksheet.  Check student math.  A few meals a week would be safe for the average sized student.  It depends on body weight.  If someone comes up with 12, they better weigh 30 lbs.  For the question: What populations in your home town would regularly consume much more fish that this allowable amount?  Don't be surprised if students come up with animals or people.  It depends on your area.  There may be a nesting group of wading birds, many raccoons, or a group of people engaging in subsistence fishing.  Any population engaging in over-consumption of contaminated fish would develop symptoms of mercury poisoning.   The second paragraph should address the risks in reference to the sampled lakes.   The map will identify current lakes under advisories.  Our three lakes are not listed.  They should be.  The current solution for any contaminant is to fillet the fish properly.  This will not be effective for mercury poisoning because the fillet is fish tissue (meat) which is precisely what people eat.  A new guideline should be recommended for consumption of mercury laden fish.  The last paragraph should be about the two health concerns of mercury poisoning.  Students should address pregnant mothers, children, and developing fetuses and Minamata Disease.  Links are provided for these two topics.

Task 3

For Maryland students using the webquest, they may choose any other state the want to compare to Maryland.  Also, where it says, "Does one state have more Mercury contamination than the other? Can you explain this using the information you have gained in this exercise?" discuss science process flaws that could have occurred in the sampling.  For example, one state may have a very active testing program and another may only be beginning their water quality testing.

End Product

When done, the students should hand in a report containing approximately 6 paragraphs addressing the questions asked.  They should also attach their worksheets that assisted in computing fish allowable intake.  Finally, they should have included some copies of graphs and websites that were useful and a copy of the mercury warnings in another state as a comparison.  

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