How does the acidity of lake water affect the hardness of Zebra mussel shells?
The hypothesis that a lake with more acidic water will produce Zebra mussels with softer shells is proven correct.
Pollutant gasses released into the atmosphere by factories and vehicles return to us in the form of acid rain. The acidification of our oceans and fresh water lakes threatens the survival of plants, animals and fish that live in the water. Crustaceans and clams, are now more vulnerable because their shells, which are the only protection that they have, are slowly dissolving and weakening as a result of the acidification of water bodies such as lakes and oceans.
What would happen if this science fair project were to be repeated with seawater mussels instead of freshwater mussels?
Would your results differ if a larger sample were to e used? (ie: samples of mussel shells from 20 different lakes, of varying pH levels?) Would the results be perhaps more accurate, given the larger sample?
You should also consider checking calcium levels in the water to ascertain if this makes a difference to your results.
Mussel - http://en.wikipedia.org/wiki/Mussel
Zebra mussel - http://animaldiversity.ummz.umich.edu/site/accounts/information/Dreissena_polymorpha.html
Basic safety requirements