Lagoon Days at the ELC Pre-fieldtrip Lesson & Activities for Indian River County 4th Graders Includes: Introduction to Water Quality Salinity Experiment Acidity (pH) Experiment

Water, Water, Everywhere! 70% of Earth’s surface is covered in water Only 2.5% is fresh water (and only 1% accessible!)

What types of bodies of water do we find in the environment? What differences might we find in each of these bodies of water?

What is Water Quality? Water quality refers to the chemical, physical, biological, and radiological (a type of energy) characteristics of water. Some of the things scientists test for in water are: amount of salt, nutrients, chemicals, bacteria, gas, pH (how acidic something is), and temperature.

Why do we test Water Quality? Scientists test water quality to determine the degree to which water is clean or polluted, whether the water is suitable for drinking or swimming, for making plants grow, or for fish to live in, etc. (collinsdictionary.com)

Our Indian River Lagoon Freshwater from ditches, canals, runoff   Saltwater from ocean Mixes in Lagoon to create BRACKISH water Why might scientists be interested to know the amount of salt in a body of water?

Nitrate Unit of Measurement: Parts Per Million – used for small concentrations - This means that there is 1 part of solute (nitrate) for every 1 million parts of solution (water) Scientist use testing kits to measure how much nitrate is in a sample of water Photo credit: Pedro Portal/TNS/Newscom

Salinity This Hydrometer is a scientific tool used to measure how much salt is in a sample of water Unit of Measurement: Parts Per Thousand - Ocean water is about 35 ppt, which means that for every 1000 grams of water there is 35 grams of salt (3.5% is salt)

EGGSperiment Time! Procedure: Materials: Fill the two containers with tap water. Add salt into one container and stir it well with a tablespoon until the salt has completely dissolved (the amount of salt needed is dependent on the size of the container). Place one egg in each of the containers and observe which egg floats and which one sinks. Have students record results, determine if the results support their hypotheses, and discuss together as a class. Materials: 2 raw eggs 2 clear, identical containers Table salt Tap water Have class make hypotheses -or educated guesses- about whether an egg will float or sink in: Freshwater Saltwater Have students record their hypotheses.

pH Acids & Bases Acids are all around us and even in us! We clean with acid, we eat acid and we even break down the food in our stomachs with acid. pH is a scale we use to measure how acidic or basic something is (like a liquid) Scientists use a chart that goes from 0 to 14 Discuss examples of acidic and basic solutions using the chart to the right Things that affect pH in our waters: industrial waste, agriculture runoff, improper drainage from mining

The Vanishing Shell Experiment Procedure: Place 200 mL of water into one container and 200 mL of vinegar into the other container (enough for each shell to be fully submerged) Weigh each seashell and record the weights in grams Carefully place one shell into the water container and the other into the vinegar container Keeping shells submerged in each solution, record any observations after half an hour After one hour, remove each shell from its container, being careful not to mix the shells up Dry each shell, then weigh again and record the weights in grams Have students complete the following math equation for each shell: Weight before experiment – weight after experiment = ____(this is the amount of shell that dissolved in the solution) Have students record and compare results, determine if the results support their hypotheses, and discuss together as a class. Materials: Vinegar (acid) Scale that measures in grams Tap water 2 clear, identical containers 2 seashells of the same type 2 spoons Background information on ocean acidification: climatekids.nasa.gov/acid-ocean Have class make hypotheses -or educated guesses- about what might happen to the weight of a shell placed in: Water Vinegar Have students record their hypotheses.