Vernier Software and Technology
Vernier Software & Technology

Investigating Salinity

Figure from experiment 7 from Investigating Environmental Science through Inquiry


Salinity is a measurement of the saltiness or concentration of salt in water. Ocean water contains many different salts, but the most abundant is sodium chloride, also know as table salt. Sodium chloride accounts for about 86% of all the ions present in ocean water. Other salts that can be found in ocean water at significant levels are calcium chloride and magnesium chloride.

While the average salinity of ocean water is 35 ppt (parts per thousand) of salt dissolved in water, there are several factors that can increase or decrease its salinity. At the polar regions, freezing of ocean water increases the salinity of the surrounding water. Evaporation in hot, arid regions also increases the salinity. The Dead Sea, located in Israel, has salinity nearly seven times that of most ocean water. At the ocean’s surface, rain, snow, and melting ice are all responsible for decreasing the salinity. As rivers enter the ocean, they carry large volumes of fresh water into the ocean, causing salinity to decrease.


In the Preliminary Activity, you will gain experience using a Conductivity Probe while determining the salinity of a saltwater sample provided by your teacher.

After completing the Preliminary Activity, you will first use reference sources to find out more about salinity before you choose and investigate a researchable question dealing with that subject.

Sensors and Equipment

This investigation features the following Vernier sensors and equipment.

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Standards Correlations

See all standards correlations for Investigating Environmental Science through Inquiry »

Investigating Environmental Science through Inquiry

See other experiments from the lab book.

1Seasons and Angle of Insolation
2A Local Weather Study
3Investigating Dissolved Oxygen
4Water Quality
5Long Term Water Monitoring
6Water Treatment
7Investigating Salinity
8Soil Temperature
9Soil Salinity
10Soil pH
11Soil Moisture
12Soil and Acid Rain
13Managing Garden Soil Moisture
14Cell Respiration (CO2)
15Biodiversity in Ecosystems
16Biochemical Oxygen Demand
17Water Cycle Column Investigations
18Decomposition Column Investigations
19Ecocolumn Investigations
20Global Warming
21UV Investigations
22Comparing Sunscreens
23Primary Productivity
24Modeling Population Growth
25Insulation Study
26Fossil Fuels
27Energy Conversion
28Wind Power
29Photovoltaic Cells
30Investigation of Passive Solar Heating
31The Effect of Acid Deposition on Aquatic Ecosystems
32Measuring Particulates
33Investigating Indoor Carbon Dioxide Concentrations
34A Pollution Study

Investigation 7 from Investigating Environmental Science through Inquiry Lab Book

<em>Investigating Environmental Science through Inquiry</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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Dev Reference: VST0407

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