Investigating Water Turbidity





Christine Price


The purpose of this project is to find the relationship in the turbidity of water and what organisms live in this environment. Turbidity is defined as how cloudy, opaque, or thick the suspended matter is.

Why is it important to science? Science researches ways that the different factors affect the environment because conservation of living organisms is important. Also natural resources are key to the survival of organisms. This experience allowed me to see this by providing an experience where I was able to follow biology students work both in the field and in the labs.

Methods & Procedures






This topic is suitable for middle schoolers.

Lesson Plan

5E Lesson Plan

Salty Science Student Hand-out

Name: Salty Science

Objective: The students will determine the levels of salinity based on water samples they bring in from local bodies of water. Then they will use technology to research the types of organisms that are commonly found in those bodies of water. The final result will be a poster representing what organisms live and don’t live in the body of water they are assigned to present to the class in a gallery walk format.

Supplies Needed

Table Salt

Five Samples of Water in area


Handout Copies for Students

Poster Board

Computer Access

Post its (for Gallery Walk)

Needed Vocabulary


Salinity is the dissolved salt content of water which can be measured with a refractometer.


An instrument for measuring a refractive index


Students will watch the following videos as an introduction to what the local bays and estuaries are and what is in them.

Take a few minutes to ask the answers on worksheet for each video and expand on those with the given vocabulary.


The students will be divided into groups that will remain for the entire project. One student will gather all materials needed. Then they will follow the steps below to test each water sample and log the results.

1. Label sample on chart

2. Use Refractometer to measure the salinity of the sample.

a. Mix up water sample

b. Take a small portion of water and place on screen of fractometer

c. Then read the measurement of the fractometer

d. Log on chart

3. Add the specified amount of salt on the chart and return to Step 2.

4. Repeat these steps for each water sample.

5. Once all the samples have been measured clean up the area and put all supplies away.


At this time all students will go back to a discussion format on the data that they collected, what they found, and compare information.

Then students will use technology to research each of the areas that a water sample was collected from and determine the types of organisms in each area.


Once the students have enough information on each water sample and the information relating to that body of water they will use that information to draw inferences on why or why not certain species live in that body of water. Philosophical Chairs can be used at this point.


Students will use technology to find data that either confirms or denies the conclusions that they decide are valid based on the experiment relating salinity of water to living organisms found on those bodies of water. And support why or why not?

This information will be presented on a poster board for the body of water that they have been assigned based on the samples.

Each student will participate in a Gallery Walk of the posters and use a post it note to comment on a poster that interests them. They can post questions, comments, or peer review the posters given a rubric provided by the teacher.


Students will learn of other experiments that have been done with similar variables in their local environment.

TEKS: 5th grade level
(2) Scientific investigation and reasoning. The student uses scientific methods during laboratory and outdoor investigations. The student is expected to:
(A) Describe, plan, and implement simple experimental investigations testing one variable
(B) Ask well-defined questions, formulate a testable hypothesis, and select and use appropriate equipment and technology
(C) Collect information by detailed observations and accurate measuring
(D) Analyze and interpret information to construct reasonable explanations from direct (observable) and indirect (inferred) evidence.
(F) Communicate valid conclusions in both written and verbal forms
(G) Construct appropriate simple graphs, tables, maps, and charts using technology, including computers, to organize, examine, and evaluate information.
(1) Mathematical process standards. The student uses mathematical processes to acquire and demonstrate mathematical understanding. The student is expected to:
(A) apply mathematics to problems arising in everyday life, society, and the workplace;
(B) use a problem-solving model that incorporates analyzing given information, formulating a plan or strategy, determining a solution, justifying the solution, and evaluating the problem-solving process and the reasonableness of the solution;
(3) Research and information fluency. The student acquires, analyzes, and manages content from digital resources. The student is expected to:
(A) create a research plan to guide inquiry;
(B) use and evaluate various search strategies, including keyword(s) and Boolean operators;
(C) select and evaluate various types of digital resources for accuracy and validity; and
(D) process data and communicate results.
(4) Critical thinking, problem solving, and decision making. The student makes informed decisions by applying critical-thinking and problem-solving skills. The student is expected to:
(A) identify and define relevant problems and significant questions for investigation;
(B) plan and manage activities to develop a solution, design a computer program, or complete a project;
(C) collect and analyze data to identify solutions and make informed decisions;
(D) use multiple processes and diverse perspectives to explore alternative solutions;
(E) make informed decisions and support reasoning; and
(F) transfer current knowledge to the learning of newly encountered technologies.
(5) Digital citizenship. The student practices safe, responsible, legal, and ethical behavior while using technology tools and resources. The student is expected to:
(A) understand and practice copyright principles, including current fair use guidelines, creative commons, open source, and public domain;
(B) practice ethical acquisition of information and standard methods for citing sources;
(C) practice and explain safe and appropriate online behavior, personal security guidelines, digital identity, digital etiquette, and acceptable use of technology; and
(D) understand the negative impact of inappropriate technology use, including online bullying and harassment, hacking, intentional virus setting, invasion of privacy, and piracy such as software, music, video, and other media.