Marine Biology Mrs. Weber Measuring Water Quality Turbidity- measures the cloudiness of water, caused by the amount of particles suspended in it. Colder water has more oxygen Warmer water has less oxygen o Less photosynthesis o Less plant life o Less marine life Secchi Disk- instrument used to measure turbity. Disk is attached to a rope and then lowered until you can no longer see the design. The distance to the surface from the disk below is then measured. Salinity- the amount of salt, or dissolved salt, found in a body of water.