Why dissolved oxygen

The pycnocline acts as a physical barrier that prevents the two layers from mixing together. During the summer, when algae-consuming bacteria are most active, the pycnocline cuts off oxygen-deprived bottom waters from oxygen-rich surface waters.

This can create large areas of low- or no-oxygen at the bottom of the Bay. The bottom of the Bay is not flat—rather, it has varying shallow and deep areas. This phenomenon often takes place each summer in:. Discover the Chesapeake Ecosystem Dissolved Oxygen. Dissolved oxygen DO is one of the most important indicators of water quality.

It is essential for the survival of fish and other aquatic organisms. Oxygen dissolves in surface water due to the aerating action of winds. Oxygen is also introduced into the water as a byproduct of aquatic plant photosynthesis. When dissolved oxygen becomes too low, fish and other aquatic organisms cannot survive.

The colder water is, the more oxygen it can hold. As the water becomes warmer, less oxygen can be dissolved in the water. Salinity is also an important factor in determining the amount of oxygen a body of water can hold; fresh water can absorb more oxygen than salt water.

Oxygen levels also may be reduced when there are too many bacteria or algae in water see Biochemical Oxygen Demand. After the algae complete their life cycle and die, they are consumed by bacteria. During this decay process the bacteria also consume the oxygen dissolved in the water. This can lead to decreased levels of biologically available oxygen, in some cases leading to fish kills and death to other aquatic organisms.

Do you want to test your local water quality? Water test kits are available from World Water Monitoring Challenge WWMC , an international education and outreach program that builds public awareness and involvement in protecting water resources around the world. Teachers and water-science enthusiasts: Do you want to be able to perform basic water-quality tests on local waters?

WWMC offers inexpensive test kits so you can perform your own tests for temperature , pH , turbidity , and dissolved oxygen. Do you think you know a lot about water properties? Want to know more about dissolved oxygen and water? Follow me to the Nutrients and Eutrophication website! Looking at water, you might think that it's the most simple thing around. Pure water is practically colorless, odorless, and tasteless. But it's not at all simple and plain and it is vital for all life on Earth.

Where there is water there is life, and where water is scarce, life has to struggle or just "throw in the towel. The range goes from 0 to 14, with 7 being neutral. The pH of water is a very important measurement concerning water quality. Yes, water below your feet is moving all the time, but, no, if you have heard there are rivers flowing below ground, that is not true.

Water moves underground downward and sideways, in great quantities, due to gravity and pressure. Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going. Water temperature plays an important role in almost all USGS water science. Water temperature exerts a major influence on biological activity and growth, has an effect on water chemistry, can influence water quantity measurements, and governs the kinds of organisms that live in water bodies.

Water and electricity don't mix, right? Well actually, pure water is an excellent insulator and does not conduct electricity. The thing is, you won't find any pure water in nature, so don't mix electricity and water. Our Water Science School page will give you all the details.

Lucky for us all, our drinking water is almost always clear very low turbidity. Other water, such as the creek behind your house after a rainstorm, is likely to be highly turbid—brown with floating sediment.

Turbidity is the clarity of water and it is an important factor in water quality. The USGS collaborates with local, state, federal, tribal, university, and industry partners to conduct the science necessary to understand the causes and effects of toxic HABs and inform water management and public health decisions.

USGS is characterizing the life cycle of HABs, their asociated toxins, and the genes responsible for cyanotoxin production. This work is enhancing the ability of Cyanobacterial harmful algal blooms HABs are increasingly a global concern because HABs pose a threat to human and aquatic ecosystem health and cause economic damages. Toxins produced by some species of cyanobacteria called cyanotoxins can cause acute and chronic illnesses in humans and pets. Eutrophication, or excess nutrients in streams, is typically one of the top reasons that a stream is listed as impaired on the d list as part of the Clean Water Act.

How nutrients, primarily nitrogen and phosphorus, are transported to streams and groundwater greatly affects the best management plan to keep them on fields and out of streams and groundwater. When looking specifically at drinking water supplies within a community, dissolved oxygen levels dictate the overall taste of the drinking water in question.

When DO levels are on the higher end, the drinking water that you consume will have a better taste to it that you will likely prefer. For instance, DO levels that are too high can expedite the corrosion of water pipes. Because of the damage that can be done by high levels of dissolved oxygen, most industries will use water that contains only a small amount of dissolved oxygen. For operators of boiler plants, the optimal DO levels are below.

The four things that the exact concentration of dissolved oxygen depends on include:. For instance, any dissolved oxygen within the water will take up a certain amount of space.

If the dissolved oxygen levels are exceedingly low, minerals that are located in the bed of the lake will begin to dissolve in the water at a more rapid pace.

At water treatment facilities, there are a range of different treatments that can be used to correct the odor and taste compounds that could be present in the water if the concentration of dissolved oxygen is low.

When activated carbon is added to the water, any odor, taste, and color issues will dissipate. In the event that the pH levels are too low, sodium hydroxide can be added to the water. The amount of aluminum sulfate in the water may also be adjusted.

This is a kind of coagulant that bonds suspended particles to one another during the extensive water treatment process. Every animal that lives in a body of water needs to have some amount of oxygen to survive.