For the second summer in a row, concentrations of dissolved oxygen in Long Island Sound are higher than the long-term average, indicating improved water quality and improved ecological conditions for organisms that live in the Sound. Aquatic animals rely on oxygen that is dissolved in water to survive.

When dissolved oxygen levels decline, this can cause some animals to move away, weaken, or even die. Low dissolved oxygen can occur when nutrients such as nitrogen enter a water body in excess, over stimulating plant growth. Nutrients such as nitrogen can enter a water body through discharges of sewage and from fertilizer runoff.

In recent years, Connecticut and New York State have worked with the EPA to implement a nitrogen pollution reduction plan to improve the Sound's dissolved oxygen levels, and to protect aquatic animals and public health. Much of the improvements in water quality is attributable to wastewater treatment facility upgrades and other measures are reducing nitrogen pollution to the Long Island Sound.

See a video from "It's Relevant"...   HERE