DEEP: Hypoxia maps - Summer 2018

Summer 2018 Hypoxia Monitoring

{Example map showing summer hypoxia conditions in Long Island Sound .}

Hypoxia Monitoring Overview

The 2018 sampling schedule included routine water quality surveys as well as summer-only hypoxia surveys. 

Routine water quality surveys are conducted year-round, including during the summer months.  During these surveys water samples are collected for from 17 stations and analyzed for nutrients and other water quality parameters.  In addition, phytoplankton and zooplankton samples are collected from 6 stations in the Sound. 

Hypoxia surveys are conducted during the months of June through September at an additional 30 stations.  During hypoxia surveys, stations are sampled for dissolved oxygen to get a more accurate understanding of the extent of summer hypoxia conditions in Long Island Sound bottom waters.

DEEP's Long Island Sound Water Quality Monitoring Program utilizes data from both surveys to  monitor the extent of low dissolved oxygen in Long Island Sound bottom waters, or 'summertime hypoxia'.  Hypoxia condition maps were posted as soon as possible after each survey.   Biweekly newsletters, summarizing the results of each survey, are also distributed to interested parties.

2018 Monitoring Results

Select a sampling date below to view the progression of hypoxia in the western Sound throughout the summer of 2018.

June 2018

July 2018:
August 2018
September 2018


LIS Hypoxia Monitoring Distribution List

Interested in receiving future biweekly survey summary newsletters?  Email Katie O'Brien-Clayton at to be added to the distribution list.



Long Island Sound Water Quality Monitoring Program Maps

Content last updated January 18, 2018