Ecosystem Targets and Supporting Indicators
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Meeting this target requires an average reduction in the area of impaired sediment of 0.7 per year from 2006-2035.
The Sediment Quality Index (SQI) from EPA 2020 National Coastal Condition Assessment for Long Island Sound (23 spatially-weighted sampling sites), showed that sediment condition was good at 56% of the sites, fair at 23% of the sites, and poor at 21% of the sites. This compares with the 2010 Assessment for Long Island Sound (22 spatially-weighted sampling sites), which showed that sediment condition at 72% of the sites was good, 23% of the sites fair, and 5% poor. Further analysis is necessary to determine the cause and potential impact. While further research is necessary to identify direct causes for the decline in SQI, changes in environmental conditions may have impacts including, but not limited to, increased storm frequency and intensity and changes in upstream river conditions.
The SQI Ecosystem Target, to reduce the area of impaired sediment by 20% from the 2006 baseline, had been met but is not currently being maintained. In 2006, the area of impaired sediment was 47% (37% fair and 10% poor); while in 2020, the area decreased to 42% (23% fair and 15% poor). This is a 6% decrease from the 2006 baseline. Note there are data challenges, see below, with this set and further analysis is necessary to evaluate progress, impacts and causes.
The EPA National Coastal Condition Assessment is currently conducted only every five years.
The current number of sampling locations in the open Long Island Sound is considered too low for good statistical significance; 50 locations would be required for such significance.
The Long Island Sound Partnership has very limited management tools to improve sediment quality.
Sediment quality is measured by the Sediment Quality Index (SQI) of the EPA National Coastal Condition Assessment. This index is a combination of measurements of both sediment toxicity and sediment contaminants. The most recent Assessment provides information from 2020.
Sediment quality is important because contaminated sediment can harm organisms that live in the sediment and potentially concentrate the contamination in organisms that consume these sediment-dwelling organisms.
Dr. James Ammerman, Long Island Sound Partnershipjames.ammerman@longislandsoundstudy.net
EPA National Coastal Condition Assessment, https://www.epa.gov/national-aquatic-resource-surveys
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