Nantucket Water Health Report
Capaum Pond - 2020
This Nantucket Land Council Water Report uses an index to measure the nutrient-related health of island water bodies. It provides a snapshot using monitoring data collected by the Nantucket Land Council and analyzed in a laboratory. Each Water Quality Indicator is assigned a score from 100 to 0, with 100 being pristine water and 0 representing severe nutrient pollution.
Water Quality Indicator
Score
Summary
Transparency
17
Algae in Capaum’s water column was so dense it blocked most light from reaching the bottom. Average visibility was 2.5 feet. Capaum’s max depth: ~8 feet.
Nutrient Concentration
38
High phosphorus concentrations lead to dense phytoplankton (algae) communities, including toxin producing species.
Chlorophyll-a
34
High concentrations of this common plant pigment (a measure of algae abundance) exceed healthy levels for a pond of this size.
Overall Water Quality
30
High phosphorus concentrations drove severe and lengthy harmful algal blooms.