Embayment Monitoring
Barnstable’s seven (7) embayments – Barnstable Harbor, Centerville Harbor, Halls Creek, Lewis Bay, Popponessett Bay, Rushy Marsh, and Three Bays – are sampled four times annually throughout July and September. This data is then reported annually to the Cape Cod Commission where it is integrated into the agency’s Cape Cod Water Quality Data Portal. Data and trends can be viewed by monitoring site, pond, or embayment.
The Cape Cod Water Quality Data Portal is a map-based viewer that allows users to explore marine (and freshwater) water quality data compiled by the Cape Cod Commission for the region. Click below to discover marine water quality data and analyze trends for multiple characteristics at hundreds of embayment monitoring stations across Cape Cod.
Water Quality Measurements
Since 2001, the Town of Barnstable, along with the Barnstable Clean Water Coalition (BCWC), and citizen volunteers, have completed annual emabyment monitoring efforts to assess the health of our coastal embayments. Currently, water quality samples are collected at a total of 85 sentinel stations in Barnstable Harbor, Lewis Bay, Halls Creek, Centerville River, and Three Bays.
Measurements specifically look for trends related to excess nitrogen loading, low dissolved oxygen, poor water quality, algae / harmfu algal blooms, loss of eelgrass habitat, and loss of shellfish habitat. Barnstable’s Embayment Monitoring Program provides critical baseline data for our estuaries along with the ability to track nitrogen improvements as we implement the Town’s Comprehensive Wastewater Management Plan (CWMP).
This data also helps to inform the Town and its partners on solutions for remediation including traditional sewering as well as non-traditional nature-based initiatives such as pond, cove, and cranberry bog restoration projects, aquaculture, and inlet widening.
Dissolved Oxygen
A dissolved oxygen (DO) water quality sample measures the amount of gaseous oxygen dissolved in a water body, a crucial indicator of water health. DO is essential for aquatic life, and its levels are influenced by factors like temperature, salinity, and biological activity. Analyzing DO levels helps assess the overall health of an aquatic ecosystem and identify potential pollution sources.
Water Clarity
Water quality in a water sample is assessed by measuring various physical, chemical, and biological parameters. These measurements help determine if the water is safe for its intended use, such as drinking, recreation, or supporting aquatic life. Key indicators include pH, turbidity, dissolved oxygen, temperature, and the presence of bacteria or other contaminants.
Nutrients
In a water quality sample, nutrients typically refer to the levels of nitrogen and phosphorus, which are essential for plant and algal growth but can cause problems when present in excess.
Chlorophyll
Chlorophyll in a water quality sample is primarily used as an indicator of phytoplankton biomass and photosynthetic activity, which in turn can reflect water quality and ecosystem health. Excessive chlorophyll levels can indicate problems like algal blooms and poor water clarity, while low levels might suggest nutrient limitations or other issues.
Salinity
Salinity in a water quality sample refers to the concentration of dissolved salts in the water. It’s a crucial factor in determining water quality and its suitability for various uses, as different organisms and applications require specific salinity levels. Salinity is often measured in parts per thousand (ppt) or parts per million (ppm).
Learn More
The Cape Cod Water Quality Data Portal
Cape Cod Commission
Marine & Aquaculture Water Quality Monitoring
Barnstable County
Total Daily Maximum Load (TMDL) Map
MA Department of Environmental Protection
Section 208 Area Wide Water Quality Management Plan
Cape Cod Commission