Water Quality & Habitat

Historically, Buzzards Bay and Narragansett Bay and the rivers and estuaries feeding them were home to abundant populations of wildlife including bay scallops, quahogs, soft shell clams, and oysters, as well as several fish species such as striped bass, bluefish, and river herring. Human actions and land use, however, have led to water pollution and habitat degradation that have decimated the bay scallop population and had severe impacts on eelgrass, shellfish, and fish populations. Climate change also plays a role with warming ocean temperatures and increased stormwater runoff contributing to habitat declines.

In 1998, the Environmental Protection Agency designated Buzzards and Narragansett Bays as “estuaries of national significance” that are threatened by pollution and land development [CIT. 31]. The Buzzards Bay Coalition, formed in 1987 with the goal of restoring the health of the bay, runs a robust volunteer program to monitor water quality at over 250 points. They classify half of the bay’s harbors, coves, ponds, and rivers as degraded by pollution, namely excess nutrients [CIT. 32]. The good news is that through the successful efforts of multiple watershed partners, water quality is beginning to improve.

Currently, nitrogen pollution is the number one cause of habitat degradation in Buzzards Bay as identified by the Coalition. Nitrogen causes algal blooms to flourish which both depletes the water of oxygen and shades out the eelgrass beds growing below. Thirty years ago, the bay was home to over 11,000 acres of eelgrass beds that supported young fish, blue crabs, bay scallops, and other wildlife [CIT. 8]. Approximately 43% of these eelgrass beds have disappeared in the years since [CIT. 8], causing a subsequent decline in the wildlife that depends on them (e.g. 90% decline in bay scallop harvest in the last 30 years) [CIT. 9]. If water quality continues to improve, there is hope that nature can rebound. Acreage of eelgrass beds, for example, has increased by approximately 850 acres since 2017 [CIT. 8].

Excess nitrogen in Buzzards Bay comes primarily from three sources: septic systems, inadequate wastewater treatment, and stormwater laden with fertilizers and other pollutants [CIT. 32]. As the climate changes, higher intensity rainfall events and warmer water temperatures in the bay are projected to increase the impact of these pollutants. Nature is less resilient when it is stressed. We need to act now to clean up this waterbody, allowing eelgrass and wildlife to rebuild so they can better adapt to a changing future.

WHAT THE DATA SHOWS

Water quality and wildlife habitat are linked. Data in this region shows that impairments from nutrients correspond to declines in wildlife populations. Consider:

• There are 38 harbors, coves and tidal rivers flowing into Buzzards Bay that fall below established water quality standards for excess nutrients as identified by the Commonwealth [CIT. 33].

• Eelgrass beds in Buzzards Bay have suffered a 43% decline in just 30 years. These beds, which provide nursery and foraging habitat for many species, numbered 11,040 acres in the 1980s and fell to 6,275 by 2021 [CIT. 8].

• The bay scallop population in Buzzards Bay has suffered a near collapse correlated with the loss of eelgrass beds. The harvest of scallops has gone from nearly 70,000 bushels in 1985 to just 1,770 bushels on average over the last five years — a more than 90% decline in the harvest in just 30 years [CIT. 9].

LOOKING AHEAD

A healthy ecosystem can be more resilient to climate changes. Let’s work together to:

Improve septic systems: Conventional septic systems do not remove much nitrogen and can result in ground and surface water contamination. Encouraging better maintenance of septic systems and installation of new innovative system designs can reduce contamination. In West Falmouth, the Buzzards Bay Coalition partnered to install 30 nitrogen-reducing systems that are removing over 70% of the nitrogen that would have otherwise ended up in the bay [CIT. 34].

Expand and improve wastewater treatment: Connecting more homes to the sewer system would reduce nitrogen pollution to our waterways. One solution proposed by several regional partners is the expansion of the Wareham Water Pollution Control Facility, allowing it to meet the current and future needs of Marion, Wareham, Bourne, South Plymouth, and the MA Maritime Academy. Doing this could reduce nitrogen pollution by an estimated 100,000 lbs/year — the equivalent of 3,450 septic systems [CIT. 35].

In some cases, our wastewater treatment plants can do better. Wareham, Falmouth, and Marion have upgraded their plants to remove up to 90% of nitrogen from their discharges.

Reduce stormwater pollution: Replacing pavement and other impervious surfaces and implementing green stormwater infrastructure practices such as raingardens, permeable pavement, and green roofs allow the soil to filter runoff before it reaches our rivers and bays. Stopping these pollutants at the source is also critical. Best practices can be used with fertilizer and manure applications on both residential and agricultural lands (including cranberry bogs) to reduce or eliminate polluted runoff.

Protect and expand natural areas: Forests and marshes along our coast and waterways act as buffers that filter out pollutants and absorb nitrogen. Maintaining these as protected areas is critical for improving water quality, buffering storms, and providing wildlife habitat.