Spotlight: Unquity Brook

Rainbow Smelt - image courtesy of Neponset River Watershed Association

Unquity Brook has headwaters near the Milton Police Station, and flows to Gulliver Creek, which flows directly into the Neponset River. 

The brook is an ecologically and economically important breeding ground for Rainbow Smelt, a small fish that is fished commercially and for sport. The smelt is also an important food source for larger Atlantic fish, including striped bass. Smelt was historically a high-population fish in New England fisheries, but smelt populations have long been declining. In 2004, the US National Marine Fisheries Service listed the rainbow smelt as a Species of Concern due to its waning population and need for conservation efforts.

Water quality is essential for these bodies in order for smelt to reproduce successfully. Each spring, smelt swim upstream from saltier ocean waters through the Neponset River to Unquity Brook to breed. They lay eggs in the quickly-moving water, which sink to the bottom and adhere to cobbles, small stones on the bottom of the brook.

The most common pollutants in Milton waters are excess phosphorus, sediment, and bacteria. Siltation and sedimentation can bury the cobbles at the bottom of the stream, leaving no room for fish to reproduce. An excess of phosphorus can also damage fish habitat.

Bacteria pollution is bad news for humans and fish alike. Fecal coliform and E. coli carry diseases that make recreation unsafe in polluted streams like Unquity. Bacteria can also serve as a food source for aquatic plants and algae, which can upset the balance of plant and animal populations. When plants and algae populations bloom, they overuse the water’s oxygen, leaving little left for fish. Low levels of oxygen in the water can cause fish to die off.

So how can we help?

At home, residents can practice “good housekeeping” measures, such as using phosphate-free fertilizer and picking up after pets. Picking up pet waste reduces phosphorus and bacteria pollution in local waters by preventing the waste from washing into storm drains. The Town does its part by using low-phosphate pesticides on Town property.

At construction sites, the Town of Milton requires developers to utilize stormwater management best practices that prevent pollution and erosion of sediment. Erosion and sedimentation control plans are required for developers. Some examples of control measures for construction sites include safe storage of chemicals, silt fencing to prevent sediment from washing away, and installation of plants to prevent soil erosion on the edge of sites.

In our community, the Neponset River Watershed Association helps lead restoration efforts for the brook. NepRWA has partnered with the Town and the Massachusetts Department of Coastal Zone Management to monitor water quality in the brook and plan structural improvements that will prevent contamination. The Town has helped fund some of these structural improvements, including tree filter boxes along Lincoln and Brook Road. These filter boxes allow plants and soil to filter pollutants in runoff before it makes its way to the brook.

Clean water is everyone’s business – so do your part to help keep pollutants out of the brook.

Image courtesy of Neponset River Watershed Association