Kettle Pond History and Ecology
Folks all over the world travel to Cape Cod every year to enjoy its beautiful coastline. But the coastline is not the only place to find water on the Cape! In fact, there are 996 freshwater ponds, 182 of which are in the town of Barnstable.
Kettle ponds were formed some 15,000 years ago when the retreating Laurentide ice sheet moved across the outwash plain that is now called Cape Cod. Ice blocks were left behind by the retreating glacier and buried by outwash sand and gravel deposits. The ice blocks slowly melted, causing the land above to collapse and leave deep depressions in the ground. Rising sea levels caused the Cape Cod freshwater lens to be pushed upward, flooding these deep depressions with water. To this day, these kettle holes are recharged by precipitation and groundwater, with little-to-no surface water inflows or outflows.
There are a variety of plant species that rely on Barnstable’s kettle ponds. A number of species grow successfully in shallow waters like wool grass, pickerelweed, and pipewort. In areas of the pond up to six feet deep, there are plants like the spatterdock and white-water lilies that have the important job of decreasing algal growth by keeping the pond’s surface temperature cool.
Despite not having any connections to streams, kettle ponds in Barnstable have fish that call these water bodies home. Decades ago, these ponds were stocked with several species of trout. They share the water with fish like pumpkinseed sunfish and pickerel. Amphibians and reptiles are also found in and around kettle ponds. Snapping turtles, eastern box turtles, eastern painted turtles, and spotted turtles can be found sunbathing on a partially submerged log on warm days. As for amphibians, there are green frogs, pickerel frogs, spring peepers, bullfrogs, and wood frogs that can be seen hopping throughout the water.
Throughout the year, waterfowl use the kettle ponds and surrounding areas as a food source and habitat. They feed on the plants and macroinvertebrates that live in the sediment and within the water column.
Barnstable’s kettle ponds cover 1,856 acres of the town and play significant environmental and economic roles. This is why the Barnstable Clean Water Coalition is doing their part to improve local water quality by promoting new clean water technology for irrigation and septic systems, and working to remove nutrients at the source before they can reach these vital habitats.