Habitat description
Waterbodies with a limited water temperature gradient that receive water primarily through inflowing streams. Water level fluctuations are fairly limited along with typically low residence times but will vary based on watershed size relative to waterbody surface area or volume. Aquatic plants and algae may grow in moderate to dense stands throughout the waterbody due to high water clarity and/or shallow depths. Water clarity may also be turbid throughout the summer growing season because of the dominance of phytoplankton and sediment in the water column. Waterbodies vary in surface area but will tend to be relatively small (e.g., <25 acres) with gradual basin slopes. Substrates are dominated by finer materials including silt, sand, gravel, and accumulations of organic matter except for coarse material along wind and wave swept shorelines in waterbodies with larger surface areas. Water chemistry (e.g., alkalinity, pH, dissolved organic carbon) varies based on the underlying geology and terrestrial watershed features. Typically located lower in watersheds, these waterbodies have relatively large drainage areas and therefore will receive high nutrient loads. Relatively larger waterbodies with protected watersheds and shorelines may possess more nutrient-poor waters. Waterbodies may be natural in origin, enhanced by an impoundment, or completely artificial from damming. These are the most abundant lake and pond habitats in Massachusetts.
Associated habitat types
Inflowing streams and hydrologically connected marginal wetlands including shrub swamps, marshes, wet meadows, and bogs.
Characteristic communities and species
Specific communities will vary by watershed and will consist of warm-water and cool-water fish species. Waterbodies with connection to the ocean may be temporarily inhabited by diadromous fish species. Typical fish species include Brown Bullhead, Bluegill, and Chain Pickerel among others. Waterbodies underlain by karst geologic types (i.e., limestone) with alkaline waters will support unique plant and invertebrate communities adapted to higher pH, and greater concentrations of species such as shell-building organisms. Freshwater mussels can be abundant and diverse within these waterbodies particularly along the coastal plain. Typical species include Eastern Elliptio and Eastern Floater in western and central watersheds with the addition of Eastern Lampmussel, Alewife Floater, Eastern Pondmussel, and Tidewater Mucket in eastern watersheds (e.g., Taunton, Cape Cod, Merrimack). Shallow drainage lakes and associated habitats also host a variety of species seasonally and annually including turtles, amphibians, waterfowl, fish- and insect-eating birds, beaver, and muskrat.
Ecological processes
A generally large upstream watershed area combined with a generally small waterbody volume will contribute to high nutrient status and low water residence times. Nutrient loading is primarily driven by upstream contributing waters and is accompanied by internal phosphorus cycling from aquatic plants and algae. High nutrient levels (eutrophication) are typified by increased rates of sedimentation, reductions in water clarity, abundant macrophyte growth, and periodic algal and cyanobacteria blooms. Due to these characteristics, shallow, isolated, headwater lakes and ponds may support abundant beds of aquatic vegetation with their character (e.g., submerged, floating, emergent growth forms) and extent determined in part by local water chemistry, clarity, and temperature.
Threats
Watershed and nearshore land use alterations, shoreline armoring and or homogenization, drawdown, nonnative species introductions, and cyanobacteria blooms. The impacts of climate change will vary across pond systems because of differences in lake morphometry (e.g., mean depth, surface area), water clarity, watershed land cover, current pond management actions, and the current biological community. These pond-level differences can work to amplify or dampen the effects of climate change. Summer droughts can lower water levels, increase residence time, and concentrate nutrient levels. Increases in nutrient levels and water temperature will increase algal and cyanobacteria biomass and alter native plant communities. This may lead to increased hypoxic conditions (i.e., a lack of sufficient oxygen) for invertebrate and fish communities.
Restoration & management recommendations
- Water Quality Restoration: Lake aging or eutrophication is a natural process by which lake habitats slowly enrich over time, display greater abundances of phytoplankton and aquatic vegetation, increased rates of sedimentation and decreased water clarity. Humans accelerate these processes via land use modifications that directly and indirectly increase nutrient loading to lakes. Shallow drainage lakes are susceptible to eutrophication because of their typically small water volume and large contributing watershed. Once present, nutrients are difficult and expensive to physically remove and will overtime result in eutrophication. Actions taken to manage or improve water quality should balance short term temporary symptom relief with long-term solutions to nutrient control. Nutrient control strategies include diverting runoff to groundwater, modifying watershed and shoreline land use and management practices to reduce nutrient loads, maintaining shoreline vegetative buffers, and addressing septic leaks. Temporary solutions to water quality include in-lake alum treatments, aquatic plant management, or dosing stations at tributary mouths and dredging.
- Buffer and Shoreline Restoration: Watershed and shoreline actions could focus on restoring vegetative buffers, diverting runoff to groundwater, land management modification, and education. Where shorelines have been homogenized, complexity could be created by leaving in place woody debris which falls in the water.
- Water Quantity Restoration: Lake water levels are often manipulated (e.g., drawdowns) to meet a variety of management goals (e.g., aquatic plant control, drinking water supply). However, water level management practices may not fall within the range of natural water level fluctuations set by hydromorphological variables (e.g., watershed size, lake size, water residence time) for a given lake. Consequently, shallow-water habitat supporting aquatic plants, invertebrates, and fish can be impaired or reduced. Restoration of lake water levels in shallow drainage lakes should carefully consider the rate, timing, duration, and magnitude of managed water levels within the constraints of large watershed size and small waterbody volume.
- Invasive Species Control: Invasive aquatic plant and mollusk species (e.g., Zebra mussel, Asian Clam) detrimentally impact lake ecosystem biological communities and resources across Massachusetts. Prevention of their spread and managing for their reduction and eradication are critical to maintaining and restoring native lake biological communities (e.g., plants, invertebrates). Invasive species can be prevented from spreading by thoroughly washing and drying water-based gear and equipment between lake visits. Early detection and rapid response is critical for eradication and preventing establishment within a waterbody. Invasive aquatic plants can be managed using a variety of tools including herbicides, pulling, harvesting/cutting, raking, and dredging. Extensive literature on this topic can be found in the practical guide to lake and pond management.
Examples
- Three Mile Pond (Sheffield)
- Lake Wickaboag (West Brookfield)
- Harbor Pond (Towsend)
- Lake Nippenicket (Bridgewater)
- Snipatuit Pond (Rochester)
- Wheelers Pond (Warwick)
Additional resources
Stop Aquatic Hitchhikers Handout