Habitat description
These waterbodies have very limited water temperature gradients and receive water primarily through groundwater exchange and seasonal stream inputs. Water level fluctuations may be substantial and will vary with groundwater levels and seasonal precipitation. Water residence time can be high but will vary based on watershed size relative to waterbody surface area or volume. Aquatic plants and algae may grow in sparse to dense stands throughout the waterbody due to high water clarity and/or shallow depths. Waterbodies vary in surface area but will tend to be relatively small (e.g., <25 ac) 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. These waterbodies have relatively small drainage areas and therefore may receive limited total nutrient loads. However, because of this habitat’s suitable growing conditions, nutrient levels are often high. 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 waterbodies occur across the state from western watersheds to relatively dense concentrations in the southeast featuring waterbodies such as Coastal Plain Ponds.
Associated habitat types
Coastal Plain Ponds, small seasonal streams, 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 warmwater and coolwater fish species. Typical species include Brown Bullhead, Chain Pickerel, and Golden Shiner among others. Waterbodies with connection to the ocean may be temporarily inhabited by diadromous fish species. Furthermore, 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 but are also often absent in these waterbodies. These 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
The generally small upstream watershed area of these waterbodies will limit nutrient inputs and increase water residence times. Internal nutrient cycling (e.g., phosphorus) may play a larger role in nutrient dynamics depending upon legacy land use and the amount of shoreline modification and development. Water level fluctuations may vary considerably as they are primarily influenced by precipitation patterns channeled through groundwater and seasonal surface water inflows. Water levels may be further regulated by the presence of beaver dams. Due to these characteristics, shallow, isolated, headwater lakes 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. May be highly impacted by climate change through changes in water level fluctuations but may be buffered by stable groundwater exchange and hydrologically connected wetlands. Anticipated impacts will be highly variable across ponds. Increased air temperatures will increase surface water temperatures and may have more of an impact on smaller surface area waterbodies where temperatures are naturally cooler via shading from riparian vegetation. Extreme weather events such as drought will contribute to increased variability in lake water levels.
Restoration & management recommendations
- Water Quality Restoration: Lake aging or eutrophication is a natural process by which lentic 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 isolated and headwater lakes are susceptible to eutrophication because of their typically small water volume. 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. Restoration of protection of riparian buffers in these waterbodies should be a high priority because of its typically small watershed size.
- 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 isolated or headwater lakes should carefully consider the rate, timing, duration, and magnitude of managed water levels within the constraints of their relatively small watershed and inflows.
- 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
- Baddacook Pond (Groton)
- Windsor Lake (North Adams)
- Wickett Pond (Wendell)
- Goss Pond (Upton)
- Woods Pond (Stoughton)
- Grassy Pond (Falmouth)
Additional resources
The Practical Guide to Lake Management in Massachusetts
Stop Aquatic Hitchhikers Handout