Sunset on Oneida Lake (winter-stratified monomictic lake) Shane Gebauer

Sunset on Oneida Lake (winter-stratified monomictic lake)
Shane Gebauer

System
Lacustrine
Subsystem
Natural Lakes And Ponds
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S2
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines.
Global Conservation Status Rank
G3G4
Vulnerable globally, or Apparently Secure - At moderate risk of extinction, with relatively few populations or locations in the world, few individuals, and/or restricted range; or uncommon but not rare globally; may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign either G3 or G4.

Summary

Did you know?

Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). With a surface area of nearly 80 square miles Oneida Lake is the largest winter-stratified monomictic lake in New York, and the largest lake entirely within New York State.

State Ranking Justification

Very few lakes in NY have the physical setting to meet the large surface area and shallow depth thresholds that define the community (e.g., Lake Oneida). The condition of these lakes are threatened by nutrient and pollution runoff; and several aquatic invasive species. The current trend of this community is probably stable for actively protected/managed lakes, or declining slightly elsewhere due to moderate threats related to watershed development, invasive aquatic species, and alteration to the natural hydrology.

Short-term Trends

The number and acres of winter-stratified monomictic lakes in New York have likley remained stable in recent decades given that very few lakes in NY have the have the physical setting to meet the large surface to shallow depth ratio that define the community (e.g., Oneida Lake and Perch Lake). However, the water quality of these lakes is threatened by excessive run-off of nutrients, pathogens, and toxins from the surrounding watershed; and they are also threatened by the spread of numerous aquatic invasive species.

Long-term Trends

The number and acres of winter-stratified monomictic lakes in New York are probably comparable to historical numbers, but the water quality of several of these lakes has likely declined significantly as a result of several human caused disturbances (e.g., nutrient and pollution run-off, invasive species, watershed development, etc.).

Conservation and Management

Conservation Overview

Where practical, establish and maintain a lakeshore buffer to reduce storm-water, pollution, and nutrient run-off, while simultaneously capturing sediments before they reach the lake. Buffer width should take into account the erodibility of the surrounding soils, slope steepness, and current land use. If possible, minimize the number and size of impervious surfaces in the surrounding landscape. Avoid habitat alteration within the lake and surrounding landscape. For example, roads should not be routed through the lakeshore buffer area. If a lake must be crossed, then bridges and boardwalks are preferred over filling and culverts. Restore lakes that have been affected by unnatural disturbance (e.g., remove obsolete impoundments and ditches in order to restore the natural hydrology). Prevent the spread of invasive exotic species into the lake through appropriate direct management, and by minimizing potential dispersal corridors. Look for more lake-specific information on this topic in the following reports and management plans: Oneida Lake State of the Lake and Watershed Report (Central New York Regional Planning and Development Board 2003) and Oneida Lake Watershed Management Plan (Central New York Regional Planning and Development Board 2004).

Threats

These lakes are threatened by the spread of aquatic invasive species, such as common carp (Cyprinus carpio), zebra mussel (Dreissena polymorpha), bloody red shrimp (Hemimysis anomala), Eurasian watermilfoil (Myriophyllum spicatum), variable leaf watermilfoil (Myriophylluum heterophyllum), and curly-leaved pondweed (Potamogeton crispus).

Threats to water quality in Lake Oneida include the following (excerpted from the Oneida Lake Watershed Management Plan): Water chestnut was first detected in Lake Oneida in 1999. Dense plant growth on the lake surface blocks the sunlight from penetrating the water column, shades out native plants, reduces fish habitat, and restricts boating and other recreational usage. Zebra mussels were first detected in Lake Oneida in 1991. These organisms have dramatically changed water clarity patterns in Oneida Lake and have caused the extinction of all native clams. Zebra mussel induced water clarity patterns have resulted in aquatic plant growth extending into deeper water and have likely impacted the behavior and abundance of turbid water fish species like walleye. Increased light penetration has caused mats of algae to grow on the lake bottom at shallow depths and windrows of aquatic plants and algae to accumulate on the shoreline in late summer and early fall. Boating pressures: Overuse of the lake by boaters and other watercraft is a concern. Salt application and storage: The application of deicing salts on roadways and unprotected salt storage areas can impact both surface water and groundwater. High salt content in groundwater and surface water can alter water chemistry, making it unfit for aquatic life or human consumption. Septic systems and other human influences: While phosphorus levels and nutrient enrichment have declined in Oneida Lake over the past 20 years, nutrients and other elements originating from agricultural and street runoff and poorly maintained septic systems remain a concern. Erosion: The loss of soil from the Oneida Lake watershed due to poor land use practices associated with agriculture, forestry, highway maintenance, and construction is a major issue of concern especially in the southern portion of the watershed. Loss of soil into Oneida Lake destroys valuable fish habitat and introduces nutrients and other pollutants to the lake. Sedimentation: Excess sediment loading at the mouth of tributaries and in Oneida Lake can result in negative impacts on aquatic biota, fish, and fish habitat. As areas of the lake bottom become shallow as a result of heavy sedimentation, boating and other recreational activities are greatly hampered. Flooding: Flooding occurs in the regions surrounding Oneida Lake, often after major storm events or rapid winter thaws. Lake water levels: Problems within the lake community can develop if the lake water levels are either too high or too low.

Conservation Strategies and Management Practices

Where practical, establish and maintain a lake shore buffer to reduce storm-water, pollution, and nutrient run-off, while simultaneously capturing sediments before they reach the lake. Buffer width should take into account the erodibility of the surrounding soils, slope steepness, and current land use. If possible, minimize the number and size of impervious surfaces in the surrounding landscape. Avoid habitat alteration within the lake and surrounding landscape. For example, roads should not be routed through the lake shore buffer area. If portions of a lake must be crossed, then bridges and boardwalks are preferred over filling and culverts. Restore lakes that have been affected by unnatural disturbance (e.g., remove obsolete impoundments and ditches in order to restore the natural hydrology). Prevent the spread of invasive exotic species into the lake through appropriate direct management, and by minimizing potential dispersal corridors.

Development and Mitigation Considerations

When considering road construction and other development activities, minimize actions that will change what water carries and how water travels to this lake community, both on the surface and underground. Water traveling over-the-ground as run-off usually carries an abundance of silt, clay, and other particulates during (and often after) a construction project. While still suspended in the water, these particulates make it difficult for aquatic animals to find food; after settling to the bottom of the lake, these particulates bury small plants and animals and alter the natural functions of the community in many other ways. Thus, road construction and development activities near this lake type should strive to minimize particulate-laden run-off into this community. Water traveling on the ground or seeping through the ground also carries dissolved minerals and chemicals. Road salt, for example, is becoming an increasing problem both to natural communities and as a contaminant in household wells. Fertilizers, detergents, and other chemicals that increase the nutrient levels in lakes cause algae blooms and eventually an oxygen-depleted environment where few animals can live. Herbicides and pesticides often travel far from where they are applied and have lasting effects on the quality of the natural community. So, road construction and other development activities should strive to consider: 1. how water moves through the ground, 2. the types of dissolved substances these development activities may release, and 3. how to minimize the potential for these dissolved substances to reach this natural community. Look for more lake-specific information on this topic in the following reports and management plans: Oneida Lake State of the Lake and Watershed Report (Central New York Regional Planning and Development Board 2003) and Oneida Lake Watershed Management Plan (Central New York Regional Planning and Development Board 2004).

Inventory Needs

Resurvey known occurrences and search for new occurrences statewide to advance documentation and classification of winter-stratified monomictic lakes. A statewide review of winter-stratified monomictic lakes is desirable. Continue searching for large lakes in good condition (A- to AB-ranked). Review and incorporate data from partner organizations to create a new occurrence record of winter-stratified monomictic lake for Oneida Lake, and to update the Perch Lake and Horseshoe Lake occurrrences (e.g., Central New York Regional Planning and Development Board). Review and incorporate data on occurrences in NY gathered by the Adirondack Lakes Survey Corporation, the Adirondack Park Invasive Plant Program, and the New York State Federation of Lake Associations, Inc.

Research Needs

There is a need to research the composition of winter-stratified monomictic lakes statewide in order to characterize variations. Only two to three ecoregional variants are suspected (Great Lakes, Northern Appalachian, and possibly Lower New England types), potentially differing in dominant, and characteristic vascular plants, fishes, mollusks, and insects.

Rare Species

  • Apalone spinifera (Spiny Softshell) (guide)
  • Gavia immer (Common Loon) (guide)
  • Potamogeton pulcher (Spotted Pondweed) (guide)

Range

New York State Distribution

This community is uncommon in upstate New York, north of the North Atlantic Coast Ecoregion. Probably limited to the Great Lakes Ecoregion and adjacent parts of other ecoregions such as the Northern Appalachians and concentrated in or restricted to non-mountainous areas of the state.

Global Distribution

This broadly-defined community may be worldwide. Examples with the greatest biotic affinities to New York occurrences are suspected to span north to southern Canada, west to Minnesota, southwest to Indiana and Tennessee, and southeast to North Carolina.

Best Places to See

  • Joe Indian Pond (St. Lawrence County)
  • St. Regis Pond (Franklin County)
  • Fern Lake (Clinton County)
  • Duck Lake (Franklin County)
  • Black Lake (St. Lawrence County)
  • Horseshoe Lake (St. Lawrence County)
  • Oneida Lake (Oneida County)
  • Perch Lake (Jefferson County)

Identification Comments

General Description

Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). With a surface area of nearly 80 square miles (207 sq. km.) Oneida Lake is the largest winter-stratified monomictic lake in New York. The lake is about 21 miles (34 km) long and about 5 miles (8.0 km) wide with an average depth of 22 feet (6.7 m).

Characters Most Useful for Identification

Characteristic fishes are walleye (Stizostedion vitreum), largemouth bass (Micropterus salmoides), yellow perch (Perca flavescens), bullhead (Ictalurus spp.), white sucker (Catostomus commersoni), muskellunge (Esox masquinongy), and trout perch (Percopsis omiscomaycus). Characteristic macroinvertebrates may include isopods (Isopoda), amphipods (Amphipoda), and ramshorn snails (Planorbidae). Characteristic phytoplankton may include Dinobryon spp., and Ceratium spp. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.

Best Time to See

Winter-stratified monomictic lakes can be easily observed from the shoreline where there is public access, or by boat during calm weather.

Winter-stratified Monomictic Lake Images

Classification

Characteristic Species

Nonvascular plants

stoneworts (Chara spp.)

Floating-leaved aquatics

Lemna minor (common duckweed)

Nuphar variegata (common yellow pond-lily, common spatter-dock)

Nymphaea odorata ssp. odorata (fragrant white water-lily)

Potamogeton nodosus (long-leaved pondweed)

Spirodela polyrhiza (common duck-meal)

Submerged aquatics

Ceratophyllum demersum (common coon-tail)

Elodea canadensis (Canada waterweed)

Heteranthera dubia (water star-grass)

Myriophyllum heterophyllum (various-leaved water milfoil, variable-leaved water milfoil)

Najas flexilis (common water-nymph, common naiad)

Potamogeton obtusifolius (blunt-leaved pondweed)

Potamogeton perfoliatus (clasping-leaved pondweed)

Potamogeton praelongus (white-stemmed pondweed)

Potamogeton pusillus (common narrow-leaved pondweed)

Potamogeton richardsonii (Richard's pondweed)

Potamogeton zosteriformis (flat-stemmed pondweed)

quillworts (Isoetes spp.)

Stuckenia pectinata (Sago pondweed)

Utricularia vulgaris ssp. macrorhiza (greater bladderwort)

Vallisneria americana (water-celery, tape-grass)

Unvegetated

amphipods (Amphipoda)

bullhead (Ameiurus spp.)

crustacean - water fleas (Cladocera)

isopods (Isopoda)

largemouth bass (Micropterus salmoides)

muskellunge (Esox masquinongy)

phytoplankton (Ceratium spp.)

phytoplankton (Dinobryon spp.)

ramshorn snails (Planorbidae)

trout perch (Percopsis omiscomaycus)

walleye (Stizostedion vitreum)

white sucker (Catostomus commersoni)

yellow perch (Perca flavescens)

Similar Ecological Communities

  • Bog lake/pond (guide)
    Bog lake/pond: The aquatic community of a dystrophic lake (an acidic lake with brownish water that contains a high amount of organic matter) that typically occurs in a small, shallow basin (e.g., a kettehole) that is protected from wind and is poorly drained. These lakes occur in areas with non-calcareous bedrock or glacial till; many are fringed or surrounded by a floating mat of vegetation (in New York usually either bog or poor fen). Characteristic features of a dystrophic lake include the following: murky water that is stained brown, with low transparency; water that is low in plant nutrients (especially low in calcium), with naturally low pH (less than 5.4); and the lake may have oxygen deficiencies in deeper water (the profundal zone). The lack of calcium blocks bacterial action, reducing the rate of decay of organic matter with subsequent accumulation of peat or muck sediments. Colloidal and dissolved humus material reduces transparency and increases acidity of the water. Characteristic macrophytes include water-shield (Brasenia schreberi), fragrant white water lily (Nymphaea odorata), yellow pond-lily (Nuphar microphylla and Nuphar variegata), bladderworts (Utricularia vulgaris, U. geminiscapa, U. purpurea), pondweeds (Potamogeton epihydrus, P. oakesianus), bur-reeds (Sparganium fluctuans, S. angustifolium), and clubrush (Scirpus subterminalis). Characteristic zooplankton may include the rotifers Keratella spp. and Brachionus spp. Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Eutrophic dimictic lake (guide)
    Eutrophic dimictic lake: The aquatic community of a nutrient-rich lake that occurs in a broad, shallow basin. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall); they are thermally stratified in the summer, and they freeze over and become inversely stratified in the winter. Aquatic macrophytes are abundant in shallow water, and there are many species present, but species diversity is generally lower than in mesotrophic lakes. Characteristic plants include tapegrass (Vallisneria americana), pondweeds (Potamogeton spp.), bur-reeds (Sparganium spp.), and the floating aquatic plants white water-lily (Nymphaea spp.), yellow pond-lily (Nuphar luteum), and water-shield (Brasenia schreberi). Characteristic features of a eutrophic lake include the following: yellow, green, or brownish-green water that is murky, with low transparency (Secchi disk depths typically less than 2.5 m, but up to 4 m in some cases); water rich in plant nutrients (especially high in phosphorus, nitrogen and calcium); high primary productivity (inorganic carbon fixed = 75 to 250 g/m2/yr); lake sediments that are rich in organic matter (usually consisting of a fine organic silt or copropel); water that is well-oxygenated above the summer thermocline, but oxygen-depleted below the summer thermocline or under ice; epilimnion volume that is relatively large compared with hypolimnion; and a weedy shoreline. Alkalinity is typically high (greater than 12.5 mg/l calcium carbonate). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Eutrophic pond (guide)
    Eutrophic ponds: The aquatic community of a small, shallow, nutrient-rich pond. Species diversity is typically high. Aquatic vegetation is abundant. Characteristic plants include coontail (Ceratophyllum demersum), duckweeds (Lemna minor, L. trisulca), waterweed (Elodea canadensis), pondweeds (Potamogeton spp.), water starwort (Heteranthera dubia), bladderworts (Utricularia spp.), naiad (Najas flexilis), tapegrass or wild celery (Vallisneria americana), algae (Cladophora spp.), common yellow pond-lily (Nuphar variegata), and white water-lily (Nymphaea odorata). The water is usually green with algae, and the bottom is mucky. Eutrophic ponds are too shallow to remain thermally stratified throughout the summer; they often freeze and become inversely stratified in the winter (coldest water at the surface), therefore they are winter-stratified monomictic ponds. Additional characteristic features of a eutrophic pond include the following: water that is murky, with low transparency (Secchi disk depths typically less than 4 m); water rich in plant nutrients (especially high in phosphorus, nitrogen, and calcium), high primary productivity (inorganic carbon fixed = 75 to 250 g/m2/yr) and a weedy shoreline. Alkalinity is typically high (greater than 12.5 mg/l calcium carbonate). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Great Lakes deepwater community (guide)
    Lake Ontario and Lake Erie are summer-stratified monomictic lakes, not winter-stratified monomictic lakes. They are classified as Great Lakes deepwater community because of their larger size, and access to estuarine biota through the St. Lawrence River, and the Welland Canal. Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Meromictic lake (guide)
    Meromictic lake: the aquatic community of a relatively deep lake with small surface area that is so protected from wind-stirring that it has no annual periods of complete mixing, and remains chemically stratified throughout the year. These lakes may be protected from mixing by a sheltered surrounding landscape (e.g., a deep basin) or by adjacent tree cover. Meromictic lakes in New York freeze over and become inversely stratified in the winter (coldest water at the surface); they pass through spring, and fall periods of isothermy without circulating. Meromictic lakes frequently have dichothermic stratification, meaning that the minimum temperature occurs in the middle stratum. The stagnant waters in the lower part of a meromictic lake become heavily loaded with dissolved salts, and lack oxygen. Chemical stratification is most often measured by salinity gradients, or total cation and anion concentrations. Gradients may be present for chemicals, such as hydrogen sulfide, ammonia, phosphorus, or iron. Flushing rates are typically low. Some examples of this lake type may be dystrophic, and thus resemble bog lakes. Species diversity is low because very few organisms can tolerate the extreme chemical conditions of the lower strata of a meromictic lake. Fishes are absent or sparse. Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Mesotrophic dimictic lake (guide)
    Mesotrophic dimictic lake: The aquatic community of a lake that is intermediate between an oligotrophic lake and a eutrophic lake. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall), they are thermally stratified in the summer (warmest water at the surface), and they freeze over and become inversely stratified in the winter (coldest water at the surface). These lakes typically have a diverse mixture of submerged macrophytes, such as several species of pondweeds (Potamogeton amplifolius, P. praelongus, P. robbinsii), water celery or tape grass (Vallisneria americana), and bladderworts (Utricularia spp.). Characteristic features of a mesotrophic lake include the following: water with medium transparency (Secchi disk depths of 2 to 4 m); water with moderate amounts of plant nutrients; moderate primary productivity (inorganic carbon fixed = 25 to 75 g/m2/yr); lake sediments with moderate amounts of organic matter; and moderately well-oxygenated water. Alkalinity is typically moderate (slightly greater than 12.5 mg/l calcium carbonate). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Oligotrophic dimictic lake (guide)
    Oligotrophic dimictic lake: The aquatic community of a nutrient-poor lake that often occurs in deep, steeply-banked basins. These lakes are dimictic, meaning they have two periods of mixing and turnover (spring and fall); they are stratified in the summer, then they freeze in winter and become inversely stratified. Common physical characteristics of oligotrophic lakes include blue or green highly transparent water (Secchi disk depths from 4 to 8 m), low dissolved nutrients (especially nitrogen and calcium), low primary productivity, and sediment with low levels of organic matter. Additionally, the lakes have an epilimnion volume that is low relative to the hypolimnion, high dissolved oxygen levels year-round through all strata, and low alkalinity. The plant community is primarily in the shallow parts of the lake, between 1 and 3 m (3 to 10 feet), and is dominated by rosette-leaved aquatic species. Characteristic species include seven-angle pipewort (Eriocaulon aquaticum), water lobelia (Lobelia dortmanna), quillworts (Isoetes echinospora ssp. muricata, I. lacustris), milfoils (Myriophyllum alterniflorum, M. tenellum), bladderworts (Utricularia purpuea, U. resupinata), tape grass (Vallisneria americana), and creeping buttercup (Ranunculus repens). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Oligotrophic pond (guide)
    Oligotrophic pond: The aquatic community of a small, shallow, nutrient-poor pond. The water is very clear, and the bottom is usually sandy or rocky. Aquatic vegetation is typically sparse, and species diversity is low. Characteristic species are rosette-leaved aquatics such as pipewort (Eriocaulon aquaticum), water lobelia (Lobelia dortmanna), and quillwort (Isoetes echinospora). Oligotrophic ponds are too shallow to remain thermally stratified throughout the summer; they often freeze and become inversely stratified in the winter (coldest water at the surface), therefore they are winter-stratified monomictic ponds. Additional characteristic features of an oligotrophic pond include the following: blue or green water with high transparency (Secchi disk depths of 4 to 8 m); water low in plant nutrients (especially low in nitrogen, also low in calcium); low primary productivity (inorganic carbon fixed = 7 to 25 g/m2/yr). Alkalinity is typically low (less than 12.5 mg/l calcium carbonate). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.
  • Summer-stratified monomictic lake (guide)
    Summer-stratified monomictic lakes are so deep (or large) that they have only one period of mixing or turnover each year (monomictic), and one period of stratification. These lakes generally do not freeze over in winter (except in unusually cold years), or form only a thin or sporadic ice cover during the coldest parts of midwinter, so the water circulates and is isothermal during the winter (similar temperature though the water column). These lakes are typically thermally stratified only in the summer (warmest water at the surface); they are oligotrophic to mesotrophic and alkaline. Characteristic aquatic macrophytes include pondweeds (Potamogeton gramineus, P. richardsonii, P. pectinatus), horned pondweed (Zannichellia palustris), naiad (Najas flexilis), waterweed (Elodea canadensis), tapegrass or wild celery (Vallisneria americana), and coontail (Ceratophyllum demersum). Winter-stratified monomictic lakes have only one period of mixing each year because they are very shallow in relation to its size and is completely exposed to winds. These lakes continue to circulate throughout the summer and typically never become thermally stratified in that season. They are only stratified in the winter when they freeze over and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic. Littoral, and epilimnion species assemblages predominate. Pelagic species assemblages are well developed. Vascular plants are typically diverse. Characteristic aquatic macrophytes include water stargrass (Heteranthera dubia), coontail (Ceratophyllum demersum), waterweed (Elodea spp.), naiad (Najas flexilis), tapegrass (Vallisneria americana), and pondweeds (Potamogeton perfoliatus, P. pectinatus, P. pusillus, P. richardsonii, P. nodosus, P. zosteriformis). The macroalgae Chara may be abundant.

Vegetation

Emergent aquatics
1%
Floating-leaved aquatics
2%
Submerged aquatics
12%

Percent cover

This figure helps visualize the structure and "look" or "feel" of a typical Winter-stratified Monomictic Lake. Each bar represents the amount of "coverage" for all the species growing at that height. Because layers overlap (shrubs may grow under trees, for example), the shaded regions can add up to more than 100%.

Additional Resources

References

Berg, C.O. 1963. Middle Atlantic states. Chapter 6 from Limnology in North America. The University of Wisc. Press.

Bloomfield, J.A., ed. 1978a. Lakes of New York State. Vol. I. Ecology of the Finger Lakes. Academic Press, New York.

Central New York Regional Planning and Development Board. 2003. Oneida Lake State of the Lake and Watershed Report. Central New York Regional Planning and Development Board, Syracuse, NY.

Central New York Regional Planning and Development Board. 2004. A Management Strategy for Oneida Lake and Its Watershed. Central New York Regional Planning and Development Board, Syracuse, NY.

Edinger, G. J., D. J. Evans, S. Gebauer, T. G. Howard, D. M. Hunt, and A. M. Olivero (editors). 2014. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke’s Ecological Communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation, Albany, NY. https://www.nynhp.org/ecological-communities/

Hunt, David M. 1998. Community ranking and general description. Lake Champlain, summer-stratified monomictic lake. Unpublished report. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY.

New York Natural Heritage Program. 2021. New York Natural Heritage Program Databases. Albany, NY.

Nichols, W. F. 2015. Natural Freshwater Lakes and Ponds in New Hampshire: Draft Classification. NH Natural Heritage Bureau, Concord, NH.

Olivero-Sheldon, A. and M.G. Anderson. 2016. Northeast Lake and Pond Classification. The Nature Conservancy, Eastern Conservation Science, Eastern Regional Office. Boston, MA.

Links

About This Guide

This guide was authored by: Gregory J. Edinger

Information for this guide was last updated on: June 2, 2021

Please cite this page as:
New York Natural Heritage Program. 2021. Online Conservation Guide for Winter-stratified monomictic lake. Available from: https://guides.nynhp.org/winter-stratified-monomictic-lake/. Accessed June 15, 2021.

Back to top