Summary

Did you know?

Mesotrophic lakes have moderate levels of nutrients; they are intermediate in richness between eutrophic and oligotrophic lakes. Dimictic lakes turn over twice a year, during the spring and the fall. This remixes dissolved oxygen and nutrients, needed by plants and animals in the lake. In the fall, the surface water becomes cooler and denser than the bottom waters. This cooler water sinks to the bottom, mixing the lake water. In the winter as temperatures drop further, ice forms on top of the lake and stops any further mixing. During the spring, the lake is heated by the sun and the cooler, less dense water floats to the top and the warmer, denser water extends to the bottom. As summer progresses, the temperature and density differences between upper and lower water layers become more distinct. These lakes generally become physically stratified into three identifiable layers in the summer and winter.

State Ranking Justification

There are several hundred occurrences statewide and currently includes bays and coves of larger lakes, such as Lake Champlain. Few occurrences are presumed to have good viability and are protected on public land or private conservation land. This community has statewide distribution, and includes several large, high quality examples. The current trend of this community is probably stable for occurrences on public land, or declining slightly elsewhere due to moderate threats related to lakeshore development, invasive species, and atmospheric deposition.

Short-term Trends

The numbers and acreage of mesotrophic dimictic lakes in New York have probably remained stable in recent decades as a result of wetland protection regulations. However, the condition of some of these lakes may have declined slightly to moderately due to the spread of invasive aquatic species. There may be a few cases of slight decline due to alteration of hydrology (e.g., ditching and impoundments) and reduced water quality from nutrient input from surrounding developed uplands.

Long-term Trends

The numbers and acreage of eutrophic dimictic lakes in New York have probably remained stable in recent decades as a result of wetland protection regulations. However, the condition of some of these lakes may have declined slightly to moderately due to the spread of invasive aquatic species. There may be a few cases of slight decline due to alteration of hydrology (e.g., ditching and impoundments) and reduced water quality from nutrient input from surrounding developed uplands.

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.

Threats

Mesorophic dimictic lakes are threatened by shoreline development and its associated run-off (e.g., residential, commercial, agricultural, and roads), recreational overuse (e.g., powerboats, intensive fish stocking and removal), and habitat alteration in the adjacent landscape (e.g., excessive land clearing, pollution run-off, and increased impervious surfaces within the watershed). Many of these lakes are threatened by the spread of aquatic invasive species, such as alewife (Alosa pseudoharengus), fishhook waterflea (Cercopagis pengoi), common carp (Cyprinus carpio), Asian clam (Corbicula fluminea), zebra mussel (Dreissena polymorpha), scud (Echinogammarus ischnus), green sunfish (Lepomis cyanellus), Eurasian watermilfoil (Myriophyllum spicatum), brittle naiad (Najas minor), starry stonewort (Nitellopsis obtusa), curly leafed pondweed (Potamogeton crispus), rudd (Scardinius erythrophthalmus), and water chestnut (Trapa natans).

Conservation Strategies and Management Practices

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.

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.

Inventory Needs

Survey for occurrences statewide to advance documentation and classification of mesotrophic dimictic lakes. A statewide review of mesotrophic dimictic lakes is desirable. Continue searching for large lakes in good condition (A- to AB-ranked). 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 mesotrophic dimictic lakes statewide in order to characterize variations. Continued research is needed on the impacts that atmospheric deposition has on this community. Research is needed to inform the classification of the mesophic bays and coves along the margins of larger summer-stratified monomictic lakes lakes (e.g., King Bay and Monty Bay in Lake Champlain).

Rare Species

• Aeshna clepsydra (Mottled Darner) (guide)
• Apalone spinifera (Spiny Softshell) (guide)
• Argia translata (Dusky Dancer) (guide)
• Gavia immer (Common Loon) (guide)
• Hippuris vulgaris (Mare's Tail) (guide)
• Myriophyllum alterniflorum (Alternate-flowered Water Milfoil) (guide)
• Notropis heterodon (Blackchin Shiner) (guide)
• Potamogeton alpinus (Red Pondweed) (guide)
• Potamogeton hillii (Hill's Pondweed) (guide)
• Potamogeton pulcher (Spotted Pondweed) (guide)
• Potamogeton strictifolius (Straight-leaved Pondweed) (guide)
• Potamogeton x ogdenii (Ogden's Pondweed) (guide)
• Valvata sincera (Mossy Valvata) (guide)

Range

New York State Distribution

This community is widespread throughout New York State, and includes the following lakes: Hemlock Lake, Livingston and Ontario Counties; Canadice Lake, Ontario County; Conesus Lake, Livingston County; Otisco Lake, Onondaga County; Lower St. Regis Lake, Franklin County; Rich Lake, Essex County; Yellow Lake, St. Lawrence County.

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

• Hemlock Lake (Livingston, Ontario Counties)
• Canadice Lake (Ontario County)
• Conesus Lake (Livingston County)
• Otisco Lake (Onondaga County)
• Lower St. Regis Lake (Franklin County)
• Rich Lake (Essex County)
• Yellow Lake (St. Lawrence County)
• Middle Saranac Lake (Franklin County)
• Lake Clear (Franklin County)
• Brant Lake (Warren County)
• Trout Lake Bolton (Warren County)
• Osgood Pond (Franklin County)
• Eagle Lake (Essex County)
• Lake Durant (Hamilton County)
• Kiwassa Lake (Franklin County)
• Cedar Lake (St. Lawrence County)
• Ossetah Lake (Franklin County)
• Lower St. Regis Lake (Franklin County)
• West Caroga Lake (Fulton County)
• Raquette Lake (Hamilton County)
• Lows Lake (Hamilton County)
• Green Pond Floodwood Road (Franklin County)
• Twin Pond West (St. Lawrence County)
• Chautauqua Lake North (Chautauqua County)

Identification Comments

General Description

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). Profundal and pelagic species assemblages are usually well developed. Characteristic fishes are mostly warmwater fishes, such as yellow perch (Perca flavescens), largemouth bass (Micropterus salmoides), northern pike (Esox lucius), bluegill (Lepomis macrochirus), and pumpkinseed (Lepomis gibbosus). Smallmouth bass (Micropterus dolomieui) is a characteristic cool water fish in these lakes. Characteristic invertebrates may include pea clams (Pisidium spp.) and mayflies (Hexagenia spp.). 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 plankton may include the phytoplankton Asterionella and the zooplankton Daphnia dubia. More data on this community are needed. This community may occur as a single lake basin, or part of a larger lake type. Relatively shallow, mesotrophic bays and coves of large, deep summer-stratified monomictic lakes are included under this type (e.g., King Bay and Monty Bay in Lake Champlain).

Characters Most Useful for Identification

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). 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.).

Elevation Range

Known examples of this community have been found at elevations between 80 feet and 1,567 feet.

Best Time to See

Mesotrophic dimictic lakes can be easily observed from the shoreline where there is public access, or by boat in mid- to late summer when fragrant white water lily and spatter dock are in bloom in the shallow areas.

Mesotrophic Dimictic Lake Images

Mesotrophic dimictic lake at Duck Lake, Cayuga County
Stephen M. Young

Mesotrophic dimictic lake at Chautauqua Lake
D.J. Evans

Mesotrophic dimictic lake at Duck Lake, Cayuga County

Mesotrophic dimictic lake at Duck Lake, Cayuga County

Mesotrophic dimictic lakes (ConesusLake, Hemlock Lake, Canadice Lake)

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Classification

Characteristic Species

• Nonvascular plants

  • Chara vulgaris

• Emergent aquatics

  • Alisma gramineum (grass-leaved water-plantain)
  • Eleocharis acicularis (needle spike-rush)
  • Pontederia cordata (pickerelweed)
  • Sagittaria graminea ssp. graminea (grass-leaved arrowhead)
  • Schoenoplectus acutus var. acutus (hard-stemmed bulrush)
  • Schoenoplectus tabernaemontani (soft-stemmed bulrush)

• Floating-leaved aquatics

  • Brasenia schreberi (water-shield)
  • Lemna minor (common duckweed)
  • Lemna trisulca (star duckweed)
  • Nuphar variegata (common yellow pond-lily, common spatter-dock)
  • Nymphaea odorata ssp. odorata (fragrant white water-lily)
  • Potamogeton amplifolius (big-leaved pondweed)
  • Potamogeton epihydrus (ribbon-leaved pondweed)
  • Potamogeton gramineus (grass-leaved pondweed)
  • Potamogeton natans (floating-leaved pondweed)
  • Potamogeton spirillus (northern snailseed pondweed)

• Submerged aquatics

  • Ceratophyllum demersum (common coon-tail)
  • Elodea canadensis (Canada waterweed)
  • Heteranthera dubia (water star-grass)
  • Isoetes tuckermanii (Tuckerman's quillwort)
  • Myriophyllum alterniflorum (alternate-flowered water milfoil)
  • Myriophyllum sibiricum (northern water milfoil)
  • Myriophyllum spicatum (Eurasian water milfoil)
  • Najas flexilis (common water-nymph, common naiad)
  • Potamogeton crispus (curly pondweed)
  • Potamogeton perfoliatus (clasping-leaved pondweed)
  • Potamogeton praelongus (white-stemmed pondweed)
  • Potamogeton pusillus (common narrow-leaved pondweed)
  • Potamogeton richardsonii (Richard's pondweed)
  • Potamogeton robbinsii (Robbins's pondweed, fern pondweed)
  • Potamogeton zosteriformis (flat-stemmed pondweed)
  • Ranunculus aquatilis var. diffusus (white water butter-cup, white water crow-foot)
  • Stuckenia pectinata (Sago pondweed)
  • Utricularia spp. (bladderworts)
  • Vallisneria americana (water-celery, tape-grass)

• Unvegetated

  • bluegill (Lepomis macrochirus)
  • largemouth bass (Micropterus salmoides)
  • mayflies (Hexagenia spp.)
  • northern pike (Esox lucius)
  • pea clams (Pisidium spp.)
  • phytoplankton (Asterionella spp.)
  • pumpkinseed (Lepomis gibbosus)
  • smallmouth bass (Micropterus dolomieui)
  • yellow perch (Perca flavescens)
  • zooplankton (Daphnia dubia)

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. 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).
• 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). 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).
• Eutrophic pond (guide)
  Eutrophic pond: 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). 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).
• 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. 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).
• 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). 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).
• 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). 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).
• 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). 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 lake (guide)
  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: 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).

Vegetation

Additional Resources

References

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

Cole, G.A. 1979. Textbook of limnology. The C.V. Mosby Co., Saint Louis, MO.

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/

Maitland, P.S. 1978. Biology of fresh waters. John Wiley, and Sons, New York.

New York Natural Heritage Program. 2023. 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.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Links

• Adirondack Lakes Survey Corporation
• Adirondack Park Invasive Plant Program (APIPP) Aquatic Program Early Detection Reports
• Hemlock Lake (NYS DEC)
• Lakes and Rivers (NYS DEC)
• Lower St. Regis Lake (NYS DEC)
• New York State Federation of Lake Associations (NYSFOLA) Aquatic Invasive Species by County
• Northeast Lake and Pond Classification System (TNC)
• Rich Lake (NYS DEC)
• Yellow Lake (NYS DEC)

About This Guide

This guide was authored by: Gregory J. Edinger

Information for this guide was last updated on: June 3, 2021

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Mesotrophic dimictic lake. Available from: https://guides.nynhp.org/mesotrophic-dimictic-lake/. Accessed October 3, 2023.