Oxbow Lake/Pond

Air photo of oxbow lake along Genesee River near Geneseo, NY
NYS Digital Orthoimagery Program

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
S3
Vulnerable in New York - Vulnerable to disappearing from New York due to rarity or other factors (but not currently imperiled); typically 21 to 80 populations or locations in New York, few individuals, restricted range, few remaining acres (or miles of stream), and/or recent and widespread declines.
Global Conservation Status Rank
G4
Apparently Secure globally - Uncommon in the world but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors.

Summary

Did you know?

Geographically distinct variants of oxbow lake occur in New York and differ in dominant and characteristic vascular plants, fishes, mollusks, and insects. In addition, three morphological variants are also known in New York: 1) classical oxbow lakes formed from old river channels, 2) small levee lakes formed as pools from levee overwash, and 3) floodplain lakes formed and replenished during high annual water of the associated river.

State Ranking Justification

There are probably several hundred occurrences statewide, although most are likely small and degraded. Very few documented occurrences have good viability and few are protected on public land or private conservation land. This community is somewhat limited to the floodplains of large streams and rivers across the state, and includes very few large, high quality examples. The current trend of this community is probably stable for occurrences on public land and private conservation land, or declining slightly elsewhere due to moderate threats related to development pressure. This community has declined substantially from historical numbers likely correlated with past hyrdorlogical alterations, conversion to agriculture, and other development.

Short-term Trends

The number and acreage of oxbow lakes on the floodplains of unconfined rivers in New York have probably remained stable in recent decades as a result of water quality regulations.

Long-term Trends

The number and acreage of oxbow lakes on the floodplains of unconfined rivers in New York are probably comparable to historical numbers.

Conservation and Management

Threats

Oxbow lakes are threatened by development (e.g., residential, agricultural) in the surrounding landscape. Other threats include habitat alteration (e.g., road crossings, excessive clearing in adjacent floodplain), and relatively minor recreational overuse (e.g., ATVs, trampling by visitors). Threats to adjacent rivers may apply to oxbow lakes (e.g., channelization, pollution, nutrient loading, sedimentation, impoundments/flooding).

Conservation Strategies and Management Practices

Where practical, establish and maintain a riparian buffer to reduce storm-water, pollution, and nutrient run-off, while simultaneously capturing sediments before they reach the oxbow 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 river and surrounding landscape. For example, roads should not be routed through the riparian buffer area. If the oxbow lake must be crossed, then bridges and boardwalks are preferred over filling and culverts. Restore past impacts, such as removing obsolete impoundments and ditches in order to restore the natural hydrology. Prevent the spread of invasive exotic species into the oxbow 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 community, both on the surface and underground. Water traveling over-the-ground as runoff 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 system, they 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 community 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 wetlands cause algal blooms and eventually an oxygen-depleted environment in which 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 oxbow lakes (e.g., Genesee River). A statewide review of oxbow lakes is desirable. Continue searching for large oxbow lakes in good condition (A- to AB-ranked) preferably comprised of multiple waterbodies of varriable size and depth.

Research Needs

Research is needed to fill information gaps about oxbow lakes, especially to advance our understanding of their classification, hydrology, floristic variation, and characteristic fauna. In addition, there is a need to collect sufficient quantitative data to support the recognition of a smaller variant tentatively called "oxbow pond".

Rare Species

  • Arigomphus cornutus (Horned Clubtail) (guide)
  • Cardamine rotundifolia (Round-leaved Water Cress) (guide)
  • Hippuris vulgaris (Mare's Tail) (guide)
  • Potamogeton alpinus (Red Pondweed) (guide)

Range

New York State Distribution

This community is widespread throughout upstate New York north of the North Atlantic Coast Ecoregion. It is concentrated in the non-mountainous areas of upstate New York.

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 Georgia.

Best Places to See

  • Raquette River Harrietstown
  • Saranac Lakes Wild Forest
  • High Peaks Wilderness Area

Identification Comments

General Description

An oxbow lake is a small, shallow, usually stagnant lake or pond of fluvial origin that occurs in an old river meander or oxbow that has been cut off from an unconfined river or marsh headwater stream by deposition of a levee on both upstream and downstream ends. Typically, the associated river periodically overflows this levee, restoring river water and biota to the lake. Many examples of this lake type may be relatively short-lived in dynamic river complexes, transforming either into backwater sloughs through permanent breaching of the downstream levee, or into riverine communities through permanent breaching of the upstream levee. Oxbow lakes are usually eutrophic.

Characters Most Useful for Identification

Oxbow lakes are completely separated from their associated riverine community most of the year during an average year. The river should generally overflow the dividing levee once or more every five years, otherwise the occurrence may grade into a eutrophic pond. Characteristic biota are typically riverine species assemblages. Aquatic macrophytes may include species typical of eutrophic ponds such as pondweeds (Potamogeton spp.), white water-lily (Nymphaea odorata), and water-shield (Brasenia schreberi). Associated shrub and herbaceous vegetation can vary widely by ecoregion and by the surrounding floodplain vegetation. Characteristic fauna may include odonates (Odonata).

Elevation Range

Known examples of this community have been found at elevations between 1,545 feet and 1,730 feet.

Best Time to See

The flora of oxbow lakes is at its peak in mid to late summer. Aquatic plant species such as water lobelia and bladderwort can be observed in bloom at this time.

Oxbow Lake/Pond Images

Classification

Characteristic Species

  • Emergent aquatics

    • Dulichium arundinaceum var. arundinaceum (three-way sedge)
    • Eleocharis robbinsii (Robbins's spike-rush)
    • Eriocaulon aquaticum (northern pipewort, northern hat-pins)
    • Pontederia cordata (pickerelweed)
  • Floating-leaved aquatics

    • Brasenia schreberi (water-shield)
    • Lemna minor (common duckweed)
    • Nuphar microphylla (small-leaved yellow pond-lily, small-leaved spatter-dock)
    • Nuphar variegata (common yellow pond-lily, common spatter-dock)
    • Nymphaea odorata ssp. odorata (fragrant white water-lily)
    • Sparganium fluctuans (floating bur-reed)
  • Submerged aquatics

    • Myriophyllum sibiricum (northern water milfoil)
    • Potamogeton amplifolius (big-leaved pondweed)
    • Utricularia cornuta (horned bladderwort)
    • Utricularia purpurea (purple bladderwort)

Similar Ecological Communities

  • Backwater slough (guide)
    Backwater sloughs are only separated from an associated river by a levee at their upstream end. Oxbow lakes are cut off completely.
  • Eutrophic pond (guide)
    Eutrophic ponds do not receive overflow from an associated riverine community. Oxbow lakes are flooded by an associated river once or more every five years.

Vegetation

Shrubs < 2m
29%
Herbs
20%
Submerged aquatics
0%

Percent cover

This figure helps visualize the structure and "look" or "feel" of a typical Oxbow Lake/Pond. 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

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/

Edinger, Gregory J., D.J. Evans, Shane Gebauer, Timothy G. Howard, David M. Hunt, and Adele M. Olivero (editors). 2002. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke's Ecological Communities of New York State. (Draft for review). New York Natural Heritage Program, New York State Department of Environmental Conservation. Albany, NY. 136 pp.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

New York Natural Heritage Program. No date. Field forms database: Electronic field data storage and access for New York Heritage ecology, botany, and zoology. New York Natural Heritage Program, New York State Department of Environmental Conservation. 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.

Smith, C.L. 1985. The Inland Fishes of New York State. New York State Department of Environmental Conservation. Albany, NY. 522pp.

Links

About This Guide

This guide was authored by: Gregory J. Edinger

Information for this guide was last updated on: November 7, 2023

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Oxbow lake/pond. Available from: https://guides.nynhp.org/oxbow-lakepond/. Accessed March 28, 2024.