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.
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.
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.
The number and acreage of oxbow lakes on the floodplains of unconfined rivers in New York are probably comparable to historical numbers.
Oxbow lakes are threatened by development (e.g., residential, agricultural) in the surrounding landscape. Other threats include habitat alteration (e.g., road crossings, excessive logging 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).
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.
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.
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 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" or change the current name to "oxbow lake/pond" and broadened the concept.
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.
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.
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.
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).
Known examples of this community have been found at elevations between 1,550 feet and 1,575 feet.
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.
Chamaedaphne calyculata (leatherleaf)
Larix laricina (tamarack)
Myrica gale (sweet gale)
Spiraea tomentosa (steeplebush)
Thuja occidentalis (northern white cedar, arbor vitae)
Carex hystericina (porcupine sedge)
Carex utriculata (bottle-shaped sedge)
Eriophorum virginicum (tawny cotton-grass)
Euthamia graminifolia (common flat-topped-goldenrod)
Glyceria canadensis (rattlesnake manna grass)
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%.
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. http://www.dec.ny.gov/docs/wildlife_pdf/ecocomm2014.pdf
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. 2019. 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.
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.
This guide was authored by: Gregory J. Edinger
Information for this guide was last updated on: March 22, 2017
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Oxbow lake/pond. Available from: https://guides.nynhp.org/oxbow-lakepond/. Accessed January 18, 2019.