EPA - National Lakes Assessment - Zooplankton - 2007

Latest version published by United States Geological Survey on May 21, 2020 United States Geological Survey

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The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S. Environmental Protection Agency (EPA) worked with states and tribes to conduct the assessment in 2007. These are the results of the assessment for zooplankton.

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The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 17,498 records.

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How to cite

Researchers should cite this work as follows:

U.S. Environmental Protection Agency (USEPA). 2009. National Lakes Assessment: A Collaborative Survey of the Nation’s Lakes. EPA 841-R-09-001. U.S. Environmental Protection Agency, Office of Water and Office of Research and Development, Washington, D.C.


Researchers should respect the following rights statement:

The publisher and rights holder of this work is United States Geological Survey. To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 111105f7-661d-416e-bb9d-9e291d5fdb1f.  United States Geological Survey publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF-US.


Occurrence; assessment; zooplankton; Observation


Susan Holdsworth
  • Originator
  • Point Of Contact
Chief, Office of Water Monitoring Branch
US Environmental Protection Agency
1200 Pennsylvania Avenue, N.W.
20460 Washington
District of Columbia
+1 (202) 566-1187
Derek Masaki
  • Originator
US Geological Survey, Science Analytics and Synthesis program
12201 Sunrise Valley Drive, Mail stop 302
20192 Reston
Annie Simpson
  • Metadata Provider
biologist and information specialist
US Geological Survey, Science Analytics and Synthesis program
12201 Sunrise Valley Drive, Mail stop 302
20192 Reston
+1 703 6484281

Geographic Coverage

geographic scope = 48.97903 to 26.93623 latitude; -67.6993 to -124.6325 longitude

Bounding Coordinates South West [26.936, -124.632], North East [48.979, -67.699]

Taxonomic Coverage

127 different taxa of zooplankton: Acari Chaoborus Keratella ##[4] Bosmina Chaoborus punctipennis Cyclopidae ##[7] Diaptomidae Lecanidae Lepadella ##[10] Ploesoma Polyarthra Synchaeta ##[13] Trichocerca Diaphanosoma Daphnia ambigua ##[16] Temoridae Anuraeopsis Brachionus angularis ##[19] Conochilidae Hexarthra Kellicottia bostoniensis ##[22] Keratella taurocephala Platyias Pompholyx ##[25] Notommata Asplanchna Brachionus caudatus ##[28] Brachionus havanaensis Filinia Gastropus ##[31] None present Ceriodaphnia Chydoridae ##[34] Chironomidae Daphnia mendotae Kellicottia longispina ##[37] Daphnia Polyphemus Daphnia catawba ##[40] Sida Calanoida Chaoborus flavicans ##[43] Holopedium gibberum Collotheca Rotifera ##[46] Daphnia parvula Keratella hiemalis Leptodora ##[49] Moina Euchlanis Daphnia retrocurva ##[52] Eubosmina Dreissena bugensis Dreissena polymorpha ##[55] Testudinella Ergasilus Bdelloidea ##[58] Mytilina Brachionus calyciflorus Brachionus quadridentatus ##[61] Brachionus forficula Keratella testudo Hesperodiaptomus ##[64] Brachionus urceolaris Keratella quadrata Notholca ##[67] Daphnia lumholtzi Tylotrocha Chaoborus albipes ##[70] Centropagidae Cercopagis Unionicola ##[73] Holopedium amazonicum Brachionus bidentata Ascomorpha ##[76] Daphnia laevis Collothecidae Daphnia longiremis ##[79] Aglaodiaptomus Encentrum Colurella ##[82] Ceratopogonidae Brachionus Ptygura ##[85] Brachionus satanicus Brachionus budapestinensis Harpacticoida ##[88] Trichotria Keratella chussa Scapholeberis ##[91] Mysis relicta Wolga Chaoborus americanus ##[94] Lophocharis Simocephalus Proales ##[97] Kellicottia Keratella serrulata Copepoda ##[100] Latona Sinantherina Daphnia ctenodaphnia ##[103] Macrothricidae Brachionus zahniseri Cephalodella ##[106] Epiphanidae Monommata Epiphanes ##[109] Keratella ticinensis Keratella irregularis Daphnia dubia ##[112] Dreissena Brachionus leydigi Keratella valga ##[115] Limnias Wierzejskiella Artemia ##[118] Gammaridae Notommatidae Bythotrephes ##[121] Eurycercus Brachionus pterodinoides Brachionus falcatus ##[124] Resticula Bosminidae Coliothecidae ##[127] Bosminopsis

Kingdom animalia (Animals)

Temporal Coverage

Start Date 2007-01-01

Project Data

No Description available

Title US Environmental Protection Agency's 2007 National Lake Assessment - zooplankton
Funding EPA
Study Area Description NLA results are reported for the continental U.S. and for 9 ecological regions (ecoregions). Areas are included in an ecoregion based on similar landform and climate characteristics (see Chapter 6 and Figure 20). Assessments were conducted at the ecoregion level because the patterns of response to stress are often best understood in a regional context. Some states participating in the NLA assessed lake condition at an even finer state-scale resolution than the ecoregional scale by sampling additional random sites within their state boundaries. Although these data are included in the analysis described in this report, state-scale results are not presented.

The personnel involved in the project:

Susan Holdsworth
  • Custodian Steward

Sampling Methods

In preparation for the survey, each target lake was screened to verify that it met the established criteria for inclusion in the survey. Throughout the summer of 2007, 86 field crews, consisting of 2 to 4 people each, sampled lakes from Maine to California. At each lake site, crews collected samples at a single station located at the deepest point in the lake and at ten stations around the lake perimeter (Figure 4). At the midlake station, depth profiles for temperature, pH, and dissolved oxygen were taken with a calibrated water quality probe meter or multi-probe sonde. A Secchi disk was used to measure water clarity and depth at which light penetrates the lake (the euphotic zone). NLA analysts used these vertical profile measurements to determine the extent of stratification and the availability of the appropriate temperature regime and level of available oxygen necessary to support aquatic life. Single grab water samples were collected to measure nutrients, chlorophyll-a, phytoplankton, and the algal toxin microcystin. Zooplankton samples were collected using a fine mesh (80µm) and course mesh (243µm) conical plankton net. A sediment core was taken to provide data on sediment diatoms and mercury levels. The top and bottom layers of the sediment core were analyzed to detect possible changes in diatom assemblages over a period of time.

Study Extent Initial discussion by states and EPA regarding the scope of the survey focused on the size of lakes that were to be considered in the target population. It was agreed that, to be included, the site had to be a natural or man-made freshwater lake, pond or reservoir, greater than 10 acres (4 hectares), at least 3.3 feet (1 meter) deep, and with a minimum of a quarter acre (0.1 hectare) open water. The Great Lakes and the Great Salt Lake were not included in the survey, nor were commercial treatment and/or disposal ponds, brackish lakes, or ephemeral lakes. After applying the criteria, 68,223 waterbodies were considered lakes by the NLA definition and thus comprised the target population.
Quality Control To ensure consistency in data collection and quality assurance, the crews attended a three-day training session, used standardized field methods and data forms, and followed strict quality control protocols including field audits.

Method step description:

  1. Since a census of every lake in the country is cost prohibitive and beyond the reach of any program, EPA used a statistical sampling approach incorporating state-ofthe-art survey design techniques. The first step, to ascertain the number of lakes in the country, was challenging because there is no comprehensive list or source for all lakes in the U.S. The best resource available is the USGS/EPA National Hydrography Dataset or NHD.

Additional Metadata

Purpose The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S.
Alternative Identifiers 111105f7-661d-416e-bb9d-9e291d5fdb1f