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Laboratory Methods Manual

Laboratory Methods Manual Volume 1 - Biological and Physical Analyses

U.S. EPA 1995. Office of Research and Development, Narragansett, RI EPA/620/R-95/008.

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Section 1


1. Background

1.1 The U.S. Environmental Protection Agency is developing the Environmental Monitoring and Assessment Program (EMAP) to determine the current status, extent, changes and trends in the condition of our nation's ecological resources on regional and national scales. The nation's ecological resources are a national heritage, as essential to the country now and in the future as they have been in the past. Data indicate that regional and international environmental problems may be endangering these essential resources. The potential threats include acid rain, ozone depletion, nonpoint-source pollution, and climate change.

1.2 Unfortunately, the status of the national environment is not well documented, rendering it impossible to assess quantitatively where resources may be degrading and at what rate the degradation may be occurring. The EPA Science Advisory Board (SAB) recognized this deficiency and recommended in 1988 that EPA initiate a program that would monitor ecological status and trends, as well as develop innovative methods for anticipating emerging problems before they reach crisis proportions. EPA's response to the SAB's recommendations is EMAP.

2. Objectives

2.1 The primary goal of EMAP is to provide environmental decision makers with statistically valid interpretive reports describing the health of our nation's ecosystems. Knowledge of the health of our ecosystems will give decision makers and resource managers the ability to make informed decisions, set rational priorities, and make known to the public the costs, benefits, and risks of proceeding or refraining from implementing specific environmental regulatory actions. EMAP's ecological status and trends data will allow decision makers to assess objectively whether or not the nation's ecological resources are responding positively, negatively, or not at all, to the regulatory programs put in place ostensibly to benefit them.

2.2 To accomplish its goals, EMAP is to document the condition of the nation's forest, wetlands, estuarine and coastal waters, inland surface waters, Great Lakes, agricultural lands, and arid lands in an integrated manner, on a continuing basis. Although EMAP is designed and funded by EPA's Office of Research and Development (ORD), other offices and regions within EPA and other federal agencies have contributed to its development and will participate in the collection and use of EMAP data. When fully implemented, EMAP will form a complex national monitoring network, with a large proportion of the data collection and analysis being accomplished by other federal, state, and local agencies.

2.3 The following four objectives guide EMAP (from Thornton et al., 1993):

  • Estimate the current status, trends, and changes in selected indicators of the Nation's ecological resources on a regional basis with known confidence.
  • Estimate the geographic coverage and extent of the Nation's ecological resources with known confidence.
  • Seek associations between selected indicators of natural and anthropogenic stresses and indicators of ecological resources.
  • Provide annual statistical summaries and periodic assessments of the Nation's ecological resources.

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3. Scope

3.1 EMAP-Estuaries (EMAP-E) is that part of the overall program which is monitoring the health of estuaries and marine waters along our nation's coastline. Estuaries, which occur in tidally-influenced portions of rivers and embayments, represent a vital component of near-coastal ecosystems. Estuaries form a key ecological link between the nation's rivers and the coastal waters of the continental shelf. Estuarine environments encompass tidal wetlands; submerged aquatic vegetation communities; and inlets, bays, and lagoons. Estuaries provide critical spawning and nursery habitat for commercial fish and shellfish, while the land around these ecosystems is becoming highly populated. These valuable and threatened ecosystems are easily abused. Estuaries directly receive much of the wastewater, after it has been treated, that is generated by homes, businesses, and industries in estuarine watersheds. In addition, effluent or runoff that enters rivers at points far from the coastline eventually can reach estuarine environments.

3.2 EMAP-E has divided all the nation's coastline into discrete regions for study. The first of these regions to be studied, called the Virginian Province, extends from Cape Cod, Massachusetts to Cape Henry, Virginia. Study began in Virginian Province bays and estuaries in the summer of 1990. Monitoring in the Gulf of Mexico (Louisianian Province) began in the summer of 1991. Sampling of other regions will be phased in over the next several years, until all of the coastal waters in the country are sampled yearly.

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4. Approach

4.1 Assessing the status and trends for the nation's estuarine and coastal ecological resources requires data collected in a standardized manner, over large geographic scales, for long periods of time. Such assessments cannot be accomplished solely by aggregating data from the many individual, short-term monitoring programs that have been conducted in the past and are being conducted currently. Differences in the parameters measured, the collection methods used, timing of sample collection, and program objectives severely limit the usefulness of historical monitoring data for conducting regional and national status and trends assessments. The EMAP-E program will monitor a defined set of parameters (i.e., indicators of estuarine and coastal environmental quality) on a regional scale, over a period of decades, using standardized field sampling and laboratory methods with a probability based sampling design. These characteristics distinguish EMAP-E from other monitoring programs and will provide the data for preparing the regional and national scale assessments that are needed to address the environmental issues of the 1990's and beyond.

4.2 EMAP-E does not have the resources to monitor all ecological parameters of concern to the public, Congress, scientists, and decision makers. Therefore a defined set of parameters that serve as indicators of environmental quality are being measured. Categories of indicators identified and sampled are as follows:

  • Biotic condition indicators - Measurements that quantify the integrated response of ecological resources to individual or multiple stressors. Included are benthic species composition, abundance and biomass; gross pathology of fish; fish species composition and abundance; relative abundance of large burrowing bivalves; and histopathology of fish.
  • Abiotic condition indicators - Physical, chemical, and biological measurements that quantify pollutant exposure, habitat degradation, or other causes of degraded ecological condition. Included are sediment contaminant concentration; sediment toxicity; contaminants in fish flesh; contaminants in large bivalves; and continuous and point measurements of dissolved oxygen concentration.
  • Habitat indicators - Physical, chemical, and biological measurements that provide basic information about the natural environmental setting. Included are sediment characteristics; water salinity, temperature, pH, depth, and clarity; chlorophyll a fluorescence and the amount of photosynthetically active radiation (PAR) in the water column.

4.3 Recommended protocols for those indicator parameters that are measured in the laboratory are presented in the later sections of this document and in Volume II - Chemistry Methods [Volume II not completed]. Protocols for indicator parameters collected or measured in the field are contained in EMAP-E Field Operations Manuals (Macauley, 1994; Reifsteck et al., 1993).

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