Bioassessment and Biocriteria Technical Guidance

The authors wish to express their sincere appreciation to the Estuarine and Coastal Marine Biocriteria Workgroup and the peer reviewers (Arthur Newell - NYDEC, Judith Weis - Rutgers University, John Gentile - University of Miami, Edward Long - NOAA, and Robert Diaz - Virginia Institute of Marine Science). Additional scientific, technical, editorial and production contributions were made by William Swietlik (USEPA), Laura Gabanski (USEPA), Jim Latimer (USEPA), David Scott (Dalhousie University), Gail Chmura (McGill University), Zorana Spasojeviz (McGill University). ), Jerome Diamond (Tetra Tech, Inc.), Abby Markowitz (Tetra Tech, Inc.), Kristen Pavlik (Tetra Tech, Inc.), Brenda Fowler (Tetra Tech, Inc.), Erik Leppo (Tetra Tech, Inc. ), and Regina Scheibner (Tetra Tech, Inc.).

CONTENTS (CONTINUED)

THE ASSESSMENT OF DEMERSAL FAUNA (MACROINVERTEBRATES

DERIVED FROM PONAR, EPIBENTHIC TRAWL, AND SWEEP NET

METRICS DEVELOPED FOR BENTHIC HABITATS: INDIAN RIVER

OF THE USE OF MARINE BIOCRITERIA SURVEY TECHNIQUES TO EVALUATE THE EFFECTS OF OCEAN SEWAGE OUTFALLS

LIST OF TABLES Table

LIST OF TABLES (CONTINUED) Table

Acronym List

Executive Summary

This guide provides detailed descriptions of appropriate habitat measurements to make the subsequent physical classification to be achieved. Reference conditions and biocriteria should be specific to each part of the country in order to be responsive and useful for decision-making.

Introduction: Bioassessment and Biocriteria

Rationale

Water Quality Monitoring The recognition that chemical water
Advantages of Bioassessment and Biocriteria

Legal Origins

Clean Water Act
Biocriteria

Uses of Biocriteria

The Use of Bioassessment Data to Establish Biocriteria
Expansion and Improvement of Water Quality Standards
Detection of Problems Other Methods May Miss or
Helping the Water Resource Manager Set Priorities
Use of Biosurveys and Biocriteria to Evaluate the

Program Interdependence
Implementing Biological Criteria
Characteristics of Effective Biocriteria
Conceptual Framework

Indicators of Biological
Comparison to a Reference As noted earlier, establishing biocriteria
Assessment Tiers

is a desktop screening assessment that consists of compiling documented
is the least complex of the survey approaches. It consists of a one-time
is somewhat more complex. A higher level of detail is incorporated into
is the most rigorous survey tier

The establishment of biocriteria based, in part, on characterized reference conditions and designated use classes of the state. Review of the literature and existing data is an important initial phase in the biocriteria development process.

Biological Survey

Indicators of Biological Integrity
Primary Measures of Community Condition

Benthic Macroinvertebrates The benthic infauna have long been
Fish
Aquatic Macrophytes
Phytoplankton

Measures of Community Condition and Change

Zooplankton
Epibenthos
Paleoenvironmental

The Use of Indexes to Compile And Evaluate
Indicator Taxa

This approach provides greater certainty of data interpretation than reliance on any single index. As part of the biological research process, individual indicator species are useful in reducing analytical costs.

Habitat Characterization

Flow and Hydrography

Circulation and Tidal Regime Circulation is the physical process that

The absolute values of the abiotic factors are not as important as the extent to which. In classical estuarine gravity circulation, the pressure surfaces of the fresh water are tilted seaward and the pressure surfaces of the salt water are tilted towards the head of the estuary.

Habitat Types

Open Water
Soft Bottom Substrates A "soft bottom" deposit may be
Hard Bottom Substrates Hard bottom substrates can include
Beaches
Sandflats
Mudflats
Emergent Marshes
Mangrove Forests

In the Ten Thousand Islands region of the Florida Everglades, persistent northerly winds largely drain the water out of large parts of the estuary. Ecological niches are found in the sediment, between the rhizomes, along the surfaces of the leaves and in the protected part of the water column in the bed. Mangroves are also valuable as stabilizers of tidal sediments, and the structural complexity of the plug roots provides habitat for many commercially and recreationally important fish.

Water Column Characteristics

Salinity
Temperature
Dissolved Oxygen Dissolved oxygen (DO) is a basic
Turbidity
Nutrients
Contaminants
Depth

Measurement of the ionic strength of estuarine and sea waters is usually done using salinity. Another important indicator of the chemical state of estuarine and coastal sea waters is pH. Phosphorus may be limiting in some of these areas during parts of the year (Mallin 1994).

Bottom Characteristics

Sediment Grain Size
Total Organic Carbon, Total Volatile Solids, and Acid
Sediment Oxidation-Reduction Potential
Sediment Contamination Sampling the surface sediments for the

The AVS normalization approach assumes that selected trace metals bind to sediment sulfide, specifically the sulfide fraction soluble in cold acid, known as AVS (Allen et al. 1993). The depth at which oxygen is completely depleted and the redox potential goes to zero has been termed the redox potential discontinuity (RPD) layer (Day et al. 1989). Pollutant runoff from agricultural areas is also an important source of pollutant input to estuaries (Boynton et al. 1988, Pait et al. 1989).

Proposed Habitat Parameters

Tier 0
Tier 1
Tier 2
Tier 3

The extent of such delineation will depend on the size of the area of concern and the nature of the environmental gradients. Much of the habitat information needed in this level can be obtained from state or federal agency records. An assessment of the cover and types of coastal zone vegetation can contribute to the overall assessment of the condition of estuarine and coastal marine habitat.

Physical Classification and the Biological Reference

Classification Approach
Physical Classification

Geographic Region
Estuarine Categories
Watershed Characteristics Watershed characteristics affect estuary
Waterbody Characteristics The third level of the classification

Establishing Biological Reference Conditions

Historical Data
Reference Sites
Models
Expert Opinion/Consensus In any data evaluation, it is important to

Use of Reference Sites to Characterize Reference

Selected Reference Sites In this approach, reference conditions
Reference Condition Derived from Population Distribution
Site-specific Reference Sites The site-specific approach is analogous

Ultimately, physical classification can be used to develop a predictive model of those estuarine and coastal marine characteristics that influence the values of biological metrics and indices at reference sites. This information becomes the reference condition and part of the biocriteria for each test site in the region. A representative sample is taken from the entire population of estuaries or coastal marine areas (Figure 4-8).

Sampling Program Issues Biological Assemblages

Assemblages

Benthic Macroinvertebrates (Infauna)
Fish
Phytoplankton
Zooplankton (Developmental)
Epibenthos (Developmental) The epibenthos assemblage is also
Paleoenvironmental Systems (developmental)

The selection of appropriate methods and tools will depend on the sampling objectives and the habitat to be sampled. The Young grab sampler works similarly to the Van Veen and Smith-McIntyre, but the sample can be accessed seamlessly from the top of the grabber through a hinged door like the Smith-McIntyre. The total number of cores taken in a given estuary depends on the hydrological complexity of the estuary.

Sampling Design Issues

Statement of the Problem The first task in developing a
Definition of the Assessment Unit
Specifying the Population and Sample Unit
Sources of Variability
Alternative Sampling Designs
Optimizing Sampling Ferraro et al. (1994, 1989) present a

The objective of the analysis is to be able to say something (estimate) about the population. Statistical measurement error is the ability of the investigator to accurately characterize the sampling unit. Systematic sampling is the systematic selection of each kth population unit from one or.

Water Column & Bottom Characteristics

Salinity, Temperature, Dissolved Oxygen, & pH
Secchi Depth
Depth
Sediment Grain Size

Estimation of “percent fines”
Sediment Grain Size (Tiers 2 and 3)

RPD Layer Depth
Total Volatile Solids
Sediment Contaminant Toxicity

Static Acute Toxicity Tests with Echinoid Embryos
Toxicity Tests Using Marine Bivalves

Nutrients (Tiers 2&3)
Total Organic Carbon (Tiers 2&3)
Water Column

In the early years of the assessment program, this analysis should be performed for each sampling period. Response of the amphipods to the test sediment is compared with the response observed in control or reference. In the early years of the assessment program, TOC analysis should be performed for each station in each sampling period.

Contaminants (Tier 3)

Acid Volatile Sulfides (Tier 3)

Once the research agency is confident that an accurate sediment TOC characterization exists for each station, the analysis may be performed only once every two or more years (on samples collected in the index period), unless stations that appear to be affected are identified by organic input (e.g. sewage discharges). In this case, the TOC analysis should be performed for these stations for each sampling period.

Sediment Contaminants

Desktop Screening

Area and

Geomorphometric Classification

Habitat Type
Watershed Land Use The pollutant and sediment load of fresh
Population Density This indicates the potential for the
NPDES Discharges Industrial and municipal point source
Biological Assemblages Existing information on any of the target
Water Column and

Resource partitioning by habitat type (open water, soft-bottom substrates, hard-bottom substrates, aquatic macrophytes, high/low-energy beaches, sand flats, mud flats, emergent marshes) will usually be required, and the extent of partitioning will depend on system size and environmental gradients. Initial divisions should be based on salinity gradients, water depth and sediment type, especially in coastal marine areas. Knowing the number, type, and location of point discharges could provide the basic information needed to identify the pollutants entering the estuary and the regions within the estuary or coast that would be most affected by the discharges.

Bottom Characteristics

Tier 1

Benthos

Sampling Procedure The primary objective of benthic
Index Period
Analysis

Fish

Sampling Procedure Various nets can be used to sample
Sample Processing

Macrophytes
Phytoplankton

The sampling period should be chosen to allow countries to answer the question: "What information do we want to obtain from a single site visit?" For example, it could be carried out with a single field visit in late summer, when the concentration of dissolved oxygen is low. The warp length should be at least six times the water depth, and a trawl speed of about 2 knots at a distance of 0.5 nautical miles is suitable for coastal marine waters. At the time of measurement, any deformities, ulcers, bleeding, fin rot, bulging eyes or other signs of disease should be noted and the fish saved for histopathology.

Tier 2

Benthos

Sampling Procedure Primary objectives of Tier 2 benthic
Index Period
Analysis

Fish

Sampling Procedure
Sample Processing
Analysis

Macrophytes

Index Period
Analysis

Phytoplankton

Sampling Procedure Phytoplankton standing stock is
Index Period
Analysis

Epibenthos (Developmental)

Index Period
Analysis

Metrics selected by the country can then be calculated to assess the state of the composition. Other sampling periods should be chosen based on the specific objectives of the Tier 2 assessment, perhaps for measurement. Other sampling periods should be selected based on the specific objective of the Level 2 assessment.

Tier 3

Benthos

Sampling Procedure Primary objectives of Tier 3 benthic
Index Period
Analysis

Fish

Sample Processing
Analysis

Macrophytes

Index Period
Analysis

Phytoplankton

Index Period
Analysis

Epibenthos (Developmental)

Index Period
Analysis

Zooplankton (Developmental)

Sampling Procedure Three replicate vertical tows using a
Index Period
Analysis

Paleoenvironmental Systems

Based on the enumerated species list, metrics selected by the state can be calculated to evaluate potential decline of the fish assemblage, to develop or refine biocriteria, to examine seasonal dynamics of the assemblage, or to diagnose sources and causes of impairment. Detailed pathological observations should be made; they can be used to assess potential causes of. Phytoplankton should be sampled at least once during an appropriate index period and at least three other times per year to capture.

Developmental)

Sampling Procedure Cores are generally taken with

The drag must be vertically integrated; that is, from 0.5 m from the bottom to the surface, with a retrieval rate of 0.5 to 1 ms-1. Zooplankton should be sampled once during an appropriate index period and a minimum of three other times during the year to capture seasonal variations in taxonomic composition and abundance.

Sample Processing

Analysis

Index Development

Overview

All three methods use the same general approach: sites are evaluated by comparing the assemblage of organisms found at a site to an expectation derived from observations of many relatively undisturbed reference sites. This chapter will first discuss classification methods, with an emphasis on those that have been successful in estuaries and coastal waters. This chapter is not intended to be an instruction manual for the use of various statistical methods; it is intended to show, with selected examples, the techniques that have been used for the development of biological indices.

Classification and Characterization of

Existing Classifications With the growth of efforts to improve
Assessing a priori Classifications

Many of the correlations were statistically significant at p < 0.05, but salinity alone accounted for 20% or more of the variation (Summers et al. 1993). Overall, depth was found to be the determining factor in the organization of each assemblage (Allen et al. 1999, Bergen et al. 1999). Often one of the first steps is a cluster analysis of the species composition of the sites to determine whether sites can be divided into groups (e.g. Weisberg et al. 1997, Smith et al. 2000).

Index Development

Multimetric Index
Discriminant Model Index Discriminant Model Approach
Index Derived from Multivariate Ordination

The definition of a metric is a characteristic of the biota that changes in a predictable manner with increasing human influence (Barbour et al. 1995). The validity of categories of biological conditions is evaluated by comparing the index scores of the reference and known stress locations. The performance of the discriminant models was good in distinguishing reference sites from degraded sites in the calibration data: 100% for the Gulf of Mexico sites (Engle et al.

Quality Assurance

Design, Precision and Management

Program Design

Formulation of a Study Design A study design is developed to answer
Establishment of Uncertainty Limits
Optimizing the Study Design

For example, the average abundance at a test location is equal to the average abundance at the reference locations. The probability of making a Type I error is equal to the significance level ("") of the test and is selected by the data analyst. This is because the distribution of the sample mean will approximate a normal distribution even if the data from which the average comes from.

Management

Personnel
Resources

Equation 12-5 shows that estimating medians or quartiles from small samples can lead to large samples. For example, the 90% confidence interval for the bottom quartile of a sample of n=10 includes the first five observations. This is the reasoning behind a general “rule of thumb” that the estimate of reference conditions should, if possible, be based on a sample of 10 or more locations.

Operational Quality Control

Field Operations
Laboratory Operations The QC elements in laboratory
Data Analysis
Reporting

The division of samples into subsamples can be used to check the accuracy of the methodology, and reprocessing of completed samples is used to check the accuracy of the laboratory. For the field operations aspect of an ecological study, the most important QC elements are: instrument calibration and. Problems with managing the database can occur if steps are not taken to oversee data handling, analysis and summarization.