Environmental Monitoring And Assessment Program Research Articles

ANALISIS INTENSITAS KERUSAKAN MAHONI (Swietenia mahagoni) AKIBAT SERANGAN HAMA DAN PENYAKIT TUMBUHAN

Mahoni (Swietenia mahagoni) is a type of tree that is widely used as a greening plant and also used as a pollution cleaning plant because it is able to absorb pollutants in the air. In order for this tree to be able to work well, it should be noted for its health. This research on mahoni aims to analyze the damage from mahoni trees and calculate the percentage of mahoni tree damage due to pests and plant diseases carried out in permanent nursery management centers for watersheds and protected forests for three months. Mahoni trees used as the object of research amounted to 81 trees while the tools used were binoculars and writing instruments.The method used in this research is to use Environmental Monitoring and Assessment Program (EMAP) method. The results obtained from this research are based on observations in the field, it was found that there were four parts of the tree that were damaged which thas was lower trunk, upper trunk, branches, and leaves.Based on observations also found there are four different types of damage suffered by mahoni which that was wounds, broken and dead, damaged leaves, and leaf discoloration. Based on these results, the most damaged part of the tree was the branch and the least was the lower trunk. Other results show the type of damage most suffered by mahoni was broken and dead while the least was wounds. There were 126 cases of damage suffered by mahoni in which as many as 15 cases were caused by pests and 111 cases the rets were caused by diseases. Based on these data, it can be concluded that mahoni damage caused by disease was higher than that caused by pests.Keywords: Mahoni; Pest; Disease

Forecasting fish biomasses, densities, productions, and bioaccumulation potentials of mid-atlantic wadeable streams.

Regional fishery conditions of Mid-Atlantic wadeable streams in the eastern United States are estimated using the Bioaccumulation and Aquatic System Simulator (BASS) bioaccumulation and fish community model and data collected by the US Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP). Average annual biomasses and population densities and annual productions are estimated for 352 randomly selected streams. Realized bioaccumulation factors (BAF) and biomagnification factors (BMF), which are dependent on these forecasted biomasses, population densities, and productions, are also estimated by assuming constant water exposures to methylmercury and tetra-, penta-, hexa-, and hepta-chlorinated biphenyls. Using observed biomasses, observed densities, and estimated annual productions of total fish from 3 regions assumed to support healthy fisheries as benchmarks (eastern Tennessee and Catskill Mountain trout streams and Ozark Mountains smallmouth bass streams), 58% of the region's wadeable streams are estimated to be in marginal or poor condition (i.e., not healthy). Using simulated BAFs and EMAP Hg fish concentrations, we also estimate that approximately 24% of the game fish and subsistence fishing species that are found in streams having detectable Hg concentrations would exceed an acceptable human consumption criterion of 0.185 μg/g wet wt. Importantly, such streams have been estimated to represent 78.2% to 84.4% of the Mid-Atlantic's wadeable stream lengths. Our results demonstrate how a dynamic simulation model can support regional assessment and trends analysis for fisheries.

Agarwood (Aquilaria malaccencis) Health at Nursery

Gaharu (Aquilaria malaccencis) is a tree species included in Thymelleaceae family, Agarwood can grow in lowland as well as mountains, up to 750 m above sea level. The average temperature required is 32 ° C and the average humidity is 70%, with annual rainfall of about 2000 mm. This plant produces a resin powder which has a distinctive aroma fragrance infected due to fungal diseases (fungi) that enter through the trunk wound. The objective of this study is to identify the characteristics of attack which causes damage to the agarwood plant seedlings (Aquilaria malaccencis) and to elucidate the intensity of pests and diseases on agarwood plant seedling (Aquilaria malaccencis). By using code of Environmental Monitoring and Assessment Program (EMAP) which had been modified so that it was obtained the damage cause, damaged parts of plants, the type and the level of severity of damage suffered by the plant. Based on the results, data showed that the biggest cause of the damage suffered by the agarwood plant was a disease characterized by symptoms on the leaves where the damage type was in the form of leaf discoloration with the level of severity of 20-29%. The intensity of damage was 44. 66%, damage due to pest was 8%, and damage due to illness was 32%.

Assessing California's bar-built estuaries using the California Rapid Assessment Method

Bar-built estuaries are generally found at the mouths of smaller watersheds with seasonal precipitation, episodic streamflow and seasonal swell dynamics. Low streamflows and constructive wave forces form a sand bar at the mouth isolating the stream from the ocean, creating a ponded lagoon, and inundating the surrounding marsh plain. Bar-built estuaries are wide spread in California comprising over 50 percent of California's more than 500 estuaries. By connecting terrestrial, freshwater, and marine realms bar-built estuaries are complex and dynamic providing great habitat and ecosystem services. California has suffered some of the highest losses of wetland habitats, and the wetland habitats of bar-built estuaries continue to be threatened by further development, pollution, and climate related changes including diminished streamflows and sea level rise. Given this loss and threat we developed a California Rapid Assessment Method (CRAM) to assess the condition of California's bar-built estuaries. CRAM uses visual indicators to accurately reflect current wetland condition with regards to buffer habitat, hydrology, physical complexity, plant diversity and structure, and landscape influences. Here we validate this method by comparing results of CRAM for bar-built estuaries to other accepted measures of wetland condition that we simultaneously collected with CRAM including vegetative surveys, water nutrient levels, and GIS landscape scale measures of stress for 32 sites throughout California. CRAM correlated well with each of these three independent methods of assessing condition. Notably, the Environmental Monitoring and Assessment Program (EMAP) number of natives metric significantly correlated with CRAM Index and all Attribute scores. The strong correlations of CRAM to nutrient levels is particularly important considering the documentation of the negative impact of nutrients on fish populations, the use of bar-built estuaries by juveniles of commercially important species, and the nursery role of bar-built estuaries for maintaining imperiled populations of species such as steelhead. GIS measured percent impervious, percent agriculture, and percent dams all correlated well with expected CRAM Attribute scores at appropriate watershed scales relative to the area of inference for each CRAM metric. Further, CRAM for bar-built estuaries works well throughout California's diversity of environmental conditions and regardless of geography, timing, or whether the bar was open or closed during the survey. We hope that the availability of CRAM combined with available data repositories will enable local, state, and federal decision makers to better manage, restore, and conserve valuable bar-built estuaries in the face of continual threats like development, drought, and sea level rise.

Towards a protocol for stream macroinvertebrate sampling in China

Standard protocols are critical for maximizing data comparability and aggregation in national monitoring programs, and taxa richness is a common indicator of site condition and biological diversity. There are two general approaches for sampling stream macroinvertebrate assemblages: targeted richest habitat and site wide. At seven sites, we compared three methods: Ontario Benthic Biomonitoring Network (OBBN), Environmental Monitoring and Assessment Program (EMAP), and Rapid Bioassessment Protocol (RBP). The OBBN method produced a biased sample at a site with a single small riffle, the RBP method produced the most total taxa, and the EMAP method produced the most taxa at four sites and the most individuals at six sites. The RBP method produced asymptotes for percent tolerant individuals, percent chironomid individuals, and Hilsenhoff Biotic Index score after five to ten stations. The EMAP method produced asymptotes for those metrics after 10 to 20 stations per site. The EMAP method typically required half the number of stations as the RBP method to obtain 70-90% of true taxa richness as estimated by the Jaccard coefficient. We conclude that the EMAP method is preferable because of its greater precision in taxa richness estimates.

Macroinvertebrate tolerance values and an assemblage tolerance index (ATI) for western USA streams and rivers

Macroinvertebrate taxon tolerances to human disturbance have been key components of bioassessment since the early 20th century. Initially, tolerances were used to evaluate organic pollution, but more recently, their use has been generalized to evaluate overall disturbance. Numeric tolerance values have been assigned to individual taxa in many previous studies, but their origins can be unknown, and the values can lack empirical basis. We used macroinvertebrate data collected at 1106 stream and river sites in 12 western states sampled during the Environmental Monitoring and Assessment Program (EMAP) in 2000 to 2004 to develop macroinvertebrate tolerance values for western US lotic ecosystems. We used principal components analysis to create a 9-variable synthetic disturbance variable (SDV) for overall human disturbance at those sites. The SDV included measures of nutrients, site-scale physical habitat, and catchment-scale land use. For taxa found at ≥20 sites, we calculated tolerance values at multiple levels of taxonomic resolution as the weighted (mean + standard deviation) of the SDV at the sites with relative abundances as the weights. We then used the taxon tolerance values and relative abundances at each site to calculate an assemblage tolerance index (ATI) score at several levels of taxonomic resolution. These results should help inform discussions of the level of taxonomic resolution needed for bioassessments. We also discuss how the tolerance values could be used to improve the sensitivity of bioassessment metrics.

Comparison of Three Pebble Count Protocols (EMAP, PIBO, and SFT) in Two Mountain Gravel‐Bed Streams1

Abstract: Although the term ``pebble count'' is in widespread use, there is no standardized methodology used for the field application of this procedure. Each pebble count analysis is the product of several methodological choices, any of which are capable of influencing the final result. Because there are virtually countless variations on pebble count protocols, the question of how their results differ when applied to the same study reach is becoming increasingly important. This study compared three pebble count protocols: the reach‐averaged Environmental Monitoring and Assessment Program (EMAP) protocol named after the EMAP developed by the Environmental Protection Agency, the habitat‐unit specific U.S. Forest Service’s PACFISH/INFISH Biological Opinion (PIBO) Effectiveness Monitoring Program protocol, and a data‐intensive method developed by the authors named Sampling Frame and Template (SFT). When applied to the same study reaches, particle‐size distributions varied among the three pebble count protocols because of differences in sample locations within a stream reach and along a transect, in particle selection, and particle‐size determination. The EMAP protocol yielded considerably finer, and the PIBO protocol considerably coarser distributions than the SFT protocol in the pool‐riffle study streams, suggesting that the data cannot be used interchangeably. Approximately half of the difference was due to sampling at different areas within the study reach (i.e., wetted width, riffles, and bankfull width) and at different locations within a transect. The other half was attributed to using different methods for particle selection from the bed, particle‐size determination, and the use of wide, nonstandard size classes. Most of the differences in sampling outcomes could be eliminated by using simple field tools, by collecting a larger sample size, and by systematically sampling the entire bankfull channel and all geomorphic units within the reach.

Assessing Stream Ecosystem Condition in the United States

When the U.S. Congress passed the Federal Water Pollution Control Act in 1972, later amended by the Clean Water Act (CWA) of 1977, it tasked the newly created U.S. Environmental Protection Agency (EPA), in cooperation with the states, with periodically assessing the quality of U.S. waters and reporting on progress toward meeting the goals of the CWA. In subsequent decades, reviews by various governmental and nongovernmental organizations consistently have found available water quality data and reporting to be inadequate to evaluate the nation's progress [Shapiro et al., 2008]. In response to these concerns, in 1989 EPA's Office of Research and Development initiated the Environmental Monitoring and Assessment Program (EMAP) to develop and demonstrate scientific tools to monitor the status of, and trends in, U.S. aquatic resources and environmental stressors affecting them.Recent EPA‐led efforts involve monitoring wadeable perennial streams (streams or rivers shallow enough to be wadeable during seasonal low flows), which make up an estimated 90% of the total length of all perennial flowing waters in the United States [EPA, 2006]. Selected results from the first national survey of these streams, the national Wadeable Streams Assessment (WSA) [EPA, 2006; Paulsen et al., 2008], illustrate how such surveys can provide critical information to guide management of this important resource. Nonmonitoring applications of data from the WSA and earlier regional surveys show the wide‐ranging applicability of these rich data sets.

Quantifying human disturbance in watersheds: Variable selection and performance of a GIS-based disturbance index for predicting the biological condition of perennial streams

Characterizing the relative severity of human disturbance in watersheds is often part of stream assessments and is frequently done with the aid of Geographic Information System (GIS)-derived data. However, the choice of variables and how they are used to quantify disturbance are often subjective. In this study, we developed a number of disturbance indices by testing sets of variables, scoring methods, and weightings of 33 potential disturbance factors derived from readily available GIS data. The indices were calibrated using 770 watersheds located in the western United States for which the severity of disturbance had previously been classified from detailed local data by the United States Environmental Protection Agency (USEPA) Environmental Monitoring and Assessment Program (EMAP). The indices were calibrated by determining which variable or variable combinations and aggregation method best differentiated between least- and most-disturbed sites. Indices composed of several variables performed better than any individual variable, and best results came from a threshold method of scoring using six uncorrelated variables: housing unit density, road density, pesticide application, dam storage, land cover along a mainstem buffer, and distance to nearest canal/pipeline. The final index was validated with 192 withheld watersheds and correctly classified about two-thirds (68%) of least- and most-disturbed sites. These results provide information about the potential for using a disturbance index as a screening tool for a priori ranking of watersheds at a regional/national scale, and which landscape variables and methods of combination may be most helpful in doing so.

Quantifying structural physical habitat attributes using LIDAR and hyperspectral imagery

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity, and riparian vegetation cover and structure. The Environmental Monitoring and Assessment Program (EMAP) is designed to assess the status and trends of ecological resources at different scales. High-resolution remote sensing provides unique capabilities in detecting a variety of features and indicators of environmental health and condition. LIDAR is an airborne scanning laser system that provides data on topography, channel dimensions (width, depth), slope, channel complexity (residual pools, volume, morphometric complexity, hydraulic roughness), riparian vegetation (height and density), dimensions of riparian zone, anthropogenic alterations and disturbances, and channel and riparian interaction. Hyperspectral aerial imagery offers the advantage of high spectral and spatial resolution allowing for the detection and identification of riparian vegetation and natural and anthropogenic features at a resolution not possible with satellite imagery. When combined, or fused, these technologies comprise a powerful geospatial data set for assessing and monitoring lentic and lotic environmental characteristics and condition.

Survey design and extent estimates for the Wadeable Streams Assessment

The US Environmental Protection Agency (EPA) conducted a Wadeable Stream Assessment (WSA) of all wadeable streams and rivers in the conterminous US between 1999 and 2005. The assessment was led by the EPA Office of Water, in cooperation with EPA regions, states, tribal nations, and the EPA Office of Research and Development (ORD). The WSA was implemented as 2 large-scale regional surveys of streams and rivers. Both studies used EPA's River Reach File (RF3) as the basis for the sample frame. The Environmental Monitoring and Assessment Program (EMAP) Western Pilot Study, conducted by ORD in cooperation with EPA Regions 8, 9, and 10 and 12 western states, assessed all streams and rivers in the 12 western states (EMAP-West). A stratified, unequal probability survey design (50 sites/state and additional sites in 5 intensive study areas) was used to select sites from all streams and river segments coded as perennial in RF3. The unequal selection depended on Strahler order, aggregated Omernik level III ecoregion, and special study region. The WSA study used the EMAP-West wadeable streams (WSA-West) and implemented a new design for the remaining 36 eastern conterminous states (WSA-East). The WSA-East design was an unequal probability survey design with unequal selection depending on Strahler order, Omernik Level II ecoregion, and EPA region. RF3 includes 5.29 million km of rivers and streams, of which 39% (2.07 million km) are coded as perennial. The WSA sample frame included 2.84 million km of streams (54% of the total length in RF3), of which 2.24 million km were in WSA-East and 0.60 million km were in WSA-West. Each selected site was classified on the basis of wadeability and the presence of flowing water. The estimated length of wadeable streams and rivers in the 48 conterminous states was 1.30 6 0.025 (SE) million km (45.7 6 1.1% of the stream length in the sample frame). Of this wadeable stream length, 78.6 6 1.0% (1.02 million km) was estimated to be appropriate for sampling. Nationally, 11.5 6 0.8% and 5.2 6 0.6% of this length could not be sampled because of access denial or physical inaccessibility, respectively. The proportion of length affected by access denial was higher in Southern Plains, Northern Plains, and Xeric West aggregated ecoregions, whereas stream length affected by physical inaccessibility was greatest in the Western Mountains aggregated ecoregion. Improvements in the sample frame (RF3 and its successors National Hydrography Database (NHD) and NHD-Plus) would reduce field costs for national surveys.

Assessing environmental impact on riparian benthic community vigor with unconditional estimates of quantile differences

Quantile regression and an extension of a Oaxaca/Blinder decomposition are applied to US EPA’s Environmental Monitoring and Assessment Program (EMAP) Southwestern stream survey data to estimate the impact of physical and chemical stressors on benthic community fitness. Observations were collected in xeric and mountainous ecoregions with distinct natural environments, of diverse and confounding land uses, and exhibiting different ranges of benthic fitness. The behavior of the benthic community fitness at the extremes is of particular interest to resource managers for prioritizing stressors. Quantile regression characterizes behavior of specific response percentiles (the response for which the specified percent of population responses are at or below that value), depending on related conditions (covariates). In this application it is used to asses the change in association of fitness score and stream condition as the level of disturbance in stream segments changes. Quantile regression models the response behavior conditional on the covariates taken together. The Oaxaca/Blinder method estimates the unconditional effect of a particular covariate after accounting for explainable differences due to the rest of the covariates. Modeling the unconditional behavior provides a region-wide description of fitness-stressor associations. In this application, Melly’s (2006) extension of the Oaxaca/Blinder decomposition is employed to estimate differences between quantiles of stream segments with a stressor condition above or below a dividing threshold after accounting for differences due to the other conditions. The effect of having increased concentrations of nitrogen and phosphorus and increased levels of conductivity are generally more detrimental to benthic communities of streams segments that are more compromised.

Regional application of the PnET‐BGC model to assess historical acidification of Adirondack lakes

The Adirondack region of New York has high inputs of acidic deposition and large numbers of acidic lakes. The biogeochemical model, PnET‐BGC, was applied to 44 statistically representative Environmental Monitoring and Assessment Program (EMAP) lake watersheds in the Adirondacks. Model simulations help provide an understanding of historical effects of acidic deposition on soils and lake waters. Model simulations indicate that median annual concentrations of SO42− and NO3− in the 44 EMAP lakes were 15.9 μeq/L and 3.8 μeq/L, respectively, in 1850, compared to the median current measured values of 88.8 μeq/L and 20.0 μeq/L. Simulated median values of pH, acid‐neutralizing capacity (ANC), and soil percent base saturation were 6.63, 67.7 μeq/L, and 12.3%, respectively, in 1850, compared to the median current measured values of 5.95, 27.8 μeq/L, and 7.9%. The estimated historical surface water acidification was greatest in lakes having low ANC below values of 100 μeq/L. This pattern of historical acidification is in agreement with a previous paleolimnological investigation.

Relationships Among Exceedences of Sediment Guidelines, the Results of Ambient Sediment Toxicity Tests, and Community Metrics in Estuarine Systems

To use bioassessments to help diagnose or identify the specific environmental stressors affecting estuaries, we need a better understanding of the relationships among sediment chemistry guidelines, ambient toxicity tests, and community metrics. However, this relationship is not simple because metrics generally assess the responses at the community level of biological organization whereas sediment guidelines and ambient toxicity tests generally assess or are based on the responses at the organism level. The relationship may be further complicated by the influence of other chemical and physical variables that affect the bioavailability and toxicity of chemical contaminants in the environment. Between 1990 and 1993, the U.S. Environmental Protection Agency (USEPA) conducted an Environmental Monitoring and Assessment Program (EMAP) survey of estuarine sites in the Virginian Province of the eastern United States. The surveys collected data on benthic assemblages, physical and chemical habitat characteristics, and sediment chemistry and toxicity. We characterized these estuarine sites as affected by sediment contamination based on the exceedence of sediment guidelines or on ambient sediment toxicity tests (i.e., 10-day Ampelisca abdita survival). Then, benthic invertebrate metrics were compared among affected and unaffected sites to identify metrics sensitive to the contamination. A number of benthic invertebrate metrics differed between groups of sites segregated using the organism-level measures whereas other metrics did not. The difference among metrics appears to depend on the sensitivity of the individual metrics to the stressor gradient represented by metals or persistent organic toxics in sediments because the insensitive metrics do not effectively quantify the changes in the benthic invertebrate assemblage associated with these stressors. The significant relationships suggest that a relationship exists between the organism-level effects assessed by chemistry or ambient toxicity tests and the community-level effects assessed by community metrics and that the organism-level effects are predictive, to some extent, of community-level effects.

Combining HGM and EMAP procedures to assess wetlands at the watershed scale — status of flats and non-tidal riverine wetlands in the Nanticoke River watershed, Delaware and Maryland (USA)

The hydrogeomorphic (HGM) approach to wetland assessment was combined with the Environmental Monitoring and Assessment Program (EMAP) survey design procedures to evaluate the condition of non-tidal riverine and flats wetlands in the Nanticoke River watershed (Delaware and Maryland, USA). We found degradation of wetland functions below reference standard levels for the majority of wetlands in both classes. Wetland condition was also related to the level of disturbance in both wetland classes. In flats, the most common disturbances were associated with hydrologic and vegetation modifications. Flat wetlands with low HGM function scores for the Plant Community and Habitat functions had almost all been converted from hardwood forest to Loblolly pine plantations. Most modifications associated with riverine wetlands were associated with stream channelization. Results of this study demonstrate that a site-specific and reference-based approach to assessment (i.e., the HGM method) can successfully be applied at the scale of an entire watershed if it is combined with a sampling approach that allows sites to be selected without geographic bias. The approach can also be used to determine if wetland functions vary from one sub-basin to another, and results of this project can be used by managers to begin to develop strategies for restoration of wetland functions at the watershed scale.

Adequacy of Visually Classified Particle Count Statistics From Regional Stream Habitat Surveys1

Abstract: Streamlined sampling procedures must be used to achieve a sufficient sample size with limited resources in studies undertaken to evaluate habitat status and potential management‐related habitat degradation at a regional scale. At the same time, these sampling procedures must achieve sufficient precision to answer science and policy‐relevant questions with an acceptable and statistically quantifiable level of uncertainty. In this paper, we examine precision and sources of error in streambed substrate characterization using data from the Environmental Monitoring and Assessment Program (EMAP) of the U.S. Environmental Protection Agency, which uses a modified “pebble count” method in which particle sizes are visually estimated rather than measured. While the coarse (2ϕ) size classes used in EMAP have little effect on the precision of estimated geometric mean (Dgm) or median (D50) particle diameter, variable classification bias among observers can contribute as much as 0.3ϕ, or about 15‐20%, to the root‐mean‐square error (RMSE) of Dgm or D50 estimates. Dgm and D50 estimates based on EMAP data are nearly equal when fine sediments (<2 mm) are excluded, but otherwise can differ by up to a factor of 2 or more, with Dgm < D50 for gravel‐bed streams. The RMSE of reach‐scale particle size estimates based on visually classified particle count data from EMAP surveys, including variability associated with reoccupying unmarked sample reaches during revisits, is up to five to seven times higher than that reported for traditional measured pebble counts by multiple observers at a plot scale. Nonetheless, a variance partitioning analysis shows that the ratio of among site to revisit variance for several EMAP substrate metrics exceeds 8 for many potential regions of interest, suggesting that the data have adequate precision to be useful in regional assessments of channel morphology, habitat quality, or ecological condition.

Effect of sampling method on diatom composition for use in monitoring and assessing large river condition

AbstractMultiple diatom sampling methods exist for the assessment of lotic systems but few comparisons of their application efficacies in monitoring have been conducted. In this study 60 sites were sampled on four large, non‐wadeable rivers in Ohio and Kentucky, USA, which varied in depth, flow rate, surrounding land use and hydrologic modification. Four algae sampling methods were tested: three methods U.S. Environmental Protection Agency (U.S. EPA) Environmental Monitoring and Assessment Program (EMAP), U.S. Geological Survey (USGS QUAL and USGS QUAN) collected algae from rocks, debris and sediment in the littoral zone along a 1–2 km reach, while one method (USGS PHYTO) consisted of three cross‐river phytoplankton grab samples collected from a boat. Physical and chemical data were also collected. Little difference in diatom assemblage composition was found among the EMAP, QUAL and QUAN methods. Although compositionally similar, the PHYTO method collected a substantial proportion of relatively unique diatoms compared to the littoral zone methods.Two disturbance gradients were calculated, one based on 1 km upstream land use within a 500 m buffer, and the other based on principal component analysis dimension reduction of measured water parameters (PCAWQ). Metrics, generally indicators of eutrophication, were calculated for each sampling method and correlated with the disturbance gradients. After Bonferroni corrections, the EMAP method had six metrics correlated with the PCAWQ, while the PHYTO and QUAL methods each had four correlated metrics. Two QUAN metrics were correlated with the PCAWQ. Few metrics were correlated with the land use measure of disturbance. While the EMAP method had the most correlated metrics, this method, along with QUAL and QUAN methods are time and labour intensive (>1 h), relative to the phytoplankton method (<20 min). Resource managers may desire to weigh the benefits of two additional metrics with the EMAP method versus the costs associated with increased sampling time and effort. Published in 2007 by John Wiley & Sons, Ltd.

Assessment of the Extent to Which Intensively-studied Lakes are Representative of the Adirondack Region and Response to Future Changes in Acidic Deposition

Many lakes in the Adirondack Mountains, New York, have acidified over the past century due to acidic atmospheric deposition. More recently, most monitored lakes have shown signs of chemical recovery (increase in acid neutralizing capacity) as sulfur deposition levels have declined in response to the Clean Air Act and other emissions control legislation. We used measured and modeled trends in past lakewater acidification and projections of future recovery from acidification to extrapolate results from judgment samples of intensively studied lakes to the population of acid-sensitive Adirondack lakes. Simulations were developed for 70 watersheds using the Model of Acidification of Groundwater in Catchments (MAGIC) to classify lakes according to their sensitivity to change in atmospheric S and N deposition. MAGIC simulations suggested that the modeled Adirondack Long-Term Monitoring Project (ALTM) and Adirondack Effects Assessment Project (AEAP) lakes were largely among the lakes in the population that had acidified most between 1850 and 1990. Most of the modeled ALTM/AEAP lakes were within the top 36% of acid sensitivity, based on model projections of past acidification and future chemical recovery, compared with the 1,829 Adirondack lakes in EPA’s Environmental Monitoring and Assessment Program (EMAP) statistical frame. Results of this research will allow fuller utilization of data from on-going chemical and biological monitoring and process-level studies by providing a basis for regionalization of findings and developing/refining relationships among watershed characteristics, chemical change, and biological responses to changing levels of acidic deposition.

Model-based combination of spatial information for stream networks

Evolutionary improvements in Geographic Information Systems (GIS) now routinely allow the management and mapping of spatial-temporal information. In response, the development of statistical models to combine information of different types and spatial support is of vital importance to environmental science. In this paper we develop a hierarchical spatial statistical model for environmental indicators of stream and river systems in the United States Mid-Atlantic Region by combining information from separate monitoring surveys, available contextual information on hydrologic units and remote sensing information. These models are used to estimate the indicators throughout the riverine system based on information from multiple sources and aggregate scales. The analysis is based on information underlying the Landscape Atlas of the mid-Atlantic region produced by the US Environmental Monitoring and Assessment Program (EMAP). We also combine information from two overlapping separate monitoring surveys, the EMAP Stream and River Survey and the Maryland Biological Streams Survey. We present a general framework for comparative distributional analysis based on the concept of a relative spatial distribution. As an application, the spatial model is used to predict spatial distributions and relative spatial distributions for a watershed.

Comparisons of targeted-riffle and reach-wide benthic macroinvertebrate samples: implications for data sharing in stream-condition assessments

Recent comparisons of benthic macroinvertebrate (BMI) sampling protocols have shown that samples collected from different habitat types generally produce consistent stream classifications and assessments. However, these comparisons usually have not included biological endpoints used by monitoring agencies, such as multimetric indices (e.g., benthic index of biotic integrity [B-IBI]) or observed-to-expected (O/E) indices of taxonomic completeness, as target variables, and estimates of method precision are rarely provided. Targeted-riffle (TR) and reach-wide (RW) benthic samples have been collected at thousands of sites across the western USA, but little guidance is available for understanding: 1) the extent to which raw data sets can be combined in regional or large-scale analyses, 2) the degree of precision afforded by each method, or 3) the efficacy of cross-application of biological indicators derived from one sample type to the other. To address these issues, we used data from 193 sites in California where the Environmental Monitoring and Assessment Program (EMAP) collected the 2 samples side by side. We also conducted a separate study wherein 3 replicates of each sample type were collected from 15 streams to estimate minimum detectable difference (MDD) as a measure of each method’s precision. Metrics calculated from TR and RW samples showed similar dose–response relationships to stressor gradients and similar raw scoring ranges. Biological indices (B-IBI, O/E0, and O/E50) derived from RW samples were more precise than those derived from TR samples, but precision differences were not substantial. On average, pairwise differences in any index between TR and RW sample types were much less than the MDD associated with either sampling method. We observed a weak but consistent bias toward higher O/E50 scores from TR samples than from RW samples at the highest elevations and in the largest watersheds. Broad-scale condition assessments were nearly identical when B-IBI and O/E0 were used as endpoints, and assessments based on O/E50 were only slightly less similar. Our analyses indicate that raw data sets and biological indicators derived from TR and RW samples may be generally interchangeable when used in ambient biomonitoring programs.