Vincent H. Resh

Freshwater biomonitoring and benthic macroinvertebrates

Introduction to freshwater biomonitoring and benthic macroinvertebrates-- D. M. Rosenberg and V. H. Resh A history of biological monitoring using benthic macroinvertebrates-- J. Cairns, Jr. and J. R. Pratt The literature of biomonitoring-- K. E. Marshall Freshwater biomonitoring using individual organisms, populations, and species assemblages of benthic macroinvertebrates-- R. K. Johnson, T. Weiderholm and D. M. Rosenberg Contemporary quantitative approaches to biomonitoring using benthic macroinvertebrates-- V. H. Resh and E. P. McElravy Rapid assessment approaches to biomonitoring using benthic macroinvertebrates-- V. H. Resh and J. K. Jackson Analysis and interpretation of benthic macroinvertebrate surveys-- R. H. Norris and A. Georges Monitoring freshwater benthic macroinvertebrates and benthic processes: measures for assessment of ecosystem health-- S. R. Reice and M. Wohlenberg Paleolimnological biomonitoring using freshwater benthic macroinvertebrates-- I. R. Walker toxicity studies using freshwater benthic macroinvertebrates-- A. L. Buikema, Jr. and J. Reice Voshell, Jr. Field experiments in biomonitoring-- S. D. Cooper and L. Barmuta Future directions in freshwater biomonitoring using benthic macroinvertebrates-- R. O. Brinkhurst.

The Role of Disturbance in Stream Ecology

We define disturbance in stream ecosystems to be: any relatively discrete event in time that is characterized by a frequency, intensity, and severity outside a predictable range, and that disrupts ecosystem, community, or population structure and changes resources or the physical environment. Of the three major hypotheses relating disturbance to lotic community structure, the dynamic equilibrium hypothesis appears to be generally applicable, although specific studies support the intermediate disturbance hypothesis and the equilibrium model. Differences in disturbance frequency between lentic and lotic systems may explain why biotic interactions are more apparent in lakes than in streams. Responses to both natural and anthropogenic disturbances vary regionally, as illustrated by examples from the mid-continent, Pacific northwest, and southeastern United States. Based on a generalized framework of climatic-biogeochemical characteristics, two features are considered to be most significant in choosing streams for comparative studies of disturbance: hydrologic regimes and comparable geomorphology. A method is described for quantifying predictability of the hydrologic regime based on long-term records of monthly maximum and minimum stream flows. Different channel forms (boulder and cobble, alluvial gravelbed, alluvial sandbed) have different responses to hydrologic disturbance from spates. A number of structural and functional components for comparing disturbance effects within regions and across biomes are presented. Experimental approaches to studying disturbance involve spatial-scale considerations, logistic difficulties, and ethical questions. General questions related to disturbance that could be addressed by stream ecologists are proposed.

The reference condition: a comparison of multimetric and multivariate approaches to assess water-quality impairment using benthic macroinvertebrates

Traditional methods of establishing control sites in field-oriented biomonitoring studies of water quality are limited. The reference-condition approach offers a powerful alternative because sites serve as replicates rather than the multiple collections within sites that are the replicates in traditional designs using inferential statistics. With the reference-condition approach, an array of reference sites characterises the biological condition of a region; a test site is then compared to an appropriate subset of the reference sites, or to all the reference sites with probability weightings. This paper compares the procedures for establishing reference conditions, and assesses the strengths and deficiencies of multimetric (as used in the USA) and multivariate methods (as used in the UK, Canada, and Australia) for establishing water-quality status. A data set of environmental measurements and macroinvertebrate collections from the Fraser River, British Columbia, was used in the comparison. Precision and accuracy of the 2 multivariate methods tested (AUStralian RIVer Assessment Scheme: AusRivAS, BEnthic Assessment of SedimenT: BEAST) were consistently higher than for the multimetric assessment. Classification by ecoregion, stream order, and biotic group yielded precisions of 100% for the AusRivAS, 80-100% for the BEAST, and 40-80% for multimetrics; and accuracies of 100%, 100%, and 38-88%, respectively. Multimetrics are attractive because they produce a single score that is comparable to a target value and they include ecological information. However, not all information collected is used, metrics are often redundant in a combination index, errors can be compounded, and it is difficult to acquire current procedures. Multivariate methods are attractive because they require no prior assumptions either in creating groups out of reference sites or in comparing test sites with reference groups. However, potential users may be discouraged by the complexity of initial model construction. The complementary emphases in the multivariate methods examined (presence / absence in AusRivAS cf. abundance in BEAST) lead us to recommend that they be used together, and in conjunction with, multimetric studies.

STREAM PERIPHYTON AND INSECT HERBIVORES: AN EXPERIMENTAL STUDY OF GRAZING BY A CADDISFLY POPULATION'

The effects of grazing by the herbivorous caddisfly Helicopsyehe borealis on benthic algae and bacteria were experimentally studied in a northern California stream, Big Sulphur Creek. By elevating artificial substrate tiles above the stream bottom, larvae of Helicopsyche, but not other herbivorous insects, were effectively excluded. In three replicate experiments, grazing by Helico- psyche resulted in low amounts of algae (as chlorophyll a, 0.3-1.4 /ug/cm2) and bacteria (0.3-0.7 x 108 cells/cm2) but a high algal turnover rate (02 evolved per unit chlorophyll a = 34 fg.,Ug-i h-i).

Taxonomy and stream ecology—The benefits of genus- and species-level identifications

Why do people name things? Would we get the same information content if we refer to a particular structure as a black oak tree, an oak tree, a tree, a plant, a living object, or just as a thing? Regular observers at sporting events know the truth behind the aphorism ‘‘you can’t tell the players without a scorecard’’. The value of naming an organism is that after we name it, we can assign characteristics to it and know those characteristics the next time or place we see it. It also allows us to refine its categorization by comparing and contrasting it to similar organisms. The value of a name is also readily apparent when we look at aquatic organisms. We may encounter thousands of different organisms, from microscopic bacteria to fish, if we study just a single stream. Some groups of stream organisms are well-known and generally easy to name (e.g., fish), others require some training (e.g., invertebrates and algae), and some groups can be named only by a few specialists (e.g., bacteria). Naming even all the well-known groups in a single stream segment, such as identifying all the aquatic insects, can be a daunting task. Merritt et al. (1984) estimated that 100 to 250 insect species typically occupy headwater streams (orders 1–3) and 200 to 500 insect species occupy midreach rivers (orders 4–6). High numbers of macroinvertebrate taxa at single stream sites also have been found in North Carolina, where repeated summer collections (n 5

After site selection and before data analysis: sampling, sorting, and laboratory procedures used in stream benthic macroinvertebrate monitoring programs by USA state agencies

A survey of methods used by US state agencies for collecting and processing benthic macroinvertebrate samples from streams was conducted by questionnaire; 90 responses were received and used to describe trends in methods. The responses represented an estimated 13,000–15,000 samples collected and processed per year. Kicknet devices were used in 64.5% of the methods; other sampling devices included fixed-area samplers (Surber and Hess), artificial substrates (Hester–Dendy and rock baskets), grabs, and dipnets. Regional differences existed, e.g., the 1-m kicknet was used more often in the eastern US than in the western US. Mesh sizes varied among programs but 80.2% of the methods used a mesh size between 500 and 600 μm. Mesh size variations within US Environmental Protection Agency regions were large, with size differences ranging from 100 to 700 μm. Most samples collected were composites; the mean area sampled was 1.7 m2. Samples rarely were collected using a random method (4.7%); most samples (70.6%) were collected using “expert opinion”, which may make data obtained operator-specific. Only 26.3% of the methods sorted all the organisms from a sample; the remainder subsampled in the laboratory. The most common method of subsampling was to remove 100 organisms (range = 100–550). The magnification used for sorting ranged from 1 (sorting by eye) to 30×, which results in inconsistent separation of macroinvertebrates from detritus. In addition to subsampling, 53% of the methods sorted large/rare organisms from a sample. The taxonomic level used for identifying organisms varied among taxa; Ephemeroptera, Plecoptera, and Trichoptera were generally identified to a finer taxonomic resolution (genus and species) than other taxa. Because there currently exists a large range of field and laboratory methods used by state programs, calibration among all programs to increase data comparability would be exceptionally challenging. However, because many techniques are shared among methods, limited testing could be designed to evaluate whether procedural differences affect the ability to determine levels of environmental impairment using benthic macroinvertebrate communities.

Benthic macroinvertebrate assemblages and macrohabitat connectivity in Mediterranean-climate streams of northern California

Abstract Drought leads to a loss of longitudinal and lateral hydrologic connectivity, which causes direct or indirect changes in stream ecosystem properties. Changes in macrohabitat availability from a riffle–pool sequence to isolated pools are among the most conspicuous consequences of connectivity loss. Macroinvertebrate assemblages were compared among 3 distinct stream macrohabitats (riffles [R], pools connected to riffles [Pc], disconnected pools [Pd]) of 19 Mediterranean-climate sites in northern California to examine the influence of loss of habitat resulting from drought disturbance. At the time of sampling, 10 sites were perennial and included R and Pc macrohabitats, whereas 9 sites were intermittent and included only Pd macrohabitats. Taxa richness was more variable in Pd, and taxa richness was significantly lower in Pd than in Pc but not R. These results suggested a decline in richness between Pc and Pd that might be associated with loss of connectivity. Lower Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness relative to Odonata, Coleoptera, and Heteroptera (OCH) richness was observed for Pd than R and Pc macrohabitats. Family composition was more similar between R and Pc than between R or Pc and Pd macrohabitats. This similarity may be associated with greater connectivity between R and Pc macrohabitats. Correspondence analysis indicated that macroinvertebrate composition changed along a gradient from R to Pc and Pd that was related to a perennial–intermittent gradient across sites. High variability among macroinvertebrate assemblages in Pd could have been related to variability in the duration of intermittency. In cluster analysis, macroinvertebrate assemblages were grouped by macrohabitat first and then by site, suggesting that the macrohabitat filter had a greater influence on macroinvertebrate assemblages than did local site characteristics. Few taxa were found exclusively in Pc, and this macrohabitat shared numerous taxa with R and Pd, indicating that Pc may act as a bridge between R and Pd during drought. Drought is regarded as a ramp disturbance, but our results suggest that the response of macroinvertebrate assemblages to the loss of hydrological connectivity among macrohabitats is gradual, at least in Mediterranean-climate streams where drying is gradual. However, the changes may be more dramatic in arid and semiarid streams or in Mediterranean-climate streams if drying is rapid.

Year-to-Year Variation in the Aquatic Macroinvertebrate Fauna of a Northern California Stream

The benthic macroinvertebrate community of a third-order coastal stream in northern California was examined in mid May (end of the wet season) and late August (near the end of the dry season in the prevailing Mediterranean climate of the region) over a 7-yr period in which there was substantial year-to-year variability in precipitation and, consequently, stream discharge. Ephemeroptera, Trichoptera, and Diptera were the dominant components of the macrobenthic community, accounting for 93% of total individuals and 62% of the 81 taxa collected in mid May, and 96% of total individuals and 64% of the 69 taxa collected in late August. In mid May, significant reductions in species richness and Simpsons diversity were observed during a year of extreme drought and in years with above-average wet season rainfall. Macroinvertebrate density decreased and relative abundance of Chironomidae increased as wet season rainfall increased. In late August, year-to-year variability in community parameters measured was substantially reduced. Drought conditions favored proliferation of a few tolerant taxa (e.g., the caddisfly Gumaga nigricula). An understanding of the influence of abiotic conditions on biotic patterns can be useful in separating the effects of perturbation from natural variability.

Macroinvertebrates as Biotic Indicators of Environmental Quality

Abstract Macroinvertebrates are used more often than any other groups of organisms when assessing the environmental quality of lotic systems. In this chapter we describe the many ways macroinvertebrates are used as indicators of environmental quality—from the molecular-through the community-level of biological organization. We highlight more recent advances in the use of DNA bar coding and species traits and then describe in detail the most commonly used macroinvertebrate-based methods for assessing the quality of streams and rivers. Two exercises are provided. The first can be completed as a full day project by students or volunteers and includes a laboratory-only option. The second provides the basic background and information for a college-level senior thesis, graduate study or governmental monitoring organization.

Patterns and processes of biological invasion: The Chinese mitten crab in San Francisco Bay

Abstract The Chinese mitten crab, native to coastal rivers and estuaries of central Asia, has invaded several European countries over the past century, causing widespread concern because of its periodically extreme abundance and burrowing behavior that causes bank erosion. San Francisco Bay and its tributaries contain the first and, currently, only known established population of the Chinese mitten crab in North America. Discovered in South San Francisco Bay in 1992, the mitten crab has spread rapidly to cover several thousand km2 surrounding the Bay. Between 1995 and 2001, we monitored distribution, population dynamics, and life history attributes of the Chinese mitten crab in San Francisco Bay and its tributaries. Burrow densities increased from a mean of 6 burrows/m2 in 1995 to >30 burrows/m2 in 1999 in tidal portions of South Bay tributaries. Mitten crabs are associated with: tidally influenced portions of Bay tributaries as young juveniles; with freshwater streams (≤250 km from their confluence with the Bay) as older, migrating juveniles; and with the open waters of the Bay as reproductive adults after migrating from fresh water to reproduce between late fall and early spring. Population size peaked in 1998, with 750,000 crabs counted in fall migration in a North Bay tributary and 2.5 crabs/tow collected from North Bay breeding grounds; abundance subsequently declined greatly (2500 crabs in the same river system, 0.8 crabs/tow). Average size of adult crabs diverged between the North Bay population, which increased in size between 1996 and 2001, and the South Bay population, which decreased. The rapid establishment and spread of this species, its tolerance for a wide range of biotic and abiotic conditions, and its cyclical population dynamics pose challenges for control. Die in Flussen und stuaren Zentralasiens beheimatete Chinesische Wollhandkrabbe hat im letzten Jahrhundert einige europaische Lander erobert und verursacht weit verbreitete Bedenken, aufgrund ihrer periodisch auftretenden extremen Haufigkeit und ihres Grabverhaltens, das Ufererosion verursacht. In der Bucht von San Francisco und ihren Zuflussen befindet sich die erste und bisher einzige etablierte Population der Chinesischen Wollhandkrabbe in Nordamerika. Nach ihrer Entdeckung im Suden der Bucht von San Francisco 1992 hat sich die Wollhandkrabbe schnell uber einige tausend Quadratkilometer in der Umgebung der Bucht ausgedehnt. Zwischen 1995 und 2001 untersuchten wir die Verbreitung, die Populationsdynamik und die Eigenschaften der Lebensweise der Chinesischen Wollhandkrabbe in der Bucht von San Francisco und ihren Zuflussen. Die Dichte der Hohlen nahm in den Gezeitenbereichen der Zuflusse in der sudlichen Bucht von einem Mittelwert von 6 Hohlen/m2 1995 auf >30 Hohlen/m2 1999 zu. Wollhandkrabben sind als junge Juvenile mit gezeitengepragten Bereichen der Zuflusse der Bucht assoziiert, als altere, wandernde Juvenile mit Suswasserflussen (≤250 Kilometer vom Zusammenfluss mit der Bucht) und als reproduktive Adulte mit dem offenen Wasser der Bucht, nachdem sie zwischen Spatherbst und zeitigem Fruhjahr zur Reproduktion aus dem Suswasser eingewandert sind. Die Populationsgrose erreichte 1998 mit 750.000 Krabben ihren Hohepunkt, die wahrend der Herbstmigration in einem Zufluss der nordlichen Bucht gezahlt wurden, sowie mit 2,5 Krabben/Schleppzug, die in den Brutarealen der nordlichen Bucht gesammelt wurden. Anschliesend nahm die Haufigkeit sehr stark ab (2500 Krabben in dem gleichen Fluss, 0,8 Krabben/Schleppzug). Die durchschnittliche Grose der adulten Krabben unterschied sich zwischen der Population der nordlichen Bucht, deren Grose zwischen 1996 und 2001 zunahm, und der Population der sudlichen Bucht, bei der sie abnahm. Die rasend schnelle Etablierung und Ausbreitung dieser Art, ihre Toleranz fur einen weiten Bereich biotischer und abiotischer Faktoren und ihre zyklische Populationsdynamik stellen eine Herausforderung fur ihre Kontrolle dar.