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Brian J. Caskey

Publications and source records attributed to Brian J. Caskey.

11 recordsLinked to original sources
USGS2013

Identifying nutrient reference sites in nutrient-enriched regions-Using algal, invertebrate, and fish-community measures to identify stressor-breakpoint thresholds in Indiana rivers and streams, 2005-9

Excess nutrients in aquatic ecosystems can lead to shifts in species composition, reduced dissolved oxygen concentrations, fish kills, and toxic algal blooms. In this study, nutrients, periphyton chlorophyll a (CHLa), and invertebrate- and fishcommunity data collected during 2005-9 were analyzed from 318 sites on Indiana rivers and streams. The objective of this study was to determine which invertebrate and fish-taxa attributes best reflect the conditions of streams in Indiana along a gradient of nutrient concentrations by (1) determining statistically and ecologically significant relations among the stressor (total nitrogen, total phosphorus, and periphyton CHLa) and response (invertebrate and fish community) variables; and (2) determining the levels at which invertebrate- and fish-community measures change in response to nutrients or periphyton CHL a . For water samples at the headwater sites, total nitrogen (TN) concentrations ranged from 0.343 to 21.6 milligrams per liter (mg/L) (median 2.12 mg/L), total phosphorus (TP) concentrations ranged from 0.050 to 1.44 mg/L (median 0.093 mg/L), and periphyton CHL a ranged from 0.947 to 629 mg/L (median 69.7 mg/L). At the wadable sites, TN concentrations ranged from 0.340 to 10.0 mg/L (median 2.31 mg/L), TP concentrations ranged from 0.050 to 1.24 mg/L (median 0.110 mg/L), and periphyton CHLa ranged from 0.383 to 719 mg/L (median 44.7 mg/L). Recursive partitioning identified statistically significant low and high breakpoint thresholds on invertebrate and fish measures, which demonstrated the ecological response in enriched conditions. The combined community (invertebrate and fish) mean low and high TN breakpoint thresholds were 1.03 and 2.61 mg/L, respectively. The mean low and high breakpoint thresholds for TP were 0.083 and 0.144 mg/L, respectively. The mean low and high breakpoint thresholds for periphyton CHL a were 20.9 and 98.6 milligrams per square meter (mg/m 2 ), respectively. Additive quantile regression analysis found similar thresholds (TN of 0.656 mg/L, mean TP of 0.118 mg/L, and periphyton CHLa of 27.2 mg/m 2 ) for some stressor variables as determined by the breakpoint analysis. The TN and TP concentrations in this study showed a nutrient gradient that spanned three orders of magnitude. Sites were divided into Low, Medium, and High nutrient groups based on the 10th and 75th percentiles. The invertebrate and fish communities were similar along the nutrient gradient, using an analysis of similarity, demonstrating there was not a species trophic gradient. Within all nutrient groups, invertebrate and fish communities were dominated by nutrient tolerant taxa (algivores, herbivores, and omnivores) that included invertebrates, such as Cheumatopsyche sp., Physella sp., and fish such as Stonerollers ( Campostoma spp.) and Bluntnose Minnow ( Pimephales notatus ). To determine if low nutrient concentrations at some sites were caused by algal uptake and not oligotrophic conditions, sites with low nutrient concentrations (less than 10th percentile for TN or TP) were examined based on the Low (less than or equal to the 10th percentile) and High (greater than the 75th percentile) periphyton CHL a concentrations. Within low nutrient sites, the invertebrate and fish communities were statistically different between Low and High periphyton CHL a categories. The majority of variance between the Low and High periphyton CHL a categories was caused by Cheumatopsyche sp. (caddisfly), Physella sp. (pulmonate snail), and Caenis latipennis (a mayfly) in the invertebrate community; and caused by Stonerollers, Western Blacknose Dace ( Rhinichthys atratulus meleagris ), and Creek Chub ( Semotilus atromaculatus ) in the fish community. The dominance of tolerant herbivore and omnivore taxa in the High periphyton CHL a group indicates that low nutrient concentrations are a result of nutrient uptake and increased algal growth. This study highlights the importance of assessing multiple lines of evidence when attempting to identify the trophic condition of a site.

Indiana↗
USGS2010

Breakpoint analysis and assessment of selected stressor variables on benthic macroinvertebrate and fish communities in Indiana streams: Implications for developing nutrient criteria

Water chemistry, periphyton and seston chlorophyll a (CHL a ), and biological community data were collected from 321 sites from 2001 through 2005 to (1) determine statistically and ecologically significant relations among the stressor (total nitrogen, total phosphorus, periphyton and seston CHL a , and turbidity) variables and response (biological community) variables; and, (2) determine the breakpoint of biological community attributes and metrics in response to changes in stressor variables. Because of the typically weak relations among the stressor and response variables, methods were developed to reduce the effects of non-nutrient biological stressors that could mask the effect of nutrients. Stressor variable concentrations ranged from 0.30 to 11.0 milligrams per liter (mg/L) for total nitrogen, 0.025 to 1.33 mg/L for total phosphorus, 2.9 to 768 milligrams per square meter (mg/m 2 ) for periphyton CHL a , and 0.37 to 42 micrograms per liter (µg/L) for seston CHL a . Turbidity, another stressor variable, ranged from 0.8 to 65.4 Nephelometric turbidity units (NTUs). When the nutrient and CHL a data were compared to Dodds’ trophic classifications, 75.0 percent of the values for total nitrogen, 46.6 percent of the values for total phosphorus, 35.8 percent of the values for periphyton CHL a , and 3.5 percent of the values for seston CHL a , were eutrophic. The invertebrate communities were dominated by families considered highly nutrient tolerant, Chironimidae, (41.7 percent relative abundance), Hydropsychidae, (17.3 percent relative abundance), and Baetidae, (10.2 percent relative abundance). Fish communities were dominated by algivores and nutrient-tolerant species, specifically central stonerollers (13.3 percent relative abundance), creek chubs (9.9 percent relative abundance), and bluntnose minnows (9.3 percent relative abundance). Although not the dominant taxa, white sucker, spotted sucker, green sunfish, and bluegill species were correlated (p ‹0.05) with the stressor variables. The median breakpoints ranged from 2.4 to 3.3 mg/L for total nitrogen, from 0.042 to 0.129 mg/L for total phosphorus, from 54 to 68 mg/m 2 for periphyton CHL a , from 4.5 to 7.5 µg/L for seston CHL a , and from 14.1 to 16.1 NTU for turbidity. The breakpoints determined in this study, in addition to Dodds’ trophic classifications, were used as multiple lines of evidence to show changes in fish and invertebrate community and attributes based on annual exposure to nutrients.

Indiana↗
USGS2010

Breakpoint analysis and relations of nutrient and turbidity stressor variables to macroinvertebrate integrity in streams in the Crawford-Mammoth Cave Uplands Ecoregion, Kentucky, for the development of nutrient criteria

To assist Kentucky in refining numeric nutrient criteria in the Pennyroyal Bioregion, the U.S. Geological Survey and the Kentucky Division of Water collected and analyzed water chemistry, turbidity, and biological-community data from 22 streams throughout the Crawford-Mammoth Cave Upland ecoregion (U.S. Environmental Protection Agency Level IV Ecoregion, 71a) within the Pennyroyal Bioregion from September 2007 to May 2008. Statistically significant and ecologically relevant relations among the stressor (total phosphorus, total nitrogen, and turbidity) variables and response (macroinvertebrate-community attributes) variables and the breakpoint values of biological-community attributes and metrics in response to changes in stressor variables were determined. Thirteen of 18 macroinvertebrate attributes were significantly and ecologically correlated (p-value < 0.10) with at least one nutrient measure. Total number of individuals, Ephemeroptera-Plecoptera-Trichoptera richness, and average tolerance value were macroinvertebrate measures that most strongly correlated with the concentrations of nutrients. Comparison of the average macroinvertebrate-breakpoint value for the median concentration of total phosphorus (TP, 0.033 mg/L) and for median concentration of total nitrogen (TN, 1.1 mg/L) to Dodds' trophic classification for TP and TN indicates streams in the Crawford-Mammoth Cave Uplands ecoregion within the Pennyroyal Bioregion would be classified as mesotrophic-eutrophic. The biological breakpoint relations with median concentrations of TP in this study were similar to the U.S. Environmental Protection Agency proposed numeric TP criteria (0.037 mg/L), but were 1.5 times higher than the proposed numeric criteria for concentrations of TN (0.69 mg/L). No sites were impacted adversely using median turbidity values based on a 25 Formazin nephelometric turbidity unit biological threshold. The breakpoints determined in this study, in addition to Dodds' trophic classifications, were used as multiple lines of evidence to show changes in macroinvertebrate community and attributes based on exposure to nutrients.

Kentucky↗
USGS2009

Biological-Community Composition in Small Streams and its Relations to Habitat, Nutrients, and Land Use in Agriculturally Dominated Landscapes in Indiana and Ohio, 2004, and Implications for Assessing Nutrient Conditions in Midwest Streams

The objective of this study was to relate algal-, invertebrate-, and fish-community composition to habitat, nutrients, and land-use variables in small streams in agriculturally dominated landscapes of the Midwest in Indiana and Ohio. Thirty sample locations were selected from a single ecoregion; all were small wadable streams within agriculturally dominated landscapes with similar substrate and canopy. Biological and nutrient samples were collected during stable flow conditions in August 2004. Canonical correspondence analysis was used to determine which variables most influenced each community. Total phosphorus concentrations significantly influenced the depositional-targeted habitat algal-diatom community and the richest-targeted habitat invertebrate community. Multivariate statistical analysis showed that habitat variables were more influential to the richest-targeted habitat algal-diatom and fish communities than nutrient concentrations. Although the nutrient concentrations measured during this study indicate that most streams were not eutrophic, the biological communities were dominated by eutrophic species, suggesting streams sampled were eutrophic. Consequently, it was concluded that biological relations to nutrients in agriculturally dominated landscapes are complex and habitat variables should be included in biological assessments of nutrient conditions in agriculturally dominated landscapes.

Scientific Investigations Report↗
USGS2008

Occurrence and distribution of algal biomass and Its relation to nutrients and selected basin characteristics in Indiana streams, 2001-2005

Algal biomass and nutrient data were gathered at 322 randomly selected sites on 261 streams in the West Fork White River, Whitewater River, East Fork White River, Upper Wabash River, Kankakee River, Lower Wabash River, Tributaries to the Great Lakes, and Tributaries to the Ohio River Basins in Indiana from May through October for years 2001 through 2005. Basin characteristics (land use and drainage area), substrate, turbidity, and nutrient concentrations were determined for the basin and sampling sites. The relations of the seasonal algal biomass parameters periphyton chlorophyll a (CHLa), ash-free dry mass (AFDM), seston CHLa, and particulate organic carbon (POC) to concentrations of the seasonal nutrients nitrate, total Kjeldahl nitrogen (TKN), total nitrogen (TN), and total phosphorus (TP) were determined using Spearman&rsquo;s rho. The effects of streamflow were determined using data collected at U.S. Geological Survey (USGS) streamflow-gaging stations spatially located throughout the study basins. Throughout the 5-year study, the magnitude and frequency of stream discharge varied monthly and annually and greatly influenced algal biomass concentrations through scour and algal drift. Algal biomass median concentrations in Indiana streams consisted of periphyton CHLa, 41.2 milligrams per square meter (mg/m 2 ); AFDM, 52.1 grams per square meter (g/m 2 ); seston CHLa, 2.44 micrograms per liter (&micro;g/L); and POC, 0.75 milligrams per liter (mg/L). Approximately 32 percent of the periphyton CHLa and 6 percent of the seston CHLa samples would be considered eutrophic (nutrient enriched). To ascertain seasonal variability, samples were collected in the spring (May), summer (June through August), and fall (September through October). The highest median concentration of periphyton CHLa was in the spring, 63.2 mg/m 2 , while the highest median concentrations of AFDM, seston CHLa, and POC were in the summer 55.4 g/m 2 , 2.96 &micro;g/L, and 0.81 mg/L respectively. There were no significant differences among seasons for periphyton CHLa and AFDM; there were significant differences among seasons for seston CHLa and POC. There were no significant relations with nutrients and periphyton or seston CHLa parameters. The only significant positive relations were observed between summer POC and summer TP as well as summer POC and summer TKN. Positive relations also related spring POC and spring TP. These significant relations with TP are most likely related to phosphorus associated within seston algal cells and attached to sediment. Drainage area and land use were analyzed to understand the effect of site location on algal growth. Study basins varied in size (headwater streams, 0&ndash;51 km 2 ; wadable streams, 52&ndash;2,590 km 2 ; and boatable streams, 2,591&ndash;38,900 km 2 ) and were dominated by agricultural land use. Basin characteristics (land use, drainage area) as well as substrate type, turbidity, and nutrients, affected the concentration of algal biomass parameters. Of the eight basins in which samples were collected during the 5-year study, the Whitewater River Basin (2002) had the highest median concentration of periphyton CHLa (63.1 mg/m 2 ), the Tributaries to the Great Lakes (2005) exhibited the highest median concentration for AFDM (160 g/m 2 ), the East Fork White River Basin (2002) had nearly twice the median concentration (4.01 &micro;g/L) of seston CHLa as the other basins, and the West Fork White River Basin (2001) exhibited the highest median concentration of POC (1.10 mg/L). Of the eight major basins sampled, 15&ndash;45 percent of the periphyton CHLa and up to 20 percent of the seston CHLa samples were eutrophic. Samples collected at headwater and wadable streams were the most eutrophic for periphyton CHLa (31&ndash;36 percent) and 28 percent of samples collected at boatable streams were eutrophic for seston CHLa. As basin size increased, seston CHLa and POC concentrations increased while periphyton CHLa and AFDM concentrations decreased. The median turbidity values ranged from 6.95 NTU for headwater streams to 8.27 NTU for wadable streams, and 17.0 NTU for boatable streams. In addition, the types and availability of periphytic substrates (epilithic, epipsammic, or epidendric) were an important factor when comparing periphyton CHLa and AFDM concentrations in the study due to the periphytic substrates individual susceptibility to bed movement and scouring. Periphyton CHLa median concentrations ranged from 53.8 mg/m 2 for epilithic substrates, to 41.8 mg/m 2 for epipsammic substrates, and 17.2 mg/m 2 for epidendric substrates. Higher AFDM concentrations were collected from epipsammic substrates during years of low stream discharge velocity, which enhanced the settling of organic matter on epipsammic substrates. AFDM median concentrations ranged from 141 g/m 2 for epipsammic to 28.8 g/m 2 for epilithic and 22.9 g/m 2 for epidendric substrates. The seasonal values for nutrients (nitrate, TKN, TN, and TP) and algal biomass (periphyton CHLa, AFDM, seston CHLa, and POC) were compared to published U. S. Environmental Protection Agency (USEPA) values for their respective ecoregions. Algal biomass values either were greater than the 25th percentile published USEPA values or extended the range of data in Aggregate Nutrient Ecoregions VI, VII, IX and USEPA Level III Ecoregions 54, 55, 56, 71, and 72. If the values for the 25th percentile proposed by the USEPA were adopted as nutrient water-quality criteria, then about 71 percent of the nutrient samples and 57 percent of the CHLa samples within the eight study basins would be considered nutrient enriched.

Scientific Investigations Report↗
USGS2007

Nutrient, Habitat, and Basin-Characteristics Data and Relations with Fish and Invertebrate Communities in Indiana Streams, 1998-2000

An analysis of existing nutrient, habitat, basin-characteristics, and biological-community (fish and invertebrate) data assessed significant relations between nutrients and biological data. Data from 1998 through 2000 for 58 sites in the Upper Wabash River Basin, Lower Wabash River Basin, and tributaries to the Great Lakes and Ohio River Basins were analyzed. Correspondence analysis was used to assess significant relations among nutrients, habitat, basin-characteristics, and biological-community data. Canonical correspondence analysis was used to identify which environmental parameters most influenced the biological communities. When all 58 sites were assessed, six biological-community attributes, metric scores, or site scores were statistically sigificant but weak. When a subset of data was analyzed for eight headwater streams in one ecoregion to minimize the naturally occurring variability associated with the 58 sites, the strength of the relations increased and 24 attributes, metric scores, or site scores were significantly related. Fish-community composition in the 58 sites was most influenced by habitat and land use but not by nutrients. The invertebrate-community composition in the 58 sites was most influenced by habitat, land use, soils, and one nutrient (total Kjeldahl nitrogen [TKN]).

Indiana↗
USGS2007

Relations of Principal Components Analysis Site Scores to Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and Biological-Community Data in the West Fork White River Basin, Indiana, 2001

Data were gathered from July through September 2001 at 34 randomly selected sites in the West Fork White River Basin, Indiana for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (drainage area and land use) and biological-community attributes and metric scores were determined for the basin of each sampling site. Yearly Principal Components Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related, using Spearman's rho, to the seasonal algal-biomass, basin-characteristics, habitat, seasonal nutrient, biological-community attribute and metric score data. The periphyton PC1 site score, which was most influenced by ash-free dry mass, was negatively related to one (percent closed canopy) of nine habitat variables examined. Of the 43 fish-community attributes and metric scores examined, the periphyton PC1 was positively related to one fish-community attribute (percent tolerant). Of the 21 invertebrate-community attributes and metric scores examined, the periphyton PC1 was positively related to one attribute (Ephemeroptera, Plecoptera, and Trichoptera (EPT) index) and one metric score (EPT index metric score). The periphyton PC1 was not related to the five basin-characteristic or 12 nutrient variables examined. The seston PC1 site score, which was most influenced by particulate organic carbon, was negatively related to two of the 12 nutrient variables examined: total Kjeldahl nitrogen (July) and total phosphorus (July). Of the 43 fish-community attributes and metric scores examined, the seston PC1 was negatively related to one attribute (large-river percent). Of the 21 invertebrate-community attributes and metric scores examined, the seston PC1 was negatively related to one attribute (EPT-to-total ratio). The seston PC1 was not related to the five basin-characteristics or nine habitat variables examined. To understand how the choice of sampling sites might have affected the results, an analysis of the drainage area and land use was done. The 34 randomly selected sites in the West Fork White River Basin in 2001 were skewed to small streams. The dominant mean land use of the sites sampled was agriculture, followed by forest, and urban. The values for nutrients (nitrate, total Kjeldahl nitrogen, total nitrogen, and total phosphorus) and chlorophyll a (periphyton and seston) were compared to published U.S. Environmental Protection Agency (USEPA) values for Aggregate Nutrient Ecoregions VI and IX and Level III Ecoregions 55 and 72. Several nutrient values were greater than the 25th percentile of the published USEPA values. Chlorophyll a (periphyton and seston) values were either greater than the 25th percentile of published USEPA values or extended data ranges in the Aggregate Nutrient Ecoregions and Level III Ecoregions. If the proposed values for the 25th percentile were adopted as nutrient water-quality criteria, many samples in the West Fork White River Basin would have exceeded the criteria.

Indiana↗
USGS2007

Relations of principal components analysis site scores to algal-biomass, habitat, basin-characteristics, nutrient, and biological-community data in the Whitewater River and East Fork White River basins, Indiana, 2002

Data were gathered from May through September 2002 at 76 randomly selected sites in the Whitewater River and East Fork White River Basins, Indiana, for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (land use and drainage area) and biolog-ical-community attributes and metric scores were determined for the basin of each sampling site. Yearly Principal Compo-nents Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related using Spearman's rho to the seasonal algal-biomass, basin-charac-teristics, habitat, seasonal nutrient, and biological-community attribute and metric score data. The periphyton PC1 site score was not significantly related to the nine habitat or 12 nutrient variables examined. One land-use variable, drainage area, was negatively related to the periphyton PC1. Of the 43 fish-community attributes and metrics examined, the periphyton PC1 was negatively related to one attribute (large-river percent) and one metric score (car-nivore percent metric score). It was positively related to three fish-community attributes (headwater percent, pioneer percent, and simple lithophil percent). The periphyton PC1 was not statistically related to any of the 21 invertebrate-community attributes or metric scores examined. Of the 12 nutrient variables examined two were nega-tively related to the seston PC1 site score in two seasons: total Kjeldahl nitrogen (July and September), and TP (May and September). There were no statistically significant relations between the seston PC1 and the five basin-characteristics or nine habitat variables examined. Of the 43 fish-community attributes and metrics examined, the seston PC1 was positively related to one attribute (headwater percent) and negatively related to one metric score (large-river percent metric score) . Of the 21 invertebrate-community attributes and metrics exam-ined, the seston PC1 was negatively related to one metric score (number of individuals metric score). To understand how the choice of sampling sites might have affected the results, an analysis of the drainage area and land use was done. The sites selected in the Whitewater River Basin were generally small drainage basins; compared to Whitewater River Basin sites, the sites selected in the East Fork White River Basin were generally larger drainage basins. Although both basins were dominated by agricultural land use the Whitewater River Basin sites had more land in agriculture than the East Fork White River Basin sites. The values for nutrients (nitrate, total Kjeldahl nitrogen, total nitrogen, and total phosphorus) and chlorophyll a (per-iphyton and seston) were compared to published U.S. Environmental Protection Agency (USEPA) values for Aggregate Nutrient Ecoregions VI and IX and USEPA Level III Ecore-gions 55 and 71. Several nutrient values were greater than the 25th percentile of published USEPA values. Chlorophyll a (periphyton and seston) values were either greater than the 25thpercentile of published USEPA values or they extended data ranges in the Aggregate Nutrient and Level III Ecore-gions. If the values for the 25th percentile as proposes by the USEPA were adopted as nutrient water-quality criteria, many samples in the Whitewater River and East Fork White River Basins would have exceeded the criteria.

Indiana↗
USGS2007

Relations of principal components analysis site scores to algal-biomass, habitat, basin-characteristics, nutrient, and biological-community data in the Upper Wabash River Basin, Indiana, 2003

Data were gathered from May through October 2003 at 38 randomly selected sites in the Upper Wabash River Basin, Indiana, for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (drainage area and land use) and biological-community attributes and metric scores were determined for each sampling site's basin. Yearly Principal Components Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related, using Spearman's rho, to the seasonal algal-biomass, basin-characteristics, habitat, seasonal nutrient, biological-community attribute and metric score data. The periphyton PC1 site score, which was most influenced by September chlorophyll a, was not related to the five basin-characteristics, nine habitat, or 12 nutrient variables examined. Of the 43 fish-community attributes and metric scores examined, the periphyton PC1 was negatively related to one attribute (tolerant percent) and positively related to one metric score (insectivore percent metric score). Of the 43 invertebrate-community attributes and metric scores examined, the periphyton PC1 was negatively related to three attributes (Ephemeroptera, Plecoptera, and Trichoptera (EPT) count, EPT-to-total ratio, and number of taxa) and four metric scores (EPT count metric score, EPT to total ratio metric score, macroinvertebrate Index of Biotic Integrity metric score, and number of taxa metric score). The seston PC1 was not related to the five basin-characteristics, nine habitat, or 12 nutrient variables or to the 43 fish- and 21 invertebrate-community attributes or metric scores examined. To understand how the choice of sampling sites might have affected the results, an analysis of the drainage area and land use was done. The random site selection in 2003 in the Upper Wabash River Basin was skewed to small streams. The lack of large streams in the Upper Wabash River Basin could account for the few relations among the seston and the biological-community data. The values for nutrients (nitrate, total Kjeldahl nitrogen, total nitrogen, and total phosphorus) and chlorophyll a (periphyton and seston) were compared to published U.S. Environmental Protection Agency (USEPA) values for Aggregate Nutrient Ecoregions VI and VII and USEPA Level III Ecoregions 55 and 56. Several nutrient values were greater than the 25th percentile of the published USEPA values. Chlorophyll a (periphyton and seston) values either were greater than the 25th percentile of published USEPA values or extended data ranges in the Aggregate Nutrient and Level III Ecoregions. If the proposed values for the 25th percentile were adopted as nutrient water-quality criteria, many samples in the Upper Wabash River Basin would have exceeded the criteria.

Indiana↗