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Geology topics

Kathryn M. Kuivila

Publications and source records attributed to Kathryn M. Kuivila.

4 recordsLinked to original sources

Field-level exposure of bumble bees to fungicides applied to a commercial cherry orchard

Bumble bees, Bombus spp. (Apidae), are important native pollinators; however, populations of some species are declining in North America and agricultural chemicals are a potential cause. Fungicides are generally not highly toxic to bees, but little is known about sublethal or synergistic effects. This study evaluates bumble bee exposure to fungicides by quantifying concentrations of boscalid and pyraclostrobin in nectar and pollen collected by colonies of Bombus huntii Greene, 1860 (Hunt bumble bee) deployed in a commercial cherry Prunus avium L. orchard in the spring of 2016. Seven colonies were placed adjacent to an orchard block that was sprayed with a fungicide mixture of boscalid and pyraclostrobin and a control group of seven colonies was placed next to an unsprayed block of orchard 400 m away from the treated block. Nectar and pollen were collected daily, beginning 1 d before spray application and continuing for a total of 12 d, and analyzed for both fungicides. Fungicide concentrations varied spatially by colony and temporally by day. The highest concentrations in nectar occurred 1 and 3 d after spraying: up to 440 ng/g boscalid and 240 ng/g pyraclostrobin. Six days after application, pollen from cherry flowers contained the highest concentrations of the fungicides: up to 60,500 ng/g boscalid and 32,000 ng/g pyraclostrobin. These data can help to determine field-level fungicide concentrations in nectar and pollen and direct future work on understanding the effects of these compounds, including their interactions with important bumble bee pathogenic and beneficial symbionts.

Journal of Economic Entomology

Expanded target-chemical analysis reveals extensive mixed-organic-contaminant exposure in USA streams

Surface water from 38 streams nationwide was assessed using 14 target-organic methods (719 compounds). Designed-bioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-organics included eight pesticides (desulfinylfipronil, AMPA, chlorpyrifos, dieldrin, metolachlor, atrazine, CIAT, glyphosate) and two pharmaceuticals (caffeine, metformin) with detection frequencies ranging 66–84% of all sites. Detected contaminant concentrations varied from less than 1 ng L –1 to greater than 10 μg L –1 , with 77 and 278 having median detected concentrations greater than 100 ng L –1 and 10 ng L –1 , respectively. Cumulative detections and concentrations ranged 4–161 compounds (median 70) and 8.5–102 847 ng L –1 , respectively, and correlated significantly with wastewater discharge, watershed development, and toxic release inventory metrics. Log 10 concentrations of widely monitored HHCB, triclosan, and carbamazepine explained 71–82% of the variability in the total number of compounds detected (linear regression; p -values: < 0.001–0.012), providing a statistical inference tool for unmonitored contaminants. Due to multiple modes of action, high bioactivity, biorecalcitrance, and direct environment application (pesticides), designed-bioactive organics (median 41 per site at μg L –1 cumulative concentrations) in developed watersheds present aquatic health concerns, given their acknowledged potential for sublethal effects to sensitive species and lifecycle stages at low ng L –1 .

Environmental Science & Technology

Glyphosate, other herbicides, and transformation products in Midwestern streams, 2002

The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre‐emergence herbicides, after the application of post‐emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre‐emergence, 40 percent of post‐emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre‐emergence, 83 percent of post‐emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre‐emergence, 96 percent of post‐emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre‐emergence and 33 percent of post‐emergence samples.

Illinois, Indiana, Iowa, Kansas, Michigan, Minneso

Rice pesticide concentrations in the Colusa Basin Drain and the Sacramento River, California, 1990-1993

The pesticides molinate, thiobencarb, and carbofuran are applied to rice ( Oryza sativa L.) fields in the Sacramento Valley, California, each year during April through June. These pesticides are of concern because of their adverse effects on water quality and their potential adverse effects on aquatic life. Therefore, the California Regional Water Quality Control Board (CRWQCB) mandated the holding of irrigation-return water in rice fields to increase pesticide degradation and dissipation before the water is released to the Sacramento River. The CRWQCB also established performance goals to maintain drinking water quality for the city of Sacramento and to protect the habitat for aquatic life. The objectives of this study were to determine the effects of increased irrigation-return water holding times on rice pesticide concentrations and loads in the Colusa Basin Drain and the Sacramento River. Dissolved pesticide concentrations were measured in water samples collected in May through July during 1990–1993 at the Colusa Basin Drain at Road 99E near Knights Landing (Colosa Basin Drain) and at the Sacramento River at Sacramento. Pesticide concentrations and loads at both sites showed a decrease from 1990–1992 and an increase in 1993. This trend cannot be explained by the yearly holding time regulations but can be explained by the amount of yearly emergency releases. The yearly changes in pesticide concentration detected demonstrate that continued monitoring and management of pesticides is necessary to maintain water quality.

California