bioRxiv Science⌕ Search

Biology subjects

Bessler, S.

Publications and source records attributed to Bessler, S..

2 recordsLinked to original sources
bioRxiv2018

Evaluating Improvements to Exposure Estimates from Fate and Transport Models by Incorporating Environmental Sampling Effort and Landscape-level Contaminant Use

AO_SCPCAPBSTRACTC_SCPCAPThe Pesticide in Water Calculator (PWC) is a fate and transport model used by the Environmental Protection Agency and Health Canada to estimate pesticide exposures in lentic freshwater ecosystems and make pesticide registration decisions. We leverage over 600,000 field measurements of 31 common insecticides and herbicides to test whether incorporating environmental sampling effort (number of times a pesticide is sampled) and landscape-level contaminant use (national application amount) can improve PWC validation and prediction, respectively. We found that maximum measured concentrations of 38% of herbicides and 42% of insecticides exceeded maximum estimated environmental concentrations (EECs) generated by the PWC, suggesting that EECs often do not represent worst-case exposure. For lentic systems, variance in pesticide field measurements explained by EECs increased by 50% when sampling effort was included. For lotic systems, variance explained increased by only 4%, most likely because lotic systems are sampled over 4.9 times as much as lentic systems. Including landscape-level use more than doubled the ability of the PWC to predict maximum pesticides concentrations in lentic systems. Exposure characterization in risk assessment can be improved by including sampling effort in model validation and landscape-level use in predictions, thus providing more defensible environmental standards and regulations.\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC=\"FIGDIR/small/472969_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (122K):\norg.highwire.dtl.DTLVardef@601b22org.highwire.dtl.DTLVardef@19591e5org.highwire.dtl.DTLVardef@9d6196org.highwire.dtl.DTLVardef@71c96c_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗
bioRxiv2018

Impacts of thermal mismatches on chytrid fungus Batrachochytrium dendrobatidis prevalence are moderated by life stage, body size, elevation and latitude

Global climate change is increasing the frequency of unpredictable weather conditions; however, it remains unclear how species-level and geographic factors, including body size and latitude, moderate impacts of unusually warm or cool temperatures on disease. Because larger hosts and lower-latitude hosts generally have slower acclimation times, we hypothesized that their disease susceptibility increases under \"thermal mismatches\", or differences between baseline climate and the temperature during surveying. Here, we examined how thermal mismatches interact with body size, life stage, habitat, latitude, elevation, phylogeny, and IUCN conservation status to predict infection prevalence of the chytrid fungus Batrachochytrium dendrobatidis (Bd) in a global analysis of 38,967 amphibian hosts. As hypothesized, we found that the susceptibility of larger hosts and hosts from lower latitudes was strongly influenced by thermal mismatches. Furthermore, hosts of conservation concern are more susceptible than others following thermal mismatches, suggesting that thermal mismatches might have contributed to recent amphibian declines.\n\nData Accessibility StatementShould the manuscript be accepted, the data supporting the results will be archived in an appropriate public repository such as Dryad or Figshare and the data DOI will be included at the end of the article.

ecology↗