DOI: 10.5061/dryad.sq72d
title: Data from: Multiple stressors and the cause of amphibian abnormalities

description: The repeated occurrence of abnormal amphibians in nature points to
 ecological imbalance, yet identifying causes of these abnormalities has
 proved complex. Multiple studies have linked amphibian abnormalities to
 chemically contaminated areas, but inference about causal mechanisms is
 lacking. Here we use a high incidence of abnormalities in Alaskan wood
 frogs to strengthen inference about the mechanism for these abnormalities.
 We suggest that limb abnormalities are caused by a combination of multiple
 stressors. Specifically, toxicants lead to increased predation, resulting
 in more injuries to developing limbs and subsequent developmental
 malformations. We evaluated a variety of putative causes of frog
 abnormalities at 21 wetlands on the Kenai National Wildlife Refuge,
 south-central Alaska, USA, between 2004 and 2006. Variables investigated
 were organic and inorganic contaminants, parasite infection, abundance of
 predatory invertebrates, UVB, and temperature. Logistic regression and
 model comparison using the Akaike information criterion (AIC) identified
 dragonflies and both organic and inorganic contaminants as predictors of
 the frequency of skeletal abnormalities. We suggest that both predators
 and contaminants alter ecosystem dynamics to increase the frequency of
 amphibian abnormalities in contaminated habitat. Future experiments should
 test the causal mechanisms by which toxicants and predators may interact
 to cause amphibian limb abnormalities.
description: AnalyticAttributesDescriptions and comments about samples logged by field personnel at the time of sample collection. Some location information for snow transect samples.AnalyticResultsFile provides analytical chemistry information for metals, anions, and organic carbon concentrations in wetland water, sediment, tadpole tissue, and soil, dust, and snow collected on transects from roads adjacent to the wetlands from 2010-2012.DryadRevisedAnalyticResults.v2.csvBreedingMetamorphicDatesThis file details the first observed date of egg mass deposition and the date of metamorphosis. Sites were monitored approximately once per two weeks to provide these dates. Additional site monitoring data is provided in other data files.ConductivityFile provides information from 6 wetlands instrumented with continuous specific conductance loggers. Wetland position can be obtained in the "SiteLocation" file and road traffic and distance are in the "RoadsInfo" file.FrogAbnormalitiesInformation on abnormalities, size, and developmental stage for the over 9,000 frogs examined for abnormalities on the Kenai Peninsula from 2000 through 2012.FrogDevelopmentThis table describes each site visit during the follow up study to the published study, whether frogs were found and what developmental stage they were, and how much time was spent assessing the site and performing the frog survey.HabitatThis data set includes habitat data that were collected from 2010-2012.InvertThis file contains data on the invertebrate community composition for lentic wetlands sampled to determine the effects of roads on water quality and the invertebrate community.invert.csvRoadsInfoThis file contains the measured distance from each wetland to the nearest road and whether the road was paved or gravel.SiteEventsFile describes observations from site visits made to measure water chemistry, water quality, and amphibian development between 2010 and 2012.SiteLocationsFile provides locations of all sites sampled for amphibians or water quality on the Kenai Peninsula, AK between 2000 and 2012.Temperature DataContains temperature data from deep and shallow loggers programmed to record hourly during the summer months. When loggers were out of water or data were otherwise suspect, data were deleted. Please see TemperatureAnomalies.csv file for issues with loggers and their resolution when dates are missing from the Temperature.csv file.Temperature.csvWaterQualityThis table describes water quality information collected with a YSI sonde and by field observers during each site visit. See “Methods.txt” file for more information on field data collection methodology.WetlandDepthVolumeThe WetlandDepthVolume.csv data set includes wetland depth and area data that were collected for 36 sites between 2010 and 2012 to follow up on the published study.ANC_WQ_STUDY_2009This file contains information on a study from 2009, which was a follow-up to the published study and a pre-cursor to data shared in this submission. The study title was: Storm Water Runoff: What effects do best management practices (BMPs) and storm events have on water quality in wetlands in the Anchorage Bowl? More information about the study is included in the readme file.AnchorageRawSedWaterResultsMethodsQCThis file includes information about laboratory methods and quality control information for the Anchorage water quality study data included in this submission.AnchorageSampleLogThis file contains Information about the sites sampled for the Anchorage Water Quality Pilot Study and provides a join field to the “SiteLocations.csv” file, which provides the latitude and longitude for each site included in this data submission.AnchorageSedimentMetalsThe “AnchorageSedimentMetals.csv” file provides metals concentrations in sediment for the Anchorage 2009 study. These are metals data analyzed by ICP/MS and are sediment digest samples, and are comparable to the sediment samples from the Kenai data set, based on the methods used. Further information regarding quality control, and analytical lab methodology can be found in the file: “AnchorageRawSedWaterResultsMethodsQC.pdf”, included with this data submission.AnchorageWaterMetalsThe “AnchorageWaterMetals.csv” file provides metals concentrations in sediment for the Anchorage 2009 study. These are metals data analyzed by ICP/MS and are unfiltered water samples, and are comparable to the samples labeled as sample type, “total” from the Kenai data set, based on the methods used.Kenai_Roads_AmphibianAbnormalities_ClimateChange_ProposalA follow up study to the published study was conducted. This document is the proposal under which the data collection for this submission was funded. Unfortunately the data were not analyzed due to federal budget cuts, but we wanted to share the data and the proposed analyses with the public.BDFilterResultsBDFilterResults.csv data set includes information on 222 water filters that were analyzed for Bd (Batrachochytrium dendrobatidis), a chytrid fungus that can cause chytridiomycosis in amphibians. Samaples were analyzed by the U.S. Geological Survey using methods similar to those described in Kirshtein et al., 2007.WaterQualityBDFilters“WaterQualityBDFilters.csv” – This table describes water quality information collected with a YSI sonde concurrent with sampling for Batrachochytrium dendrobaditis in water. See “Methods.txt” file for more information on field data collection methodology.Site SelectionThis is a text file documenting the site selection procedures for the project. This information is also included with figures and tables in the "DataSummaryReport.pdf" document.Field methodsText contained in this document is repeated with maps and other figures in the “DataSummaryReport.pdf” file included with this data submission. This file describes field methods in a .txt format to ensure readability in multiple computer formats.ListOfFilesContains a brief description of all files included in this data submission.Project Data Summary ReportThis report provides background on the project, a full summary of site selection and field methods (with maps and figures), and a summary of the information contained in each data file included with this submission.7N26_Roads_AmphibianAbnormalities_ClimateChangeFinal.pdf2010 Kenai Chemistry Analysis Pilot Year SummaryThis document describes the results of preliminary analyses conducted after the 2010 pilot year of the study. These results were used to determine the sampling design for 36 sites in 2011 and 2012.2010 Kenai Chemistry Analysis Summary.pdfTemperature_AnomoliesProvides dates, issues, and resolution when temperature loggers included in the Temperature.csv file were out of water or otherwise malfunctioning. If blocks of data are missing from the Temperature.csv file, check here for dates.