DOI: 10.5061/dryad.57v9d68
title: Data from: El Niño drives a widespread ulcerative skin disease outbreak in Galapagos marine fishes

description: Climate change increases local climatic variation and unpredictability,
 which can alter ecological interactions and trigger wildlife disease
 outbreaks. Here we describe an unprecedented multi-species outbreak of
 wild fish disease driven by a climate perturbation. The 2015–16 El Niño
 generated a +2.5 °C sea surface temperature anomaly in the Galapagos
 Islands lasting six months. This coincided with a novel ulcerative skin
 disease affecting 18 teleost species from 13 different families. Disease
 signs included scale loss and hemorrhagic ulcerated patches of skin, fin
 deterioration, lethargy, and erratic behavior. A bacterial culture
 isolated from skin lesions of two of the affected fish species was
 identified by sequencing of the 16S rRNA gene as a Rahnella spp. Disease
 prevalence rates were linearly correlated with density in three fish
 species. In January 2016, disease prevalence reached 51.1% in the
 ring-tailed damselfish Stegastes beebei (n = 570) and 18.7% in the king
 angelfish Holacanthus passer (n = 318), corresponding to 78% and 86%
 decreases in their populations relative to a 4.5-year baseline,
 respectively. We hypothesize that this outbreak was precipitated by the
 persistent warm temperatures and lack of planktonic productivity that
 characterize extreme El Niño events, which are predicted to increase in
 frequency with global warming.
description: ONI_3.4Oceanic Niño Index for the years 1980-2017galcostaShapefile for Galapagos coastlinesiteLocationsGeographical description of study sitespredictors_chlaSatellite-derived sea surface chlorophyll a values from MODISchla_anomaly_rasterAnomaly for the month of January 2016 using MODIS-derived clorophyll a values relative to a baseline of 2003-2017predictors_sstSea surface temperature values from MODIS satellite in the Galapagos region for the period of 2003-2017sst_anomaly_rasterSea surface temperature anomaly for January 2016 relative to a baseline of 2003-2017 from MODI satellitefishIDTraits database for fish species in the Galapagos Islandscommunity_transects10x5 m transects counting fish abundance for all species encountered during the studySick-Fish-Full-Transects10 x 5 m transects counting all fish on Galapagos reefs with the specific goal of detecting fish diseasefocus_species_transectsTransects looking for four focal target species showing the highest prevalence of diseaseroving_transectsSearches over wider areas of Galapagos reefs to detect all species showing disease signscommunity_prevalenceFile with total number of infected species by siteHermanos_nov_2016_focus_species_transectsTarget species transects from 4 Hermanos East site of high prevalence in November 2016Hermanos_july_2017_focus_species_transectsTarget species transects from Cuatro Hermanos East July 2017geographic_prevalenceFile containing disease prevalence data for each sitespecies_prevalenceFile describing prevalence for each site and speciessst.anomalySST anomaly for each sitechl.a.anomalyChlorophyll a anomaly for each sitesummary_satellite_tempsSatellite temperatures for all study sitespasser_beebei_fishcamsCensuses from stationary video deployments at Cuatro Hermanos East of Stegastes beebei and Holacanthus passer using "MaxN": max number of individuals in a single frameScientific_reports_submissionAll R code for analysis and figure creation. Note: for use all data files must be in same folder as working directory.