DOI: 10.5061/dryad.d7wm37q6g
title: Lake water chemistry and local adaptation shape NaCl toxicity in Daphnia ambigua

description: The increasing application of road deicing agents (e.g., NaCl) has caused
 widespread salinization of freshwater environments. Chronic exposure to
 toxic NaCl levels can impact freshwater biota at genome to ecosystem
 scales, yet the degree of harm caused by road salt pollution is likely to
 vary among habitats and populations. The background water chemistry may
 strongly impact NaCl toxicity, with greater harm occurring in ion-poor
 freshwater environments. In addition, populations exposed to salinization
 may evolve increased NaCl tolerance. We examined the potential for these
 two factors, genetics and environmental context, to interact in shaping
 NaCl toxicity in natural populations of the water flea Daphnia ambigua. We
 performed a reciprocal transplant toxicity trial using Daphnia clones from
 three lakes varying in ion availability. NaCl toxicity greatly increased
 in calcium-poor (1.7 mg/L) lake water compared with a high-calcium (7.2
 mg/L) environment, especially for Daphnia from the high-calcium lake.
 Meanwhile, Daphnia from an ion-rich lake showed evidence of adaptation to
 NaCl exposure, especially in their natal lake water. Our findings that the
 lake water environment, adaptation to that environment, and adaptation to
 a contaminant of interest may interact to shape toxicity demonstrate the
 importance of considering environmental and genetic complexity in
 mitigating pollution impacts.
description: Microsoft Excel to open CSV files. R or a text
 reader to open the R script.
description: # Title of Dataset: Lake water chemistry and local adaptation shape NaCl
 toxicity in Daphnia ambigua *** Four CSV files with data used to run
 statistical analyses and produce figures in the manuscript. We conducted a
 set of experiments examining the effects of lake water source, lake of
 origin, and NaCl (road salt) exposure on Daphnia survival duration,
 reproduction (likelihood of reproduction, total offspring produced if
 reproduction occurred, timing of first reproduction), and the intrinsic
 rate of increase (r). r was calculated from life table data of daily
 survival and reproduction rates for each Daphnia clone (3-4 per lake). The
 work was conducted in two temporal time blocks. Trial 1 paired Hall Pond
 and Egypt Pond Daphnia and lake water. Trial 2 paired Hall Pond and Sewall
 Pond Daphnia and lake water. Files:
 NaCl\_HallvEgypt\_survival\_offspring.csv and
 NaCl\_HallvSewall\_survival\_offspring.csv provide survival and
 reproduction data for each Daphnia individual tracked through the two
 trials. HE\_r\_adjusted.csv and HS\_r\_adjusted.csv include estimates of
 the intrinsic rate of increase (r) for each clonal lineage x lake x water
 x NaCl treatment combination. ## Description of the Data and file
 structure NaCl\_HallvEgypt\_survival\_offspring.csv and
 NaCl\_HallvSewall\_survival\_offspring.csv have the same column headings.
 * Order: numerical order of data when sorted by Lake, Clone, Water, Trt,
 Rep. * Lake: lake of origin (Hall, Egypt or Sewall Pond) * Clone: name of
 Daphnia clonal lineage (numbers have no meaning) * Water: Lake water used
 in the exposure (H: Hall, E: Egypt, S: Sewall) * Trt: Treatment (either
 control (Ctrl) or NaCl spiked (NaCl)) * Rep: replicate (1-10) *
 survival.days: number of days the individual survived (out of 14) *
 reproduced: 1= reproduced, 0= did not reproduce * total.babies: total
 offspring produced over the 14 day trial * day5.babies: number of
 offspring produced on day 5 (earliest any individuals reproduced) * ...
 day14.babies: number of offspring produced on day 14. * offspring counts
 are 0 or blank if animal did not reproduce that day. * day.reproduced: day
 of the experiment when first offspring were observed ## Sharing/access
 Information Links to other publicly accessible locations of the data: N/A
 Was data derived from another source? No If yes, list source(s):