DOI: 10.5061/dryad.mw6m9069p
title: Data from: How do freshwater prey respond to combinations of predation risk and salinity?

description: Freshwater salinization is a growing problem worldwide and negatively
 affects many freshwater organisms. Many of the prior experiments studying
 the effects of salinity on freshwater organisms have examined the effects
 of salinity in isolation from natural stressors such as predation risk.
 However, stressors such as predation risk can synergistically interact
 with many pollutants to affect prey survival and growth, so it is
 important to determine if it interacts with salt pollution. In this
 experiment, we looked for interactive effects of salinity and predation
 risk on freshwater snails using a full-factorial mesocosm experiment that
 crossed four salt concentrations (no added salt, 250 mg Cl- /L, 500 mg
 Cl-/L, and 1000 mg Cl-/L) with three predator regimes (no predator,
 crayfish cues, and water bug cues). Snails were raised in the mesocosms
 from juveniles to reproductively mature adults, and we measured their
 survival, mass, reproduction, and shell morphology. We discovered a
 synergistic effect of salinity and predation risk on the survival of
 snails at the highest salt concentration. At the highest salinity, adding
 crayfish cues caused a 66% increase in snail mortality, whereas adding
 water bug cues caused a 143% increase in snail mortality. In contrast, the
 effects of predation risk and salinity on snail mass, reproduction, and
 shell morphology were additive. Our results suggest that experiments
 testing salinity in isolation from other stressors may underestimate the
 full impact of salt pollution in freshwater environments.
description: # Data from: How do freshwater prey respond to combinations of predation
 risk and salinity? #### Description of the data and file structure
 Freshwater salinization harms many organisms, and its effects can interact
 with natural stressors like predation risk. This experiment tested how
 salinity and predator cues together affect freshwater snails, finding that
 their combined impact greatly increased snail mortality at high salt
 levels. However, their effects on snail growth and reproduction were
 additive, highlighting the importance of studying multiple stressors
 together to understand salt pollution’s true impact. **File:
 PHYSA-SaltPred_Morphology.csv** **Column Explanation:** * SnailID: Unique
 ID code for each snail - Pool- Mesocosm of origin for this snail * Pred -
 Predator treatment for this snail (Belostoma = water bug cue; Crayfish =
 crayfish/crushed snail cue; No Predator = no predator cue) - Salt - Salt
 exposure for this snail (mgCl-/L) * Mass- snail body/shell mass (g) -
 Snail.Number- unique number of this snail * Landmark.ID- name of shell
 morphological feature - Measurement.mm- measurement of shell morphological
 feature (area = sq.mm; length/width = mm) * Empty.Shell - if 1, this is
 the shell is empty - Damage to.Shell - if 1, the shell is damaged *
 Aperture. Unclear - if 1, the aperture in this photo is damaged or
 obscured - Shell.Length.Width.Unclear - if 1, the shell length or width to
 be measured accurately * Spire. Unclear - if 1, the spirecane to bis e
 measured accurately - Scale.Bar.Unclear - if 1, the scale bar is missing
 or unable to be measured * Comments - unique comments relating to the
 morphological photos **File: PHYSA-SaltPred_MesocosmData.csv** **Column
 Explanation:** * Pool- Number designation of mesocosm - Pred- Predator
 treatment of mesocosm (Bel = water bug; Cry = crayfish/crush; Nop = No
 predator) * Salt -Salt addition treatment of mesocosm (mgCl-/L) - T.Snails
 - Total # Snails found at the end of the experiment * T.LiveSnails - Total
 # live snails found at the end of the experiment - T.DeadSnails - Total #
 dead snails found at the end of the experiment * EggMass - Number of egg
 masses found in mesocosm - SnailMass -_End Mean snail mass at end of
 experiment