DOI: 10.5061/dryad.cfxpnvxj7
title: Data from: Caught in the surge: Effects of a pulse of suspended sediments from agricultural run-off on Atlantic salmon smolts

description: Suspended sediments (SS) from agricultural run-off pose an increasing risk
 to Atlantic salmon (Salmo salar) smolts, with unclear consequences to
 smoltification and seawater tolerance. We investigated the effects of an
 environmentally relevant SS pulse on migrating S. salar smolts.
  In the lab, smolts were exposed to an 11-hour SS pulse at 0, 20,
 60, and 100 NTU, then allowed to recover for 43 h in clean freshwater
 (mimicking completion of river downstream-migration), before facing a 24h
 seawater challenge (mimicking entry to the marine environment). Exposure
 to SS caused a rapid reduction in gill surface area, an increase in blood
 glucose levels, and a slight decrease in plasma chloride levels. Transient
 reductions of the gill Na+-K+ ATPase (NKA) and hematocrit levels were also
 observed after 5h of exposure, possibly due to the gill remodeling.
 Physiological recovery was observed after 43h in clear water, and seawater
 tolerance was not affected by a previous exposure to SS. Overall, SS
 exposure could transiently affect the physiology of down-migrating
 Atlantic salmon smolts, but with limited impacts on seawater adaptation.
description: # Data from: Caught in the surge: Effects of a pulse of suspended
 sediments from agricultural run-off on Atlantic salmon smolts
 [https://doi.org/10.5061/dryad.cfxpnvxj7](https://doi.org/10.5061/dryad.cfxpnvxj7) ## Description of the data and file structure In the lab, we mimicked a smolts migration scenario, which was based on environmental conditions occurring in a SS-impacted watershed in New-Brunswick, Canada. First, smolts were exposed to an 11 hour pulse of SS collected from an agricultural sediment trap, at four environmentally relevant turbidity levels (0, 16, 59, 94 NTU). Smolts were then allowed to recover for 43 h in clean freshwater (mimicking completion of river down-migration), before facing a 24h seawater challenge (mimicking entry to the marine environment). Blood markers (hematocrit levels, blood glucose), osmoregulation (NKA, plasma ions) and gill histology (interlamellar diameter, secondar lamellar width) were examined over time. Each datapoint corresponds to the mean of the parameter for two fish collected in the same tank at the same timestep.  ### Files and variables #### File: Bories_et_al_2025_database.csv **Description:**  ##### Variables * Time : Period at sampling. Quarantine : sampling post 20 days of acclimation ; T5: sampling post 5h of exposure, T11: sampling post 11h of exposure, T43: sampling post 43h in clear water, SW: sampling post 24h seawater challenge.  * Tank: Tank identification for each treatment.  * Treatment: Name of the treatment. Quarantine : refer to the fish sampled in the rearing tanks, Control : refers to the "blank control" (prepared with only DeCl water) , Low : refers to the low treatment (16 NTU), Medium: refers to the medium treatment (59 NTU), Extreme: refers to the extreme treatment (96 NTU), Baseline : refers to the "filtrate control" (prepared prepared by diluting the collected sediment concentrate 10x with ultrapure water (as for the extreme turbidity treatment), centrifuging this dilution at 6000g for 15 minutes, and filtering the supernatant on 0.45 µm PES filters) .  * Treatment mean turbidity (NTU): Mean turbidity measured during the 11h period of exposure to suspended sediments (in NTU).  * Fork_length (Cm): Mean fish fork length (cm) * Weight (g): Mean fish weight (g) * Blood glucose (mM): Mean fish whole blood glucose levels (mM) * Hematocrit (%): Mean fish blood hematocrit levels (%) * NKA (mol ADP.mg? protein.h?): Mean fish gill NKA activity (umol ADP.mg-1. protein.h-1) * Plasma Na (mM): Mean fish plasma sodium levels (mM) * Plasma Ca (mM): Mean fish plasma calcium levels (mM) * Plasma Mg (mM): Mean fish plasma magnesium levels (mM) * Plasma K (mM): Mean fish plasma potassium levels (mM) * Plasma Cl (mM): Mean fish plasma chloride levels (mM) * Interlamella diameter (m): Mean fish gill interlamella diameter (um) * Secondar lamella width(m): Mean fish secondar lamella width (um) Empty cells were replaced by the "null" value. For physiological parameters, including blood glucose, hematocrit levels, gill NKA activity, and plasma ions, "null" data corresponds to values that were considered as outliers and then removed from the dataset. For histology, including interlamellar diameter and secondar lamellar width, "null" data corresponds to samples that were not analysed for histology. ## Code/software All plots and statistical analysis were performed on R software version 4.2.2. R basic functions were used for statistical analysis (lm for linear models, t.test and wilcox test for pairwise comparisons, shapiro wilk test for normality, aov function for anova and Tuckey test for post-hoc comparison). All plots were created using the ggplot2 package.