Data from: Caught in the surge: Effects of a pulse of suspended sediments from agricultural run-off on Atlantic salmon smolts

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.