Effects of short-term acid and aluminum exposure on the parr-smolt transformation in Atlantic salmon (Salmo salar): Disruption of seawater tolerance and endocrine status

Monette, MY; Björnsson, BT; McCormick, SD

HERO ID

1759396

Reference Type

Journal Article

Year

2008

Language

English

PMID

18606407

HERO ID 1759396
In Press No
Year 2008
Title Effects of short-term acid and aluminum exposure on the parr-smolt transformation in Atlantic salmon (Salmo salar): Disruption of seawater tolerance and endocrine status
Authors Monette, MY; Björnsson, BT; McCormick, SD
Journal General and Comparative Endrocrinology
Volume 158
Issue 1
Page Numbers 122-130
Abstract Episodic acidification resulting in increased acidity and inorganic aluminum (Al(i)) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either control (pH 6.7-6.9) or acid/Al (pH 5.4-6.3, 28-64 microgl(-1) Al(i)) conditions for 2 and 5 days, and impacts on freshwater (FW) ion regulation, seawater (SW) tolerance, plasma hormone levels and stress response were examined. Gill Al concentrations were elevated in all smolts exposed to acid/Al relative to controls confirming exposure to increased Al(i). There was no effect of acid/Al on plasma ion concentrations in FW however, smolts exposed to acid/Al followed by a 24h SW challenge exhibited greater plasma Cl(-) levels than controls, indicating reduced SW tolerance. Loss of SW tolerance was accompanied by reductions in gill Na(+),K(+)-ATPase (NKA) activity and Na(+),K(+),2Cl(-) (NKCC) cotransporter protein abundance. Acid/Al exposure resulted in decreased plasma insulin-like growth factor (IGF-I) and 3,3',5'-triiodo-l-thyronine (T(3)) levels, whereas no effect of treatment was seen on plasma cortisol, growth hormone (GH), or thyroxine (T(4)) levels. Acid/Al exposure resulted in increased hematocrit and plasma glucose levels in FW, but both returned to control levels after 24h in SW. The results indicate that smolt development and SW tolerance are compromised by short-term exposure to acid/Al in the absence of detectable impacts on FW ion regulation. Loss of SW tolerance during short-term acid/Al exposure likely results from reductions in gill NKA and NKCC, possibly mediated by decreases in plasma IGF-I and T(3).
Doi 10.1016/j.ygcen.2008.05.014
Pmid 18606407
Wosid WOS:000258312200018
Is Certified Translation No
Dupe Override No
Comments Source: Web of Science WOS:000258312200018
Is Public Yes
Language Text English
Keyword acid rain; aluminum; parr-smolt transformation; seawater tolerance; gill Na+,K+-ATPase; gill Na+,K+,2Cl(-) cotransporter; cortisol; growth hormone; insulin-like growth factor I; thyroid hormones
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