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Effects of salinity on striped bass eggs and larvae from the Savannah River, Georgia

Transactions of the American Fisheries Society

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Abstract

Operation of a tide gate installed in the Savannah River by the U.S. Army Corps of Engineers to reduce dredging activities increased salinities upstream in important spawning habitat for striped bass Morone saxatilis. To assess the effects of salinity on survival and growth of striped bass at early life stages, newly fertilized eggs and 48-h-posthatch were exposed to serial dilutions of seawater, with salinities ranging from 0 to 33 permill (g/L) in increments of 3 permill in addition, older larvae (5-d posthatch) were exposed to salinities of 0, 6, 12, 18, and 24 permill. Eggs were exposed until 24 h posthatch, 48-h-posthatch larvae were exposed for 10 d, and 5-d-posthatch larvae were exposed for 6 d. Eggs died within 24 h in salinities greater than 18 permill. Both survival and total length of larvae hatched from eggs exposed to salinities of 15 permill or higher were reduced. Percent mortality and mean total lengths of newly hatched larvae followed the same pattern for each of three sets of salinity regimes (i.e., changes in salinities over time) that striped bass eggs might encounter during passage downstream in the Savannah River. Hardening eggs in freshwater did not increase survival or length of hatched larvae over that shown by eggs hardened in saline water. The 5-d-posthatch larvae were less sensitive to salinity than the 48-h-posthatch larvae. Survival of larvae was negatively con-elated with both salinity and exposure time. For 48-h-posthatch larvae, the 10-d LC50 (the salinity lethal to 50% of the test fish within 10 d) was 10 permill. Probabilities of survival for larval striped bass exposed to different salinities for different amounts of time can be estimated from curves generated from models of survival analysis. Salinities judged to be critical to Savannah River striped bass eggs and larvae are those greater than 9 permill.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of salinity on striped bass eggs and larvae from the Savannah River, Georgia
Series title:
Transactions of the American Fisheries Society
Volume
123
Issue:
6
Year Published:
1994
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
904-912
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Transactions of the American Fisheries Society
First page:
904
Last page:
912
Number of Pages:
9