Latent Toxicity of Endothall to Anadromous Salmonids During Seawater Challenge

2016 ◽  
Vol 96 (5) ◽  
pp. 573-579
Author(s):  
Lauren A. Courter ◽  
Thomas M. Garrison ◽  
Ian I. Courter
Keyword(s):  
Seawater Challenge

Annual Variations in Rheotactic Behaviour and Seawater Adaptability in Landlocked Arctic Char (Salvelinus alpinus)

1992 ◽  
Vol 49 (3) ◽  
pp. 448-452 ◽  
Author(s):  
Monika Schmitz
Keyword(s):  
Seasonal Changes ◽  
Salvelinus Alpinus ◽  
Challenge Test ◽  
Early Summer ◽  
Rapid Decrease ◽  
Arctic Char ◽  
Migratory Behaviour ◽  
Annual Variations ◽  
Seawater Tolerance ◽  
Seawater Challenge

The existence of basic smoltification characteristics, measured by means of seasonal changes in rheotactic behaviour and seawater adaptability, was studied from February to November in 1- and 2-yr-old landlocked Arctic char (Salvelinus alpinus). Up- and downstream directed movements were monitored in an annular stream tank at a water velocity of 0.2 m/s. A 48-h seawater challenge test using 25‰ seawater was performed at monthly intervals throughout the year to assess seawater adaptability. The 1-yr-old char displayed mainly nondirectional behaviour during spring, but from August onwards the movements were predominantly against the current. Seawater performance improved slightly in this group in May and June. The 2-yr-old char progressively developed a downstream behaviour and exhibited an increased seawater adaptability during spring and early summer. In late August, a marked reversal in rheotactic behaviour occurred, followed by a rapid decrease in seawater tolerance. The results demonstrate that seasonal changes in seawater adaptability and changes in migratory behaviour which were directionally consistent with smolting still exist in a population of Arctic char that has been landlocked for about 6000 yr.

Osmoregulatory Ability of Wild Coho Salmon (Oncorhynchus kisutch) and Dolly Varden Char (Salvelinus malma) Smolts

1988 ◽  
Vol 45 (8) ◽  
pp. 1487-1490 ◽  
Author(s):  
Scott W. Johnson ◽  
Jonathan Heifetz
Keyword(s):  
Water Temperature ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Small Stream ◽  
Fish Size ◽  
Dolly Varden Char ◽  
Seawater Challenge ◽  
Osmoregulatory Ability

Osmoregulatory ability of wild coho salmon (Oncorhynchus kisutch) and Dolly Varden char (Salvelinus malma) smolts migrating from a small stream in southeastern Alaska was assessed by plasma Na+ levels after a 24-h seawater challenge. Osmoregulatory ability of coho salmon was unaffected by time of out-migration, water temperature, and fish size. Osmoregulatory ability of Dolly Varden char was apparently affected by time of out-migration or water temperature but not by fish size. Char migrating in the first half of the migration period, when water temperature was usually < 8.0 °C, had lower plasma Na+ levels than did char migrating in the second half when temperatures were [Formula: see text]. A plasma Na+ threshold of 170 mmol∙L−1, used by others to separate smolts from silvery parr, indicated that 70% of the coho salmon and 80% of the Dolly Varden char we sampled were physiologically prepared to enter seawater. The remaining fish may have suffered some level of osmoregulatory stress.

Twenty-Four-Hour Seawater Challenge Test for Coastal Cutthroat Trout

1991 ◽  
Vol 53 (3) ◽  
pp. 173-176 ◽  
Author(s):  
Choo-Guan Yeoh ◽  
Theodore H. Kerstetter ◽  
Eric J. Loudenslager
Keyword(s):  
Challenge Test ◽  
Cutthroat Trout ◽  
Coastal Cutthroat Trout ◽  
Seawater Challenge

Interactive effects of cortisol treatment and ambient seawater challenge on gill Na+,K+-ATPase and CFTR expression in two strains of Atlantic salmon smolts

Aquaculture ◽  
2003 ◽  
Vol 222 (1-4) ◽  
pp. 15-28 ◽  
Author(s):  
Thomas D. Singer ◽  
Bengt Finstad ◽  
Stephen D. McCormick ◽  
Steve B. Wiseman ◽  
Patricia M. Schulte ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Interactive Effects ◽  
Ambient Seawater ◽  
Seawater Challenge

Effect of Short-Duration Seawater Exposure on Plasma Ion Concentrations and Swimming Performance in Coho Salmon (Oncorhynchus kisutch) Parr

1992 ◽  
Vol 49 (11) ◽  
pp. 2399-2405 ◽  
Author(s):  
C. J. Brauner ◽  
J. M. Shrimpton ◽  
D. J. Randall
Keyword(s):  
Moisture Content ◽  
Coho Salmon ◽  
Swimming Performance ◽  
Oncorhynchus Kisutch ◽  
Strong Relationship ◽  
Swimming Velocity ◽  
Elevated Plasma ◽  
Ion Concentrations ◽  
Critical Swimming Velocity ◽  
Seawater Challenge

The effect of seawater (sw) on plasma ion concentrations and critical swimming velocity (Ucrit) was investigated in hatchery-reared coho salmon (Oncorhynchus kisutch) parr exposed to one of four treatments: 24 h of seawater exposure (SW1), 5–7 d of seawater (SW5), 24 h in seawater followed by 24 h in fresh water (SW-FW), and a freshwater control (FWC). Only the SW1 fish demonstrated a reduced Ucrit and, at rest, elevated plasma [Na+], [Cl−], and [SO42−]. With exercise, SW1 fish were characterized by an increase in plasma ion concentrations and a decrease in both hematocrit (Hct) and muscle moisture content. There is a strong relationship between plasma [Na+] at rest and Ucrit, where an optimal swimming velocity is obtained in animals with resting levels of approximately 147 mEq∙L−1. Traditionally, the 24-h seawater challenge is used to test the hypoosmoregulatory ability in smolting salmonids, however, our data suggest that it may also predict the aerobic swimming potential of salmonids following seawater transfer. We suggest that the reduction in Hct and increase in plasma [Na+] result in reduced oxygen delivery to the muscle and that decrease in muscle moisture content impairs the contractile process.

A Field Experiment to Test the Importance of Estuaries for Chinook Salmon (Oncorhynchus tshawytscha) Survival: Short-Term Results

1988 ◽  
Vol 45 (8) ◽  
pp. 1366-1377 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Colin D. Levings ◽  
Carey D. McAllister ◽  
U. H. M. Fagerlund ◽  
J. R. McBride
Keyword(s):  
Transition Zone ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Dispersal Pattern ◽  
Estuarine Site ◽  
Fish Predators ◽  
Marine Site ◽  
River Estuarine ◽  
Seawater Challenge

In late April of 1983, 1984, and 1985, 140 000 marked chinook salmon (Oncorhynchus tshawytscha) smolts (2–4 g) were transported by helicopter from Quinsam Hatchery to four release sites near Campbell River, B.C. (river, estuarine, transition, and marine), in an experiment to test the importance of estuarine residency to chinook survival. At the marine site, fish were released directly into seawater. These fish had high cortisol levels and larger interrenal nuclear diameters than those at the estuarine site, indicating a transitory stress response to seawater exposure. Nevertheless, there was little direct mortality due to stress or osmoregulatory shock at any of the release sites. Marine-released fish were exposed to more bird and fish predators. Mortality of caged chinook was higher at the marine location than at all other sites despite seawater challenge tests indicating that the chinook were smolted and "ready for sea." Beach seine data obtained biweekly for 4 mo after the releases showed that fish released directly into marine waters rarely dispersed to the Campbell River estuary. Fish released immediately adjacent to the mouth of the estuary (transition zone) had the widest immediate dispersal pattern, with many of them returning to the estuary. Estuarine zone fish displayed the most restricted distribution. Fish released to the river and estuary remained in the sampling area for a longer period (34–47 d) than those released in the marine or transition zone (20–23 d).

Comparisons between hatchery and wild steelhead trout (Oncorhynchus mykiss) smolts: physiology and habitat use

2006 ◽  
Vol 63 (7) ◽  
pp. 1627-1638 ◽  
Author(s):  
Megan S Hill ◽  
Gayle Barbin Zydlewski ◽  
William L Gale
Keyword(s):  
Habitat Use ◽  
Atpase Activity ◽  
Oncorhynchus Mykiss ◽  
Plasma Osmolality ◽  
Wild Fish ◽  
Microhabitat Use ◽  
Steelhead Trout ◽  
Hatchery Fish ◽  
Before And After ◽  
Seawater Challenge

Hatchery steelhead trout (Oncorhynchus mykiss) smolts, progeny of a newly founded native origin broodstock, were released into Abernathy Creek, Washington, in 2003 and 2004. After release, saltwater tolerance, gill Na+,K+-ATPase activity, and habitat use were compared. A subsample of hatchery and wild steelhead trout were implanted with 23 mm passive integrated transponder (PIT) tags each year. PIT-tagged migrants were used for physiological comparisons. Hatchery fish were significantly larger than wild fish. Hatchery migrants expressed significantly lower levels of gill Na+,K+-ATPase activity than wild migrants. After a 24 h seawater challenge, hatchery migrants had significantly higher plasma osmolality and [Na+] than wild migrants. Microhabitat use of PIT-tagged hatchery and wild individuals in a control (wild fish only) and effect (hatchery and wild fish) site were compared before and after the introduction of hatchery fish. No difference was detected in hatchery and wild smolt habitat use. Wild fish did not change their habitat use after the introduction of hatchery fish. Although hatchery and wild fish differed in smolt physiology, differences in short-term use of freshwater habitat were not detected, and hatchery fish did not appear to displace wild fish.

Androgens impair seawater adaptability in smolting Baltic salmon (Salmo salar)

1989 ◽  
Vol 67 (7) ◽  
pp. 1733-1736 ◽  
Author(s):  
H. Lundqvist ◽  
B. Borg ◽  
I. Berglund
Keyword(s):  
Salmo Salar ◽  
Challenge Test ◽  
Fork Length ◽  
Temporal Organization ◽  
Control Fish ◽  
Plasma Sodium ◽  
High Sodium ◽  
Negative Effect ◽  
Mature Fish ◽  
Seawater Challenge

Sexually immature (females and males) and mature male two-summer-old Baltic salmon (Salmo salar) were implanted with silastic capsules containing testosterone or 11-ketoandrostenedione in spring before the smoltification period. The seawater adaptability of the hormone-treated fish and intact control fish or control fish implanted with empty capsules was tested periodically from May to July using a common seawater challenge test with 25‰ saltwater. Fish were selected from the Norrfors hatchery stock (Ume River, (63°50′N, 20°05′E)) and ranged in fork length from 13 to 17 cm. At all sampling times the immature control fish displayed a better seawater adaptability than the previously mature males. Both groups exhibited a seasonal smoltification pattern with maximal adaptability in mid-June, when the mean plasma sodium levels after challenge were 161 mmol in the immature and 193 mmol in the mature fish. At all times both androgens impaired the seawater adaptability of the immature fish, which displayed high sodium levels comparable to those in untreated previously mature males. Even higher sodium levels were reached in previously mature males treated with androgen capsules. However, in all categories of fish the lowest levels of plasma sodium were found at the same time in mid-June. This indicates that although there is a marked, negative effect of sexual maturation and androgens on seawater adaptability, the temporal organization of smoltification is not affected.

scholarly journals Rearing strategies alter patterns of size-selective mortality and heritable size variation in steelhead trout (Oncorhynchus mykiss)

2017 ◽  
Vol 74 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Barry A. Berejikian ◽  
Jeffrey J. Hard ◽  
Christopher P. Tatara ◽  
Donald M. Van Doornik ◽  
Penny Swanson ◽  
...  
Keyword(s):  
Body Size ◽  
Oncorhynchus Mykiss ◽  
Size Variation ◽  
Fork Length ◽  
Steelhead Trout ◽  
Selective Mortality ◽  
Food Ration ◽  
Family Effects ◽  
Growth Opportunity ◽  
Seawater Challenge

Steelhead trout (Oncorhynchus mykiss) reared under two different regimes: high food ration for 1 year (S1; typical strategy) or low ration for 2 years (S2) were subjected to a seawater challenge during the corresponding spring outmigration period. The S1 smolts were smaller and suffered greater seawater challenge mortality (23.9% compared with 0.7% for the S2 smolts) that was significantly and negatively related to body size. Heritability of body size was similar for the two treatments during the parr stage (fork length: S1 = 0.181, S2 = 0.245; mass: S1 = 0.372; S2 = 0.447), but higher for the S1 treatment during the smolt stage for length (S1 = 0.212, S2 = 0.002) and body mass (S1 = 0.145, S2 = 0.015). Strong family effects for both traits and significant family by environment interactions for parr mass and smolt length indicated significant phenotypic plasticity. A genetic response to size-selective mortality caused by insufficient growth opportunity in the S1 treatment is plausible and may affect fitness in the natural environment through effects on correlated traits.

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