Long-term effects of catch-and-release angling on ascending Atlantic salmon during different stages of spawning migration

2007 ◽  
Vol 85 (3) ◽  
pp. 316-320 ◽  
Author(s):  
Eva B. Thorstad ◽  
Tor F. Næsje ◽  
Ivar Leinan
2004 ◽  
Vol 61 (4) ◽  
pp. 511-518 ◽  
Author(s):  
Sveinung Fivelstad ◽  
Anne Berit Olsen ◽  
Sigurd Stefansson ◽  
Sigurd Handeland ◽  
Rune Waagbø ◽  
...  

Atlantic salmon (Salmo salar) smolts (mean start weight 42 g) in soft freshwater were exposed to three pH ranges (two replicates in each group) for 35 days: pH 6.5–6.8 (control group), pH 5.9–6.3 (medium-pH group), and pH 5.4–5.9 (low-pH group). All exposures had citrate added to remove labile, toxic Al from the water. On day 35, all groups were transferred to 34‰ seawater and kept there for 100 days. H+ was the main stressor in the exposures because labile Al was <6 µg·L–1 and the gill Al was lower than 27 µg·g dry weight–1 (highest in the medium group). The exposure environments did not cause any significant changes to gill tissue structures, gill Na+,-K+-ATPase activity, mortality, and growth parameters during the freshwater period. However, haematocrit was significantly increased and mean plasma chloride was significantly reduced (p < 0.05) in the low-pH group compared with the control group. This study indicated that the H+ concentrations in the pH range 5.4–5.9 in water containing no to little gill-reactive Al do not impact salmon growth and physiology during smoltification. However, the reduction in blood haematocrit in the low-pH group 3 months after seawater transfer may imply long-term effects of the treatment.


Aquaculture ◽  
2013 ◽  
Vol 388-391 ◽  
pp. 8-13 ◽  
Author(s):  
Dean Basic ◽  
Åshild Krogdahl ◽  
Joachim Schjolden ◽  
Svante Winberg ◽  
Marco A. Vindas ◽  
...  

Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.


Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.


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