Publication Date

Fall 2013

Degree Type


Degree Name

Master of Science (MS)


Moss Landing Marine Laboratories


Kenneth Coale


ATPase, chinook, dietary, growth, mercury, salmon

Subject Areas

Environmental science; Physiology; Developmental biology


Hatchery reared Chinook salmon from California's Central Valley were fed for 67 days (Apr-Jun, 2008) on fish pellets mixed with either 0, 1, 3, or 5 µg*g-1 methylmercury hydroxide. Weight, fork length, condition factor, and Na+,K+- ATPase measurements were determined every two weeks and a 96-h seawater challenge was conducted at the conclusion of the experiment.

Results from two-way ANOVA, with treatment and date as independent variables, indicated no significant differences for weight (F3, 32 = 1.38; P = 0.280), length (F3, 32 = 0.986; P = 0.412) and condition factor (F3, 32 = 0.239; P = 0.869). Post-hoc analysis following two-way ANOVA indicated mean ATPase activity in the high (× ̅ = 3.08, S.E. = 0.19; P = 0.008) and medium treatments (× ̅ = 2.86, S.E. = 0.57; P = 0.017) was significantly increased in early May compared with the control group (× ̅ = 1.47, S.E. = 0.34). The results from the 96 h seawater challenge were consistent with those of other studies indicating weight has the greatest influence for survival in the transition from freshwater to seawater. Overall, results from this study indicated methylmercury, a known neurotoxin, altered ATPase activity in fall-run Chinook but did not significantly affect mortality in the transition from freshwater to seawater.