Pretty comprehensive testing and discussion in this paper:
Scott D. Reid. Physiological impact of acute molybdenum exposure in juvenile kokanee salmon (Oncorhynchus nerka). Comparative Biochemistry and Physiology Part C 133 (2002) 355–367
Abstract:A series of experiments were conducted to determine the physiological impact of acute sublethal molybdenum
exposure to juvenile kokanee salmon (Oncorhynchus nerka Kennerlyi). Molybdenum was found to be relatively nontoxic
to kokanee as the 96 h LC was greater than 2000 mg Mo ly1. Exposure to either 25 or 250 mg Mo.ly1 for 7
50 days was found to stimulate a significant 1.6- to 1.7-fold increase in ventilation which was later characterized to be
dose-dependent between 5 and 250 mg Mo ly1. Acute sublethal molybdenum exposure was found to have little or no
impact on kokanee oxygen consumption at rest or immediately following a bout of forced activity or on physiological
indicators of stress such as plasma lactate, sodium and cortisol. Despite these findings, prior exposure to 25 or 250 mg
Mo ly1 resulted in post-exercise loss of equilibrium and exercise-induced delayed mortality that were not observed in
controls. Molybdenum accumulation in gill and liver of kokanee was also characterized. The findings of this study
suggest that despite the non-toxic nature of molybdenum, acute sublethal exposure to this metal has physiological
consequences to those fish exposed even for only a brief period.
From the paper:
"For fish it has been demonstrated that this metal is relatively nontoxic. Toxicity estimates of molybdenum to freshwater fish, based on 96 h LC50’s, range from 70 to )3000 mg ly1 depending on the species, size of fish and test condition"
"The results of the toxicity test were unequivocal. Kokanee mortality was observed at a nominal concentration as low as 100 mg Mo ly1, but at no concentration was a mortality of greater than 50% observed within the 96 h period of exposure. At the highest concentration, 2000 mg Mo ly1, only 20% kokanee mortality as observed."
the discussion goes into the pathophysiology and stuff and compares the effect of Mo in other animals. The conclusion is that it is of low toxicity, but not sure what that is relative to. Also only 7 days, so no indication of long term effect
Guess the best thing to do would be to set up the gear and see how much Mo would dissolve in the water, but would probably need high tech stuff to measure the Mo concentration. There's sure to be stuff in the literature about dissolution rates of Mo, but it's sure to be affected by the chemical compound and putting electricity through it.
