Sniggler…

Very good post

You are very correct regarding lead nitrates. The fact that metallic lead may be deposited deep within river sediments does not mean it is gone forever. Water flows above the gravels in a river as well as under. The flow of water under the gravel is very important to the incubation of salmonid eggs that is why salmon and steelhead can be very picky about where they build their redds.

As to the problems caused by lead nitrate on trout…

Found at: http://www.inchem.org/documents/ehc/ehc/ehc85.htm

“Holcombe et al.(1976) exposed three generations of brook trout (Salvelinus fontinalis) to lead nitrate in the water. All second generation trout exposed to 0.235 or 0.474 mg total lead/litre, and 34% of those exposed to 0.119 mg/litre, developed spinal deformities. Scoliosis developed in 21% of newly hatched third generation fish exposed to 0.119 mg lead nitrate/litre. The weights of these same third generation fish were significantly reduced 12 weeks after hatching. The authors calculated a MATC for brook trout, based on the scoliosis effect, of between 0.058 and 0.119 mg total lead/litre (0.039 and 0.084 mg dissolved lead/litre) in soft water (hardness: 44 mg CaCO3/litre) at a pH of between 6.8 and 7.6.”

This study would indicate that the "affects" of lead nitrate exposure do accumulate over several generations. Does anyone have a clue as to what could be happening after 50 to 100 years of exposure?

POS Clerk