Not all that recent, and not exactly natal streams, but if you haven't seen these:
Patton, G.W., D.D. Dauble, and C.A. McKinstry. 2007. Evaluation of Early Life Stage Fall Chinook Salmon Exposed to Hexavalent Chromium from a Contaminated Groundwater Source. Environmental Monitoring and Assessment. 133(1-3): 285-294
Farag, A.M., D.D. Harper, L. Cleveland, W.G. Brumbaugh, and E.E. Little. 2006. The potential for chromium to affect the fertilization process of Chinook salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River, Washington, USA. Archives of Environmental Contamination and Toxicology. 50(4): 575-579. http://dx.doi.org/10.1007/s00244-005-0010-2
(There were various agency reports prior to publication with the same material, perhaps in more detail, and the same author lists. Email me and I can send if desired.)
Reid, S.D. 2011. Molybdenum and Chromium. Fish Physiology: Homeostasis and Toxicology of Essential Metals. 31(PART A): 376-415. http://dx.doi.org/10.1016/S1546-5098(11)31006-0 (sorry, just have a hard copy of this one)