The best available actual data on nutrient need by streams for nutrients (converted to salmon carcasses) is 2 kilograms of carcass per square metre of stream surface area as measured at summer low flow. That is 2 kilos per stock. One km of stream 10 m wide would need 20,000 kg. This would be 20K 1 kg pinks, 4,000 5 kg chum or coho, or 2,000 10 kg Chinook.

Any and every thing helps but we are in a nutrient chasm.