Kjackson,

Flip lips were installed at many of the mainstem dams where nitrogen supersaturation was a significant problem causing mortality to migrating juvenile salmon.

Plunker,

If your understanding is meager, why do you assume the article consists of simplistic misinformation and propaganda? This issue is fairly simple. Reduced spill directs migrating juvenile salmon and steelhead through the turbines, where mortality ranges from low to severe, depending on the specific turbine and its operating conditions and the species and size of the fish.

Scientific studies being as confounded by multiple variables as they are, the experts disagree on the surivival differences between barging and inriver migration. As one might expect, those working for interests adversely affected by spill favor barging, while those working for interests that favor fish are partial to inriver migration.

More natural flows in the river is exactly what salmon experts have recommended, and that results in increased spill, as "more natural" spring flows are higher than the powerhouse turbines can run. The natural spring flood is the normative river condition that salmon and steelhead evolved with. But the natural spring flood is now stored in reservoirs from Montana and Wyoming to British Columbia and Idaho, and mostly not available for fish migration. If it were, you could most certainly expect significantly higher smolt to adult survival of Snake/Columbia salmon and steelhead. The simplistic reason is that the migration to the ocean would be faster, in keeping with the fish's biological life cycle requirements, there would be less predation during the migration, and the Columbia River estuary would function better to meet the freshwater to seawater transition of the migrating fish.

Sincerely,

Salmo g.