MSY is about dead fish in the boat. Period. If one wants ecosystem values and a wide variety of life history trajectories then we have to allow significantly more fish to spawn.

Most who have looked at it suggest that current wild salmon escapement in at least the lower 48 is 5-10% of "historic". Current harvest rates are 30-50%. Say current run is 100. That leaves an MSY harvest of 30-50 fish and an escapement of 50-70.

If the current run is 10% of historic, that run should be 1,000. At a 10% harvest rate you catch 100 and leave 900. EVEN IF the 900 escapement only produces 100 harvestable it is more than now.