The concept of Maximum Sustained Yield (MSY) is but one construct that managers can rely upon to regulate our popular sport fisheries. An alternative construct that has received far less attention is the concept of Maximum Sustained Recreation (MSR).

From the standpoint of a purely recreational salmon or steelhead fishery, what matters most to participants is ensuring sheer abundance of fish so as to maximize angler-encounters with those fish. All other things being equal, the angler experience is maximally enhanced by having lots of fish in the river. Successful management by MSR is predicated upon putting the maximum number of fish in the river that are still capable of replacing themselves after spawning. If 19,000 fish spawn and later produce 20,000 returning adults, that would be considered a glowing MSR success.

In contrast, successful management by MSY means the ability to harvest all the “surplus” fish (the yield) that is not needed for maximal production, as measured by the ratio of returning adults per spawner (RPS). RPS ratios of one or less would be considered an utter MSY failure. Spawning escapements resulting in a RPS ratio approaching 1.0 essentially produce zero yield within the MSY construct. Using the same 19,000 fish example above, a return of 20,000 fish would be considered a very undesirable outcome in the MSY mindset, a dismal yield of barely over 5%. That 1000 fish “surplus” might only support a measly two or three days of fishing.

How then does one reconcile the fact that a return of identical magnitude can be viewed so positively in one construct and so negatively in the other? It really boils down to values; what we as a society and fishing community consider to be the highest and best use of the resource. Is it the medieval mindset of maximal harvest or is it the more modern mindset of maximal recreation? As some have so bluntly put it, are we fishing for food or are we fishing for fun? For many of our modern-day fisheries, the answer probably lies somewhere in the middle. This less dogmatic view of “highest and best use” should be taken into consideration in determining how to manage the resource more evenhandedly.

MSY and MSR are actually polar opposites in a continuum of management strategies that have their foundations in tweaking RPS ratios for different goals and outcomes. Theoretically, as long as RPS ratios are not allowed to dip below 1.0, the spawning escapement will replace itself, and the run will be sustained in perpetuity.

MSY is the “tried and true” strategy of harvest-based management that seeks to minimize escapements to produce the highest RPS ratios the available habitat can support. If the habitat is capable of producing 4 returning adults per spawner on an MSY escapement of 5,000 fish, then 20,000 fish would come back, resulting in a yield of 300% or 15,000 harvestable fish. As the fishing season progresses, there are fewer and fewer fish available to catch. The fishing gets tougher as more and more of them are harvested, particularly so for participants further upriver.

MSR boils down to abundance-based management that seeks to maximize escapements which result in RPS ratios hovering at or just above 1.0. If the habitat is capable of producing 1.1 returning adults per spawner at an MSR escapement of 19,000 fish, then 20,000 fish would come back, leaving a buffer of 1000 fish for hook and release mortality. The vast majority of the fish remain in the “catchable” pool of fish all season long to sustain maximal recreational opportunity.

I am not suggesting that either of these strategies is the right way to go about managing all of our fisheries. However, there must be some room for flexibility in management to reflect society’s changing values. For far too long, harvest-based management has ruled the roost. We’re due for a little change.