FYI, From the Wild Steelhead Coalitions book "Biological and Economic Benefits of Wild Steelhead Release"
I know it's a long read, but-
Maximum Sustainable Yield: An Antiquated and High-risk Concept for Wild Steelhead Management
A Brief Historical Perspective on the Maximum Sustainable Yield Concept
Maximum Sustainable Yield, or MSY, is a theory for fish population dynamics that for several decades has influenced fishery management in many parts of the world. The MSY theory basically states the following: (1) there is a fixed functional relationship between the number of spawners and the number of viable offspring ("recruits"); (2) there is an escapement level, the so-called MSY-population point, that provides for maximal harvest by optimizing the number of recruits relative to a minimum number of spawners needed to produce those recruits; and (3) setting harvest rules to maintain escapements at the MSY population point provides for a never-ending maximum sustainable yield. The tenets of MSY were developed by fishery scientists in the mid-20th Century.
In the 1950's and 1960's many fishery management agencies incorporated MSY principals into policy. The 1958 International Law of the Sea, for instance, adopted MSY as the goal of international fishery management (Christy and Scott 1965). At the time, the MSY concept was an attractive alternative to existing management policies because it promised objective science-based guidance for setting harvest rates while offering long-term protection for the targeted fish population (Nielsen 1976). It is widely recognized that the early implementation of MSY-influenced policies heralded an important shift to science-based fishery management (Larkin 1978).
Although the MSY concept spurred an historic shift in mid-20th century fishery management paradigms, MSY shortcomings have long been evident. From an ecological perspective one of the key assumptions underlying the MSY concept is that a target population can be treated as an isolated stock, yet no credible ecologist would dare argue that any wild fish population exists in a vacuum. The MSY concept is restricted to fish population dynamics, yet from a socio-economic perspective, no credible policy-maker would dare to claim that biology was the only important factor guiding fisheries management. An extensive literature on the dysfunctional politics and socio-economics of commercial and sport fisheries was well developed by the 1950's (Nielsen 1976).
The MSY concept assumes that environmental variations are accounted for in the data used to develop stock-recruit relationships, yet these data are generally so limited in time coverage and quality that developing stock-recruit relationships is often more art than science.
For steelhead, changing environmental conditions are a major source of error in run-size forecasts. Both short-term and long-term variations in stream and ocean conditions can drastically alter productivity from one year, and even one decade, to the next. From an environmental prediction perspective, no credible climate forecaster or fish biologist would dare argue that there is strong predictability for the always changing environmental conditions that influence steelhead productivity one year to the next. Each of these problems with the MSY concept, as well as many others, has been well-documented for decades (Larkin 1976).
In the 1970's the concept of Optimal Sustainable Yield, or OSY, was developed as a response to the widely acknowledged shortcomings of the biologically-isolated MSY concept. The OSY concept has been defined by Roedel (1975) as:
A deliberate melding of biological, economic, social, and political values designed to produce the maximum benefit to society from stocks that are sought for human use, taking into account the effect of harvesting on dependent or associated species.
The US Magnuson-Stevens Fishery Conservation and Management Act of 1976 recognized the multi-faceted nature of fisheries and adopted Optimum Sustainable Yield as the guiding principal for federally managed commercial fisheries. Section 28 of the Magnuson-Stevens Act defined OSY principles in the following way:
(A) [OSY] will provide the greatest overall benefit to the Nation, particularly with respect to food production and recreational opportunities, and taking into account the protection of marine ecosystems;
(B) is prescribed as such on the basis of the maximum sustainable yield from the fishery, as reduced by any relevant economic, social, or ecological factor; and
(C) in the case of an over fished fishery, provides for rebuilding to a level consistent with producing the maximum sustainable yield in such fishery.
In 1996 the Sustainable Fisheries Act (SFA) became Federal law. The SFA amended the Magnuson-Stevens Act to include numerous provisions requiring science, management and conservation action by the National Marine Fisheries Service (NMFS). In the SFA Optimum was defined explicitly as follows:
OPTIMUM: The definition has been revised (in (28)(A)) to require considering the protection of marine ecosystems in setting optimum yield. It clarifies (in (28)(B)) that social, economic, or ecological factors may be used to set OY lower than the maximum sustainable yield, but not higher. And it specifies (in (28)(C)) that, for an over fished fishery, the OY must provide for rebuilding to a level consistent with producing the MSY (NOAA 1997: http://www.nmfs.noaa.gov/sfa/s***uide/index.html).
Now consider the joint Washington Department of Fish and Wildlife/Tribal Wild Salmonid Policy of 1997 . Washington's Wild Salmonid Policy is wedded to MSY, albeit under the label Maximum Sustainable Harvest (MSH), as evidenced by the Spawning Escapement Policy guidelines stated below:
1. In each watershed region, for each species, populations and/or management units to which MSH management will apply shall be identified and the pertinent management agencies shall establish escapement goals designed to achieve MSH. MSH shall be calculated by using long-time series of accurate spawner and recruit statistics for each population. When such statistics are not available, MSH may be calculated by using historical production, habitat availability, or the best available methods for calculation.
2. The State and Tribes will seek agreement on the total escapement rates, escapement levels, or escapement ranges that are most likely to maximize long-term surplus production for wild populations or combinations of wild populations or management units. These rates, levels, or ranges will be based upon achieving MSH and will account for all relevant factors, including current abundance and survival rates, habitat capacity
and quality, environmental variation, management imprecision and uncertainty, and ecosystem interactions. (WDFW/Tribal Wild Salmonid Policy, 1997).
The first provision of this section of the Wild Salmonid Policy specifies MSH/MSY as the guiding principal for establishing wild salmonid escapement goals. The second provision states that MSH will account for "all relevant factors." Given today's understanding of steelhead ecology, environmental variability, and steelhead data quality, is it possible to accurately account for all relevant factors impacting steelhead productivity? Given today's understanding of the ecology of steelhead and the socio-economics of steelhead fishing, is MSH even desirable?
One does not have to dig very deeply to confidently answer "NO" and "NO" to those two important questions. Based on the present day understanding of steelhead ecology and the socio-economics of steelhead fishing, there is no justification for MSY-management of any wild steelhead stocks in Washington State. Recently published critiques by Gayeski (2001) and Redman (2001) highlight major deficiencies of MSY steelhead management in Washington State. Some of the major deficiencies with MSY-guided management for wild steelhead are listed and discussed in detail below.
Deficiencies with MSY-management for wild steelhead
While the MSY concept has provided a means for a data and theory-driven computation for harvest and escapement goals, the foundations for this concept as the primary consideration for fishery management have long been known to rest on very shaky ground. In this section major deficiencies are discussed from the perspectives of ecology, economics, environmental prediction, and data quality.
A. Ecology:
In its use by the Washington Department of Fish and Wildlife, the MSY concept assumes that all fish of the same stock are biologically equal. WDFW models the abundance for stocks at the level of major river basins (for example, Skykomish River winter runs or Sol Duc River summer runs). This assumption is invalid for several reasons (see Gayeski 2001, and Ostberg (this volume)):
1. Most wild steelhead populations contain distinct sub-stocks that utilize different parts and/or tributaries of the same basin, sometimes migrating and spawning at different times. Because sub-stocks are likely to have different productivity levels, MSY harvest rates for major river basins are excessive, even by MSY standards, for the least-productive sub-stocks in those basins.
2. In any year, wild steelhead spawners typically have multi-age and overlapping generations, with repeat spawners typically being the most productive spawners. Harvest rates on repeat spawners are therefore exceptionally high, as this cohort is subjected to intense fishing pressure in multiple seasons. Over time, the presence of kill fisheries reduce a population's age-structure diversity and eventually produce a population with an earlier average age at maturity.
 MSY offers no consideration for ecosystem impacts of harvest, and assumes that spawners in excess of the MSY escapement target are "waste."
1. As noted above, wild steelhead populations contain distinct sub-stocks that likely utilize stream habitat in ways that distinguish them from other sub-stocks. Such uses are likely to include adult return and spawn timing, spawning and rearing locations, and smolt migration timing. Each of these differences contributes to life history diversity as expressed by varying time-space habitat use. Life history differences within and between nearby populations are evolved traits that buffer wild steelhead metapopulations from environmental uncertainty, such as floods, droughts, mudslides, variable ocean conditions, etc.
2. Other species that utilize the same habitat are clearly sensitive to the absence or presence of spawning steelhead. For example, decomposing adult steelhead carcasses contribute significant nutrients to streams and riparian zones and nourish other generations of steelhead rearing in those streams.
B. Economics:
 MSY policies implicitly assume that maximizing harvest is the best use of the steelhead resource. For recreational fisheries, this assumption is clearly at odds with reality (see Jenkins, this volume).
1. Maximizing harvest is not necessarily relevant to the value of recreational fisheries. Washington steelhead are ruled a gamefish, and have been recognized as such for decades. The MSY concept is born of a food-production (commercial fishing) mindset. Based on economics alone, the value of a fishery should be evaluated in terms of fishery income, not fish harvested, and should argue for Maximum Sustainable Income. Based on the socio-economics of recreational fisheries, management goals should focus on Maximum Sustainable Recreation (Larkin 1976).
C. Data Quality:
 Effective identification of the MSY harvest and escapement levels requires a long-history of accurate escapement, harvest, habitat and recruitment data. Long time series (a few too many decades) of high quality steelhead and habitat data simply do not exist.
1. Because of difficulties in monitoring, strong year-to-year and decade-to-decade changes in stream and ocean conditions, and the varying impacts of fishing and hatchery practices, such data simply do not exist for any Washington stock of wild steelhead. The data that does exist is biased by the long-term presence of intense harvest rates throughout the data collection period. These collections of data likely offer a severe underestimate of the productive potential of Washington streams (Gayeski 2001).
D. Environmental Change and Prediction:
 MSY stock-recruit models assume an unchanging environment, yet this assumption is clearly invalid based on an abundance of evidence for climate-related time-varying stream and ocean impacts on steelhead survival (Coronado-Hernandez 1997; Pearcy and Mantua 1999; Smith and Ward 2000). Today's harvest rules are based on run-size predictions that are validated after harvest fisheries take place. For streams with wild steelhead harvest seasons, the lack of systematic in-season, or pre-season, run-size assessments means that over-predictions for adult returns promote over harvest.
1. Successful application of the MSY concept, at least in terms of allowing harvest while avoiding over fishing (to escapements lower than the MSY target), requires an accuracy in pre-season run-size forecasts that do not exist.
2. While it is possible to monitor streams to track smolt populations, prospects for pre-fishery monitoring of smolt-to-adult survival rates are very poor. Likewise, on the majority of streams there is no system for in-season run-size assessments (the mainstem Columbia and Snake Rivers being exceptions).
3. There is no demonstrated capability for skillfully predicting year-to-year changes in smolt-to-adult survival rates for steelhead. Such predictions may be possible, but a lack of data and a lack of understanding of how changing estuary and ocean conditions impact smolt-to-adult survival rates provides a major barrier that must be overcome. Likewise, a distinct lack of predictability in the climate system also poses a serious barrier to predicting smolt-to-adult survival rates.
Summary
While the history of fishery management has been shaped by aspects of the MSY concept, using MSY as a primary basis for fishery management is a practice whose time has passed. Groundbreaking treaties like the 1958 International Law of the Sea embraced MSY as a goal for international fishery management. Yet, for the past 25 years federal commercial fishery policies have explicitly identified MSY as a means for identifying an absolute upper limit on harvesting. Federal harvest policies are now formed after considering MSY and other important ecological, socio-political, and economic factors. In contrast, Washington State continues to identify MSY as the harvest goal for wild salmonids.
The long list of MSY/MSH steelhead management problems reviewed here and by many others begs for significant reforms in Washington's wild steelhead harvest policies. Wild steelhead management policies based on MSY lack critical scientific and socio-economic justifications. A wealth of evidence and experience paints MSY as an antiquated and high-risk basis for managing wild steelhead fisheries. In addition, this concept is based on a commercial fishing/food production world view. Even commercial fishery policies have backpedaled from pure MSY doctrines for the past 25 years. Because there are many important dimensions to the recreational wild steelhead fishery in Washington State, the MSY model is simply inappropriate.
A review of wild steelhead fisheries in Washington State highlights numerous failures of the present MSY management model. The very low wild winter-run steelhead escapements to north Puget Sound river basins in 2000 and 2001 (WDFW 2000) and the subsequent closures of spring catch-and-release fisheries in 2001 highlight some of the risks inherent in the MSY approach.
Based on escapement estimates for parent years and expectations for stable productivity, WDFW allowed wild steelhead harvests in December 1999-February 2000 when in fact the run size was much lower than predicted. The result? Over fishing, and for some populations the lowest wild steelhead escapements on record.
Escapements for several north Puget Sound rivers were not met in 2000, nor in 2001, in spite of the fact that the parent generations for these returns had met MSY spawning escapement goals. The long-term consequences of over fishing in 1999-2000 will not likely be known for many years. The short term consequences have included complete closures for March-April wild steelhead release seasons for north Puget Sound rivers in 2001 and may be repeated for at least the 2002 season.
The WDFW management response to poor escapements, in addition to the closures, has been limited to little more than a collective hope that productivity and the depressed populations will rebound sometime in the future.
The WDFW has issued many similar emergency closures to halt harvest fisheries from taking wild steelhead after significant harvests had impacted low numbers of returning spawners. An internet search on the WDFW web-site for "emergency closures" for wild steelhead yields this list for the period since 1997:
Winter Steelhead Emergency Closures
 Hoh River, January 28, 1997
 Puyallup River, March 14, 1997
 Humptulips/Chehalis Basin, November 26, 1997
 Humptulips and Hoh Rivers, February 24, 1998
 Puyallup River, November 19, 1998 (rule change to wild steelhead release)
 Skagit, Sauk, Stillaguamish, Skykomish, Snoqualmie, Snohomish, Puyallup, and Carbon Rivers, November, 2000
Summer Steelhead Emergency Closures
 Lewis and Kalama Rivers, September 16, 1997
 Wind River, August 27, 1997
It seems that the preferred management method has been to put the “burden of proof” on the spawners, which are typically counted well-after the harvest season has finished, while putting faith in the agency's pre-season run-size forecasts. When those forecasts overestimate returns and subsequent harvests further depress escapements, the agency has consistently responded with emergency closures. The net result is a lose-lose combination: imperiled fish stocks and lost fisheries.
Relative to status quo policies, Washington State now has the opportunity to strike a much better balance between recreational opportunities and resource conservation by eliminating wild steelhead harvest and offering more catch-and-release opportunities. The benefits of such a policy shift are clear: it would significantly reduce the risks of over fishing the few remaining healthy Washington State wild steelhead populations while still providing recreational opportunities. For years, wild steelhead harvests have allowed for an unacceptably skewed trade-off favoring the risk of over fishing for the sole benefit of providing harvest opportunities for a relatively small number of ecologically valuable fish. This situation has continued in spite of the fact that recent years have seen more than 80% of Washington's steelhead harvest derived from marked hatchery fish.
In conclusion, the case for MSY/MSH wild steelhead management is simply too weak to support its continued use. In many situations, wild steelhead release seasons provide an acceptable and attractive trade-off between offering recreational opportunities and protecting valuable fish stocks.
It is also clear that wild steelhead release seasons are not a cure-all for the problems faced by Washington's wild steelhead, just one step in a positive direction. Habitat restoration, with a focus on realizing some of the lost potential for wild steelhead production in Washington's once famous but now much diminished steelhead rivers, must also become a high priority for WDFW if their hopes for improved wild steelhead returns are ever to be realized.
References
Christy, F.T. Jr., and A. Scott. 1965. The common wealth of ocean fisheries: some problems of growth and economic allocations. Johns Hopkins Press, Inc. Baltimore, 281 pp.
Coronado-Hernandez, C. 1995. Spatial and temporal factors affecting survival of hatchery reared chinook, coho, and steelhead in the Pacific Northwest. Ph. D. Dissertation. University of Washington. 235 pp.
Gayeski, N. 2001. Maximum Sustainable Yield: A formula for over harvest? The Osprey 39: pp 1 and 5-9.
Larkin, P.A. 1976. Fisheries management - an essay for ecologists. An. Rev. Ecol. Sys. 9:57-73.
Larkin, P.A. 1977. An epitaph for the concept of Maximum Sustained Yield. Trans. Am. Fish. Soc. 106:1-11.
Nielsen, L.A. 1976. The evolution of fisheries management philosophy. Mar. Fish. Rev. 38(12): 15-23.
Pearcy, W. and N. Mantua. 1999. Ocean conditions and their impacts on steelhead. The Osprey 35.
Redman, B. 2001. Make escapement, not harvest, top priority. The Osprey 40: pp 3 and 19.
Smith, B.D. and B.R. Ward. 2000. Trends in wild adult steelhead abundance for coastal regions of British Columbia support the variable marine survival hypothesis. Can. J. Fish. Aquat. Sci. 57:271-284.
WDFW/Tribal. 1997. Washington Department of Fish and Wildlife/Tribal Wild Salmonid Policy. Washington Department of Fish and Wildlife, Olympia WA. 46pp. Available via the WWW at
http://www.wa.gov/wdfw/. Washington Department of Fish and Wildlife (WDFW). 2000.
http://www.wa.gov/wdfw/factshts/stlhdres.htm. Also see the WDFW Press release from February 16, 2001.