An Evaluation of Stocking Strategies in Wisconsin with an Analysis of Projected Stocking Needs By

An Evaluation of Stocking Strategies in Wisconsin with an Analysis of Projected Stocking Needs by

The Bureau of Fisheries Management and Habitat Protection 101 S. Webster Street P.O. Box 7921 Madison, Wisconsin 53707-7921

for

The Joint Legislative Audit Committee State Capitol Madison, Wisconsin 53703

April 1999 iii NOTES

______ii Contents

Report Summary ...... i Contents ...... ii Notes ...... iii

I. Introduction ...... 1 Management Goals ...... 1 Stocking Strategies ...... 1 Stocking Guidelines ...... 2 Stock Integrity and Natural Reproduction ...... 3 Stocking Plans and Quota Requests ...... 4

II. Species-specific Stocking Guidelines ...... 4 Great Lakes Trout and Salmon ...... 5 Inland Trout...... 10 Largemouth and Smallmouth Bass ...... 14 Lake Sturgeon ...... 17 Muskellunge...... 19 Northern Pike ...... 23 Walleye ...... 28

III. Summary and Recommendations ...... 33 Management Recommendations ...... 33

IV. Literature Cited ...... 35 v. Appendices ...... 37 i Report Summary

n 1997, the Wisconsin Legislative Audit Bureau published a report on the Department of Natural Resources (DNR) fish propagation and stocking programs, entitled An Evaluation Fish Stocking Department of Natural Resources Report 97-9, which recommended the DNR evaluate several aspects of its stocking program. This report specifically addresses the long- range stocking goals for the DNR and projected long-term propagation needs using the best availableI scientific information. This plan promotes the most effective use of stocking in the overall management of Wisconsins fisheries using a goal-oriented, species- and water-specific approach that minimizes impacts to existing self-sustained populations.

Species-specific stocking guidelines were reviewed and, where needed, revised to reflect current scientific knowledge. Recommended changes include: a shift from domestic to wild trout for the inland trout program; reduced emphasis on the maintenance stocking of bass; an increase in restorative sturgeon stocking; an increased emphasis on evaluation of muskellunge stocking practices; northern pike stocking based on suitable habitat and published survival rates resulting in increased opportunities for stocking; opportunities for increased walleye stocking; and, no major changes to the Great Lakes trout and salmon stocking program. Overall recommendations include protection of existing naturally reproducing populations, more evaluation and use of appropriate genetic strains, long-term quota development, elimination of per-water maximums for planning purposes to better identify potentials for contract or cooperator involvement; and the formation of a stocking team that keeps stocking and propagation on the cutting-edge of fisheries management.

Based on the best available information, annual stocking of over 11 million fish (primarily fingerlings) is needed to sustain and enhance the sport fishery in Wisconsin (Table 1). This projected level of stocking was arrived at independent of current hatchery production capacity.

Table 1. Summary of Projected Wisconsin Stocking Goals

Fish Species (size) Statewide Annual Stocking Goal

Walleye (2- 4 fingerlings) 6.5 million Muskellunge (7+ fingerlings) 140,000 Northern Pike (3-7 fingerlings) 150,000 Black bass (2 fingerlings) 210,000 Lake Sturgeon(3+ fingerlings) 75,000 Inland Trout 1.5 million Great Lakes Trout and Salmon 2.5 million

Grand Total 11.1 million 1

I. INTRODUCTION ment goals are met. The groups compiled available stocking evaluations statewide, Advances in propagation techniques, a greater examined current scientific literature, and understanding of the need for ecosystem reviewed other available information to management and genetic conservation, and produce up-to-date stocking strategies. recent renovations to the hatchery system Stocking procedures for each species include have all led to recent revisions of management suitable waters, sizes and numbers to stock, strategies for many of Wisconsins popular strain management, and projected changes in fisheries. As such, management goals, and statewide production. This report presents the associated stocking guidelines, have been desired state for our stocking program and under review for many of the major fisheries should be viewed as a working document that in the state. The recent legislative audit of the is open to continuous improvement and departments propagation program specifi- update. The recommendations contained cally prompted a consolidated review and herein should be implemented as opportuni- description of our stocking practices. ties arise. MANAGEMENT GOALS Updated stocking guidelines are intended to 1) provide the hatchery system with better The various species-specific committees information for production planning, 2) independently developed management goals ensure the most efficient use of hatchery for the major fisheries of the state. Many products needed for management purposes, similarities existed among the species-specific and 3) ensure the most prudent management goals. What follows is a consolidated list of of Wisconsins exploited stocks and associated fisheries management goals for the state that communities and ecosystems. This planning incorporates most of the goals from the effort was initiated to evaluate and update, species-specific groups: where needed, our stocking practices and to develop a statewide plan for the uses of, and I. Protect, restore and enhance fisheries demands for, stocked fish. habitat on Wisconsin waters

Clearly, stocking can not be considered in a II. Protect, restore and enhance vacuum. Central to this effort was a review Wisconsins self-sustained fisheries, fish and revision, where necessary, of the overall assemblages and aquatic communities management goals for the various fisheries of the state. The ultimate success of any stocking III. Provide a variety of quality fishing strategy should be judged based on its contri- opportunities (e.g., trophy, action, harvest) bution to achieving those management goals. within a flexible management system Species-specific stocking strategies can then more efficiently address where, how many, IV. Ensure that resource managers have what size, and what types (e.g., strain) of fish the necessary information on the status of are needed to meet overall program goals. Wisconsins fisheries and aquatic ecosys- This report suggests how many fish should be tems raised to meet the overall management goals of the program, not how many could be V. Provide technical assistance and raised. educational opportunities to Wisconsins citizens and anglers, promote the value of The major fish species stocked by the Depart- Wisconsins fisheries and ensure angling ment of Natural Resources are addressed in opportunities for future generations this report: Inland trout (domestic and wild STOCKING STRATEGIES strains), Great Lakes trout and salmon, black bass, lake sturgeon, muskellunge, northern Stocking is generally used as part of an pike, and walleye. Existing species manage- integrated approach in the management of a ment committees, which included internal and waterbody which also considers habitat external partners, reviewed, revised and restoration or improvement, harvest regula- updated management goals and developed tions, public access, and public education and stocking strategies to ensure that the manage- involvement. As part of a management plan, 2

stocking would be used to accomplish spe- We currently discourage introductions of cific, stated objectives for the waterbody species except in newly created waters such as through one of the following strategies: reservoirs or constructed ponds.

Introduction.- This strategy includes instances where a species is introduced into a newly STOCKING GUIDELINES created water or to expand the range of a Specific stocking guidelines for each species species. Ideally, the introduction results in the were developed to provide guidance for staff establishment of a self-sustained fishery with in making biologically sound stocking recom- minimal impacts on existing fisheries. mendations for a particular water and to allow for equitable and cost-effective allocation of Rehabilitation.- An interim measure to re- limited hatchery production In the first set of establish formerly self-sustained populations guidelines, based on the best available biologi- that have been extirpated or severely reduced cal information, stocking must: by catastrophic natural or intentional sources of mortality (e.g., winterkill, disease, chemical 1) Address the management goal(s) for the spill, mechanical removal, drainage of species of interest; fowages, dam failures, chemical reclamation). 2) Minimize negative impacts on existing Research or Evaluation. Experimental self-sustained fisheries, including safe- stocking done in conjunction with a research guards to protect the integrity of native or evaluation project intended to determine and naturalized stocks and consider the cost-effectiveness of stocking practices or interactions and potential impacts on other management actions. other species; and

Remediation (maintenance). Stocking to 3) Be biologically sound (i.e., likely result maintain an existing fishery that has been in fishable populations) based on the best reduced due to external impacts (e.g., loss of available scientific knowledge. spawning habitat, invasion of exotic species, long-term changes in species composition) The second set of guidelines, based primarily that cannot be readily corrected. This strategy on inevitable limitations in production from would also include instances where restora- the hatchery system, consider allocation rules tion of predator/prey imbalance is sought. for limited production. Stocking requests should: Recreation (maintenance). Stocking to create or maintain a recreational fishing 1) Be cost effective, as measured by cost opportunity that did not previously exist and per recruit to the populations or cost per is not self-sustaining. This type of fishery will fish returned to the creel; usually have some effect on existing fisheries and is typically dependent upon stocking for 2) Ensure equitable distribution of limited continued existence. hatchery production; and

All of these stocking strategies are currently 3) Utilize contracting or cooperative used on Wisconsin waters. Priority is usually agreements with private aquaculture and given to rehabilitation stockings that promise volunteer groups, where cost-effective. to establish self-sustained fisheries, or to research or evaluation stockings that promise The primary purpose for the first set of to improve the cost-effectiveness of stocking guidelines is to assist fisheries biologists in practices. Recreation stockings are generally a developing long-term management objectives relatively costly management activity but are for specific waters. The second set of guide- often needed to sustain popular fisheries in lines will allow the Department hatchery many waters. Remediation stockings are used system to equitably and cost-effectively only as a last resort after attempts to correct allocate production for maximum benefit, as underlying problems have failed and the measured by return to the angler creel. The maintenance of a stocked fishery is desired. difference, if any, between long-term stocking 3

6 recommendations and Department hatchery 5 allocation represents opportunities for contract development or cooperative agreements with 4 private businesses or volunteer groups, or for 3 the state to consider investments in the 2

Department hatchery system. Number/acre 1 In this report, we present recommendations 0 based primarily on the best available scientific Natural S tocked information. This allows comparison of Adult Dens ity Catch statewide need with existing facility capacity, as described in an earlier report to the legisla- ture (DNR 1998). However, a blend of biological and production-allocation criteria have Figure 2. Comparison of density and catch infor- historically been used in Department stocking mation on natural versus stocked walleye fisheries, guidelines. In instances where scientific 1990-1995. information is equivocal, historic practices are retained in the current recommendations. Recently, considerable work has been done on Thus, true demand for stocked fish is difficult the differentiation, fitness, and performance of to accurately assess because past stocking individual populations within a species requests have been tempered by production- (Philipp et al. 1983; Gharrett et al. 1988; allocation criteria through this historic blend Beachum et al. 1989; Krueger et al. 1989; of guidelines. Philipp 1991). The stock concept (i.e., managing individual breeding populations) STOCK INTEGRITY AND NATURAL REPRODUCTION has been bolstered over the last decade with A central goal for all management of Wiscon- improved technology (ability to discern stocks; sin fisheries should be to ensure the protection see Ryman and Utter 1987) and documenta- of existing self-sustained populations. Native tion of the superior performance of locally and naturalized populations that are self- adapted populations (see, e.g., Philipp and sustained through natural reproduction clearly Claussen 1995). Indiscriminate transfer and provide the best fishing opportunities in the mixing of stocks negatively affects the genetic state (Figures 1 and 2), are the most cost- resources of a species by reducing genetic effective to manage and, if impacted or lost, diversity among populations and by decreas- can not be easily replaced. Stocking should, ing the genetic fitness of locally adapted first and foremost, be considered an important populations through outbreeding depression restoration tool used to reestablish naturally (i.e., when genetically different populations reproducing populations. interbreed to produce inferior offspring).

In an experiment conducted by Illinois re- 0.080 40 searchers, bass from Florida, Illinois, Wiscon- sin, and Texas were stocked together in lakes 38 0.060 in all four locations. In each location the

36 survival, growth, and reproduction of the local 0.040 fish were best; nature had already produced 34

Catch Rate Catch the best adapted fish for the local conditions. 0.020 However, the few surviving transplants 32 Mean L (inchesMean ength ) interbred with the locals and eventually all the

0.000 30 bass in the lakes were hybrids with inferior NR NR +S tocked S tocked performance relative to the local stock (see Catch rate TL (inches) Jennings 1996 for an overview). A similar experiment was conducted at a smaller scale by transplanting bass from two different Figure 1. Muskellunge catch rate and mean length watersheds in Illinois. In this study, similar by reproductive category. (NR = natural reproduc- results were found: local stocks had better tion) performance (growth and survival) and fitness 4

(reproduction). These studies suggest that mended stocking guidelines for each of the indiscriminate stocking of bass in waters with stocking strategies, developed by teams of naturally reproducing populations will likely biologists and species-specific experts from result in more harm than good. throughout the state, are presented below to guide fisheries biologists. Evaluations of other We recommend a conservative approach that stocking practices are also encouraged and reasonably assumes that these results are should be supported by a research or evalua- applicable to other freshwater fish species, tion project to ensure the most efficient use of pursuant to Goal II, above. Fields et al. (1997) hatchery and fiscal resources. also recommends this approach. As such, we recommend that no stocking take place in II. SPECIES-SPECIFIC STOCKING GUIDELINES waters with self-sustained fisheries of the species in question unless the stocked fish The stocking guidelines presented in this originate from that population. report address the major fish species stocked by the Department of Natural Resources: Fields et al. (1997) developed a series of Great Lakes trout and salmon, inland trout recommendations for the sources of stocked (domestic and wild strains), black bass, lake fish based on the reproductive status of the sturgeon, muskellunge, northern pike, and population in the receiving water (Table 2). walleye. This portion of the report is divided into two sections: 1) cold water species and 2) STOCKING PLANS AND QUOTA REQUESTS warm water species which will facilitate comparisons with DNR cold water and warm In developing new requests for fish from the water hatchery capacity. hatchery system, fisheries biologists should evaluate the overall management goals, the Within each management goal, each commit- specific objectives for the basin and the tee described: waterbody, determine a desired state for the fishery, select a long-term stocking strategy for 1) The stocking strategy (e.g., rehabilita- the species of interest, and select stocking tion, remediation, recreation, etc.), if any, practices that will achieve the desired state. recommended to achieve the goal; Generally, a 10-year stocking plan should be 2) Waters appropriate for the application developed to fully evaluate whether the of that stocking strategy; desired state has been reached. Recom- 3) The recommended stocking guidelines

Table 2. Stocking decisions for conservation on native stocks (modified from Fields et al. 1997. NR means natural reproduction; Basin stock means the brood stock originates from within the major basin.

Stock Origin Reproductive Status Recommended source of broodstock

Native to waterbody Self sustained through NR Fish should not be stocked Some NR; not self sustained From that waterbody Dependent on stocking Basin stock Extirpated (rehabilitation) Basin stock

Introduced to waterbody; Self sustained through NR Fish should not be stocked native to basin Some NR; not self sustained From that waterbody Dependent on stocking or Basin stock new introduction

Introduced to waterbody; Self sustained through NR Fish should not be stocked not native to basin Some NR; not self-sustained From that waterbody Dependent on stocking or Any source new introduction 5

associated with the respective stocking been developed over a period of three de- strategy, including: cades. The program is operated in coopera- tion with agencies in Minnesota, Ontario, a) The size of fish; Michigan, Illinois, and Indiana, and in coop- b) Rates of stocking; eration with sport fishers who provide c) Frequency (e.g., annual, biannual, funding through the purchase of fishing etc.) of stocking; and licenses and Great Lakes Trout and Salmon d) Duration (e.g., 5 consecutive years; stamps. biannually for 10 years) of stocking; The salmon and trout stocking program is part 4) Criteria recommended to evaluate the of a larger inter-jurisdictional fisheries man- effectiveness of the strategy including agement program on the Great Lakes, a the cost-effectiveness of the strategy. program that involves sea lamprey control (funded by the Great Lakes Fishery Commis- 5) Projected demand for fish from the sion), a lake trout restoration program (funded hatchery system for the next 10 years. primarily by the USFWS but supported by state agencies, including the Department), regulation of sport fisheries for other species, including yellow perch, smallmouth bass, COLDWATER SPECIES walleye, sturgeon, and northern pike, and regulation of commercial fisheries on both GREAT LAKES TROUT AND SALMON STOCKING GUIDE- lakes. Because state management programs, LINES including the salmon and trout stocking program, affect other jurisdictions, the Depart- The Great Lakes trout and salmon stocking ment is a signatory to A Joint Strategic Plan program can be traced back over a hundred for the Management of Great Lakes Fisheries. years to the initial introductions of rainbow That agreement among all state fisheries trout. The program has been greatly ex- management agencies, two tribal management panded in the past three decades, and now organizations and several Canadian and U.S. supports a vital and economically important federal agencies provides a basis for joint fishery known throughout the world. Stocked management of all shared fisheries resources trout and salmon are the backbone of a sport in the Great Lakes. fishery that provides over 3,000,000 hours of relaxation and gainful entertainment to Current Stocking Practices. - The anglers each year. The program is reviewed Departments stocking program is summa- below in three sections, an overview, a sum- rized in the table below. The primary goal of mary of the major management goals and the program is to provide sport-fishing strategies, and a discussion of the cost-effec- opportunities through a put-grow-and-take tiveness of the program. stocking program, but other goals are also served. On Lake Michigan the stocking of Wisconsins Great Lakes trout and salmon salmon and trout by four states and the program involves the stocking of six species USFWS has dramatically affected the ecosys- of fish lake trout, brook trout, rainbow trout, tem of Lake Michigan by reducing the abun- brown trout, chinook salmon, and coho dance of the alewife, a non-indigenous species salmon in Lake Michigan, Lake Superior, that had proliferated and become a major and tributaries. The splake, a cross between ecological and aesthetic pest by the mid lake and brook trout, is also stocked in both 1960s. On Lake Superior the stocking of lakes. This program provides sport-fishing rainbow trout is intended to not only provide opportunities, regulates the abundance and sport fishing opportunities, but also to en- ecological impacts of alewives in Lake Michi- hance naturally reproducing populations in gan, and promotes restoration of naturally- the Brule River and elsewhere. reproducing populations of lake trout and rainbow trout. The salmon and trout stocking plan for 1999- 2000 (excluding lake trout stocked by the U.S. This complex program, which involves the Fish and Wildlife Service), is summarized in annual stocking of nearly 5 million fish, has Table 3. 6

Table 3. Proposed Great Lakes trout and salmon stocking for 1999-2000.

Species Lake Number stocked

Brook trout Superior 0 Michigan 160,080 109,700 fall fingerlings and 50,380 yearlings, all from domestic brood stock.

Brown trout Superior 100,000 all yearlings, half Seeforellen strain from feral Lake Michigan brood stock and half from a feral Soda Lake brood stock Michigan 1,232,940 682,200 fall fingerlings and 242,550 yearlings from domestic brood stock, and 308,190 Seeforellen strain yearlings from feral Lake Michigan brood stock.

Rainbow trout Superior 100,000 all yearlings from naturally-reproducing feral Brule River brood stock Michigan 500,300 169,900 Chambers Creek strain yearlings, 160,500 Ganaraska strain yearlings, and 169,900 Skamania strain yearlings, all from feral Lake Michigan brood stock

Lake trout Superior 89,400 all domestic yearlings Michigan 0

Splake Superior 120,000 all yearlings from domestic brood stock Michigan 40,000 all yearlings from domestic brood stock

Chinook salmon Superior 400,000 all spring fingerlings from feral Lake Michigan brood stock Michigan 1,467,000 all spring fingerlings from feral Lake Michigan strain brood stock

Coho salmon Superior 0 Michigan 498,000 100,000 fall fingerlings and 398,000 yearlings, all from feral Lake Michigan brood stock

The Great Lakes fisheries management This report is limited to fisheries manage- program benefits from extensive public ment goals directly served by the involvement. For example, over 150 individu- Departments stocking program. More als participated in the development of the complete reviews of the fisheries manage- Lake Michigan Integrated Fisheries Plan, 1995- ment programs on Lake Superior and Lake 2001. During 1998, a lake-wide review of Michigan are provided in the Lake Superior stocking levels for Lake Michigan involved a Fisheries Management Plan, 1988-1998 and public stocking conference held in Benton the Lake Michigan Integrated Fisheries Harbor, Michigan and three open public Management Plan, 1995-2001. This discus- meetings in Green Bay, Cleveland, and Mil- sion of stocking strategies does not include waukee. Lake-wide conferences of that type the stocking of lake trout in Lake Michigan have also been held to involve the public in or Lake Superior by the US Fish and Wild- management decisions related to coho salmon life Service for the purpose of restoring and yellow perch. Also, because a significant naturally reproducing populations. Those portion of the cost of obtaining, rearing, and programs are overseen by all the manage- stocking salmon and trout is covered by ment jurisdictions on the lakes and sup- receipts from the sale of Great Lakes Trout and ported by appropriate state and tribal Salmon Stamps, a biennial report of those harvest regulations. The Department does expenditures is prepared and circulated not stock lake trout in the Great Lakes widely for public comment. except for limited stocking in the Western 7 end of Lake Superior to enhance the sport facilities on Lake Michigan, the fishery. Strawberry Creek weir, serve as our primary source for stocking. We do Specific Great Lakes Trout and Salmon Goals not know the genetic basis, if any, for and Strategies. - The fisheries management distinguishing those chinook salmon goals for the Great Lakes, including the from others, but, because those fish salmon and trout stocking objectives, are have performed better than chinook described in the Lake Superior Fisheries salmon taken at other facilities, it is Management Plan, 1988-1998 and the Lake important to continue to work with Michigan Integrated Fisheries Management that strain. Plan, 1995-2001. Because the purpose of this review is to assist in the evaluation of the Strategy: Match stocking to available Departments hatchery system, we are listing forage. here only the goals and strategies that have direct implications for how fish are obtained, Fish can be stocked in numbers that reared, and stocked. exceed the carrying capacity of the receiving ecosystem. This was illus Goal Provide sport fishing opportunities in trated in Lake Michigan in the 1980s Lake Michigan, Lake Superior, and tributaries. when the alewife forage base declined under the pressure of intensive Strategy: Stock a diverse mix of salmon salmon and trout stocking. This and trout. resulted in declines in chinook salmon growth rates, increased prevalence of The table above summarizes stocking a stress-mediated disease, bacterial plans for the fall of 1999 and the kidney disease, and widespread spring of 2000. It illustrates a diverse die-off of adult chinook salmon. In mix of species, and reflects the 1998 concerns about a possible repeat expressed interests of the angling of those events led to a lake-wide public. The major elements of this review of the issue, involving program varies little from year to year, management agencies in Michigan, reflecting a stable stocking strategy Illinois, and Indiana, as well as that hasevolved over three decades. Wisconsin, and also extensive public consultation. Strategy: Select appropriate strains to provide quality and variety in fishing Strategy: Distribute stocking to serve opportunities. sport fishing needs.

The Department continues to explore Salmon and trout are stocked widely and develop the use of alternative in the Great Lakes to serve angler strains of salmon and trout. The needs. On Lake Michigan, the current mix of three rainbow trout distribution of fish is guided by a strains used in Lake Michigan, for computer model that takes into example, provides stream angling consideration the distribution of opportunities through most of the harvest, the distribution of facilities year, while also supporting the open such as launch ramps, and the number lake rainbow trout fishery. of miles of tributary streams available Department biologists are currently to migrating salmon and trout. looking into using other rainbow trout strains to provide near shore fishing Goal Rehabilitate naturally-reproducing opportunities in Lake Michigan. The anadromous rainbow trout runs in the Brule use of Seeforellen brown trout has River, a tributary to Lake Superior. improved the quality of the brown trout fishery. Chinook salmon Strategy: Stock offspring of naturally returning to one of the three spawning reproducing rainbow trout. 8

On the Brule River past attempts to Strategy: Use feral brood stocks to the rehabilitate the naturally-reproducing extent possible. population by stocking the offspring of stocked fish have not been success- Feral brood stocks are fish that swim ful. Currently a program of capturing wild in the lakes. They are collected adult rainbow trout that themselves in fall or spring when they return to were the products of natural repro- tributaries to reproduce, and are duction in the Brule River, and mated to produce the next generation stocking their offspring back into the of fish for stocking. They are Brule River, is being pursued and distinguished from domestic brood evaluated. stocks, which are adult fish held in hatcheries for propagation purposes. Strategy: Evaluate alternative ages for Feral brood stocks are a superior stocking. source for propagation. Because they have survived in the open lakes, they The Brule River rehabilitation pro- are known to possess desirable genetic gram has involved the stocking of properties. Also, because huge rainbow trout at different ages. For numbers of fish are included in the 1999-2000, yearling rainbow trout will feral brood stocks, they allow the be stocked, and the success of those maintenance of desirable broad plants will be compared with the genetic diversity. success of plants of younger ages. Strategy: Maximize the numbers of Goal Minimize disease in wild fish popula- breeding pairs used in propagation. tions. The preservation of genetic diversity Strategy: Limit importation of new within individual species is vital to the salmon and trout strains into the Great long-term health of the stocking Lakes drainage basin. program. Therefore, protocols are followed that assure the use of the Because of the high risk of importing largest numbers of breeding pairs that virulent diseases, Wisconsin along is feasible. with other Great Lakes states sub- scribes to the Great Lakes Fish Disease Strategy: Use breeding pairs from Control Policy and Model Program, throughout a run. developed by the interagency Great Lakes Fish Health Committee of the Because the timing of spawning runs Great Lakes Fishery Commission. is, in part, genetically programmed, This program includes stringent the preservation of genetic diversity limitations on the importation of fish also requires the use of parent fish from outside the Great Lakes basin. from all parts of a spawning run.

Strategy: Cull sick fish at the weir. Goal Evaluate propagation strategies In order to limit the spread of infec- tious diseases, especially bacterial Strategy: Compare returns from different kidney disease, adult salmon and breeding, rearing, and stocking strategies. trout are examined and fish that have clinical signs of disease are not used To continually improve rearing for propagation. and stocking practices, special studies are conducted to evaluate stocking Goal Maintain genetic diversity within strategies. For example, the stocking individual species. of fall-fingerling coho salmon has been compared with the stocking of yearlings, the stocking of rainbow 9

trout reared to different ages is being brook trout yearlings the most expensive at studied on the Brule River, and the $12.67 per captured fish. importance of age-at-spawning is being studied in chinook salmon. There are at least three cost/benefit ratios that can be computed to measure the value and Cost-effectiveness of the Great Lakes Stocking effectiveness of this program. One measure of Program. - The salmon and trout stocking the relationship between costs and benefits is program has had a large impact on the econo- suggested above; it is the ratio of the cost of mies of the Great Lakes States. According to the program ($1.7 million) to the amount of the American Sportfishing Association (ASA), direct economic activity generated ($200 in 1996 all sport fishing on all five of the Great million dollars in economic output). Another Lakes generated expenditures of $1.9 billion, cost/benefit ratio is the amount spent on economic output of $5.4 billion, and earnings stocking divided by the number of fish of $1.4 billion, while supporting 60,298 jobs. harvested. In 1997, approximately 490,000 These figures include sport fisheries not salmon and trout were captured by anglers, at supported by stocking (for example the large a cost per fish of a little over $3.47. This walleye fishery in Lake Erie), but stocked figure is somewhat ambiguous, however, salmon and trout are responsible for a signifi- because some of the harvest is attributable to cant share of this economic activity. Wisconsin naturally-reproduced fish. Also, stocked fish residents benefit greatly. The same ASA swim throughout each lake, so some fish survey suggested Great Lakes fishing in stocked by Wisconsin are captured in other Wisconsin accounted for $100 million in direct states and some of the fish captured in Wis- expenditures, $200 million economic output, consin waters were stocked elsewhere. Fi- and supported 3,214 jobs. nally, the overall cost of the program, divided by the amount of Great Lakes fishing each This represents a substantial return in eco- year in Wisconsin waters (approximately nomic activity for a Department program that 3,000,000 hours) yields a cost of about $0.57 costs less than $2.5 million annually, and that per hour. The relative cost-effectiveness of is not only entirely supported by anglers, but stocking different life stages of the Great Lakes is largely supported by the direct beneficiaries, trout and salmon species is still poorly under- the trout and salmon anglers. Approximately stood. In the future, we need to more directly $1.2 million is provided annually by anglers measure costs and benefits and experiment through the purchase of Great Lakes Salmon with stocking different life stages in order to and Trout Stamps and 2-day Great Lakes improve overall cost-effectiveness of the Licenses (Keim 1998). program.

The total cost of Wisconsins Great Lakes Recommended Stocking Guidelines.- No fishery management program is approxi- changes are recommended at this time, except mately $2.5 million, but that includes costs of that stocking of chinook salmon will be assessing the salmon and trout fishery, costs of reduced by 15% to accommodate a lake-wide managing a large commercial fishery, and goal of reducing chinook salmon density. This costs related to management of yellow perch, reduction was agreed to by all the states smallmouth bass, walleye, and other species around Lake Michigan in order to reduce the not considered part of the trout and salmon likelihood of a recurrence of bacterial kidney program. The actual cost of obtaining, propa- disease, which severely reduced chinook gating, rearing, and stocking salmon and trout salmon in the 1980s. The Lake Michigan for the Great Lakes is approximately $1.7 Fisheries Team and the Lake Superior Geo- million per year. graphic Management Unit will review and develop requests for stocking and ensure Cochrane and others (1992), analyzed salmo- compliance with interstate agreements and nid stocking costs for Wisconsin waters of negotiate with the Propagation Coordinator to Lake Michigan. They found that chinook balance other requests for cold water fish salmon fingerlings were the least expensive of species. all species at $0.35 per captured fish, and 10

Projected Demand for Great Lakes Trout and brook trout take place from within the same Salmon.- We do not anticipate changes to the watershed, where possible, or, at a minimum, numbers listed in the above table over the take place within the basins delineated on foreseeable future. The chinook quota above Figure 3. does not reflect a 15% reduction that we expect to implement. This 15% reduction will Genetic analysis of brown trout proved be revisited annually. difficult and is generally recognized to be of less importance than brook trout because brown trout were introduced from Europe in th INLAND TROUT STOCKING GUIDELINES the late 19 century. However, stocked wild brown trout have survived better than domes- The inland trout stocking program consists of tic brown trout in paired stockings. Local stocking brook trout, brown trout, rainbow strains of brown trout have also faired better trout, lake trout, and splake. This program than non-local strains in northeast Wisconsin. serves a number of purposes such as provid- Because of the importance of broodstock, and ing immediate fisheries, improving existing different rearing techniques, it is critical to fisheries, and restoring fisheries in waters with maintain a high level of quality control during improved habitat. The program has a long the rearing of wild trout. history and is well supported by the angling public. Waters stocked, species stocked, and numbers stocked are currently based on the local managers request using stocking guidelines in the Fish Management Handbook, results of surveys, results of historical stocking practices, and public input.

Over the past decade, inland stocking requests for brook, brown, and rainbow trout have remained fairly stable, with total numbers ranging from 1.4 to 1.7 million. Requests were reduced by 25% in 1995-97 because of budget shortfalls. In 1994 we began experimenting with stocking trout derived from wild parents in order to improve the survival of stocked fish and create better long-term fisheries. The results of this program have been encouraging and we continue to receive requests for additional wild trout. Increased production of wild fish has been limited by hatchery space limitations, fish health concerns, and the need for a comprehensive review of trout stocking Figure 3. Recommended genetic management guidelines. Meeting the future demand for zones for wild brook trout in Wisconsin. wild fish will be a major challenge to our current hatchery system.

Stock Integrity. Recent concerns have arisen Specific Management Goals for the Inland about the effects of our past stocking practices Trout Fishery on the genetic integrity of our native stocks. The Illinois Natural History Survey was I. Protect, restore, and enhance habitat and contracted to do a genetic analysis of brook water quality trout and brown trout. The results of the brook trout report suggest genetic manage- II. Emphasize wild, naturally-reproducing ment zones for conservation of genetic diver- trout populations sity of brook trout (Fields and Philipp 1998). We therefore recommend that transfers of wild III. Provide diverse angling opportunities 11

IV. Use the best scientific management yearling size fish are the management goal. possible, based on population and habitat Although no comprehensive summary of trout monitoring and utilizing the principles of survival rates is available in Wisconsin, rates ecosystem management over 35% would be considered high, which suggests that stocking yearlings will be more V. Have the support of an informed, cost-effective. educated, and involved public Recent unpublished DNR surveys show that Cost effectiveness of inland trout stocking.- wild fish survive better than domestic fish in The most recent cost information we have for high-quality class 2 streams (streams that trout propagation is from WLAB (1997). Costs show good survival and carry over of adult vary be type and size of trout, but are not trout, may have some natural reproduction, available for wild trout or for spring finger- but not enough to utilize the habitat). Even lings, which make up a large part of the wild though wild fish may be more expensive to trout needs. Costs include only operational rear than domestic fish their improved sur- costs and not capital costs such as buildings vival may make up for it. Also, wild fish may and maintenance. Costs for wild trout have survive better at smaller sizes, so that cheaper been estimated to be at least twice as much as spring fingerlings can be used. If captive domestic trout because they can only be raised brood stocks were not necessary for wild fish at half the density. Additional costs of wild this would also reduce their total cost. If trout are for collecting and transporting brood stocking wild fish creates self-sustaining stock, doing fish health assessments, and fisheries, the long-term costs are much re- buying automatic feeders. Some costs may be duced. More studies on costs and measures of less, such as those related to manual feeding effectiveness need to be done for wild fish. and maintaining a captive brood stock. Some benefits of wild fish to anglers, such as appearance, fighting ability, species preferences, and wildness are very difficult to Cost effectiveness needs to be considered in quantify. terms of the type of fishery desired. In a pure put-and-take fishery, such as the urban trout Recommended Stocking Guidelines. - The ponds, legal trout are necessary to provide an following stocking objectives (in priority immediate consumptive fishery. Historical order) are used to address goals II, III, and V: information shows that the fish should be legal size and stocked as close as possible to 1. Restoration or rehabilitation. Restoration the open season to maximize returns. In this applies when a water is returned to the type of fishery, return to the creel can be used ecological state present before degrada- as a direct measure of effectiveness. A recent tion. Wild fish transfers are recommended study by Loomis and Fix (1998) in Colorado over stocking hatchery fish and native showed that if all the costs are included for brook trout should be given priority over put-and-take fisheries, the costs outweigh the exotic species where possible. Rehabilita- benefits. tion applies to an altered ecosystem that cannot be restored but can be managed in In put-grow-and-take fisheries, longer-term its altered state. Both restoration and survival becomes more important than rehabilitation should have a time limit of immediate return to the creel. In these fisher- three years of stocking unless exceptions ies, survival to a certain size or age may be a are documented. Generally, trout popula- better measure of effectiveness. If survival is tions should be self-sustaining within the high, smaller fish that are cheaper to raise can 3-year time period. be stocked in these waters. On a pure cost basis, using the 1997 cost figures, fingerlings 2. Experimental management evaluations. would be more cost effective than yearlings if These are active projects with approved over-winter survival is greater than 24% for experimental designs that are being brook trout, 45% for brown and 39% for assessed by research or management. rainbow trout. This assumes that growth is They may have specific requests for type similar in the hatchery and the wild, and that of fish or strain, and should have a time 12

limit to the evaluation and stocking return and higher use. Put-and-take request. waters that are regionally important or provide exceptional returns can be priority 3. Special management with demonstrated 3 if results are documented. results. These are special cases that have demonstrated exceptional or unique Projected Demand for Inland Trout The results as measured by creel surveys, Trout Team sent out mock quota requests to all angler use surveys, exceptional growth or fish managers with the above guidelines but carry-over, or a unique fishery for that without artificial constraints on the number area such as lake trout in Big Green Lake, requested and that wild trout be used in better or the urban fishing program in the class 2 streams where survival is expected to southeast. be high. Demand for the urban fishing program was assumed to be stable. The 4. Put, grow, and take. Put-grow-and-take results are shown in Table 4. fish realize significant growth before harvest. These waters are class II streams In summary we are proposing to replace about and lakes/spring ponds capable of 55% of the current quotas for domestic brown overwintering fish on the basis of habitat. trout and brook trout with increased numbers Fish stocked in this priority should be of wild trout. The numbers increased because spring or fall fingerlings, unless justified of the projected use of more spring fingerlings. in writing. Lakes or streams could be There are no wild rainbows because Wisconsin higher priority in this category based on does not have any wild rainbow populations management goals and past results; in streams that are large enough to use as a individual waters differ greatly so it is brood stock and most rainbows are used in difficult to generalize. put-and-take fisheries. The shift from domestic trout to wild trout (Figure 4) should result 5. Put and take. Put-and-take fish are in improved fishing opportunities in the better harvested soon after stocking and have class 2 streams where wild fish should survive limited survival (<10% by number) the better and result in more naturally-reproduc- first year because of harvest or poor ing fisheries. Domestics will continue to be habitat. They will be yearlings or legal- used in put-and-take fisheries in class 3 size fish. Lakes are higher priority than streams and lakes. streams because they generally have better

2.00

Domestic 1.60 Wild

1.20

(Millions) 0.80

F ingerlings Yearlings and 0.40

0.00 1990 1992 1994 1996 1998 2000 2002 2004

Figure 4. Recent and projected demand for inland brook, brown and rainbow trout, 1990-2005. 13

Table 4. Comparison of current (1999) and projected (2000) needs for inland trout stocking by species and size.

Species Current Quotas Projected Need

Brook trout (domestic) Spring fingerlings 1,000 Fall fingerlings 48,250 15,700 Yearlings 156,125 78,400

Total 205,375 94,100

Brook trout (wild) Spring fingerlings 53,550 106,550 Fall fingerlings 13,950 70,050 Yearlings 27,700 91,750

Total 95,200 268,350

Brown trout (domestic) Spring fingerlings 70,000 Fall fingerlings 233,690 91,300 Yearlings 260,550 161,900

Total 564,240 253,200

Brown trout (wild) Spring fingerlings 144,550 272,030 Fall fingerlings 177,800 391,810 Yearlings 9,280 6,700

Total 331,630 670,540

Rainbow trout (domestic) Spring fingerlings 20,200 19,200 Fall fingerlings 28,650 48,750 Yearlings 237,250 148,750

Total 286,100 216,700

Lake trout (unspecified) Fall fingerlings 20,000 20,000 Yearlings 25,000 25,000

Total 45,000 45,000

Lake trout (Trout Lake) Spring fingerlings 100,000 Fall fingerlings 100,000

Total 100,000 100,000

Splake(Yearlings) 4,000 4,000

Grand Total 1,482,545 1,651,890 14

WARM WATER SPECIES Stocking is currently a minor component of the bass management program in Wisconsin. During the 1980s and 1990s an average of about LARGEMOUTH AND SMALLMOUTH BASS STOCKING 500,000 fry and fingerlings were stocked annu- GUIDELINES ally (374,629 to 622,416), with about 3,400 th yearling and adult stock transfers each year. By the turn of the 20 century, serious Most stocking is used to re-establish severely habitat loss and declining water quality depressed (intentionally or naturally) popula- prompted concerns for Wisconsins fisheries. tions. Stocking generally occurs on lakes that In 1903, a hatchery was established at have had a winter-kill or have been rehabilitated Minoqua to produce bass for stocking. using chemical fish toxicants. Klingbiel (1981), described the history of stocking in Wisconsins bass management Summary of Current Stocking Practices. - The program from 1900 to 1980: Bass stocking majority of black bass fingerlings requested for increased steadily until about 1940, when management purposes are largemouth bass there were 8 state-operated bass hatcheries fingerlings for Northern Region waters (50% of stocking between 1.5 and 2.5 million fry and waters; see Table 5). Most waters stocked in the fingerling bass each year. Maintenance Northern Region are winter-kill lakes, while stocking was widespread throughout the most waters stocked in the West Central Region state and was popular with anglers. During (32% of waters overall and 48% of all finger- the 1950s, results from numerous research lings) are for maintenance of existing popula- projects showed that maintenance stocking tions. Most smallmouth bass are stocked in the contributed little and that natural reproduc- Southeast Region for maintenance of existing tion in most waters was adequate to reach populations. carrying capacity. As a result, stocking of bass was drastically reduced and bass Most largemouth bass from the DNR propaga- production in state facilities was virtually tion system originate as brood stock from the eliminated. Almost all stocked bass then Mississippi River and the young are hatched and came from federal hatcheries. By the late raised at the Northfield rearing station in the 1960s and early 1970s, many lake reclama- WCR. Most smallmouth bass fingerlings tion projects were carried out and state originate from the state of Illinois hatchery facilities were again geared-up to produce program, although some are hatched and raised bass for chemically reclaimed waters. at the Oehmke hatchery. See Appendix Table 1 Production during this period (about 1960 to for specific stocking rates and frequencies 1980) averaged about 850,000 fry and currently used. fingerling bass annually, with almost half originating from federal hatcheries. Most Specific Management Goals and Objectives. bass were stocked in chemically reclaimed The Bass Committee has developed the follow- waters, waters experiencing winter-kills, or ing specific management goals and objectives: waters subject to some infrequent mortality events. I. Protect, restore and enhance fisheries habitat on Wisconsin waters. Stocking of bass fry or small fingerlings in waters with established populations is A. Locate, document and protect existing generally regarded as ineffective or unneces- functional littoral and riparian habitat. sary (Newburg 1975). However, bass have B. Insure that fishery concerns are incorpo- been the major beneficiary in about 65% of rated into habitat alteration decisions. the more than 400 chemically treated waters C. Review and develop educational material prior to 1981. Many of these waters have on the value of aquatic habitats. developed outstanding, self-sustained D. Ensure that effective, cost-efficient habitat fisheries. Stocking small bass in waters protection, restoration and enhancement devoid of fish or where they have been procedures are documented and used significantly reduced is often an effective consistently throughout the state. management practice to restore or develop a E. Improve enforcement of existing habitat fishery. protection regulations. 15

II. Protect and maintain Wisconsins self- fishing opportunities through a specified sustained fisheries, fish assemblages and set of management options with estab- aquatic communities. lished criteria. B. Increase opportunities to catch big A. Maintain and enhance existing self- bass. sustained bass populations. C. Endorse the concept of increasing the B. Rehabilitate formerly self-sustained Departments flexibility in establishing bass populations. conditions for the issuance of fishing C. Maintain the genetic integrity of self- tournament permits. sustained bass populations. D. Endorse the development of a waters D. Review available information on the classification system for fisheries manage- impacts and interactions of bass with ment. other species. IV. Ensure that sound, up-to-date technical III. Provide a variety of quality fishing information is available for Wisconsins opportunities (e.g., trophy, action, harvest) fisheries. within a flexible management system. A. Develop cooperative efforts with A. Provide fisheries biologists with more external partners to obtain information on flexibility to manage for a variety of bass fisheries.

Table 5. Quota requests for largemouth and smallmouth bass fingerlings, 1997 to present.

Species, Region and Year Stocking Strategy 1997 1998 1999

Largemouth bass Waters Fingerlings Waters Fingerlings Waters Fingerlings NER 7 32,435 9 35,210 6 18,550 NOR 45 170,010 37 130,750 23 119,575 SCR 8 2,850 1 450 0 0 SER 6 50,355 6 51,305 1 50,000 WCR 17 56,700 16 92,800 14 100,820

Total 83 312,350 69 310,515 44 288,945

Reason for stocking 1. Rehabilitation 32% 43% 24% 36% 14% 33% 2. Introductions 1% 0.1% 1% 0.1% 2% 1% 3. Evaluations 40% 24% 35% 30% 34% 18% 4. Maintenance 27% 32% 40% 34% 50% 48%

Smallmouth bass NER 0 0 0 0 0 0 NOR 1 9,000 0 0 0 0 SCR 0 0 0 0 1 3,100 SER 6 1,800 8 53,125 1 50,000 WCR 0 0 0 0 0 0

Total 7 10,800 8 53,125 2 53,100

Reason for stocking 1. Rehabilitation 86% 83% 88% 6% 50% 6% 2. Introductions 0% 0% 0% 0% 0% 0% 3. Evaluations 14% 16% 0% 0% 0% 0% 4. Maintenance 0% 0% 12% 94% 50% 94% 16

B. Develop a statewide strategy to Recommended Stocking Guidelines. - The ensure sufficient data are available for following stocking strategies, summarized in bass fisheries. Appendix Table B, are recommended in order to achieve the black bass management goals for V. Communicate with Wisconsin anglers Wisconsin (listed in priority order). and promote the recreational value of Wisconsins fisheries. 1. Rehabilitation: Waters Winter-kill lakes should not be stocked with bass if serious A. Increase awareness of the impor- mortality occurs more frequently than 2 times in tance of bass to aquatic systems. 10 years unless a plan to minimize the risk of B. Increase awareness of the importance future winter-kills is developed and imple- of quality bass fisheries to Wisconsins mented. economy. Size of Fish Either large fingerlings (2+) C. Educate anglers on the differences or adult transfers. between largemouth and smallmouth Source of fish Same waterbody, if bass. possible, (fingerlings), otherwise basin stock. Costs and cost-effectiveness of bass stock- Stocking rate Large fingerlings - up to ing. - The cost to produce and stock black 25/acre. Adults - up to 5/acre. If bass fingerlings is about $0.07 per fingerling production is unable to meet all quota (WDNR unpublished data); production costs requests, a maximum of 25,000/water will vary from year to year. Due to the unique be stocked. life history of black bass, stocking of fry is Frequency Three consecutive years. not recommended. Male bass guard their Evaluation - If natural reproduction is not nests and, after the fry hatch, continue to reestablished after 6 years from the onset guard fry schools until they break up of stocking, discontinue stocking until (generally by about July). When bass are action is taken to identify and correct the needed for rehabilitation stocking, either reason(s) for the poor natural recruitment. fingerlings or adult transfers are suitable choices. While we do not currently have 2. Evaluation: Very little need exists to conduct specific estimates for survival of stocked evaluations of bass stocking; we do not recom- bass and subsequent cost-effectiveness, we mend development of projects or requests for know that many bass populations have been evaluation quotas. successfully reestablished through stocking in reclaimed lakes throughout the state. 3. Remediation or Recreation: We do not Reestablishment of a self-sustaining popula- recommend development or maintenance of tion is an extremely cost-effective practice bass fisheries dependent upon stocking due to because it results in a population that is not the expense, the ubiquitous nature of bass, and dependent upon further stocking. Subse- availability of populations throughout the state. quent recruits to the fishery are free and, Other management activities should be pursued when cost-averaged, the initial stocking to enhance natural reproduction. becomes more and more cost-effective through time as benefits continue to accrue Projected Demand for Black Bass. - The commit- from a relatively small one-time investment. tee recommends, based upon current scientific evidence (much of which was presented in the Currently, we have very little flexibility in Introduction), that maintenance stocking of bass our propagation program to produce the not be used where the potential exists to impact numerous strains of bass needed to protect the genetic integrity of self-sustained bass the genetic integrity of native bass stocks. populations. Further, we do not recommend Any attempt to increase the stocking of bass increased investment in bass propagation unless without compromising their genetic integ- strain management can be done in a cost- rity will be considerably more expensive effective manner. This shift in management than the current $0.07 / fingerling, which philosophy is anticipated to reduce the current will affect the cost-effectiveness. demand by about 33% for largemouth bass and 94% for smallmouth bass. The annual demand 17 500 LMB SMB

400

300

200 (T housands) Fingerlings

100

0 1990 1992 1994 1996 1998 2000 2002 2004

Figure 5. Recent and projected demand for largemouth and smallmouth bass fingerlings, 1990-2005. for largemouth bass over the next 5 years is their historic presence on the Menominee expected to be 150,000 to 200,000 fingerlings. Reservation. Appendix Table 1 describes the (Figure 5). The committee did recommend current stocking guidelines for lake sturgeon. adding the option of stocking adult bass in These stockings have all been conducted for order to rehabilitate self-sustained popula- restoration purposes under the following tions, but these stockings would result from assumptions: 1) The lake or stream is consid- field transfers and will not impact the hatch- ered to be part of the original range; 2) No ery system. sturgeon exist there now or reproduction is absent or drastically reduced; and 3) There is a LAKE STURGEON STOCKING GUIDELINES reasonable possibility of developing a self- Lake sturgeon propagation began only re- sustaining population through natural repro- cently (late 70s) in Wisconsin and was pio- duction. neered by the hatchery staff at the Wild Rose Hatchery and fisheries management personnel Specific Management Goals for Lake Sturgeon. in Oshkosh, with assistance from Sturgeon for - Wisconsin fisheries biologists manage lake Tomorrow and the University of Wisconsin sturgeon to: Center for Great Lakes Studies. The propagation of lake sturgeon from the Winnebago I. Preserve and enhance existing naturally system in the form of eggs, fry, and fingerlings reproducing populations. has contributed to lake sturgeon management and restoration programs throughout the II. Re-establish populations in waters within Great Lakes states. Eggs, fry, and fingerlings their original range. have also been instrumental in bioenergetics, virology and cell culture, aquaculture, devel- III. Develop harvestable surpluses through opment and chemical registration projects. natural reproduction.

Sturgeon stocking in Wisconsin waters is a IV. Provide sport angling opportunities to relatively recent activity. Lake sturgeon were harvest the surpluses. stocked in the Menominee River and the waters of Lake Superior in the early 80s. Since V. Cooperate with other states in their efforts that time, there have been additional stockings to re-establish lake sturgeon populations in in the Wisconsin, Flambeau, Namekagon, and appropriate waters. Chippewa rivers. More recently, they have been stocked in the Wolf River above Keshena Cost-Effectiveness of Lake Sturgeon Stocking as part of an attempt to bring sturgeon back to In 1998, approximately 64,000 lake sturgeon 18

were propagated at the Wild Rose Hatchery. tion purposes only. Fry and fingerlings used in Propagation costs (e.g, obtaining and these restoration projects (i.e., stocking and spawning wild stock, egg incubation and transfers) must be obtained from waters hatching, rearing and feeding), stocking within the same basin. Inter-basin stocking costs, and administrative overhead totaled and transfer are no longer acceptable prac- $26,500 ($15,000 donated by Sturgeon for tices. Tomorrow, a private conservation organiza- tion). Rearing costs per thousand fish were Stocking procedures, rates and frequencies. - estimated at $414 or $0.41 per fish. This Stocking procedures include scatter planting estimate represents the propagation, rearing, fry or fingerlings, after acclimation, over fine and stocking of fish into the Menominee, sand, course gravel, or boulders. Planting in Wisconsin, Flambeau, and St. Louis rivers, and around vegetation is discouraged. The and propagation and rearing only from the biological characteristics of lake sturgeon Wolf River. (slow growing, late maturing), dictate that stocking occur for at least 25 years (time Because of the recent interest in sturgeon needed for females to reach sexual maturity). stocking and the lack of information on its Considering the extended duration of stocking effectiveness, biologists are incorporating required, the following rates are recom- stocking evaluation methodologies into their mended (see also Appendix Table 2): Fry sturgeon work. For example, we currently stocking, in most cases, has been reduced in have a cooperative project with the states of favor of fingerling and yearling stocking Michigan and Minnesota on stocking (large 3-6 fingerlings at 80/mile or 0.5/acre; sturgeon obtained from the Sturgeon River Yearling >6 at 40/mile or 0.25/acre) or in the in Michigan (a Lake Superior source) into case of adult transfers, the genetic literature the St. Louis River. All the sturgeon that are suggest 200 fish as the minimum number for a stocked in the project area receive a double viable population. micro tag. We anticipate expanding this micro-tagging statewide as we begin to Projected Demand for Lake Sturgeon. - In the evaluate our sturgeon stocking program. 90s, lake sturgeon quotas ranged from 20,000- We also have ongoing a small study to look 50,000 a year. Quota demands will likely at tagging procedures and tag retention for increase over the next few years as additional fingerling sturgeon at the Wild Rose hatch- restoration opportunities arise and interest in ery. We will be tagging the fish and holding improving fish passage at dams increases. The them at the hatchery to provide some insight projected demand will range from 55,000- on the effectiveness of the tagging proce- 90,000 sturgeon (Figure 6). The sturgeon dures. propagation program at Wild Rose is currently funded in large part (~$10,000) by Sturgeon Recommended Stocking Guidelines. - Lake for Tomorrow, a private conservation organi- sturgeon are currently stocked for rehabilita- zation.

40 (T housands) Fingerlings 30

0 1990 1992 1994 1996 1998 2000 2002 2004

Figure 6. Recent and projected demand for lake sturgeon fingerlings, 1990-2005 19

MUSKELLUNGE STOCKING GUIDELINES fingerling stocking of twice the annual harvest Little was known about the abundance of was recommended. Otherwise, a standard muskellunge in Wisconsin at the beginning of rate of 2 fingerlings per acre was used. A th the 20 century; at this time, native muskel- certain amount of stocking at this rate was lunge were apparently confined to lakes and conducted to assure adequate spawning stock streams at the headwaters of the Chippewa, in prime waters and to remediate for the loss Flambeau, Black and Wisconsin Rivers. About of spawning habitat. By 1970, the species 20 counties were believed to contain muskel- inhabited about 33 counties in all geographic lunge. The artificial propagation of muskel- areas except the extreme southwest. This lunge in Wisconsin was initiated in 1899 at expanded range was primarily a result of Woodruff. For over 25 years, little effort was stocking. directed toward rearing muskellunge beyond the sac fry stage. Up until about 1941, 18 Current stocking practices.- Since 1970, an seasonal hatcheries in northern Wisconsin average of 128,747 large fingerlings have been produced from several thousand to 28 million stocked annually. In the last 4 years, since the fry annually. Nearly all muskellunge were renovation of the two major muskellunge stocked shortly after hatching from eggs hatcheries, an average of about 72,000 muskel- incubated in jars. The rearing of muskellunge lunge have been stocked annually. Recent to fingerling size in ponds was attempted renovations, particularly the new plastic-lined sporadically from 1926 to 1938 with little rearing ponds, have resulted in a learning success. curve for hatchery managers. During 1998, the department stocked 90,177 muskellunge. A decline in muskellunge populations was The hatchery at Woodruff had an excellent observed concurrent with the growth of sport year after 5 years of trial and error. Managers fishing activity following World War II. at the hatchery in Spooner dont anticipate Although the exploitation of muskellunge long-term problems and expect improved populations by anglers was not documented, production once they fine-tune their fry it was generally believed that the annual stocking rates in rearing ponds. harvest exceeded recruitment to populations through natural reproduction. From 1940 to Requests for muskellunge from 1995 to 1999 1970, improvements in the propagation have averaged about 141,000 annually, while program helped contribute to the recovery requests from 1983 to 1993 averaged about and maintenance of fishable muskellunge 157,000. At present, approximately 216 waters populations. Systematic procedures for pond (27% of Wisconsins 804 muskellunge waters) rearing of fingerlings were developed in the are regularly stocked with muskellunge to 1940s and the two major muskellunge hatch- maintain the fishery. eries went into full production by about 1950. The shift to raising larger fingerlings (8 to 15 Current stocking practices are listed in Appen- inches) occurred in 1954, when 2 to 6 inch dix 1. Existing stocking practices under the fingerlings were cropped off and remaining Remediation and Recreation strategies, by far fish were reared to a larger size and stocked by the most common strategies, are presented in October. Table 6, along with the number of waters within each stocking strategy. By about 1970, about 30% of the muskellunge waters were stocked annually with large fingerlings. Refinements in stocking proce- Specific Muskellunge Management Goals and dures resulted in targeted plantings in critical Objectives.- problem waters. These specialized stocking situations included waters faced with heavy I. Protect and enhance Wisconsins self- depletion by angling, excessive competition sustained muskellunge populations. with northern pike, loss of spawning areas, A. Identify and protect existing spawning natural catastrophes, and stocking waters that and nursery habitat. had been reclaimed with toxicants. When B. Protect the genetic integrity of self- actual catch from a given lake is known, a sustained muskellunge populations. 20

II. Manage Muskellunge for a variety of hooking and handling mortality and unique fishing opportunities interactions with other species.

A. Trophy fisheries Increase catch of IV. Minimize User conflicts. 50+ fish. B. Action fisheries Maintain catch of 1 A. Provide unique, aesthetic fishing muskellunge/25 hour of angling. experiences. C. Improve existing Class B and C waters. Costs and Cost-effectiveness of muskellunge D. Terminate management in waters stocking. - The cost to produce and stock not suited for muskellunge, where muskellunge increases considerably with size, management activities have not resulted from about $1.36/1000 fry (WLAB 1997) to in fishable populations, and where about $5.20/spring yearling (Margenau 1992) supported due to impacts to other (Table 7); production costs can also vary consid- desirable species. erably from year to year (Margenau 1992). Cost- effectiveness is measured as the cost per stocked III. Increase available information for fish that is recruited to the fishery (i.e., of muskellunge fisheries and educational catchable size). Cost-effectiveness could also be efforts to inform anglers about the status measured as the cost per fish caught or har- and management of muskellunge fisheries. vested by anglers. The cost-effectiveness of stocking various sizes of muskellunge varies A. Monitoring Establish long-term considerably among waters and years due to trends waters; conduct regular angler variability in survival and variability in produc- surveys. tion costs. B. Evaluation Develop an index of natural reproduction; define and In general, stocking fewer large fish has been develop criteria to identify self-sus- shown to be more cost-effective than stocking tained populations; conduct a many small fish. For example, with muskel- comprehensive stocking evaluation. lunge fry stocking, the costs are relatively low C. Education - Continue to focus on the but the survival of fry is highly variable and the value of catch and release; provide likelihood of any muskellunge surviving at all in technical assistance to cooperators on any given year is very low (Hanson et al. 1986).

Table 6. Number of waters under the current muskellunge stocking practices for fall fingerlings under Remediation and Recreation strategies (priority 3 and 4 maintenance). Note: 22 waters are currently affected by the 2,500/water maximum; 10 are currently stocked at < 1 per acre (listed below) and 12 are currently stocked between 1 and 2 per acre. Note: 12 waters under Rehabilitation (priority 1 introductions; 3 waters) and Research (priority 2 evaluations; 9 waters) strategies are not included.

Nominal stocking rate (number/acre)

Frequency 0.1 0.2 0.3 0.4 0.5 1 2 Total

Annual 1 4 1 1 5 32 10 54 Alternate 0 2 1 0 4 80 75 162

1 2 3 4 5 Total 1 6 2 1 9 112 85 216

1 2 Petenwell Flowage, St. Louis River, Turtle-Flambeau Flowage, Lake Koshkonong, Chippewa Flowage, Castle Rock 3 4 5 Flowage, Lake Wisconsin, Lake Wissota, Shawano Lake, Holcombe Flowage. 21

Given a survival rate of 0.004% to fall (Hanson more consistent return on investments in et al. 1986) and a survival rate of 4.2% from stocked fish. The less time the fish is at-large the first fall to the next fall (at 18 months of when it is small and vulnerable to a whole age; Margenau 1996), 588,235 fry would need host of sources of mortality, the higher its to be stocked to result in 1 surviving muskel- chances of survival and eventual contribution lunge, at a cost of about $800.00 per muskel- to the fishery. lunge. Cost effectiveness of fall-stocked fingerlings to 18 months of age averages about Recommended Stocking Guidelines. - To fully $70.75 per surviving muskellunge. Cost per attain the above objectives that relate to spring-stocked yearling muskellunge surviv- stocking (I.B., II.B, C., and D), we recommend ing to 18 months of age averages about $27.42 obtaining better information on the efficacy of per muskellunge. our stocking practices (goal III.B.). One of the key goals of the 1979 management plan These estimates are based on averages: (WDNR 1979) was to evaluate our stocking because survival and production costs vary practices (stocking rates and frequencies), yet considerably from year to year, the cost- we have very little additional information effectiveness should be evaluated over several available at this time. Therefore, the recom- years on an individual water in order to get an mended stocking strategies and practices, accurate estimate. Also, WDNR Fisheries listed in priority order and summarized in Biologists routinely use professional judgment Appendix B, are as follows: when they determine what size of fish is most appropriate for stocking on specific waters. 1. Rehabilitation: Waters Winter-kill lakes Their primary concern is to maximize survival should not be stocked if serious mortality of stocked fish, which obviously improves occurs more frequently than once in 15 years cost-effectiveness. For this reason, the depart- unless a plan to minimize the risk of future ment often uses fry stocking in winterkill or winter-kills is developed and approved. reclaimed lakes that are free of predators, and stocks larger sizes in waters having well Size of Fish Either fry or small established fish communities with a variety of fingerlings (4-6) the first year, followed natural predators. The reason stocking is by large fingerlings (> 7) or adult even economical at all rests in the fact that the transfers in subsequent years. cost per survivor can be very inexpensive in Source of fish Same waterbody, if certain years when survival of stocked fish is possible, otherwise basin stock . excellent and production costs are low, so it is Stocking rate Fry 500/acre; small cost-effective over a longer time period. A fingerlings up to 5/acre; Large fingerlings further benefit of stocking larger fish rather up to 2/acre. If production is unable to than smaller fish is that the variability in meet all quota requests, a maximum of survival for larger fish is lower from year to 100,000 fry, 5,000 small fingerlings or 2,500 year (i.e., more likely to have at least some large fingerlings will be stocked per water. survival; e.g., Hanson et al. 1986), providing a

Table 7. Estimated cost-effectiveness for stocking different sizes of muskellunge.

Survival rate Number Cost per Production cost to 18 months stocked/ survivor Muskellunge size per fish of age survivor to 18 months

Fry $1.36/1000 0.00017% 588,235 $800.00 Fall fingerlings $2.83 4% 25 $70.75 Spring yearings $5.21 19% 5 $27.42 22

Frequency Fry or small fingerlings the requests, a maximum of 5,000 small first year, then large fingerlings for 4 fingerlings or 2,500 large fingerlings will years. be stocked per water. Evaluation - If natural reproduction is Frequency Small fingerlings or large not reestablished after 10 years from the fingerlings annually or in alternate onset of stocking, discontinue stocking years. until action is taken to identify and Evaluation - If the fishery objective is correct the reason(s) for the poor natural not met after 10 years, discontinue recruitment. stocking until action is taken to identify the reason(s) for poor survival. 2. Research: Stocking sizes and frequencies as needed to realistically meet the objectives No dramatic changes are recommended in the of the evaluation project. current recreational stocking practices because no compelling scientific evidence for change 3. Remediation or Recreation: Waters - exists. However, this does not mean that Based on evidence provided by Fields et al. inefficiencies do not exist or that improvements (1997), we recommend that no stocking are not needed, just that we lack adequate occur in waters with adequate natural information at this time. In order to obtain the reproduction, in order to minimize the information needed to sufficiently evaluate our potential negative impact of stocked fish on stocking practices, we recommend establishment naturally reproducing populations in the of a management framework to allow a compre- receiving or connected waters. hensive evaluation of our stocking practices. We propose to assign each of the 220 stocked Size of Fish Either small fingerlings muskellunge waters to a specific stocking (4-6) or large fingerlings (> 7), practice for 10 years (Table 8). During this depending upon abundance of existing period, we will assess these fisheries through predators. existing survey efforts. This will allow us to Source of fish Basin stock. evaluate the effectiveness of various rates Stocking rate Small fingerlings up to (number of muskellunge per acre) and frequen- 5/acre; large fingerlings up to 2/acre. If cies (annual, alternate years, etc.) for fall finger- production is unable to meet all quota ling stockings in a variety of waters.

Table 8. Hypothetical muskellunge stocking framework for fall fingerlings under Remediation and Recreation strategies (maintenance - priorities 3 and 4). Note: 12 waters under the Rehabilitation strategy (priority 1 introductions; 3 waters) and Research strategy (priority 2 evaluations; 9 waters) are not included.

Treatments (Nominal stocking rate; number/acre) Stocking Frequency 0 0.5 1 2 Total

Cease 30 (0) - - - 30 (0) Annual - 30 (4) 30 (32) 30 (10) 90 (54) Alternate - - 30 (80) 30 (75) 60 (162) Every fourth year - - - 30 (0) 30 (0)

1 2 Total 30 (0) 30 (19 ) 60 (112 ) 90 (85) 210 (216)

1 Ten of these waters are currently affected by the per-water-maximum: Petenwell Flowage, St. Louis River, Turtle- Flambeau Flowage, Lake Koshkonong, Chippewa Flowage, Castle Rock Flowage, Lake Wisconsin, Lake Wissota, 2 Shawano Lake, Holcombe Flowage. Twelve of these waters are affected by the per-water-maximum. 23

We will be working with regional Fisheries over the last year have confirmed that several Biologists over the next year to refine the biologists have been requesting fewer fish details of this framework, assign waters to because higher size limits, and increased categories, and phase this plan in by 2000. voluntary release of legal-sized fish by anglers Therefore, we anticipate reviewing these has reduced mortality and resulted in higher stocking practices after 2005, with potential densities of adult muskellunge. Also, higher recommendations for changes after 2010. This quality (larger) fingerlings from the hatcheries approach will 1) allow long term, consistent have higher survival and have reduced the application of experimental treatments, 2) numbers needed to improve fishing. There- provide a long-term production target for the fore, demand for muskellunge fingerlings may hatchery system, 3) aid the hatchery system in decline somewhat regardless of changes in development of basin-specific stocks, and 4) stocking policies. greatly reduce annual workload related to quota requests. Also, we recommend this framework remain somewhat flexible so NORTHERN PIKE STOCKING GUIDELINES managers can respond to interim changes in Fishing regulations for northern pike (Esox the population with changes in management lucius) have been in existence since the early strategies. Serious concerns can be reviewed 1900s. The early laws enacted by the Legisla- and addressed annually prior to the spawning ture were most likely based on the theory that period. fewer fish caught now will result in more available for future fishing. Size limits began Projected Demand for Muskellunge.- The in 1909 (12 minimum), bag limits in 1917 (15 st current demand for muskellunge has aver- daily), and closed seasons in 1935 (Jan 1 to th st th aged 138,000 fingerlings annually since the May 15 or March 1 to May 15 ). Frequent renovation of the two major warm water changes in the regulations in the early years facilities. Because we do not anticipate were often based on economic and social recommending major changes in our stocking considerations. There was little concern for practices over the next 10 years, no significant habitat. changes are anticipated in the demand for muskellunge fingerlings from the hatchery In the 1940s, a period of liberalized fishing system (Figure 7). However, we have observed regulations began for most species in the state; a trend toward lower requests in recent years. in 1953 the statewide minimum length limit Discussions with Regional Fisheries Biologists for pike was eliminated.

200

160

120

80 (T hous ands) Fingerlings

0 1990 1992 1994 1996 1998 2000 2002 2004

Figure 7. Recent and projected demand for muskellunge fingerlings, 1990-2005 24

Prevailing ideas of the time assumed high Maintenance. Stocking where evaluations have rates of total mortality, mostly due to natural shown success in establishing a viable fishery. causes rather than fishing. The first experi- Maintenance stocking may only be done in mental size limits began in the mid 1950s. waters having a history of poor natural repro- Evaluations of the regulations began to duction of northern pike. Growth rate of show that benefits size limits will vary, northern pike must be satisfactory in such depending upon exploitation rates, growth waters. Catchable size fish may be stocked for rates and structure of the fish community maintenance purposes, but only if fish become (Kempinger and Carline, 1978). It was available as a byproduct of another operation found unreasonable to assume that a single through field transfer. All maintenance stocking length limit could produce desirable results should be for put-grow-and-take management over a wide range of lake types and fishing not for put-and-take. Small fingerlings (3.5-5.5 pressure. inches long) may be stocked at a rate of no more than 5 per acre (maximum of 5,000 per water) Current Stocking Practices and Priorities.- and large fingerlings (>7 inches long) at a rate of Current stocking practices are summarized no more than 2 per acre (maximum of 5,000 per in Appendix Table 1. The current stocking water). guidelines are presented in detail below: Panfish Control. No stocking will be done Rehabilitation stocking and evaluation specifically for panfish control unless special projects requiring northern pike stocking. regulations are imposed to reduce northern pike Rehabilitation projects should stock fry harvest. (1,000/acre, maximum of 200,000 per water), followed by fingerling in the fall if Specific Management Goals and Objectives.- investigation show poor fry survival. The overall goal of northern pike management Fingerling may be stocked again the next in Wisconsin is to link the diversity of lakes and year, if desired. Small fingerlings (3.5-5.5 their pike populations to pike anglers diverse inches long) may be stocked at a rate of no attitudes and preferences. In the past manage- more than 5 per acre (maximum of 5,000 per ment actions primarily supported consumptive water) and large fingerlings (>7 inches long) interests among anglers. Today we recognize at a rate of no more than 2 per acre (maxi- that angler preferences and motivations for mum of 5,000 per water). Stocking adults northern pike fishing are diverse. One manage- (field transfer) to reproduce is also accept- ment approach cannot meet all anglers expecta- able. Winter-kill lakes that have serious tions. To account for different demands liberal mortality no more frequently than 2 times in harvest regulations may be maintained on many 10 years may be stocked. Winter-kill waters fisheries, elsewhere, regulations other than should only be stocked once after a mortal- traditional bag limits must be used to improve ity, but a second years stocking is permitted or maintain size-structures for larger fish. if the first survives poorly. For evaluation projects stocking sizes and frequency shall Likewise, lakes and their pike populations are be as required to realistically meet the ubiquitous and diverse. Northern pike popula- objectives of the evaluation project. tions are found in 2,874 waters, with 795, 1,697 and 382 occurrences in water <20 acres, 20-300 Initial Introductions. Fry should be acres and >300 acres, respectively. Growth rates, stocked, followed by fingerling later in the size-structures, and abundance of northern pike year if fry survival is poor. Fingerling populations vary widely from lake to lake. The stocking may continue for the following 2 average standing stock and biomass reported in years. Small fingerlings (3.5-5.5 inches long) selected Wisconsin waters is 7.3 fish/acre and may be stocked at a rate of no more than 5 9.2 lbs/acre, respectively. However, density and per acre (maximum of 5,000 per water) and biomass estimates ranged from 0.7 to 49 fish/ large fingerlings (>7 inches long) at a rate of acre and from <1 to 59 lbs/acre, respectively. no more than 2 per acre (maximum of 5,000 Characteristics of each lake (biological, chemical, per water). and physical) determine each pike populations, growth rate, size-structure and abundance. Wisconsin has a diverse spectrum of lakes that 25 cannot be managed similarly, but require Unlike muskellunge, northern pike tradition- different management strategies. ally have not been afforded significant protection. Managing pike in Wisconsin is changing; At one end of the spectrum are what anglers fisheries biologists utilizing this natural often refer to as hammerhandle lakes. These diversity to manage for quality northern pike, small, marshy lakes are loaded with aquatic not just on any water, but on those that are plants and spawning habitat for northern pike, best-suited for growing large northern pike. and are renowned for producing a lot of slow- growing, small northern pike. The pike are of Biologists have witnessed a decline in the an unacceptable size to many anglers. Panfish abundance and size-structure of northern pike and bass are common, however larger, soft- populations through many Southern Wiscon- rayed forage fish necessary for good pike sin waters. These declines are due to: 1) losses growth are absent. Competition between pike in spawning habitat through wetland drain- for available prey is severe, growth is limited, age, dredging, shoreline development and and most deaths in the population are the eutrophication; and 2) increased exploitation result of natural causes rather than fishing. from angling. Many eutrophic lakes of Northern Wisconsin have these characteristics. Past research and In southern Wisconsin habitat loss is often evaluations of fishing regulations and stocking typified by high phosphorus, turbid water, have shown that these actions will do little to dominance of algae, absent macrophytes, and improve the characteristics of northern pike dominance of benthivorus (carp and bullhead) in these waters. Here the fisheries manage- and planktivorus (crappie) fish. The alterna- ment objective is to manage populations for tive and preferred conditions are typified by consumptive angling opportunities (i.e., to seasonal windows of clear water where algae provide opportunities for anglers who value are heavily grazed, dominance of macro- retaining a meal of fish), though the average phytes, and a dominance of fish species size of pike caught will be smaller. closely associated with macrophytes (eg. bluegill, pumpkinseed, northern pike, and At the other end of the spectrum are waters bass). Restoration efforts often call for that are renowned for producing 10-25 lb. biomanipulation, water-level management, northern pike. These lakes are larger, cooler, and reduced phosphorus loads in attempt to deeper, and well oxygenated. Because of their shift from the turbid condition to a clear-water depth, and steeper shorelines, these lakes condition. Here the management objective is often have fewer marshy areas and less to rehabilitate/restore habitat and water aquatic plants for northern pike spawning. quality through biomanipulation and other Here pike are less abundant, however they management actions (aeration; long-term have the ability to grow to over 20 pounds. water level management; drawdowns; Their growth is good because larger, soft-ray landuse and nutrient controls; wetland forage fish (cisco, white sucker, redhorse) and protection/restoration; northern pike rearing yellow perch are generally abundant. Because marsh construction, boating restrictions, of good growth and less competition, fewer barrier islands, and temporary breakwaters to deaths in the population are the result of restore aquatic plants). Bio-manipulation and natural causes. These lakes can produce large rehabilitation involves some of the following pike, however angling pressure is considered actions: protecting piscivores like pike from the most important factor in determining harvest; northern pike stocking; chemical whether northern pike do well in these reclamation; stock suppression of carp using fisheries. Thats because angler exploitation is rotenone, and rough fish removal through a significant component of mortality among fishing contracts. pike populations of low or moderate density. Here the management objective is to manage Cost Effectiveness of Stocking Strategies for for quality- or trophy-sized pike, though catch Northern Pike. - Fry survival is extremely rates will be lower, and size limits are often variable and influenced by a host of factors quite restrictive. (climate, water levels, forage, temperature, amount of refuge from predators, etc.). Fry stockings following chemical rehabilitation 26

and winter-kill have provided excellent 8.5 in length; and 0.40 for pike 8.6-12 in survival of stocked fry and established length). These size-dependent survival esti- dense pike populations. A strategy of mates are taken from several studies of esocids stocking fry in these open environments (Hanson et al. 1986, Serns and Andrews 1986, (few predators and abundant food re- Wahl and Stein 1989, Szendrey and Wahl 1996). sources) has been shown to be the most cost- Winterkill lakes that have serious mortalities no effective approach. Where resident fish more frequently than 2 times in 10 years may be communities exist, we lack quantitative stocked. Winterkill waters should only be comparisons between fry and fingerling stocked once after a mortality, but a second pike cost-effectiveness. The estimated years stocking is permitted if the first survives proportion of pike surviving to the fall YOY poorly. For evaluation projects stocking sizes stage is dependent upon the size of pike and frequency shall be as required to realistically stocked; larger fish have significantly higher meet the objectives of the evaluation project. survival. Several general assumptions can be Stocking adults (field transfer) to reproduce is used to compare the cost-effectiveness of also acceptable. rearing and stocking pike at different sizes. Data taken from WLAB (1997) can be used Note: Acres of habitat are defined by estimates to approximate cost-effectiveness of stocking of total area that supported (remediation) or different sizes of fingerlings. Using size- would support (biomanipulation and dependent survivorship described above, rehabitation) emergent, floating-leaf, and the cost-effectiveness of small fingerlings submergent aquatic plants. (4) and large fingerlings (8) to fall YOY stage is estimated to be $2.11/pike and 2. Biomanipulation: This is a management tool $3.50/pike, respectively. Given the variabil- that involves increasing the biomass of preda- ity in the assumptions and factors which tors to alter the food web and, ultimately, influence survival of stocked fingerling pike, improve habitat or water quality. the difference between these two estimates Biomanipulation stocking typically involves is minimal. Since the differences are mini- additional actions like increasing length limits mal, other factors should be used to deter- for pike; protecting stocked fish from harvest, or mine stocking size. Size structure, density, supressing the numbers of benthivorus or and growth of the resident piscivore fish planktivorus fish. Biomanipulation projects community should be considered when must set and objective for desired endpoint for considering stocking size for fingerling pike. total acres covered by aquatic plants. Fingerlings If the potential for predation among the are the recommended size for stocking. The resident fish community is high (as evi- following equation should be used to determine denced by high CPEs of piscivores and slow fingerling stocking rates: Total number of growth) large fingerling should be stocked fingerlings to be stocked= total habitat acres X in the fall, under lower and favorable water desired density of fall YOY (use 10/acre of temperatures. habitat) / (estimated proportion of fish surviving to fall YOY which is size dependent: 0.09 for Recommended Stocking Guidelines (listed in pike 3.5-5.5 in length; 0.20 for pike 5.6-8.5 in order of priority) length; and 0.40 for pike 8.6-12 in length). Secondarily, biologists can chose to use fry 1. Rehabilitation: Rehabilitation projects instead of fingerling stocking: stock fry at a rate that involve complete chemical treatment of 1,000/ acre of habitat. should stock fry (1,000/ acre of habitat). Fingerling may be stocked the next year, if 3. Remediation: Stocking that seeks to desired. The following equation should be remediate loss of northern pike habitat to used to determine fingerling stocking rates: provide a fishery, and where a decline in the Total number of fingerlings to be stocked= northern pike population is evident. The total habitat acres X desired density of fall population decline should be reasonably shown YOY (use 10/acre of habitat; Klingbiel 1986) to be the result of habitat loss rather then over- / (estimated proportion of fish surviving to exploitation. Stocking under this category is fall YOY which is size dependent: 0.09 for recommended to be in conjunction with other pike 3.5-5.5 in length; 0.20 for pike 5.6- management actions (size-limits, land use and 27 nutrient controls; wetland protection/restora- mated proportion of fish surviving to fall YOY tion; northern pike spawning/rearing marsh which is size dependent: 0.09 for pike 3.5"-5.5" construction). All remediation stocking should in length; 0.20 for pike 5.6"-8.5" in length; and be for put-grow-and-take management not for 0.40 for pike 8.6"-12" in length). Careful put-and-take: total number of fingerlings to be considerations should be taken when stocking stocked= total habitat acres X desired density northern pike to provide an additional fishery. of fall YOY (use 10/acre of habitat) / (esti- Growth rates of existing piscivores and the mated proportion of fish surviving to fall YOY density of larger soft-rayed forage need to be which is size dependent: 0.09 for pike 3.5-5.5 carefully considered. Stocking of northern in length; 0.20 for pike 5.6-8.5 in length; and pike has a potential for negative consequences 0.40 for pike 8.6-12 in length) X (the propor- due to inter-specific competition and predation of spawning habitat lost or the historic tion impacts on other species. Major changes proportion of stocked fish contributing to the in existing fish assemblages can occur when fishery). Catchable size fish may be stocked piscivorous fishes are introduced into new for maintenance purposes, but only if fish locations. Several years of stocking winter become available as a byproduct of another rescue northern pike had negative effects on operation through field transfer. the fish community of Horseshoe Lake Minne- sota. The artificially induced increase in 4. Recreational Pike Fisheries: Stockings in northern pike population was followed by a this category are where pike is managed to sharp declines in the yellow perch, largemouth provide angling opportunities for an addi- bass, and walleye populations. The Horseshoe tional species. All stocking should be for put- Lake bluegill population eventually exploded grow-and-take management not for put-and- and their growth rates became stunted, take. Fingerling stockings are recommended. providing a very marginal fishery. Nineteen For recreational pike populations, a density years later the Horseshoe Lake fish commu- range of 1-3 YOY pike/habitat acre is recom- nity has not yet recovered . mended. The total number of fingerlings to be stocked= total habitat acres X desired density Projected Demand for Northern Pike. Due to of fall YOY (use 1-3/acre of habitat) / (esti-Northernthe uncertain pike timing of major rehabilitation R ecent and P r edi cted Demand 240 24 Recent (actual) Predicted

200 16

Fry 160 8 Fry (millions)

120 0 S mall fingerlings (Millions) (T housands)

80 -8

40 -16 Large fingerlings

F ingerlings (thous ands ) 0 -24 1990 1992 1994 1996 1998 2000 2002 2004

Figure 8. Recent and projected demand for northern pike fry and fingerlings (small and large), 1990-2005 28

projects, quota requests for northern pike all walleye stocked in the state were from the vary considerably from year to year, espe- Winnebago system. Propagation efforts moved cially for fry. Projected demand for fry is north and expanded to cover the entire state approximately 8 million per year. Priority during the early 1900s. By the year 1910, there and policy changes now place greater had been 77,904,996 walleye stocked in Wiscon- biological emphasis on size dependent sin. Walleye were probably originally found in survival of stocked pike, quantification the large river systems and large drainage lakes (actual or projected) of northern pike throughout Wisconsin. Most walleye popula- habitat, biomanipulation, and remediation tions found in small drainage and seepage lakes projects. Because projections are largely were probably the result of the walleye stocking based on historic quota requests, develop- program. Some of these waters have established ment of a field staff mock quota exercise self-sustained walleye populations, others are will be required to further refine the esti- maintained through continued stocking, and mates of projected stocking demand for others contain remnant populations that are not northern pike. The per-water-maximums are likely to improve. Because of the long history of no longer recommended, but the rates are walleye stocking, we do not fully understand the now tailored for individual waters based on effects of our stocking program on native surface acres of suitable habitat. Increases in walleye stocks. However, considerable regional demand are anticipated. The average genetic diversity still exists despite our past projected demand for northern pike fry is stocking practices. 7.8 million; small fingerlings is 80,000; and large fingerlings is 70,000 (Figure 8). These Large numbers of fish were stocked throughout estimates are based on projected increases in the state, with little or no evaluation of success. stocking rates for rehabilitation, remediation In the late 1950s and early 1960s, the efficacy of and biomanipulation projects, many of stocking practices were scientifically examined. which use fry stocking. However, if poor fry Evaluations of the size at fish stocked, survival survival is evident, fingerling demand could of stocked fish, and development of manage- be greater. For example, assuming a fall ment goals and objectives resulted in changing YOY objective of 10 pike/acre of habitat for emphasis from stocking all waters with fry to a remediation project with 50% spawning developing individual lake recommendations. habitat loss and 30% of the lake as suitable These recommendations included the size, pike habitat, the stocking rate for small number and frequency of walleye stocking. fingerlings would be about 16.7 small Improvements at both major walleye hatcheries, fingerling/acre. With the same assump- increased concern about detrimental effects of tions, large fingerling stocking demand walleye stocking on other species and on would be 3.75 large fingerling/acre. This genetically distinct walleye stocks, as well as a represents a substantial increase in stocking need to examine the cost-effectiveness of various rates for small and large fingerlings. Many stocking practices, led to the recent review of biomanipulation projects take place in walleye stocking practices. shallow lakes. Here, assuming 65% of the lake area is pike habitat, with no natural Walleye stocking success is highly variable and reproduction and a fall YOY objective of 10 is difficult to predict. There are variations in pike/acre of habitat, the stocking rate for stocking success, just as there are year-to-year small fingerlings would be 72/ lake acre, fluctuations in natural reproduction of walleye. which would also be a substantial increase Available stocking evaluations suggest that only in the stocking rate. about 50% of new stockings are effective in creating walleye populations (reviewed in Kampa and Jennings, 1999). Maintenance and WALLEYE STOCKING GUIDELINES enhancement efforts generally have even lower The fisheries management program has a success rates; walleye stocking to maintain long history of propagating and stocking populations has a lower success rate. About 85 walleye throughout the state. This program % of fry stockings result in no measurable year began in the late 1870s, with the first class (WDNR unpublished data). Waters walleye propagated from the Lake supported entirely by stocking have much lower Winnebago system. Until the early 1900s, walleye densities, and anglers catch walleye at a 29 substantially lower rate than from waters natural reproduction should not be stocked. supported by natural reproduction (see Figure Although there have been no field evaluations 2, page 3). on the genetics effects of stocking walleye, we could be causing more harm than good. We have identified genetically distinct walleye Recent research in Minnesota suggests that populations throughout the state. Based on stocked walleye suppress adjacent year this information, distinct stocks are delineated classes, resulting in no net benefit to the in Figure 9. Although we are able to deter- fishery. Most of the scientific evidence on mine genetic differences among stocks, it is stocking is relatively new in comparison to unclear whether differences in growth, fecun- our stocking program. In the future, more dity, or survival have occurred. If genetically emphasis needs to be placed on the rigorous distinct walleye populations exhibit perfor- evaluation of the cost-effectiveness of stock- mance differences (which we suspect they do), ing. mixing of these stocks could result in outbreeding depression and lower fitness of the Walleyes are a top predator, and can have a population. Genetic fitness could directly significant impact on the structure of fish affect cost-effectiveness of the propagation communities. While there have been few program. Evaluations of stock-specific experiments on the impact of walleye stocking performance and fitness differences among on fish communities, there is some anecdotal waters are underway in Wisconsin and should evidence that suggests negative interactions help to better assess benefits and risks of between bass and walleye. For example, after alternative stocking strategies. the initiation of walleye stocking, Escanaba Lake converted from a smallmouth bass- dominated fishery to a walleye dominated fishery. Conversely, the presence of bass is suspected to reduce the chances of successful walleye stocking. When walleye stocking is successful, the fish community structure is likely to change. There will likely be a change in the other predators. The net influence may be viewed as positive or negative, depending on the management objective for the specific water. Of course, the reverse is also true; other species can impact walleye populations and can seriously hinder walleye stocking efforts.

Specific Walleye Management Goals.-

I. Protect, develop, maintain, and restore critical habitats for natural walleye stocks.

II. Provide a variety of opportunities for the catch and harvest of walleye.

III. Ensure that adequate information on the Figure 9. Major Wisconsin basins recommended as walleye brood sources. status and trends of walleye populations is available.

IV. Maintain the genetic integrity of naturally The implications of genetically distinct stocks, reproducing walleye populations. along with recent research showing some negative impacts of stocking on naturally V. Provide educational opportunities to reproduced walleye year classes (Li et al. develop appreciation of Wisconsins fishery 1996), suggest that lakes with adequate resources. 30

Costs and cost-effectiveness of walleye of summer-stocked fingerlings to fall averages stocking practices. The cost to produce $7.44 per surviving walleye. Cost per large and stock walleye increases considerably fingerlings and extended growth walleye to the with size: $0.56 / 1,000 fry; small fingerling creel averaged higher than the small fingerlings at $0.04/fish; large fingerling at $0.18/fish; (Kampa and Jennings 1999). We estimated 33% and extended growth fingerlings at $4.47/ survival from age 0 fall to age 1 fall; and 49% fish (WLAB 1997)(Table 9). Production costs survival from age 1 to age 3 (recruitment into can vary considerably from year to year for the fishery) for fry and small fingerlings. the fingerling sizes that require additional forage fishes to be provided. Cost-effective- Tailoring our stocking efforts for water-specific ness is measured as the cost per stocked fish conditions improves the cost-effectiveness of that is recruited to the fishery (i.e., of walleye stocking. On average, small fingerlings catchable size). Cost-effectiveness could tend to be the most cost-effective size for stock- also be measured as the cost per fish caught ing. However, many stocked waters have or harvested by anglers. The cost-effective- shown limited survival of small fingerlings in ness of stocking various sizes of walleye the summer. Up to 30 % of stocked waters in varies considerably among waters and years some areas may show no contribution to the due to variability in survival and variability fishery from stocking small fingerlings (Rick in production costs. Cornelius, personal communication). Whether predation by other fishes or warm water tem- For walleye, stocking fewer large fish has peratures are the cause, larger fingerlings or not been shown unequivocally to be more extended growth fish may be the more appropri- effective than stocking many small fish (Kerr ate option in such waters. There is evidence that et al. 1996). However, some circumstances larger walleye survive better and return more may require the stocking of larger fish to fish to creel in certain situations. However, improve survive if predation by other fish because it costs significantly more to raise larger on walleye fingerlings is a major limiting fish, very selective use of these fish is warranted. factor. With walleye fry stocking, the costs Similarly, evidence from southern Wisconsin are relatively low but the survival of fry is lakes indicates that stocking walleye fry is often highly variable and the likelihood of any successful in lakes with low water clarity. Even walleye surviving at all in any given lake is in clearer lakes in northern Wisconsin, fry also very low (Kampa and Jennings 1999). stockings have been successful for rehabilitating Given a survival rate of 0.015% for fry to fall winter-kill lakes. It can be very cost-effective to (S. Hewett, unpublished data, 1998) 41,667 stock fry in certain situations, such as in lakes fry would need to be stocked to result in 1 with turbid waters or in winter-kill lakes that surviving walleye to the creel, at a cost of lack predators. Water specific stocking plans about $ 23.33 per walleye. Cost effectiveness and subsequent evaluations are, therefore, the

Table 9. Estimated cost-effectiveness for stocking different sizes of walleye.

Survival rate Number Cost per Production cost to 3 years stocked/ survivor Walleye size per fish of age survivor to age 3

Fry $0.56/1000 0.0024% 41,667 $23.33 Small fingerlings $0.06 0.81% 124 $7.44 Large fingerlings $0.18 1.62% 62 $11.16 Extended growth fingerlings $0.65 5.7% 18 $11.70 31 most efficient means of maximizing cost- years prior to further stocking. An effectiveness. evaluation of fingerling stocking should be done. Initial evaluations should Traditionally, nearly all walleye were hatched consist of fall electrofishing subsequent at either the Spooner or Woodruff hatchery to stocking or during years when systems. Before the renovations at these stocking does not occur, to evaluate hatcheries, most walleye were raised off-site in natural reproduction. Further, a survey leased ponds. Travel costs have been reduced should be done to assess survival of because most walleye are now raised on stocked fish to reproductive age. This hatchery grounds. However, costs to stock survey should be completed after walleye in the southern part of the state have sufficient time has passed to allow been high due to transportation costs from the multiple year classes to mature and be northern hatcheries. With recent changes in present. If adequate survival is not the propagation system, walleye for the found, rehabilitation stocking can southern part of the state are now being continue for 2 more years, after the hatched and raised at Lake Mills, lowering spring survey. After this initial distribution costs, which should improve cost- rehabilitation period is completed, an effectiveness. assessment of natural reproduction should be made. If no natural Recommended Stocking Guidelines (listed in reproduction is found, and the decision priority order).- In general, we recommend is made to continue management as a flexibility in the size of walleye available for stocked water, the water will be moved stocking to assure that the most cost-effective to the Recreation category.. Stocking stocking techniques are used and so that we should be discontinued if significant can use the latest information on stocking natural reproduction is found and if the practices to ensure that success is not limited management strategy for the water is by stocking practices. Recommended stocking changed from a rehabilitation to a practices for walleye, summarized in Appen- natural reproduction water. dix A, are as follows: 2. Research/Evaluation: Stocking practices 1. Rehabilitation; Remediation: Waters - should vary depending upon the objectives of Winter-kill lakes should not be stocked if the project. An existing or approved funded serious mortalities occur more frequently than evaluation project is required. twice in 10 years. Walleye are not recommended for lakes with more frequent winter- 3. Recreation (Maintenance): Waters Existing kills because walleye are sensitive to low waters with maintenance stocking. New oxygen concentrations and development of a maintenance quotas will be established only fishable population is unlikely. after investigation shows growth is satisfactory and there is little or no natural reproduc- Size of fish - Fry should be stocked the tion for at least 3 years. For walleye to be first year. If investigation shows poor introduced into new waters, an Environmental survival of stocked fry, 2"+ fingerlings Impact Assessment (EIA) will need to be should be stocked in subsequent years. prepared. If the EIA indicates no impact on Source of fish - Same waterbody, if pos existing species, then new introductions can be sible, otherwise basin stock. made. Stocking rate - There is some concern that current stocking densities might not be Size of fish Fingerlings (2+) or fry. adequate to develop a self-sustaining Source of fish - Basin stock for drainage walleye population. Therefore, we lakes and rivers; Basin stock for land recommend higher stocking rates, as locked lakes, if available. follows: 1,800/acre (fry) or 100/acre Stocking rate Up to 1800 fry/acre; up to (2"+ fingerlings). 100 - 2 fingerlings/acre Frequency - Annually for 5 years. Frequency Annual for fry; alternate Evaluation criteria - Rehabilitation years for fingerlings. Fingerlings may be efforts should be evaluated within 10 32

stocked annually for 4 years in new Projected Demand for Walleye.- The number of introductions. walleye requested by managers has increased Evaluation - Existing maintenance steadily since 1990 (Figure 10). Here, we focus stocking programs should be evaluated on fingerlings because this is the most common every 5-7 years and discontinued if not size used for stocking; the number of fry pro- successful in developing a fishery after 4 duced is typically only limited by demand, years of stocking fingerlings. Initial except in southern Wisconsin, where a consistent introductions should be evaluated at the egg source has not yet been identified. During start of year 5 prior to further stocking. the 1990s, quotas have ranged from about This evaluation should include an 2,000,000 to 5,400,000 fingerlings. Two of the assessment of impacts to other species. major recommendations of this report are 1) to If adequate survival is found, stocking eliminate the per-water-maximums for walleye, may continue for 2 more years. At and 2) to increase the stocking rates for all sizes that time, alternate year stocking should of walleye. We have 2 years of experience under commence to allow for evaluation of these new guidelines that suggest that the natural reproduction. If no natural demand for walleye will increase. The projected reproduction is found, stocking should number of fingerlings needed for management follow the above strategy. purposes is 5,600,000. We anticipate that the Production shortfalls - If there are quota requests will level off now that the new shortfalls in production, cuts will be guidelines are in place. Another notable change made from the bottom up. Regions relates to year-to-year fluctuations in demand. should develop their own priority Prior to the new guidelines, quota requests from system for Recreation Stocking waters. one year to the next varied by about 2 million fingerlings. After 2 years under the new guide- 4. Additional recommendations: A) Sauger lines, annual fluctuations appear to be much should not be stocked into waters with less. Demand for large (4+) fingerlings is naturally reproducing walleye populations. projected to further increase as we increase our Saugeye (walleye x sauger hybrids) efforts to evaluate the use of these fish for should not be stocked into any Wisconsin management purposes. We anticipate that the waters. B) Develop methods and proce- demand for large fingerlings will exceed 1 dures to ensure that all stocked walleye are million by 2005. marked to allow for reliable evaluation of our stocking practices. 7

6 2"+ Fingerlings

(Millions) 3 F ingerlings 2 5" + F ingerlings 1

0 1990 1992 1994 1996 1998 2000 2002 2004

Figure 10. Recent and projected demand for walleye fingerlings, 1990-2005. 33

III. SUMMARY AND RECOMMENDATIONS quota system in order to accurately assess demand. Risks associated with projections.- The projections contained in this report are based Define Self-sustained. - Many of the recom- on a combination of past stocking practices mendations in this use the term self-sus- and best professional judgment. Historically, tained to characterize fisheries supported by the demand for hatchery fish has been based natural reproduction. We need to ensure that partially on public expectations and percep- population characteristics indicative of self- tions and, to some degree, on available supply. sustained populations are identified and well Projections based on historic supply are defined. constrained by past hatchery practices which, while untested, could be modified consider- Long-term quotas.- We recommend the ably to meet demand. This is the first contem- establishment, where feasible, of stocking porary attempt by DNR to estimate demand plans with long-term quota requests for for hatchery fish, so there is some uncertainty individual waters. For the major stocked associated with these projections. However, species, the demand for stocked fish is rela- the approach taken in this report is viewed as tively constant from year to year. Develop- a logical first step from which future refine- ment of a 5- or 10-year stocking plan for ments can be made. stocked waters will reduce annual planning workload and will provide the hatchery MANAGEMENT RECOMMENDATIONS system, private fish hatcheries, and coopera- Several recommendations were common tors with a long-term demand. In cases where across many of the species reviewed in this special needs arise, the system should be report. The most important ones are high- flexible enough to address these short-term lighted below. demands from the hatcheries. Stocking plans for individual waters should clearly identify Protection of existing natural reproduction. - the desired outcome of the stocking regime This is a universal theme throughout this and an evaluation of the success of the plan. report. Populations sustained through natural Attainment of that outcome should be evalu- reproduction provide the best fishing, and are ated before renewal of another long-term therefore worthy of vigorous protection. Any commitment for fish from the hatcheries or actions we can take to reduce the risk of private providers. impacting naturally reproducing populations should be pursued, whether through the Per-Water-Maximums.- In general, the per- hatchery system, habitat protection, or harvest water-maximum numbers for stocking are regulation. eliminated in deference to the best biological recommendation, regardless of limitations in Strain Development.- The department should production. However, due to the high variabil- fully evaluate the development and use of ity in hatchery production from year to year, genetic strains. Broader use of this approach there will be inevitable shortfalls. We recom- would ensure that the most appropriate stock mend addressing this problem by prioritizing or strain is used to most efficiently manage stocking strategies statewide and, within those Wisconsins fishery resources. Therefore, as a categories, requiring cuts in the waters that are first step, basin-specific stocks should be used stocked rather than spreading out fewer fish in for most stocking in the state. This may all waters where fish were requested. This initially result in some difficulties in the approach assumes that the likelihood for hatchery system, in terms of timing and success is higher for a few waters that get location of appropriate feral stocks and adequate numbers of fish rather than for a few keeping stocks separate in the hatchery fish in a greater number of waters, assuming system. However, it is believed that this the quota requests are biologically-based. approach will, in the long term, result in stocking a product that is better suited to the Shortfalls in WDNR Hatchery Capacity- The receiving waters and, ultimately, better requested number of fish of any one species fishing. In the future, requests for different could likely be met by the hatchery system, strains will need to be evaluated through the but it would adversely affect the availability of 34

other species from the hatcheries. For tive agreements would benefit both the state and example, walleye and muskellunge are the private fish hatcheries. primary species competing for space in the warm water hatcheries while Great lakes Stocking Team.- A team of Department biolo- and inland salmonids compete for space in gists and hatchery personnel should be formed the cold water facilities. Demand for many to periodically evaluate the stocking program. of these species is currently not being met. This forum would provide an outlet for 1) presentations on in-state stocking evaluations; Examination of the need for stocked fish, 2) review of current scientific literature related to coupled with instances where we are unable stocking, propagation, and related issues; 3) to meet that need through the state hatchery increased communication between biologists system suggests that there may be room for and hatchery personnel; and 4) development of increased involvement from private fish work planning guidance for future stocking hatcheries throughout the state, as sug- evaluation projects. In short, the purpose of this gested by WDNR (1997). Development of team would be to maintain the state-of-the-art in longer-term quotas would make it easier for our stocking program through a continuous private industry to plan for and provide fish improvement process. for stocking. Development of more coopera- 35

IV. LITERATURE CITED Klingbiel, J. 1986. Population Data for Fisher- ies Management, Fish Management Reference Beacham, T., C.B. Murray, and R.E. Withler. Book. WDNR, Bureau of Fisheries Manage- 1989. Age, morphology, and biochemical ment. Madison. genetic variation of Yukon River chinook salmon. Transactions of the American Fisher- Krueger, C.C., E.J. Marsden, H.L. Kincaid, B. ies Society 118:46-63. May. 1989. Genetic differentiation among lake trout strains stocked into Lake Ontario. Fields, R.D., M.D.G. Desjardins, J.M. Hudson, Transactions of the American Fisheries Society T.W. Kassler, J.B. Ludden, J. V. Tranquilli, C.A. 118:317-330. Toline, and D.P. Philipp. 1997. Genetic analy- ses of fish species in the upper midwest. Li, J., Y. Cohen, D.H. Schupp and I.R. Aquatic Ecology Technical Report 97/5. Adelman. 1996. Effects of walleye stocking Illinois Natural History Survey. Champaign. on year-class strength. North American Journal of Fisheries Management 16:840-850. Gharrett, A.J., C. Smoot, and A.J. McGregor. 1988. Genetic relationships of even-year Loomis, J. and P. Fix. 1998. Testing the impor- northwest Alaska pink salmon. Transactions tance of fish stocking as a determinant of the of the American Fisheries Society 117:536-545. demand for fishing licenses and fishing effort in Colorado. Human Dimensions of Wildlife Hanson, D.A., M.D. Staggs. S.L. Serns, L.D. 3(3):46-61. Johnson, and L.M. Andrews. 1986. Survival of stocked muskellunge eggs, fry and finger- Margenau, T.L. 1992. Survival and cost- ling in Wisconsin Lakes. Pages 216-228 in G.E. effectiveness of stocked fall fingerling and Hall, Editor. Managing muskies. American spring yearling muskellunge in WI. North Fisheries Society Special Publication 15, American Journal of Fisheries Management Bethesda. 12:484-493.

Jennings, Martin. 1996. Genes make all the Newburg, H. J. 1975. Review of selected difference. Wisconsin Natural Resources, literature on largemouth bass life history, February. ecology, and management. Minnesota Depart- ment of Natural Resources, Investigational Kampa, J.M. and M.J. Jennings. 1998. A review Report 335. of walleye stocking evaluations and factors influencing stocking success. WDNR, Research Oehmcke, A.A. 1969. Muskellunge manage- Report. ment in Wisconsin. WDNR Division of Fish, Game and Enforcement. Bureau of Fish Keim, S. 1998. Expenditures of Great Lakes Management Report 19. Salmon and Trout Stamp Revenues; Fiscal Years 1996-1999. WDNR, Bureau of Fisheries Philipp, D.P. 1991. Genetic implications of Management and Habitat Protection. Admin- introducing Florida largemouth bass istrative Report 42. Micropterus salmoides floridanus. Canadian Journal of Fisheries and Aquatic Science 48:58- Kerr, S.J. and six other authors. 1996. Walleye 65. stocking as a management tool. Ontario Ministry of Natural Resources. Petersborough, Philipp, D.P. 1991. Survival and growth of Ontario. northern, Florida, and reciprocal F1 hybrid largemouth bass in central Illinois. Transac- Klingbiel, J. 1981. The status of bass manage- tions of the American Fisheries Society 120:58- ment - an informational report to the natural 64. resources board. WDNR, Bureau of Fish Management, Administrative Report 12. 36

Philipp, D.P., W.F. Childers and G.S. Whitt. Wahl, D.H., and R.A. Stein. 1989. Comparative 1981. Management implications for differ- vulnerablility of three esocids to largemouth ent genetic stocks of largemouth bass bass (Micropterus salmoides) predation. Cana- (Micropterus salmoides) in the United dian Journal of Fisheries and Aquatic Sciences States. Canadian Journal of Fisheries and 46:2095-2103. Aquatic Science 38:1715-1723. WDNR (Wisconsin Department of Natural Philipp, D.P. and J.E. Claussen. 1995. Fitness Resources). 1998. Production capacities of the and performance differences between two Wisconsin Department of Natural Resources stocks of largemouth bass from different Fish Propagation Facilities. WDNR, Bureau of river drainages within Illinois. American Fisheries Management and Habitat Protection, Fisheries Society Symposium 15:236-243. Madison.

Ryman, N. and F. Utter. 1987. Population WDNR (Wisconsin Department of Natural genetics and fishery management. Univer- Resources). 1997. The role of private fish hatch- sity of Washington Press, Seattle. eries in Wisconsin: in search of a clear direction. WDNR, Bureau of Fisheries Management and Serns, S.L. and L.M. Andrews. 1986. Com- Habitat Protection, Madison. parative survival and growth of three sizes of muskellunge fingerlings stocked in four WDNR (Wisconsin Department of Natural northern Wisconsin lakes. Pages 229-237 in Resources). 1979. Fish and wildlife comprehen- G.E. Hall, Editor. Managing muskies. sive plan. Part I - Management strategies 1979- American Fisheries Society Special Publica- 1985. WDNR, Madison. tion 15, Bethesda. WLAB (Wisconsin Legislative Audit Bureau). Szendrey, T.A., and D.H. Wahl. 1996. Size 1997. An evaluation - Fish stocking activities specific survival and growth of stocked Department of Natural Resources. Report 97-9. muskellunge: effects of predation and prey availability. North American Journal of Fisheries Management 16:395-402. 37 V. APPENDICES

Appendix Table 1. Previous stocking guidelines for the sizes of warm water fish available from the hatchery system. Data are stocking rates per acre (maximum number per water).

Size Muskellunge Walleye Northern pike Black bass Lake sturgeon

Fry 500/acre 1000/acre 1000/acre 100/acre 200/acre (100,000) (500,000) (200,000) (100,000) (250,000)

Small fingerling 4.0-6.0 1.75-2.25 3.5-5.5 1.5-2.0 1.0-3.0 5/acre 50/acre 5/acre 50/acre 50/acre (5,000) (100,000) (5,000) (50,000) (50,000)

Large fingerling >7.0 2.5-3.25 >7.0 2.25-2.75 >3.0 2/acre 25/acre 2/acre 25/acre 5/acre (2,500) (50,000) (2,500) (25,000) (5,000)

Extended growth ------>5.0 ------>4.5 ------10/acre 10/acre (10,000) (10,000)

Adults 50 minimum

Appendix Table 2. Revised stocking guidelines and recommended sizes of fish needed from the hatchery system. Data are stocking rates per acre (maximum number per water, if production is limited).

Size Muskellunge Walleye Northern pike Black bass Lake sturgeon

Fry 500/acre 1800/acre 1000/habitat acre ------(100,000)

Small fingerling 4.0-6.0 >1.0 3.5-5.5 ------>3.0 5/acre 100/acre 5/habitat acre 80/mile or (5,000) 0.5/acre

Large fingerling >7.0 >4.0 >5.5 2.0+ >6.0 up to 2/acre 20/acre 2/habitat acre 25/acre 40/mile or (2,500) 0.25/acre

Adults 5/acre 200 minimum