Walleye (Sander vitreus) are a popular sportfish species with a native range extending from northern Canada to the southern United States ([24]). Recreational walleye fisheries are extremely important and have a considerable economic contribution ([27]; [44]). Because walleye fisheries are subject to overharvest ([45]) with many populations historically decreased ([19]), walleye fisheries are routinely maintained using hatchery propagation and restocking ([38]). Hatchery rearing of walleye typically occurs by artificially spawning wild broodstock ([15]). Fertilized eggs are then incubated in hatcheries with the resulting newly hatched fry either directly stocked into recreational fishing waters or retained at the hatchery for further rearing to larger juvenile sizes ([5]; [70]). An estimated 1 billion fry and fingerlings are stocked annually in the United States alone ([10]; [53]).

Recreational fishing in South Dakota, USA has a major economic contribution, with direct recreational spending estimated at $530,743,523 USD in 2022 ([51]). To meet the demand for recreational fishing, the South Dakota Department of Game, Fish and Parks (SDGFP) owns and operates three fish hatcheries with a 2023 budget of over $3,000,000 USD ([47]). Walleye are the most sought-after fish species for recreational angling in South Dakota ([14]; [58]) and 75% of the walleye fisheries in South Dakota lakes and reservoirs are maintained by hatchery stocking. However, the effect of hatchery production on the economics of walleye fishing in South Dakota is unknown. Understanding the economic contributions of public hatchery operations is extremely important, given the stewardship obligations of government agencies, such as the South Dakota Game, Fish and Parks ([46]). Thus, the objective of this study was to determine the economic contribution of walleye rearing and stocking on the economy of South Dakota.

The total economic contribution of walleye rearing and stocking to the South Dakota economy was an estimated $714,694,161 (Table 5). Thus, the economic contribution per budgetary dollar spent on the hatchery rearing and stocking of walleyes was estimated to be $1066.

Table 5. Total economic contributions of the stocking of hatchery-reared walleye in South Dakota. Operational expenditures are direct expenses of hatchery rearing and stocking. Recreational expenses are those from walleye anglers.

This is the first study to determine the economic contribution of walleye hatchery production and the stocking of walleye to sustain recreational fisheries. Specific to South Dakota, the calculation of $1066 in economic contribution per budgetary dollar spent on walleye production is considerably larger than that reported previously for hatcheries producing trout and salmon in South Dakota and elsewhere. [33] stated an economic contribution of $216.47 (inflation adjusted) for every hatchery budget dollar spent on trout and salmon production at Cleghorn Springs State Fish Hatchery. [2] reported a similar economic contribution at McNenny State Fish Hatchery in South Dakota. Other hatcheries in the United States producing trout and salmon have reported economic contributions (inflation adjusted) of less than $200 per budgetary dollar spent ([59]; [31]).

The large difference in economic contribution between hatchery rearing and stocking of walleye versus trout and salmon in South Dakota can be largely explained by the relative popularity of these fish species by South Dakota anglers. Walleye are the state fish of South Dakota and have a long history of being the most sought-after sport fish in South Dakota ([11]; [12]; [58]). While over 86% of South Dakota anglers engage in walleye fishing, only 26% engage in trout fishing ([61]; [37]; [49]). Walleye anglers also spend more than trout anglers. The expenditures by anglers targeting highly preferred fish species, like walleyes in South Dakota, are greater than those for less preferred species ([28]). In addition, walleye fisheries in South Dakota are typically in large lakes and reservoirs, compared to trout fisheries which are typically in streams and ponds ([29]; [16]; [41]). [28] noted that anglers who fished in rivers and ponds spent less money than those who fished in larger water bodies. Lastly, [8] reported that walleye anglers in Wisconsin spent more than black bass and salmon anglers.

The 86.5% of the licensed anglers in South Dakota targeting walleye noted in this study was nearly identical to the 85% of licensed anglers who self-reported to prefer walleye fishing in 2021 ([63]). The number of anglers indicating a preference to catch walleye appears to have slightly risen from historical levels, at 82.2% in 2017, 78.3% in 2018, and 81.1% in 2019 ([30]; [23]). The percentage of anglers preferring to catch trout has ranged from 19% to 22% over the same time period ([30]; [23]; [63]).

The large economic contribution of state government fish hatcheries producing and stocking walleye occurs without any funding from South Dakota state general tax revenues ([50]; [2]; [33]). This is a user-pay model, whereby anglers pay for hatchery operations and stocking by purchasing fishing licenses along with an excise tax on fishing equipment ([36]; [42]). Even though licensed anglers are funding hatchery operations, the non-angling general public is receiving considerable financial benefits. Directly and indirectly, public fish hatcheries funded solely by licensed anglers are an important component of the economy of South Dakota ([54]).

The economic contribution indicated in this study is likely a conservative estimate for several reasons. First, only yearly operating expenditures were included; construction expenditures were excluded. No large infrastructure improvements or repair projects were conducted at either Blue Dog or Cleghorn Springs Hatcheries during the three years of this study. However, such projects are a part of hatchery operations and have substantial positive economic contribution with direct costs running into the tens of millions of dollars ([55]; [35]). Secondly, there is considerable research and innovation involving walleye production at both hatcheries, including those increasing pond production ([65]; [62]; [64]; [63]) and novel Recirculating Aquaculture System rearing ([25]; [26]). The results of this experimentation and innovation have economic contributions that are hard to quantify ([17]; [67]; [3]). These long-term economic contributions benefit the South Dakota economy and also extend well beyond the state ([9]; [39]; [4]).

This study is limited by the year of economic inputs used. Adult walleye populations can fluctuate from year-to-year ([34]). There can also be fluctuations in the number of licensed anglers ([22]), particularly in South Dakota ([18]). Thus, the economic impact resulting from the rearing and stocking of walleye may vary from the years used in this study. In addition, the economic inputs used in the study are somewhat variable. However, this estimate would likely become more accurate with additional and more precise data, which should be pursued in additional studies.

The economic information described in this study can be used to make decisions regarding the potential allocation of funding for hatchery operations and improvements ([66]). With over $1000 of economic contribution per hatchery budgetary dollar spent, investing in hatchery production would appear to greatly benefit the overall economy of South Dakota. Based on this high return on investment, funding prioritization should be given to hatchery maintenance and improvements. This recommendation is further strengthened by declining recruitment of naturally-produced walleyes ([20]; [7]; [21]) and an overall decline in walleye populations in the midwestern United States ([40]), making increased hatchery stocking even more important to maintain recreational fisheries ([43]).

In conclusion, with walleye being the most popular sportfish species in South Dakota, and with most walleye fisheries sustained by the stocking of hatchery-reared fish, the economic contribution per budgetary dollar spent on the hatchery rearing of $1066 reported in this study is not surprising. The total economic contribution of an estimated $714,694,161 to the South Dakota economy from walleye rearing and stocking is a substantial return on the yearly hatchery walleye rearing expenditures of approximately $700,000. This study, the first to document the economics of walleye hatchery rearing, provides considerable justification for investments in hatchery infrastructure benefitting walleye production.

Jill Voorhees and Analuisa Larson assisted with manuscript formatting.