Evaluation of Muskellunge Management and Stocking Strategies in Iowa

The primary purpose of this study is to conduct a comprehensive evaluation of Muskellunge stocking effectiveness and efficiency within Iowa's lakes and reservoirs, including those managed by the U.S. Army Corps of Engineers (USACE). This research directly addresses the USACE's interest in optimizing the management of recreational fisheries within their projects. By identifying and refining Muskellunge culture methods and stocking policies, this study aims to enhance the efficacy and efficiency of state agency stocking programs, ensuring that valuable resources are utilized to maximize angler success. The comprehensive understanding of Muskellunge survival, movement, and habitat use gained from this study will directly inform optimized stocking strategies, leading to more robust and sustainable Muskellunge populations. This, in turn, is anticipated to increase angler success rates and overall recreational satisfaction, thereby enhancing the economic and social benefits derived from recreational fishing on USACE reservoirs and similar water bodies across the state and potentially nationwide. The findings will directly inform the revision of Iowa's Muskellunge Management Plan (Meerbeek, 2014), and, critically, will establish a transferable framework for improving stocking outcomes and increasing recreational fishing opportunities in USACE reservoirs and similar water bodies across the nation.

Furthermore, this study will investigate the broader implications of its outcomes for the strategic adoption and advancement of Recirculating Aquaculture Systems (RAS). As conventional hatchery systems increasingly face challenges from extreme weather events, water shortages, aquatic invasive species, and growing demand for stocked fish due to habitat degradation (Hanson and Ostrand 2011), RAS offers a resilient solution. This research will demonstrate how RAS can enable state and Federal hatcheries, including those supporting USACE-managed waters, to meet production goals more efficiently and sustainably, thereby securing the future of recreational fisheries and enhancing the public benefits derived from USACE projects.

Tasks to be Completed:

Task 1: Population Dynamics. Prior to stocking, all Muskellunge intended for Iowa's lake and reservoirs will be tagged with passive integrated transponder (PIT) Tags, and some will also receive acoustic or radio transmitters. The initial treatment group will include Muskellunge raised traditionally (overwintered in ponds and fed live forage), musky raised in recirculating aquaculture systems (RAS) and fed pellets and RAS Musky fed live forage for about 14 days prior to stocking.

Post-stocking survival rate will be monitored using acoustic receiver arrays and manual tracking of radio tagged fish in various reservoirs and lakes. Mortality will be inferred from movement patterns of tagged fish. This survival data will support adaptive management allowing for the refining of culture and stocking methods (e.g., on-shore ramp stocking or off-shore stocking) to improve survival rates. Each subsequent refinement will be evaluated and used to implement further improvements the next year, ultimately building stronger Muskellunge populations and enhancing recreational fishing experiences.

Additionally, the movement, behavior, and habitat use of Muskellunge from different treatment groups will be studied post-stocking using acoustic receivers and manual trackers. This will help identify optimal stocking locations and potential habitat enchantments.

Furthermore, this study will also examine escapement (fish leaving stocked areas) using various tag types in systems of different size and outlet designs. Findings will guide recommendations for barrier installations, developed with the US Army Corps of Engineers (USACE), to improve fish retention in reservoirs. These measures aim to increase the number of trophy-sized Muskellunge available to anglers, boosting recreational and economic benefits of these fisheries.

Task 2: System-Specific Criteria for Optimized Muskellunge Fisheries to Revise Iowa Muskellunge Management Plan and Stocking Policy. This task will involve habitat sampling and fisheries surveys across Iowa lakes and reservoirs, including USACE-managed sites, to identify environmental and ecological factors affecting Muskellunge populations, such as water quality, habitat structure, and prey availability. The data collected will help create tailored stocking and management plans to optimize Musky fisheries in different aquatic systems.

Additionally, the feasibility of installing barriers to reduce fish escapement will be assessed for current and future Musky fisheries. This evaluation will consider environmental, hydrological, and operational factors to improve fish retention.

By understanding system specific impacts and factors for successful Muskellunge establishment, resources can be allocated more effectively, enhancing angling success, recreational participation, and visitor satisfaction at Iowa water bodies. The Iowa DNR will lead habitat sampling and surveys to ensure a comprehensive planning effort.

The information gathered will form the basis for a Comprehensive Plan for Muskellunge stocking in Iowa, which will update the Iowa Muskellunge Management Plan (Meerbeek, 2014). USACE will provide planning guidance to align the plan with federal conservation and recreational goals for USACE reservoirs.

The Comprehensive Plan will analyze project data and offer actionable recommendations for the Iowa DNR to improve Muskellunge fisheries. These updates will guide best practices for stocking and management, enhance recreational fish quality, increase angler success, and provide economic benefit to communities near Iowa water bodies. The findings will also serve as a model for improved fisheries management nationwide.

Task 3: Project Management & Cooperative Ecosystem Studies (CESU) Management. The USACE will manage this project under the Planning Assistance to States Program guidelines. Stakeholder meetings will be held to discuss technical elements and to review progress, manage budgetary aspects, and discuss study developments. The study evaluation will be jointly conducted by the Iowa DNR and CESU Contract Awardee. This PAS project facilitates the utilization of the CESU program to provide resources that would otherwise be unavailable to the IADNR. In addition to providing expertise in biology and planning, utilizing the CESU agreement extends the expertise of the USACE (Tasks 1, 2 and 3) to include the expertise of the CESU Contract Awardee. The IADNR will document match contributions such as in-kind labor, as per USACE guidance, and submit an annual report to the Corps by October 15th each year, covering the period from July through June. The USACE and the IADNR will jointly develop appropriate quality control plans and information as required by USACE standards for this study.