Assessing the impact of Muskellunge predation on Smallmouth Bass in the New River, Virginia
I am creating a flier with a QR code (a code that can be scanned with your phone) linked to a 5-minute video detailing the results of my project on Muskellunge and Smallmouth Bass in the New River. The video will describe the predatory impact that Muskellunge have on Smallmouth Bass as well as the management implications that predation has on the Smallmouth Bass fishery. Below is an outline for that video:
The ‘Monster Muskie’ – a historical context
- Description of the dislike and fear that often accompany Muskellunge and other members of the esocid family
- Quote from previous AFS president
- Where does this aversion come from?
- Resource-users are afraid that they are ‘eating machines’
- Quotes from New River fishermen
- Muskellunge will prey on other sportfish and decimate quality fisheries
- Resource-users are afraid that they are ‘eating machines’
- This fear of Muskellunge and their impact sometimes leads to anglers taking matters into their own hands
- Include a snippet of guy killing Muskie in Michigan
- Quote from Minnesota article
The ‘Monster Muskie’ – scientifically speaking
- What does Muskellunge diet and predation actually look like?
- Discuss diet studies from Wisconsin, Michigan, Minnesota
- Generally Muskellunge prefer ‘softer’ prey (e.g. Suckers, Minnows, Gizzard Shad)
- And there are many instances of successful fisheries with both Muskellunge and Smallmouth Bass (e.g. St. Lawrence River)
- HOWEVER – some evidence exists for predation on less-preferred “spiny fishes,” when preferred forage is lacking
- This can happen when there is a decrease in preferred forage or when there is a substantial increase in the number of consumers
- Describe predation on Largemouth Bass, Smallmouth Bass, and Walleye in other systems
How this applies to the New River
- Previous New River diet study – consumption of Smallmouth Bass by Muskellunge was very low
- But then the regulations for Muskellunge changed and now there are more Muskellunge and complaints of decreasing catches of Smallmouth Bass
- So, are there enough Muskellunge so that now Smallmouth Bass have become a more important part of their diet? How was consumption changed?
- We set out to answer that question!
- Pumped a lot of Muskellunge stomachs
- Throughout the year
- And throughout the New River
- Sifted through a lot of Muskellunge puke
- Found very little Smallmouth Bass – pie charts with diet composition
- Conclusion – not a very important part of their diet!
- Pumped a lot of Muskellunge stomachs
- But, what about the fact that there are more Muskie out there? Even if they eat only a little of Smallmouth Bass, couldn’t it be a lot overall?
- We set out to answer that question too!
- We estimated how much an average adult Muskellunge eats annually
- Then, we estimated how much of that is Smallmouth Bass annually
- We have an estimate of how many Muskie there are at each site, so then we multiply that consumption by how many Muskie there are, and we have the number of Smallmouth Bass consumed by Muskellunge
- We also have an estimate of how many Smallmouth Bass there are at each site
- This is how they compare! Conclusion – it’s very unlikely Muskellunge are having a substantial impact on Smallmouth Bass
What does it all mean?
The Smallmouth Bass population has seen some declines in catches of slot-sized fish over the last few years. If Muskie are not the cause, then what is?
- Increased fishing pressure
- VDGIF estimates 60% increase
- There’s also been an increase in bass tournaments
- Variable recruitment
- Water flow and Claytor Dam
Demographic trends over the next few years will hopefully help us figure out exactly what is causing the declines in certain sizes of Smallmouth Bass.
The management of a recreational fishery composed of multiple predatory species can pose a challenge to managers, as they must maintain both the ecological balance of the system and the satisfaction of divergent angler groups who may have competing interests. Historically when either the ecological or social perspective of a system or fishery has been ignored, the result is often a damaged relationship between the resource users and the managing agency (Churchill et al. 2002). Fisheries managers must understand how interactions between predators—real or perceived—affect angler perceptions of predator species. Ideally, fisheries managers can use their understanding of the occurring biological interactions to educate anglers and appropriately address any concerns and conflicts that might be present. Such conflicts exist for many recreational fisheries and are especially prevalent in fisheries surrounding large predators like muskellunge Esox masquinongy.
Muskellunge and other esocids have held a bad reputation amongst anglers for over a century (Hall 1987) and have been cited as the cause of declines in many sportfish populations over the years, including walleye Sanders vitreus (e.g. Scidmore 1964, Maloney and Schupp 1986), crappies Pomoxis spp. (e.g. Siler and Beyerle 1984), and black bass Micropterus spp. (e.g. Krishka et al. 1996, Kerr and Grant 2000). Despite these claims, evidence of muskellunge preying on and altering other sportfish populations is equivocal. Many populations of muskellunge and other sportfish, like smallmouth bass Micropterus dolomieu and walleye, exist together naturally in North America and support successful recreational fisheries (e.g. Thomas and Haas 2004, Knapp et al. 2012). Other systems exist, however, in which direct predation on other sportfish populations by muskellunge seems to be a major issue (e.g. Schmidtz and Hetfeld 1965). Thus, the muskellunge and smallmouth bass populations of the New River, Virginia provided an ideal opportunity to study and improve our understanding of the interactions between muskellunge and another popular sportfish.
Our research studied the importance of smallmouth bass in muskellunge diet in the New River, Virginia. Over two years we collected the stomach contents from 274 muskellunge using pulsed-gastric lavage. Food items were identified to the lowest level of taxonomic resolution possible, weighed (wet weight), and measured (TL for fish). We found that consumption of smallmouth bass by muskellunge was very limited. Smallmouth bass represented only 1% (of total wet weight) of muskellunge diet. The primary prey items consumed by muskellunge were suckers Catostomidae spp., smaller centrarchids (i.e. Lepomis spp. and rock bass Ambloplites rupestris), and minnows Cyprinidae spp. These prey items were consistent with those found in the diet of New River Muskellunge in 2000-2003 (Brenden et al. 2004) and with muskellunge diets reported for other systems (Kerr 2016).
The product I intend to create is a ‘flier’ with a QR code—a barcode that can be scanned with a cellphone. The QR code will take the scanner to a short 5-minute video on the project’s findings. The QR code, along with the video’s web address, will be printed on waterproof fliers and available at local tackle shops, guiding services, and boat ramps. If possible, I would also like to have the QR code and web address printed in local fishing publications. New River anglers are a diverse group, each with his or her own level of familiarity with technology. Reaching the different types of anglers will likely require multiple mediums. Thus if time permits, I would like to advertise several viewings of the video on the fliers and hold Q-and-A segments following the video.
New River anglers are my intended audience for this project, especially those that fish for smallmouth bass and muskellunge. Smallmouth bass anglers in particular are concerned about the impact Muskellunge have on the quality of the bass fishery, and this research should help ease their concerns.
Brenden, T. O., E. M. Hallerman, and B. R. Murphy. 2004. Predatory impact of Muskellunge on New River, Virginia, Smallmouth Bass. Proceedings of the Southeastern Association of Fish and Wildlife Agencies 58:12-22.
Churchill, T. N., P. W. Bettoli, D. C. Peterson, W. C. Reeves, and B. Hodge. 2002. Angler conflicts in fisheries management: a case study of the Striped Bass controversy at Norris Reservoir, Tennessee. Fisheries 27:10-19.
G. E. Hall. 1987. Managing muskies. American Fisheries Society, Special Publication 15, Bethesda, Maryland.
Kerr, S. J. 2016. Feeding habits and diet of the Muskellunge (Esox masquinongy): a review of potential impacts on resident biota. Muskies Canada Inc. and Ontario Ministry of Natural Resources and Forestry. Peterborough, Ontario.
Kerr, S. J. and R. E. Grant. 2000. Muskellunge and northern pike. Pages 325-355 in Ecological impacts of fish introductions: evaluating the risk. Fisheries Section, Fish and Wildlife Branch, Ontario Ministry of Natural Resources. Peterborough, Ontario.
Knapp, M. L., S. W. Mero, D. J. Bohlander, D. F. Staples, and J. A. Younk. 2012. Fish community responses to the introduction of muskellunge into Minnesota lakes. North American Journal of Fisheries Management 32:191-201.
Krishka, B. A., R. F Cholmondeley, A. J. Dextrase and P. J. Colby. 1996. Impacts of introductions and removals on Ontario percid communities. Report of the Introductions and Removals Working Group, Percid Community Synthesis. Ontario Ministry of Natural Resources. Peterborough, Ontario.
Maloney, J. and D. H. Schupp. 1977. Use of winter rescue northern pike in maintenance stocking. Fisheries Investigational Report 345. Minnesota Department of Natural Resources. St. Paul, Minnesota.
Schmidtz, W. R. and R. E. Hetfield. 1965. Predation by introduced Muskellunge on perch and bass II: Years 8-9. Transactions of the Wisconsin Academy of Science Arts and Letters 54:274-282.
Scidmore, W. J. 1964. Use of yearling northern pike in the management of Minnesota lakes. Fisheries Investigational Report No. 277. Minnesota Department of Natural Resources. St. Paul, Minnesota.
Siler, D. H. and G. B. Beyerle. 1984. Introduction and management of northern muskellunge in Iron Lake, Michigan. American Fisheries Society Special Publication 15:257-262.
Thomas, M. V., and R. C. Haas. 2004. Status of the Lake St. Clair fish community and sport fishery, 1996-2001. Michigan Department of Natural Resources, Fisheries Division.