Regulations In Canada, the use or possession of fish as live bait in any province other than from which it was taken is prohibited (SOR/93-55). It is illegal to bring any live fish into Ontario for use as bait (SOR/2007-237). This species is not on the Illinois Aquatic Life Approved Species List and if it is not otherwise native to Illinois it is illegal to be imported or possessed alive without a permit (515 ILCS 5/20-90).
Note: Check federal, state, and local regulations for the most up-to-date information.
Control
Biological
European smelt would likely become a suitable prey option for many of the piscivorous fish in the Great Lakes that feed on rainbow smelt (Osmerus mordax). These predators include: Atlantic salmon (Salmo salar), lake trout (Salvelinus namaycush), Brook trout (Salvelinus fontinalis), Coho salmon (Oncorhynchus kisutch), Chinook salmon (Oncorhynchus tshawytcha), rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), Splake (Salvelinus namaycush x fontinalis), burbot (Lota lota), walleye (Sander vitreus), northern pike (Esox lucius), and many other freshwater piscivores (Stewart et al. 1981; Brandt and Madon 1986; Crossman 1991; He and LaBar 1994; Kirn and LaBar 1996; GLMRIS 2012). Additionally, piscivorous birds in Europe have shown to feed heavily on European smelt indicating that birds native to the Basin such as Ibis, Great blue heron, and grebes would also consume European smelt (Piersma et al. 1988).
Several studies have noted the susceptibility of European smelt to microbial agents such as the Comet herpes virus of smelt, microsporidian parasites (e.g. Glugea spp. or Pleistophora ladogensis) and sealworm (Pseudoterranova decipiens) (Schrader 1921; Sprengel and Luchtenberg 1991; Jakob et al. 2010). Sprengel and Luchtenberg (1991) observed that smelt infected with the muscular parasites, P. ladogensis (Microsporal) and P. decipiens (Nematoda), exhibited a significant reduction in swimming speed. This implies that the infected smelt are subject to higher predation rates due to their diminished ability to escape. However, the use of pathogens or parasites to control European smelt is not practical due the potential impact these could have on native species and humans.
Physical
Various types of physical controls that have been used to control rainbow smelt and other non-indigenous fish might also be effective in managing European smelt. Patrick et al. (1985) observed that air bubble curtains have been successful in deterring rainbow smelt, alewife, and gizzard shad—especially when used in conjunction with strobe lights. Other types of physical treatments have been employed in fish control include reservoir drawdowns, traps, nets, electrofishing, and combinations of these treatments. Through their review of fish control methods, Meronek et al. (1996) observed that projects that utilized nets were the most successful of the previously listed physical treatments.
Chemical
Of the four chemical piscicides registered for use in the United States, rotenone and antimycin have been used in the majority of chemical control projects and have had varied success rates for different species and different bodies of water (Marking et al. 1983; Boogard et al. 1996; Maronek et al. 1996; GLMRIS 2012). Marking et al. (1983) found that the three most effective registered chemicals for potential use in control of rainbow smelt eggs and larvae are rotenone, potassium permanganate, and chlorine, respectively. The relatedness of rainbow smelt and European smelt might indicate that these treatments will have a similar effect on European smelt, especially since chemical piscicides typically are not species-specific. However, sensitivity to treatments varies among species so this assumption is not necessarily true (Boogard et al. 1996). Therefore, it is imperative to understand the physiology and ecology of European smelt, as well as the characteristics of the specific environment such as water quality and water volume, which might affect the success of piscicides in the control of European smelt (Marking et al. 1983; Ling 2003; Lennox et al. 2015).
Other
The temperature and dissolved oxygen requirements for European smelt can provide insight on how an introduced population might be controlled. European smelt is generally a coldwater species and mortality rate seems to be positively associated with increases in water temperature (Kangur et al. 2005; Kangur et al. 2007b; Keskinen et al. 2012). This was seen in Lake Peipsi (Estonia/Russia) where high temperatures negatively affected the catch rate of Smelt 1 and 2 years later and long periods of high water temperatures (>20?) led to extensive fish kills (Kangur et al. 2005; Kangur et al. 2007b). Keskinen et al. (2012) demonstrated how long-term warming trends threaten the survival of European smelt. They observed that the pelagic habitat of European smelt was restricted due to increases in water temperature and decreases in dissolved oxygen. Similar observations were made by Gerasimov et al. (2018) in a Russian lake. In two Dutch lakes, Keller et al. (2020) found a growing mismatch in the temporal feeding habits of European smelt and zooplankton availability due to the warming effects of climate change. Therefore, climate change may control or limit the establishment of European smelt in the Great Lakes due to their species-specific requirements for temperature and dissolved oxygen and cascading impacts on food web dynamics.
Note: Check state and local regulations for the most up-to-date information regarding permits for pesticide/herbicide/piscicide/insecticide use.