Regulations (pertaining to the Great Lakes)
The use of Rainbow Smelt is regulated in the Canadian province of Quebec under Canada Federal Statutes and Regulations SOR 90-214. A population of Rainbow Smelt in an area south of the St. Lawrence estuary is designated a vulnerable wildlife species in Quebec under Quebec Statutes and Regulations RRQ, c E-12.01, r 2. The sale of dead Rainbow Smelt is prohibited in Quebec by Quebec Statutes and Regulations RRQ, c C-61.1, r 7. In Ontario, Rainbow Smelt use as bait and non-angling fishing methods are regulated by Canada Federal Statutes and Regulations SOR 2007-237. In the state of New York, it is unlawful to use Rainbow Smelt as bait except as provided in 6 NY CRR § 19.2. Furthermore, it is unlawful to take Rainbow Smelt for sale as bait or to sell as bait, except as otherwise provided as without a pursuant license as defined in NY ECL § 11-1315. In Pennsylvania, the use of commercial trap nets under license to capture Rainbow Smelt is regulated by Penn. Admin. Code § 69.33. In Ohio, Rainbow Smelt is defined as a commercial fish and an unrestricted species under Ohio Admin. Code 1501 § 31-1-02. Commercial fish are permitted to be taken, possessed, bought, or sold unless otherwise restricted in Ohio code. In Indiana, the Rainbow Smelt sport fishing season on Lake Michigan is defined as March 1-May 30, with capture allowed only by the use of dip nets, seines, or nets with limitations provided in 312 IAC § 9-7-2. There is otherwise no bag limit, possession limit, or size limit, as defined under 312 IAC § 9-7-14. In Illinois, the sport-fishing season of Rainbow Smelt is defined as March 1-April 30 under Illinois Admin. Code 17-1 § 810.10. In Wisconsin, Rainbow Smelt is defined as an established non-native fish species in Wis. Admin. Code § NR 40.02, and is restricted per the above definition by Wis. Admin Code § NR 40.05. In Minnesota, Rainbow Smelt is a regulated invasive species under Minn. Admin Rules § 6216.0260.
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
Rainbow Smelt are heavily consumed by Atlantic Salmon (Salmo salar), Lake Trout (Salvelinus namaycush), Brook Trout (S. fontinalis), Coho Salmon (Oncorhynchus kisutch), Chinook Salmon (O. tshawytcha), Rainbow Trout (O. mykiss), Brown Trout (Salmo trutta), Splake (Brook Trout x Lake Trout), Burbot (Lota lota), Walleye (Sander vitreus), Northern Pike (Esox lucius), and many other freshwater piscivores (Brandt and Madon 1986; Crossman 1991; GLMRIS 2012; He and LaBar 1994; Kirn and LaBar 1996; Stewart et al. 1981). However, the significance of piscivore predation on Rainbow Smelt has only been studied for a few species. Observed Atlantic Salmon predation on smaller Rainbow Smelt, as well as bioenergetics modeling suggesting that by age 4, cumulative piscivory by Atlantic Salmon was nearly 10-fold greater than that of Lake Trout of the same age, implies its greater usefulness for management of Rainbow Smelt (Kirn and LaBar 1996). While Lake Trout consume large amounts of Rainbow Smelt, almost exclusively so in some studies, the species is believed to provide little potential for responsive management manipulation outside of stabilizing fluctuating prey populations, due to the long cycle of its predatory effect (peaking 3-5 years after stocking, lasting 7-8 years) (He and LaBar 1994; Kirn and LaBar 1996; Stewart et al. 1981). Chinook Salmon have been successfully used to eradicate Rainbow Smelt from small lakes in New Hampshire in 1936 (Stewart et al. 1981). Because the trade-off between fish species as agents of biological control is not directly correlated with consumption, management decisions involving shifts between species should not take consumption solely into account (Stewart et al. 1981).
Physical
The USACE Great Lakes and Mississippi River Interbasin Study notes the potential effectiveness of sensory deterrent systems in providing barriers to fish migration or eliciting fish movements (GLMRIS 2012). In situ testing of two models of strobe lights as a deterrent preventing entrainment of Rainbow Smelt through Oahe Dam, Lake Oahe, South Dakota demonstrated successful avoidance of 15-21 m horizontally and 6 m vertically by Rainbow Smelt (Hamel et al. 2008). Many large scale strobe systems consist of four individual lights that flash at a rate of 450 flashes/min., with an approximate intensity of 2634 lumens/flash (GLMRIS 2012). Hamel et al. (2008) tested the AGL FH-901 flashhead, which consists of four horizontal lights positioned at 90-degree angles, flashing 450 times/min at 2,634 lumens/flash, and the newer AGL FH-920 flashhead, which consists of an omnidirectional vertical light tube, covering a full 360 degrees with 360 flashes/min at 6,585 lumens. When using physical deterrents as barriers, combining methods can increase effectiveness, as was the case for Patrick et al. (1985), who found that Rainbow Smelt and other pelagic fishes were successfully deterred by a barrier combining air bubbles and strobe lights.
Chemical
Of the four chemical piscicides registered for use in the United States, antimycin A and rotenone are considered general piscicides (GLMRIS 2012). Marking et al. (1983) found that the three most effective registered chemicals for potential use in the control of Rainbow Smelt eggs and larvae are rotenone, potassium permanganate, and chlorine, respectively. In exposures of 6-24 hours, all chemicals were effective at concentrations from 5 to >10 mg/L (Marking et al. 1983). Rotenone demonstrated a 96h LC50 of 0.015 mg/L for Rainbow Smelt eggs and 0.001 mg/L for larvae (derived calculating only the activity of rotenone in 5% Noxfish solution) (Marking et al. 1983). Potassium permanganate demonstrated 96h LC50s of 0.074 mg/L and 0.075 mg/L for eggs and larvae, respectively. Chlorine demonstrated 96h LC50s of 0.14 mg/L for eggs and 0.31 mg/L for larvae (Marking et al. 1983). Temperature, pH, and hardness of water all affected toxicity of rotenone and potassium permanganate, with higher temperatures, softer water, and higher pH increasing toxicity (Marking et al. 1983). It should be noted that tests were carried out in a laboratory, but natural waters usually contain oxidizable material, which produces a chlorine demand and reduces it to a less active form (Marking et al. 1983).
Increasing CO2 concentrations, either by bubbling pressurized gas directly into water or by the addition of sodium bicarbonate (NaHCO3), has been used to sedate fish with minimal residual toxicity, and is a potential method of harvesting fish for removal, though maintaining adequate CO2 concentrations may be difficult in large/natural water bodies (Clearwater et al. 2008). CO2 is approved only for use as an anesthetic for cold, cool, and warm water fishes in the US, not for use as euthanasia (Clearwater et al. 2008). Exposure to NaHCO3 concentration of 142-642 mg/L for 5 min. is sufficient to anesthetize most fish (Clearwater et al 2008).
It should be noted that chemical treatment will often lead to non-target kills, and so all options for management of a species should be adequately studied before a decision is made to use piscicides or other chemicals. Potential effects on non-target plants and organisms, including macroinvertebrates and other fishes, should always be deliberately evaluated and analyzed. The effects of combinations of management chemicals and other toxicants, whether intentional or unintentional, should be understood before chemical treatment. Other non-selective alterations of water quality, such as reducing dissolved oxygen levels or altering pH, could also have a deleterious impact on native fish, invertebrates, and other fauna or flora, and their potentially harmful effects should therefore be evaluated thoroughly.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.