Trachemys scripta, usually T. s. elegans, is probably the most widely illustrated turtle in the world, appearing in numerous publications (Carr, 1952; Smith, 1961; Ernst and Barbour, 1972, 1989; Mount, 1975; Behler and King, 1979; Pritchard, 1979; Sengoku, 1979; Smith and Smith, 1979; Martof et al., 1980; Caldwell and Collins, 1981; Smith and Brodie, 1982; DeGraaf and Rudis, 1983; Pritchard and Trebbau, 1984; [Mathui], 1985; Stebbins, 1985; Garrett and Barker, 1987; Green and Pauley, 1987; Alderton, 1988; Christiansen and Bailey, 1988; [Sievert] and Sievert, [1988]; Dundee and Rossman, 1989; Harding and Holman, 1990; Ashton and Ashton, 1991; Carmichael and Williams, 1991; Leviton et al., 1992; Collins, 1993; Collins and Collins, 1993; Ernst et al., 1994; Mitchell, 1994; Brown et al., 1995; Palmer and Braswell, 1995; Degenhardt et al., 1996; McKeown, 1996; Harding, 1997; Lamar, 1997; Branch, 1998; Campbell, 1998; Conant and Collins, 1998; Cox et al., 1998; Powell et al., 1998; Bartlett and Bartlett, 1999a, b; Behler, 1999; Phillips et al., 1999; Johnson, 2000; Minton, 2001).

In Ontario, over 80% of the reported sliders were concentrated around urban areas, where they are most likely to be released into surrounding water bodies when they have overstayed their welcome as pets (Seburn, 2015). This pattern is consistent with other observational data from around the globe, as urban areas with high human population densities are impacted the most by introduced species from the pet trade (Thomson et al., 2010; Kopecky et al., 2013, Banha, 2017; Koo et al., 2020).

In the Great Lakes, the Red-eared Slider is reproducing and overwintering in the basins of Lake Michigan, Lake Erie, and Lake Ontario (Seburn, 2015; Spear et al., 2018; USGS). Reproduction has been reported and confirmed in Illinois, Indiana, Michigan, New York, Ohio, Ontario, Pennsylvania, and Wisconsin (Bunnel 2005; Kikillus et al. 2010; Seburn 2015; Spear et al. 2018; Herpetological Review; Wisconsin Herp Atlas; USGS NAS). For instance, there is evidence for reproductive populations of invasive T. s. elegans in Pleasant Prairie and Franklin, Wisconsin (Spear et al., 2018; Herpetological Review; Wisconsin Herp Atlas). The current populations of T. s. elegans in Marion County, Indiana, are reproducing, overwintering, and spreading, yet it is not clear if they represent an indigenous migration or nonindigenous introduction (Minton, 2001). Reproductive populations of T. s. elegans have been reported in New Harmony, IN (Kikillus et al., 2010; Spear et al., 2018). Overwintering success has been observed for this species as far north as southern Ontario, and has been anecdotally reported even further north into Canada (Seburn 2015;  Spear et al. 2018). A specimen record from 1948 places T. s. elegans below the ordinary high water mark in Duck Lake, Muskegon, MI (Gordon & Fowler 1961, USGS NAS) - this record suggests a range extension from Crystal Lake just north of Duck Lake. A citizen science record of T. s. elegans pictured below the ordinary high water mark in a connected waterway (to Lake Michigan) in East Pilsen, Chicago, IL has been published on GBIF and has been determined “research grade” by iNaturalist (Ueda 2021).

In nearly all of its nonindigenous localities in North America, including Canada, New York, New Jersey, Pennsylvania, Wisconsin, Illinois, Indiana, Ohio, Michigan, Virginia, North Carolina, South Carolina, and perhaps Massachusetts, isolated populations of T. s. elegans are reproducing and overwintering (Stein et al., 1980; Manchester, 1982; DeGraaf and Rudis, 1983; Harding and Holman, 1990; Cardoza et al., 1993; Ernst et al., 1994; Mitchell, 1994; D'Alessandro and Ernst, 1995; Palmer and Braswell, 1995; Platt and Snyder, 1996; Harding, 1997; Salzberg, 2000; Breisch et al., 2001; R. Burke, personal communication 1997; A. Hulse, personal communication 1997; Bunnel, 2005; Kikillus et al., 2010; Seburn, 2015; Spear et al., 2018; Herpetological Review; Wisconsin Herp Atlas; USGS NAS). Although Klemens (1993) questions whether T. s. elegans eggs can hatch at colder latitudes in Connecticut, breeding populations have been documented  in Ontario, Canada, and Michigan (Spear et al., 2018).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

Research on the environmental impacts of Trachemys scripta elegans on native Great Lakes communities and ecosystems is needed.

In captivity, Red-eared Sliders are frequently raised in poor conditions, leading to widespread disease and parasite infections. In turn, turtles that are reared in captivity and subsequently released into nature have a high likelihood of spreading pathogens and parasites to wild native turtles in the Great Lakes (Hays, 1999; O’Keefe, 2009; Harding and Mifsud, 2017; Demkowska-Kutrzepa et al., 2018, Queensland DAF Risk Assessment). Spear et al. (2018) recommend that parasite and disease introductions by T. s. elegans need to be monitored in the Great Lakes, as the species is known to host and spread salmonella, ranavirus, bacterial infections, and helminth parasites to other vulnerable species globally (Hays, 1999; Verneau et al., 2011; Brenes et al., 2014; Heritier et al. 2017; Ma and Shi, 2017; Demkowska-Kutrzepa et al., 2018; Hidalgo-Vila et al., 2020; Queensland DAF Risk Assessment).

There is little evidence to suggest that T. s. elegans poses a significant ecological threat to the endemic turtles residing in the Great Lakes. Peterman and Ryan (2009) show that the painted turtle (Chrysemys picta) and the Red-eared Slider share basking habitat preferences, however, no significant impacts from this interaction have been observed. There is no documentation of T. s. elegans negatively impacting endangered species in the Great Lakes region, such as the Blanding’s turtle (Emydoidea blandingii; Spear et al., 2018; IUCN). In addition, native northern map turtles (Graptemys geographica) and painted turtles (Chrysemys picta) that live in sympatry with these sliders do not appear to experience significant competition for food resources (Jaeger and Cobb, 2012; Haas, 2015; Spear et al., 2018). Nonetheless, more research is needed to fully determine if T. s. elegans significantly impacts other sympatric native species via competition or predation.

Intergeneric hybridization is known to occur among chelonians (Brophy et al. 2006), but it is unknown whether the Red-eared Slider would hybridize with native Great Lakes species.

Trachemys scripta elegans has a high socio-economic impact in the Great Lakes.

In addition to potentially serving as disease vectors to endemic fauna in their invaded range, Red-eared Sliders have been highly associated with salmonellosis in humans. Salmonellosis in humans can be fatal, especially for young children (CDC website). In the 1970s, approximately 14% of all salmonella cases in Americans per year were related to pet ownership of T. s. elegans (Cohen et al., 1980; Queensland DAF Risk Assessment). From 2006 to 2020, hundreds of salmonella cases and numerous outbreaks were reported in Americans that had close interactions with T. s. elegans, including those that were from the Great Lakes region (Cohen et al., 1980; CDC website). For instance in 2017 alone, over 45 people from Illinois, Indiana, Michigan, Ohio, Pennsylvania, and New York were infected with salmonellosis linked to pet turtles (CDC website).

There are no records of T. s. elegans causing damage to infrastructure, markets or economic sectors, recreational activities, tourism, or the natural aesthetic of the areas that it inhabits in the Great Lakes.

Trachemys scripta elegans has a high beneficial impact in the Great Lakes.

The Red-eared Slider is a commercially valuable species in the pet trade and is recognized as the most sought after pet turtle in the world (Mo, 2019). Approximately 52 million individuals have been distributed around the globe (Spear et al., 2018). In addition, many people purchase sliders to keep them in decorative ponds on their property for aesthetic purposes (Kraus, 2009; Mo, 2019). Some Asian cultures believe that consuming turtles can bring good luck, and T. s. elegans can often be found in Chinese food markets or novelty shops for purchase (Williams, 1999; Mo, 2019).

T. s. elegans has also been subject to frequent research focused on its adaptability to extreme environments for the purpose of finding novel solutions to difficult problems in human medicine. For instance, the ability of T. s. elegans to survive for long periods of time in anoxic conditions has been studied extensively by medical professionals and molecular biologists hoping to find solutions for hypoxia-induced injuries in humans during cerebral strokes and heart attacks (Willmore and Storey 1997; Milton et al. 2007; Nayak et al. 2009; Biggar 2020). These studies mostly center around understanding the physiological and molecular processes in T. s. elegans associated with retaining cellular health when oxygen-deprived.

In Illinois (Ill. Admin. Code tit. 8, § 25.110(c)), it is illegal to sell or possess turtles and turtle eggs that violate the Public Health Service Act (42 USCA 264; 21 CFR 1240.62; 2005) and Section 3372 of the Lacey Act (16 USCA 3372). In Indiana (312 Ind. Admin. Code 9-5- 7.5), it is illegal to sell turtles of any species or origin that are less than 4 inches in carapace length unless it is associated with scientific research, an accredited museum, educational institution, college, university, or government agency. In Michigan (Mich. Comp. Laws § 287.312), it is legal to sell turtles and viable eggs under 4 inches if the distributor provides a health advisory sheet with the purchase. In New York (N.Y. Comp. Codes R. & Regs. tit. 10 § 2.58(a)), it remains illegal to sell small turtles and health advisory warnings must be posted near every commercial or educational display where turtles may be handled by the public. In addition, turtles in NY may be tested for salmonellosis at any time and ordered humanely euthanized if they test positive for bacterial infections by health officials. Pennsylvania (35 PA. Code § 1071) maintains federal law and reinforces the ban on the sale of small turtles.

Refer to the CDC website for all regulations related to salmonellosis (https://www.cdc.gov/phlp/docs/turtle-menu.pdf).

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological

There are no known biological control methods for this species.

Physical

A rigorous approach to removing T. s. elegans has been employed and tested for efficiency in Queensland, Australia. Workers utilized a combination of physical methods including draining small water bodies, relocating native aquatic fauna, setting up pitfall traps and cathedral traps to capture sliders, and building walls around the area of focus to keep sliders from emigrating once perturbed (O’Keefe, 2009). A method of splashing and disturbing the water, with the intention of drawing turtles toward deployed seine nets was also tested for efficiency as it has been known to be productive for capturing native Australian turtles. Unfortunately, these approaches proved ineffective for the complete removal of T. s. elegans in the test site, as the species is known to burrow in the sediment in depths up to two meters when disturbed (O’Keefe, 2009). O’Keefe (2009) recommends that managers use additional methodologies to ensure complete removal including: intensive trapping and netting coupled with enhanced detection techniques such as a trained dog to locate the species terrestrially (individuals, nests, and eggs) and finding sliders via environmental DNA. In addition, Garcia-Diaz et al. (2017) recommend additional survey methods for monitoring the status of T. s. elegans by using cameras and basking traps from the start of eradication efforts.

Chemical

There are no known chemical control methods for this species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

Pond sliders are commercially raised in incredibly large numbers for the pet trade throughout the southeastern U.S., especially Louisiana (Ernst et al., 1994; Williams, 1999; Salzberg, 2000).  The sale of all turtles under the size of "4 inches" (about 100 mm) or viable eggs was banned in the United States, except for educational or research purposes, by the U.S. Food and Drug Administration in 1975 to prevent the spread of salmonellosis in children (Ernst et al., 1994; Level, 1997; Williams, 1999).  Four inches or less is thought to be the size that a child can easily stuff into his mouth (Williams, 1999).  The extensive use of antibiotics at turtle hatcheries in the U.S. has given rise to more antibiotic-resistant strains of Salmonella (Ernst et al., 1994).  In many U.S. states T. s. elegans is the subject of specific regulation (Level, 1997).  Nevertheless, undersized juvenile T. scripta are still commonly sold in pet stores in Florida, and as recently as 2002 they were sold by roadside venders at a busy intersection in Gainesville, Florida (Somma, personal observation).  The European Union has banned the import of T. s. elegans because of the negative impact that released pets can have on native European pond turtles (Emys orbicularis species complex) (Williams, 1999).