Tinca tinca has a moderate probability of establishment if introduced to the Great Lakes (Confidence level: High).
Tench have high tolerance to a broad range of environmental conditions including low pH, low dissolved oxygen, and high temperatures (Sabapathy 2014; Avlijaš et al. 2018). However, they do not typically inhabit fast flowing water (Avlijaš et al. 2018). They can likely overwinter in the Great Lakes given that they have established populations in Quebec and Ontario (Avlijaš et al. 2018). Climate match analysis rates the Great Lakes region as very high (Avlijaš et al. 2018). Tench also has a broad diet (Scott and Crossman 1973; Alas 2010; Bezmaternykh and Shcherbina 2018), which means they would also likely find appropriate food sources if introduced to the Great Lakes.

However, tench were introduced throughout the United States in the 19th century, yet are only established at a fraction of these sites today (Avlijaš et al. 2018). Some observations indicate that the failure of the tench to establish may be related to a biotic interaction with centrarchids (DeVaney et al. 2009), which are also widely distributed in the Great Lakes Region.

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

Environmental	Socioeconomic

Tench may also harm native cyprinids and other benthic species through competition (Avlijaš et al. 2018).

Experimental trials showed that tench negatively impact gastropod populations, indirectly leading to increased periphyton biomass and alter physical habitat by reducing macrophyte abundance through trophic cascades (Beklioglu and Moss 1998, Avlijaš et al. 2018). Additionally, the presence of tench is predicted to disturb sediment, reduce water clarity, and disrupt trophic cascades, further affecting macrophytes and promoting epiphytic algae in the Great Lakes region (Avlijaš et al. 2018).

There is little or no evidence to support that Tinca tinca has the potential for significant Socio-Economic impacts if introduced to the Great Lakes.
Tench are not reported to pose any threat to human health, damage infrastructure, affect water quality, harm economic sectors, or inhibit recreational activity.

Tinca tinca has the potential for moderate beneficial impacts if introduced to the Great Lakes.
Tench were originally brought to the United States for use as a food and sport fish (USFWS ERSS 2014). Tench may be mixed with other rough fish for sale (Avlijaš et al. 2018). However, there is not much demand for tench, and their economic contribution is insignificant (Dumont et al. 2002, Marcogliese et al. 2009). Tench are sometimes fished recreationally, however there are already numerous sport fish established in the Great Lakes.

Tench were introduced to Tasmania in the 19th century (Weatherley 1961).

DeVaney et al. (2009) performed ecological niche modeling to examine the invasion potential for tench and three other invasive cyprinids (common carp Cyprinus carpio, grass carp Ctenopharyngodon idella, and black carp Mylopharyngodon piceus). All of the current established populations of tench were in areas of predicted high suitability for this species. Interestingly, many areas where tench failed to become established or is currently extirpated (e.g., Great Lakes region) also had a moderate to high predicted suitability. DeVaney et al. (2009) attributed this potentially to negative interactions with sunfishes or unmeasured environmental factors.

Voucher specimens: Colorado (USNM 055569), Maryland (USNM 31003, 37850, 30336, 27234), Missouri (USNM 073666), New Mexico (UMMZ 118218), Virginia (USNM 30336, 31003, 37850).