Ecological Risk Screening Summary - Spotted Bass (Micropterus punctulatus) - High Risk

Micropterus punctulatus, spotted bass, is a fish that is indigenous to the contiguous United States. Spotted bass are native to the Mississippi River basin from southern Ohio and West Virginia to southeastern Kansas, and south to the Gulf. They are native to portions of east Texas from the Guadalupe River to the Red River. M. punctulatus has been known to hybridize with other species in the genus Micropterus. M. punctulatus is recognized as a popular game fish throughout the United States and South Africa which has contributed to establishment outside of its native range through intentional introduction and frequent stocking. Micropterus punctulatus is regulated in Arkansas, Colorado, Maryland, and New Jersey. The History of Invasiveness for Micropterus punctulatus is classified as High due to the negative impact of spotted bass populations have on smallmouth bass populations in Missouri through trophic competition and hybridization. In South Africa, Micropterus spp., including M. punctulatus, have been reported to contribute to the decline and fragment of native fish populations through predation and competition with indigenous species and invertebrates. The climate matching analysis for the contiguous United States indicates establishment concern for this species outside its native range. High climate match was found primarily around locations where the species is already established. The Certainty of Assessment for this ERSS is classified as Medium due to a limited amount of information regarding proven negative impacts and complications in understanding the species’ introduced range. The Overall Risk Assessment Category for Micropterus punctulatus in the contiguous United States is therefore classified as High.