Invasion
Invasion Description
1st Record: 5 counties (including Philadelphia)/PA/Delaware River (1880, Creveling 1881)
Geographic Extent
5 counties (including Philadelphia) /PA/Delaware River; (1880, Creveling 1881) Wilmington/DE/Delaware River (1891, Trenton/NJ/Delaware River (Raasch and Altemus 1991); Trenton-Marcus Hook/NJ-PA/Delaware River (Horwitz 1986; Weisberg 1996) Delaware River - Micropterus salmoides was probably introduced before 1893, since it was'widely introduced in Pennsylvania' (Bean 1893). Pond rearing began in Wilmington DE in 1891 (Raasch and Altemus 1991); It is now widespread in fresh-mesohaline waters of the estuary (Horwitz 1986; Raasch and Altemus 1991).
Vectors
| Level | Vector |
|---|---|
| Probable | Fisheries Accidental (not Oyster) |
Regional Impacts
| Ecological Impact | Predation | |
| Micropterus salmoides (Largemouth Bass) is a major predator in Delaware River estuary. Introduction of this and other large piscivorous fishes may have decreased the abundance both of native prey species and the two major piscivores in the estuary, Esox niger (Chain Pickerel) and Morone saxatilis (Striped Bass). However, evidence for this is scanty (Horwitz 1986). | ||
| Economic Impact | Fisheries | |
Largemouth Bass (Micropterus salmoides is a major gamefish in the Delaware River, and the surrounding watershed (Raasch and Altemus 1991). Web searches indicate that several bass tournaments were scheduled along the tidal river in 2018. | ||