Canadian border patrol agents at the Ambassador Bridge connecting Detroit with Windsor, Ontario, in Canada made the seizure Feb. 28, The Detroit News reported Tuesday.
The seizure, the fifth in the last year, involved fish from farms in the southern United States bound for markets in Toronto, where the invasive species is popular in Asian cuisine, officials said.
Possessing live Asian carp in Ontario has been illegal since 2005, and while it is legal to possess live carp in the United States, transporting them across state lines is prohibited.
"Curbing interstate transport of live bighead carp promotes the federal government's goal of preventing the carp's spread into new lakes and rivers in the United States," U.S. Fish and Wildlife Service officials said last year.
Imported to southern U.S. fish farms in the 1970s, the carp -- which can quickly dominate an ecosystem and threaten native fish -- escaped the farms and have been moving northward through the Mississippi River system.
Through the connecting Illinois River, they are now approaching the Great Lakes.