Because the Mississippi is so long, we've seen this invasion front moving further north for the last 20 years. You see that upward trend because you are constantly at this invasion front.
Further south, they do see some levelling off but still at very high levels of biomass of Asian carp. They are still at very high numbers, preventing commercial fishers from going out and fishing for other species because the fish destroy their nets and they cannot afford to fish for other species.