What animal eat sea lamprey?

The Sea Lamprey (Petromyzon marinus) is a parasitic species of fish (despite their resemblance to eels they are not related). At this point there are no 'true' predators of this species at any stage of it's life-cycle.

The Sea Lamprey is considered an invasive species in the Great Lakes region and has been decimating the fish populations. Currently the control measures are limited to chemical and mechanical processes such as sterilization, physical barriers, and poison in extreme cases.

"Sea Lamprey." USGS Great Lakes Science Center. .