Ecologists have known for some time that predators can have significant effects on terrestrial and aquatic prey populations. Culling is widely practiced as a means to limit predation on livestock and game. Changes in species' distributions and abundance illustrate that culling programs can be very effective at reducing predator density. Culling has also been used to reduce marine mammal populations in many parts of the world. Coastal pinniped species have usually been the target of such programs, but dolphins and large cetaceans have also been culled. The extent of marine mammal population reduction and the response of targeted prey populations to culls have rarely been evaluated.