|Kommentar|A fish elevator or fish lift, as its name implies, breaks with the ladder design by providing a sort of elevator to carry fish over a barrier. It is well suited to tall barriers. With a fish elevator, fish swim into a collection area at the base of the obstruction. When enough fish accumulate in the collection area, they are nudged into a hopper that carries them into a flume that empties into the river above the barrier.
On the Connecticut River, for example, a fish elevator lifts up to 500 fish at a time, 52 feet (15.85 m), to clear the Holyoke Dam. In its first year of operation, 1955, the Holyoke fish elevator carried 4,899 shad over the dam; by 2004, the typical annual number of fish lifted had risen to more than 500,000.http://en.wikipedia.org/wiki/Fish_ladder
Of course, as always, you can find some obscure use. Believe me, though, while an elevator lifts something up, AE doe not usually call an elevator a lift, and this functions clearly as an elevator.
My suggested designation stands as the norm, I'd say. Of course, the things are quite rare in the US anyway, so one or two of each name doesn't really provide a relevant statistical sample.