Shortnose Sturgeon (Acipenser brevirostrum)
Here's something you don't hear about everyday. The shortnose sturgeon, listed as vulnerable on the IUCN's Redlist, appears to be recovering, at least in certain rivers in North America. Although the article cites a 400% increase in the Hudson River since the 70s, it makes no mention of other rivers where this species is also threatened.
Here's the article.
Images of Shortnose Sturgeon.