Though the word (phrase, really) and the definition would lead one to think of it as a result of the traditional Catholic prohibition against eating meat on Fridays, it's more prosaic. Just a surfeit of the item in question in a particular place. Though I do like the idea that beef is far preferable to fish that is implied by the nickname.
Albany beef n.
Etymology: < Albany, the name of the capital city of New York State + BEEF n., in reference to the abundance of the fish in the waters of the Hudson River near Albany