[ Sporting Magazine ]
The Sporting Magazine (1792 - 1870) is considered the first general sporting magazine, though in its later decades it gave considerable emphasis to fox hunting. But it published all manner of sporting-related material, from news stories to poetry to calendars of upcoming sporting events. The subtitle of this magazine was "Monthly Calendar of the Transactions of the Turf, the Chace, and every other Diversion interesting to the Man of Pleasure, Enterprize and Spirit." [more at Wikipedia]
The April, 1820, issue carried a brief report about a Newf's fishing skills:
SINGULAR OCCURRENCE. — On Monday, April 10, as Mr. Miles, of Southfield, near Malmesbury, was walking by the side of the river with a favourite Newfoundland dog, the animal suddenly jumped into the water and caught a fine jack, weighing three pounds, which he brought to his master.
A "jack" is one of any dozens of species of sport fish; most species are oceanic but there are some that live in rivers.