Monday, November 26, 2018

Maine: Moosehead Lake Producing Lunker Brook Trout

IFW biologists handled this handsome male brook trout in the fall of 2018 that weighed in at 7.3 lbs.

By MDIFW Fisheries Biologist Tim Obrey

I know the Chinese calendar says 2018 was the year of the dog, but for those that fish Moosehead Lake, it was the year of the brook trout…big brook trout. It seemed like we were seeing photos of wild brook trout over 4 pounds every week last winter. And the hits just kept coming in the summer. I’ve never seen anything like it in my 30+ years of working in this region. It may appear like the stars aligned to create the outstanding fishing in Maine’s largest lake, but there’s more to it than sheer luck.

Back in 2006, the minimum length limit on brook trout was increased from 12 inches to 14 inches. We knew from our extensive data collection in the winter that this would protect around 40% of the brook trout that were typically harvested. Certainly, hooking mortality would still be a factor on these fish, but over time, the brook trout population should increase as long as angler use remained stable and angler use actually dipped a little since the early 2000s on Moosehead Lake.

Perhaps the biggest factor to the improved conditions for brook trout in the lake was the reduction of the lake trout population which began in 2008. If you follow fishing on Moosehead Lake at all, you will know that the lake had too many lake trout for many years. Lake trout, salmon, and to a lesser extent brook trout (once they reach a certain size), all rely on smelt for food and the over-abundant lake trout were eating us out of house and home. Growth for all three species suffered.

Liberal regulations were adopted in 2008 to finally thin out the lake trout. We estimated the removal of over 100,000 lake trout less than 18 inches and another 25,000 lake trout over 18 inches from 2008 to 2013. The smelts could finally breathe a sigh of relief and we documented significant improvements in growth for the game fish, including brook trout, as these tiny forage fish became more abundant.

Dustin Harrington landed this 24 inch – 5.8 lb brookie in the winter of 2018.

This fall we operated a weir on the Roach River to monitor the spawning run of wild brook trout and salmon in the major spawning tributary to Moosehead Lake. When we last ran the weir in 2010 and 2011, around 20% of the brook trout were over 16 inches. This year, 56% of the brook trout handled at the weir exceeded 16 inches.

While we never could have predicted the abundance of trophy brook trout that we are currently witnessing, it was clear that there were more brook trout in the lake, and both survival and growth were improving. The conditions were, and still are, exceptional for brook trout. The future is still bright for brook trout in Moosehead Lake.