A shore-spawning brook trout cruises in shallow water at Moosehead Lake. After years of speculation and second-hand reports, biologists in the region have confirmed that brook trout -- often very large ones -- spawn along the lake's shores, rather than in tributary streams. Credit: Courtesy of the Maine Department of Inland Fisheries and Wildlife

Early in my career Roger AuClair, the regional fisheries biologist for the Moosehead Lake region at that time, told us a story about shore-spawning brook trout in the big lake. AuClair knew a gentleman from Rockwood who was a caretaker for some camps, and he was also a trapper. This fellow told AuClair that he had seen brook trout spawning in Moosehead under the ice in his travels.

AuClair had done a lot of work studying brook trout in Moosehead Lake. His work at Socatean Stream was outstanding, and those of us that followed in his wader tracks have also put a high priority on understanding the wild brook trout population in Maine’s largest lake. However, no one was ever able to document shore-spawning brook trout in Moosehead Lake.

Shore-spawning does occur in smaller brook trout ponds. It’s quite common to find trout spawning in a small springhole in a remote trout pond. But on Moosehead, brook trout were found spawning in the streams and rivers. We have documented substantial runs of spawning trout in Socatean Stream, Roach River, Moose River, East Outlet and many of the smaller brooks. In all of these locations, the brook trout enter the stream in late summer and early fall, spawn in early to mid-October, and then exit the stream back into the lake. It is all wrapped up before November and well before the first skim of ice on the lake.

We have searched for shore-spawners over the years, but it felt a little like the search for Bigfoot. Was it even possible? It seemed very late to have any brook trout spawning occurring. Even togue spawning, which does occur in the lake, wraps up by early November. Maybe adult beverages were involved? It was a long-standing mystery and good fodder for discussion around the campfire.

Watch: Alewife run through Westbrook

Then we got a tip. It was around Veteran’s Day in early November a couple years ago. It was time to go Squatchin’!

It was true and spectacular. These were not run-of-the-mill brook trout from Moosehead Lake. These were the big boys (and girls). It was pretty amazing to see, and now, after a few years of evaluation, we know these fish are quite different from their counterparts that run up the Roach River or Socatean Stream.

The size difference was obvious from simple observation. That meant these fish were probably much older than typical Moosehead Lake brook trout. In fact, from our weir work on the Roach River and Socatean Stream, we know that most of those adults are age 3 and 4 when spawning in the tributaries. These shore-spawners are 6 to 9 years old. The male trout spawning in the tribs have a post-spawning mortality rate of around 50 percent to 60 percent. We estimated post-spawning mortality at half that rate for these shore-spawners. The fish in the streams are confined in a small area and must avoid predators such as eagles and otters for two months. It’s a war. But these shore-spawners can quickly evade predators by heading out into the deep water. They can swim in all directions to avoid becoming an otter’s meal ticket.

We also think the overall conditions for survival are better for brook trout since the lake trout population was thinned. More food equals improved growth and more fish are surviving compared to the past. We have been able to document better survival with our hatchery salmon and we believe we are seeing the same trends in survival for brook trout. That is good news for anglers.

These fish also are very different in their spawning habits. This is the third season we have been studying them. These fish show up some time around the end of the first week of November. While this is quite amazing in itself, here is the wicked amazing part: Some are still around the spawning site in very late December, well after ice formation and very close to the opening of the ice fishing season.

Could it be that some of these fish are still spawning during the ice fishing season? It is possible. We have seen fish caught in the early days of January that are dropping eggs and milt. That can occur post-spawning, especially with some females not releasing all their eggs during the act of spawning. Many of you may have cleaned a fish to find a few old eggs still in the body cavity. But it is not as common for males in the wild.

Our radio telemetry work shows that the shore-spawners are similar to the tributary spawners in one respect. They both retreat from the spawning site to other areas of the lake and set up shop for the winter. They move very little during the winter months, likely recuperating from the rigors of the spawning season.

Back in the 1930s, Spencer Bay was closed to winter angling because it was known to be an area where brook trout congregated, and they were heavily exploited by anglers. Back in those days, I’m sure they did not know that the vast majority of these fish had just spawned in the Roach River. We were able to verify that with our radio telemetry studies.

Socatean Bay was closed after AuClair found that his jaw-tagged trout from Socatean Stream accumulated in the bay after spawning. In 2009, our radio telemetry work re-confirmed AuClair’s findings. The closures of Spencer and Socatean bays in the winter are still very effective regulations to protect wild brook trout in Moosehead Lake.

We are studying some of these shore-spawning sites carefully. We do not want anglers fishing over actively spawning wild brook trout in Moosehead Lake. That is why our streams and rivers with wild brook trout and salmon are closed in the fall in northern Maine. We also need to determine if there are areas where these fish are congregating and are vulnerable to overexploitation. Our radio tracking and creel surveys will tell us plenty. We would appreciate it, if anglers would release any radio-tagged brook trout.

We want to thank the Moosehead Lake Fisheries Coalition for their support and the purchase of these important and rather expensive tags. We have also purchased an underwater drone to examine other potential sites.

We do live in a different time though, anglers no longer need to take that fish of a lifetime home to have it mounted. A couple quick photos and a tape measure are all that are needed to have a beautiful replica made for your wall, and you have the satisfaction of knowing that fish is still swimming. Many anglers do that already, and I applaud them for helping to conserve a unique assemblage of brook trout in Moosehead Lake. I have posted some video and pictures of these trout for you to enjoy here.

Tim Obrey works for the Maine Department of Inland Fisheries and Wildlife as the regional fisheries supervisor for the Moosehead Lake region.

Watch: Divers explore shipwrecks of Moosehead Lake for documentary