A Fish Detective’s Quest To Document More Southeast Alaska Steelhead Waters

The following appears in the November issue of Alaska Sporting Journal:

Mark Hieronymus, Trout Unlimited’s Alaska science coordinator, is exploring Southeast Alaska’s vast waterways to help verify more creeks, streams and rivers as holding anadromous fish like steelhead. (TROUT UNLIMITED)


Few Southeast Alaskans are as knowledgeable about the region’s maze of rivers, streams and creeks as Mark Hieronymus.
But even an expert sleuth like Hieronymus, Trout Unlimited’s Alaska science coordinator, is constantly learning something about these waters and the fish that live there. Especially the ones returning from the sea.

The Anadromous Waters Catalog (AWC) lists every stretch of water in the region confirmed to be home to anadromous (migrating from saltwater) species – think salmon and steelhead in the Panhandle, sturgeon, smelt and lamprey elsewhere on the West Coast.

In Anadromous Waters, a Trout Unlimited-produced short film from filmmaker Josh Duplechian, TU’s senior producer, a graphic states that Southeast Alaska contains 5,000 salmon streams. The Alaska Department of Fish and Game officially recognizes 325 of that 5,000 as supporting annual runs of steelhead. In the massive Tongass National Forest – 16.7 million acres that represent the nation’s largest such public land – Hieronymus must play part fish conservationist, part Sherlock Holmes detective.

“It’s all ours and it’s this amazing national treasure,” he says of the Tongass. “It’s loaded with fish streams. We’ve got some really good assumptions and some good monitoring. But we don’t have a full complete picture of what’s actually out there. That’s what I’m doing – filling in those gaps.”

So it seems clear there must be more steelhead runs among the thousands of streams that empty into the North Pacific and Inside Passage waters.

“The AWC was designed as at least a guide to what’s in there, and when you can make assumptions on when you can go into an area to work and when there’s going to be fish presence,” Hieronymus said during an Instagram live chat shortly before the film’s YouTube release in mid-October.

“The crux of this thing is that the AWC is nowhere near complete. (ADFG), by their own admission, says probably 50 percent of the water in Southeast is actually accounted (for).”


Hieronymus made it a point to not consider ADFG a “villain” or negligent in updating the numbers.

“Nobody else is going to do it. Fish and Game doesn’t necessarily need to go back into a place they’ve already surveyed,” he says.

But there is plenty of work to be done in continuing to add more much-needed data and implement “conservation measures” in those waters.

And he can cite plenty of sightings of steelhead that technically weren’t supposed to be where they were in Southeast Alaska.

“I can think of 20 streams off the top of my head,” says Hieronymus, who also guides Panhandle fishing trips for Juneau-based Bear Creek Outfitters (juneauflyfishing.com). “There are several that I’ve had clients with and had the intention of chasing steelhead there that aren’t listed.”

In the film, Hieronymus admits that with steelhead, “Seeing them in the river is the easy part. Getting a fish in hand or documenting the existence of that fish in such a fashion that it’s incontrovertible that it’s that species in that location in that time – the work has kind of just begun.”

If such a task seems ridiculously difficult to track, at least Hieronymus understands it better than anyone. He can also lean on a consistent group of about six locals who share observations and report potential sightings in undocumented waterways, which can start the process of determining whether they can be logged into the AWC.

As a nomadic angler/fish scientist, Hieronymus has found himself stumbling onto new data all the time.

“I added pink salmon to the assemblage of three streams this year, just by looking off the highway while I was driving,” he says. “Seeing a pink salmon, turning around, grabbing my fishing rod, going down to the highest place in the stream where I can find the pink salmon; catching that salmon and taking a picture with my cell phone; recording the GPS coordinates of where I got that fish. Then when I got home I made a nomination. ‘I saw two pink salmon and here are the pictures.’”

As Hieronymus points out, concerns over the “unprecedented stock collapse” of steelhead further down the West Coast are worth keeping an eye on, though he did say that Alaska numbers have yet to be impacted like Lower 48 drainages.

“There’s gonna be a time where you won’t be able to talk about your secret spot – because it doesn’t have fish. It’s incumbent upon all of us to put in at least what we take out, right?” he says. “I said at the end of the movie, ‘Is this valuable to society? What do people at large think about this? Is this something that matters to you?’ Hopefully the answer is yes.” ASJ

Editor’s note: Watch Trout Unlimited’s filmAnadromous Waters at youtube.com/ watch?v=fIauSqCqUkM. For more on this project, go to tu.org/blog/desperately-seek- ing-steelhead-in-alaska-for-science.