The salmon summer of 2013 ended on Sunday, when crews from the Maine Department of Marine Resources’ Bureau of Sea-Run Fisheries and Habitat tended the trap at the Veazie Dam for the final time.
On Monday, that same dam will be breached as part of the Penobscot River Restoration Project. In future years, Atlantic salmon will be counted at the Milford fish lift.
This year won’t fondly be recalled by biologists and salmon conservationists, as only 372 salmon returned to the Penobscot River this year. That’s the lowest total in the Veazie trap’s history, which stretches back to 1978.
The lowest number of returning fish before this year was 392, way back in 1983.
Richard Dill, a fisheries biologist for the Bureau of Sea-Run Fisheries and Habitat, said he and his colleagues saw signals a year ago that indicated this year’s run might be disappointing.
“Looking back to last year, 624 [salmon returned], but we had a really low number of grilse, or 1-sea-winter returns,” Dill said. “Typically our grilse make up anywhere from 25 to 45 percent of the run for a year.”
But in 2012, only 13 of the 624 returning fish — 2 percent of the total run — were grilse.
“We were concerned coming out of last year,”Dill said.
Dill’s concerns were well-founded.
In a nutshell, biologists knew that if only 2 percent of the 2012 run was grilse, that could indicate that the entire “cohort,” or group of fish from that age-class, might have encountered unexplained troubles during their sea journeys.
And if that was the case, things would get even worse this summer, when members of that cohort made up the bulk of 2-sea-winter fish returning to the Penobscot.
“If [the 2012 trend] continued, we would have expected to see less than 100 2-sea-winter fish, so our run could have been less than 100,” Dill said.
The situation didn’t deteriorate to that extent, which is a minor consolation considering more than 3,000 fish returned just two years ago.
“So, we got 316 multi-sea-winter fish this year,” Dill said. “Looking at it, we actually probably exceeded what our expectations were. The huge unknown here is the marine survival, or the marine mortality, however you want to look at it,” Dill said.
But really, it doesn’t matter how you look at it.
“This is not good,” Dill said, bluntly.
I’d like to be able to pass along some good news to dampen the blow. Unfortunately, there’s only more bad.
Dill explained that when biologists trap salmon in Veazie, they transport some of those fish to hatcheries to aid in restoration efforts.
“Typically our goal [is to transport] 400 females, and that would be used to support the smolt stocking effort on the Penobscot — 500,000 smolts — and 1 million fry a year.”
That plan took a huge hit because of this year’s low returns.
“We’ve got 166 females, so right out of the gate we’re below 50 percent to create what we’d need as broodstock for the program,” Dill said.“That’s not a good thing,” he said.
Dill said a backup plan was implemented years ago. Each year biologists set eggs aside that support a “domestic line” of fish that are held at the Green Lake National Fish Hatchery in Ellsworth. Those fish, called “F-2s” are domestic fish that are mated with domestic fish. Typically the fish that are stocked in the Penobscot are F1s, or the offspring of wild fish mated with wild fish.
This year, Dill said, according to the backup plan, the domestic line of fish will be used to provide for the fry stocking in the Penobscot.
“So the implication is that those F2s, when they haven’t been used [in the Penobscot], have been used to support [stocking] efforts on other rivers,” Dill said.
Among those rivers: The Saco, the Union, and more recently, the Sandy, which flows into the Kennebec.
“Because we need those eggs for the Penobscot, there will be less, or potentially no eggs available for the Sandy this year,” Dill said. “And that just reinforces that we need to have a stand-alone Kennebec program, but we just don’t have that right now. The Kennebec needs to have its own source of broodstock.”