ALPENA - Lake Huron anglers who catch an Atlantic salmon need to let a creel catch survey clerk know, especially if it's missing a fin.
The data these fish can provide will be crucial in determining the success of the Department of Natural Resources' Atlantic salmon program, Northern Lake Huron Fisheries Supervisor Dave Borgeson said. The department is stocking about 130,000 fish this year, up from 2013 when it stocked about 100,000. In both years, some of those fish went into the Thunder Bay River in Alpena.
Unlike their Pacific cousins, Atlantic salmon are opportunistic feeders and are more adaptable to changes in Lake Huron's food web, Borgeson said. And the offspring from a stocking program run by Lake Superior State University already are showing up at the end of anglers' lines.
"We're seeing those fish not only in the St. Mary's (River), but up and down the coast appearing in anglers' catches, to indicate relatively high survival of those stocked fish to anglers' creel," he said. "What we wanted to do is see if we could duplicate that level of success at other stocking locations."
Other stocking locations include the Au Sable River in Oscoda and Lexington, Borgeson said. The idea in Alpena and Oscoda is to potentially create pier and stream fishing opportunities as well. This year, Alpena got 25,127 fish, up from last year's 20,773. He expects fish stocked last year to start showing up by the end of this year.
The Platte River State Fish Hatchery started rearing the salmon in 2010, raising 12,698 for planting, according to the hatchery website. They're not as easy to raise as Pacific salmon like chinooks or coho, Lead biologist Aaron Switzer said. They're more susceptible to stress, and therefore, disease. With help from LSSU, the hatchery crew worked the bugs out.
"These guys are a little different," he said. "We can't raise them at high densities like Pacific salmon, for instance. In the same style tank that we can raise over 100,000 Pacific salmon in, we're only able to raise 50,000 Atlantics. They don't like to be crowded."
Atlantics need cleaner water, Switzer said. The hatchery typically recycles its river water for four passes, but Atlantics have to be raised in first-pass water. They also have to be at just the right temperature when they're going through the smolt phase.
The fish's touchy nature has inspired an unofficial motto Switzer believes he picked up from someone at LSSU: "Don't give them a reason to die."
"We're used to raising Pacific salmon here, and Pacific salmon are pretty easy to raise," he said.
With the kinks ironed out, Switzer said Platte River is hoping to raise 150,000 Atlantics for 2015. That should be the last year the program will be in its experimental phase.
Next, creel catch survey clerks need to hear from anglers who caught Atlantics, Borgeson and Switzer said. Fish stocked by the state in 2013 have clipped adipose fins, and this year they have clipped fins and a coded wire tag in their snout. That coded wire tag tells researchers where the fish were stocked, giving them an idea of how survival rates differ from location to location. Fish stocked by LSSU have clipped pectoral or ventral fins.
Either way, researchers need to know how these stocked fish are contributing to the lake's fishery, Borgeson said. He's hoping the DNR can replicate the same success LSSU has had, but he won't know until the fish start returning.
"If not, we need to figure out what's the difference between the fish stocked at Lake Superior State and the fish stocked at the Au Sable and Thunder Bay rivers," he said.