It’s been a tough year for Lake Michigan anglers, and based on a recent conversation with Michigan fisheries biologist Jay Wesley, the fishery continues to deal with ecological changes that could affect future fishing.

Most anglers know, and Wesley acknowledged, that the king salmon population is lower than it’s been since the late 1980s. That impact was really felt this year.

It was done by design, since Michigan and other states slashed stocking rates two years ago in an attempt to reduce pressure on a diminishing alewife forage base.

Fish Mangers use stocking rates to maintain a balance between game fish and the forage base. That got out of whack when they discovered a few years ago that there was more natural reproduction in king salmon than previously realized. That was putting more mouths in the lake than the forage could support.

In fact, studies show that the natural reproduction of kings has dropped by as much as 14 percent since the stocking numbers have been reduced.

“That’s a good thing because it is giving our forage a chance to rebound,” said Wesley. “I’m optimistic the alewives will come back. We’re doing an assessment this fall to see how the 2015 alewife population is doing.”

The influx of quagga muscles has added a new dimension to the fishery’s woes; Quaggas now dominate the lake floor from Michigan to Wisconsin and could impact the forage base.

Like Zebra mussels, Quaggas are not native and got here via bilge water of international cargo ships. They have out-competed the zebra mussels, are larger and can survive in deeper, colder water.

Like Zebras, they are filter-feeders, siphoning voluminous gallons of water and removing the plankton and other microscopic organisms that other small, young fish depend on for survival.

That includes young-of-the-year lake perch that seemingly struggle to find anything to eat once they are hatched. That could explain why perch anglers aren’t catching many small perch this summer.

(As a side note, Ball State Researchers report finding a good number of young-of-the-year perch during their work this summer. But whether they survive in the coming months remains to be seen.)

Now, when the lake stratifies as the water heats up as it has this summer, the plankton builds in the upper layer of the water column – above the thermocline – and out of reach of the quaggas. That could provide help to the forage base.

Furthermore, said Wesley, another exotic species, the goby, has been providing a secondary food source for adult gamefish. He said lake trout are feeding on them pretty heavily, and since they have begun targeting gobies, natural reproduction of lakers is up 40 percent.

Unfortunately, gobies are bottom fish and don’t spend much time in the part of the water column inhabited by steelhead and salmon. Lakers, brown trout, smallmouth bass, ciscoes and larger perch – fish that linger near the bottom when conditions are right, will feed on gobies during spring and early summer.

“The gobies are providing bottom feeding critters a nutritional diet despite the lack of alewives,” said Wesley.

But that doesn’t do much for the trout and salmon that feed farther up in the water column and rely on alewives to keep them fed. In fact, many anglers report catching smaller and skinnier steelhead and salmon in the big lake this summer while the lakers have been robust.

Let’s hope that the alewife study this fall indicates this year’s alewife hatch showed signs of a forage base comeback and can help bring the trout and salmon fishery back to normal.