Program sheds light on fishery's decline

Manoeuvering my vessel along the outside edge of a weedline on Sturgeon Lake, my gut told me I would find walleyes hungry enough to consume what I was about to throw in their feeding zone.
Reinforcing my belief was a slight northerly breeze that created a slight chop on the water surface, reducing the amount of sunlight cast into the water.
Tossing a pearl-coloured Phoenix grub on a quarter-ounce chartreuse coloured jig head, I let it sink to the bottom before thrusting my fishing rod in an upward motion. But before I could feel the jig moving upward, some resistance was met at the end of the line.
And some force it was.
What felt like a fish with some big shoulders turned out to be the case once I got it to within viewing distance, just a few feet below the surface.
While the fish made several mad dashes under the vessel, it eventually ran out of steam and succumbed to my wishes.
Bringing the fish into the boat, I noticed a small clear tag hanging just in front of its dorsal fin. Inscribed on it was: SSFC 27,110.
Had I won a big fish lottery that might have been conducted in the area?
As my luck would have it, no way.
But the tag I recovered is contributing to the Ministry of Natural Resources' efforts monitoring the status of the walleye sport fishery, not just on Sturgeon Lake, but in adjoining bodies of water in the Kawartha Lakes system.
Considered a bread-and-butter sport fish in the area for many years, the walleye population has experienced some hardships in recent times, noted Dave Preslie, a fish and wildlife technologist from Sir Sandford Fleming College in Lindsay.
With students from the college's school of natural resources assisting the ministry in this program since 1998, Preslie said their tagging studies indicate the invasion of foreign species, such as zebra mussels, spiny water fleas and black crappies, into the Kawartha Lakes have not done the walleye fishery any favours.
"The presence of zebra mussels, for example, has made the water clearer, thus fish like walleyes, which once used to inhabit deep-water areas, don't any more due to the amount of light that penetrates down deep," he said, noting the walleye population continues to decline.
"Now, they seek areas with weed cover, in areas five, six to nine feet in depth where light won't penetrate as much."
It is believed the presence of black crappies, which have been known to take over a lake through their proliferation, has altered the walleye fishery by their consumption of these fish at the fingerling stage.
Conducted by placing a series of trap nets on various parts of Sturgeon Lake to corral and tag collected walleyes, the program has also been beneficial in monitoring fish movements and growth rates.
The fish I had landed was originally tagged Oct. 4, 2006 in an area about two kilometres to the south. The length of the fish was 24.9 inches and weighed 4.4 pounds. The assessed age of the fish was nine years at the time of tagging. Those measurements weren't far off from when I had landed the fish.
While the tag didn't win me any money, it did enrich my knowledge of what the ministry has been up to while working to improve a vital sport fishery.
Such programs are not restricted to the Kawarthas.
In York Region, the ministry has conducted fish tagging on smallmouth bass in Lake Simcoe and migratory rainbow trout that use the Rouge River during their annual spring spawning run.
If you catch a fish with a tag, the ministry urges you to record the tag number, length and girth measurements and, if possible, the weight of the fish and then relay that information.