By J. Michael Kelly

Lake Ontario is a fishing hole in ferment, and the angler who dips his cup beneath those bobbing waves may have a hard time deciding whether it's half-full or half-empty when he brings it up for a look.

Topping the pessimistic side of the ledger, federal researchers have found that small, shrimp-like organisms called diporeia have virtually vanished from the lake in the last 10 years. That's worrisome because diporeia once filled the bellies of rainbow smelt, which used to be Ontario's primary forage species.

For Lake Ontario's trophy species the main alternative to smelt is the alewife. And although billions of alewives still swim in the big lake, they aren't growing as large, on average, as they used to.

Scientists suspect quagga mussels are to blame for the disruption of the food chain. Quaggas, the larger cousins of the better-known zebra mussels, now cover the bottom of Lake Ontario out to a depth of 300 feet. It's likely quaggas have literally crowded the bottom-dwelling diporeia out of their habitat. Furthermore, the filter-feeding mussels have consumed uncountable billions of plankton, thereby diminishing the food supply of forage species.

Photo by Ron Sinfelt

Last fall, the U.S. Fish and Wildlife Service approved new regulations for the management of double-crested cormorants. That's an important advance for Lake Ontario anglers because cormorants have been blamed for eating up to 1.3 million smallmouth bass in a single year along the east shore of the lake.

A creel census conducted by Department of Environmental Conservation personnel last year revealed that fishing for salmon, brown trout and smallmouth bass was notably better than average.

And although steelhead fishing on the lake was slow in 2003, returns of spawning adults to the Oswego River improved, and similar outcomes can be expected at other stocking locations.

Finally, state officials have agreed to a slight increase in salmon stockings in the lake beginning this year. Assuming the extra stockings don't result in undue pressure on the forage base, anglers can hope for increased catches of adult salmon beginning in 2005.

To bring the lake-wide picture into sharper focus, here's a species-by-species status report for 2004:

Open-water salmon action peaked in August, when boating anglers harvested 12,752 kings and 1,313 cohos, but the harvest rate for chinooks also exceeded 0.7 fish per trip in both July and August.

After Labor Day, a sizable spawning run of kings and cohos developed in the Salmon River.

"We had wall-to-wall chinooks at the hatchery and lots of cohos mixed in with them," said Dan Bishop, DEC Region 7 fisheries manager, who oversees the salmonid program in the Oswego-Mexico Bay sector of the lake.

Bishop anticipates improved prospects for cohos in 2004 because last fall's spawning run included a robust number of sexually immature coho "jacks."

DEC Bureau of Fisheries personnel approved a 10 percent boost in chinook salmon stocking rates effective in 2004. The slight increase was touted as a compromise between angling groups in the Niagara Falls and Rochester areas, which wanted larger stocking increases, and east shore organizations that oppose stocking changes until the status of the lake's forage base is clarified.

Brown trout action on the lake slowed in May and June, but rebounded impressively in July. The harvest rate for browns that month was 50 percent higher than the previous five-year average for July. Most charter captains credited cooler-than- normal water temperatures for the summer brown trout resurgence.

Assuming reasonable spring conditions, Bishop and other biologists expect continued good brown trout fishing this year.

State biologists suspect most of the yearling steelhead set free in Lake Ontario wind up in the gullets of large lake trout and salmon, or are chased away from a dwindling forage pantry by more numerous species.

To rejuvenate the steelhead fishery, DEC experts have stocked increasing percentages of young rainbows in net pens, as previously outlined; and they have also experimented by stocking fish in different sectors of the Salmon River watershed. Bishop noted that net-pen graduates lately have accounted for the lion's share of tagged steelhead caught by anglers in the Oswego River.

He hopes the continued use of net pens at Oswego and other points around the lake will result in improved steelhead runs in 2004 and beyond.

However, in recent seasons the harvest of lakers has declined. From April through August in 2003, for example, Ontario anglers creeled just 4,658 fish, or about one-third as many as they averaged for the same period between 1993 and 1997.

The decline probably reflects the increased availability of brown trout and chinooks in the lake. Given the opportunity, most anglers prefer to target browns and salmon even though many Ontario lakers weigh between 15 and 20 pounds.

Although lake trout are native to Lake Ontario, only a fraction of lakers found in the watershed are wild-spawned fish. Since the 1970s, the fishery has been maintained by annual seedings of juveniles from the federal hatchery system.

Bronzeback fishing in the lake is outstanding from the mouth of the Niagara River all the way around the shore to the head of the St. Lawrence River at Cape Vincent. Although cormorant predation has undoubtedly cut into catches in the northeast corner of the lake, Henderson Harbor anglers reported improved fishing last season, with numerous 3- and 4-pound smallies in the local mix.

Because large numbers of 10- to 12-inch bass were present throughout the lake in '03, there's no reason why the bass action shouldn't be even hotter this year in such areas as the bluffs east of Fair Haven Beach Park in Cayuga County, the stretch of Mexico Bay between Catfish Creek and the Little Salmon River and around the islands west of Henderson Harbor.

From April through August last year, lake fishermen creeled 499 walleyes. That's half as many as were harvested in the comparable period in 2002, but more than were reported in either 2000 or 2001.

The state creel census likely understates the quality of the walleye sport available in Lake Ontario, because it does not include the many fish caught by shore-casters.