TAHOE'S MACKINAW A MYSTERY.

Byline: BRETT PAULY Angling

The fact that lake trout, or mackinaw, survive at all in nutrient-poor Lake Tahoe is remarkable enough. But that they live to be so old and fat has biologists baffled.

``It doesn't make sense,'' said Russ Wickwire, a Department of Fish and Game associate fish biologist in Fresno. ``Most trout live in nutrient-rich water, where they grow so fast they burn out. At Tahoe, it's just the reverse.

``The lake is sterile because it's so pure; there is not a lot of food. But the lake trout grow so much slower and longer and bigger. Maybe it's the cold water. Genetics have probably changed over the years. It's an anomaly.''

Apparently a frigid bath is nature's preservative.

Most trout don't see their 10th birthday. Tahoe's mackinaw - Salvelinus namaycush - can live 40 years or longer. An 18-pound mack was aged at 23 years. The state-record 37.6-pounder caught in 1974 was surely plucked from its rocking chair.

Indeed, the oldest granddaddy of the lake was beckoning us early on a recent overcast Wednesday when our party of six boarded the Big Mack II, a 43-foot charter boat out of Carnelian Bay skippered by mackinaw guru Mickey Daniels.

``The No. 1 priority is to keep from getting the lines tangled and No. 2 is to catch fish. In that order, all the time,'' Daniels warned as he set up six 10-pound monofilament trolling lines with Rapala lures off Crystal Bay Point. ``And if you do catch a mackinaw, watch out: They'll pull the boat backward.''

Last November, one of Daniels' clients boated a 44-inch, 28-pound mackinaw after an 80-minute battle. His own top catch is a 30-pounder.

Imported from Michigan's Great Lakes in 1896 as a sporting alternative to Tahoe's native Lahontan cutthroat trout, the mackinaw - properly a char, not a true trout - appears to have outcompeted its brethren and might have contributed to a major cutthroat die-off early this century by introducing disease.

I had caught two 9-1/2-pound mackinaw - personal bests for trout; 10 pounds is considered trophy size - during trips with Daniels in the late 1980s while I was living and working in nearby Incline Village, Nev.

But this outing was not likely to yield such dimensions, since the largest fish - Tahoe's mackinaw reach maturity at age 7 and 24 inches - spawn from September to November and slow their intake down or stop eating altogether.

Fond of the cooler waters in deep lakes, the mack feel right at home at Tahoe, where depths have been measured to 1,645 feet. They are frequently caught trolling with wire line in 60 to 600 feet of water on lures and live minnows. But a stiff breeze kept the captain from targeting midlake depths. ``It's harder to fish for mackinaw in the wind; you have to go faster to keep from going sideways,'' Daniels said.

It was the second strike against us in our bid to land mackinaw.

We took the news in stride as our guide suggested targeting the lake's population of rainbow trout that hugs the nearshore at 20 to 60 feet of water and bite best in fall. Besides, with mackinaw constituting 70 percent of Tahoe's game fish - rainbow (10 percent), brown trout (5 percent) and landlocked kokanee salmon (15 percent) make up the remainder - a few were bound to be found at line's end.

``There are little fish on the surface,'' said Daniels, a staunch advocate of catch and release who fishes 200 days a year and claims to have tagged 5,000 mackinaw in 30 years of guiding.

It proved a foreshadowing, as I reeled in the first mack - an 18-incher - after four rainbows were boated. Two more lake trout - the largest 19-1/2 inches - would add to the barbecue fare for dinner. The fish with the prominent white spots, deeply forked tail and large eyes - all the better to see at the lake's darkest reaches - is as tasty as it is beautiful. Its pink, oily flesh is similar to that of salmon.

During the four-hour tour, we hooked more than two dozen trout, landed 15 and kept six, including three 'bows to 17 inches. The rest were released, most notably three tagged lake trout.

Daniels charts the length of the fish before pinning it with a tag that notes his phone number. When anglers phone, he asks for the size of the fish, determines its growth rate and dishes the data off to biologists; perhaps it will someday help unravel the mystery of Lake Tahoe's mackinaw.

CHANGING OF THE GUARD

The mackinaw is king at Lake Tahoe, but the lofty throne once belonged to the Lahontan cutthroat trout.

During the last ice age, glacial Lake Lahontan covered West-Central Nevada; the ancient trout finned up the Truckee River and populated Tahoe.

Poor competitors, Tahoe's cutthroat did not survive the numerous plants of mackinaw, rainbow and brown trout - and other game fish - in recent decades. Overfishing and introduced disease also conspired against it.

Various efforts to reintroduce the cutthroat have failed.

- Brett Pauly

CAPTION(S):

Photo, Box

PHOTO (Color) Lake Tahoe fishing guide Mickey Daniels displays two mackinaw trout.

Brett Pauly/Special to the Daily News

BOX: CHANGING OF THE GUARD (see text)