Water the color of strong tea or weak coffee sluiced down a yard-wide, spartina-lined thread of a waterway, purling where it joined the current down the bayou it fed and into the bay less than 100 yards away.

As the outgoing tide pulled water from the marsh and into the little feeder creek, it carried assorted critters along for the ride. An irregular procession of small crabs, shrimp, killifish, juvenile mullet and maybe even a few marine worms rode the flow and was swept out of the little drain, over a submerged point and into the main channel of the bayou.

That point was a perfect place for an ambush on this cool, clear late-October morning with the slightly sulfurous smell of saltmarsh hanging in a crystal-blue sky sprinkled with migrating monarch butterflies drifting south on a light north wind.

The orange/black monarchs were not the only creatures with migration on their mind. And that's what made the point a focus.

I cast a quarter-ounce, lead-head jig trimmed with a pearl/chartreuse soft-plastic body into the little drain, let the bait fall to the bottom, then slowly bounced/dragged it, allowing the current swing it over the point.

A "thunk!" shot up the line. I reeled down, snapped the rod back and felt that wonderful pulse and shiver of connection with something very much alive.

There never was a moment's doubt of the fish's identify, even before it came flapping, gliding and thrashing to the surface. It was a flounder.

She measured just a smidgen more than 14 inches, the legal minimum for flounder. (I'm certain she was a she; male southern flounder seldom grow more than foot in length.)

I thought about slipping her into the ice chest and how fine a meal of baked flounder stuffed with crab meat and shrimp and drizzled with olive oil and butter would taste.

But I didn't.

Popular targets

Instead, I worked the hook from that sideways mouth rimmed with sharp, delta-shaped teeth, admired the incredible camouflage of white stars and splotches on a brown background and those amazing fluorescent green eyes, then slipped the fish back into the bayou where it fluttered away.

There would be other flounder; this was, after all, the start of the best few weeks of the year for catching the famous flatfish. And that young female flounder needed the chance to follow instincts that had brought her to that drain mouth and would see her soon join tens of thousands of other southern flounder on a journey to create her species' next generation.

Texas' southern flounder could use a little kind consideration from the state's million-plus recreational saltwater anglers — particularly this month. Along the Texas coast, November sees the highest catches of flounder of any month of the year. That's tied directly to the fishes' natural history. And it's why Texas fisheries managers, concerned with a significant, decades-long decline in the state's flounder population, in 2009 drastically reduced the number of flounder anglers are allowed to keep, especially during November.

As autumn arrives, adult southern flounder in Texas bays begin their annual migration to the Gulf of Mexico where they will spawn during the winter.

That migration begins with flounder gathering around the mouth of drains, bayous and other waterways connecting the bay with its estuaries to gorge on the plenitude of food pouring from those great generators of marine life.

From there, waves of flounder drift down the bays, moving along the shorelines, mostly, but also along the edges of channels toward passes connecting the bays to the Gulf.

Flounder concentrate around those bay/Gulf exchanges, waiting for some combination of strong outgoing tide and cooling water (most often triggered by passage of a cold front) to make their move through the passes and into the open ocean.

This predictable migration behavior makes flounder particularly popular with autumn anglers. Not that they aren't popular for other reasons; their standing as table fare is legendary. But their availability and cooperativeness also are major attractions.

"Flounder are one of the first fish you catch when you're a kid fishing off the bank, and a fish that everybody can catch," said Bryan Treadway, a confirmed flounder fanatic with a strong drive to help ensure they remain a viable part of the coastal fishery. "You don't need a boat to catch flounder."

But a boat doesn't hurt, either, said Treadway, who organizes efforts to collect live flounder for use in Lake Jackson's Sea Center Texas' programs to spawn the fish and stock the fingerlings into Texas bays.

During autumn, anglers can bet on two basic techniques to take flounder.

"You can fish what I call 'hard structure' or fish the passes," Treadway said. "Both work great."

Through most of the autumn migration, flounder moving down the bay systems gravitate to the mouth of drains where they pick off food or around "edges" where current concentrates forage.

Fishing the mouth of bayous and the flats adjacent to those mouths are a classic tactic. So, too, is fishing around bulkheads, piers, rip-rap, jetties, navigation poles and other objects.

Packs of flounder will concentrate tight to these "hard" structures, waiting for the current to bear some unlucky killifish within range. Bouncing a jig or slowly working a live finger mullet or mud minnow or even a shrimp along the bottom will draw strikes.

Any color you like

This can be a lot like bass fishing with a plastic worm: cast near the structure, let the bait fall, then slowly work it along the bottom. Flounder are very aggressive predators, so most often the strike is not subtle. And if you catch one, keep fishing the area, Treadway said; often, a relatively small area will hold several flounder.

The other, more common tactic for fall flounder revolves around fishing the bay/Gulf exchanges and the choke points leading to them — places such as Bolivar Roads, Sabine Pass, Galveston Channel, San Luis Pass and Rollover Pass.

"They have to go through those passes," Treadway said. "That makes them extremely vulnerable."

Flounder stage near those passes and in choke points, biding their time and feeding until an outgoing tide triggers their movement into the Gulf. The same bottom-fishing tactics that work for flounder in the bays work great at the passes.

Probably the best bait for flounder is live bait, with mud minnows or "finger" mullet topping the list. Rig a 12-18-inch length of 30-pound monofilament armed with a single live-bait hook, thread an egg weight on the running line and connect the 30-pound leader to the running line with a barrel swivel — a classic "fish-finder" rig. Hook the baitfish through the lips.

Jigs trimmed with soft-plastic bodies that imitate baitfish are the best artificials for flounder.

Colors?

"An old Galveston Bay flounder fisherman once told me you can use any color as long as it's red and white," Treadway said. "Red/white definitely works. But white/chartreuse and clear/glitter tails work great, too. And Gulp worms in red, purple, pumpkinseed or just about any color are killers."

The trick is persistence and patience. Keep a bait in the water. Flounder have to go through those passes. If you can find them staging or hit it when a wave of migrants catches an outgoing tide and makes their move to the Gulf, you'll catch flounder.

Just remember: During November, you can keep no more than two a day.

And if you have a couple already in the freezer at home, consider letting a few go, particularly the larger females, Treadway suggested.

"Flounder are a great fish, and it's fine to keep a few," Treadway said. "But they're in need of a helping hand. I have a three- and four-year-old that I want to take down to San Luis Pass one of these days and sit on the bank and catch a few flounder like I did when I was a kid."

November is the best time to do just that.

May that will always be the case.

shannon.tompkins@chron.com