There’s something going on in Lake Pontchartrain, and it’s something that lots of “lake” fishermen haven’t seen in a long time.

For the past 10 days, reports begin like this: Redfish are everywhere on the bridges. The Causeway is loaded with ‘em ... so many of them that it’s hard to catch speckled trout. There’s lots of bait in the lake. Small mullet, loads of pogeys, some shrimp and, when we clean the catch, we’re finding redfish stuffed with small crabs.

OK, not stuffed the way that redfish are stuffed with crabmeat and ready for the broiler, but literally loaded with small, long-as-your-thumb crabs.

Talk with the old timers, the guys who’ve been fishing Pontchartrain for decades, and there’s an explanation.

The Bonnet Carre Spillway last was opened in 2011. It was the 10th time this system that lays between Norco and LaPlace was used to relieve the pressure from extra-high Mississippi River floodwaters on levees protecting New Orleans and other down-river locations. Millions of gallons of muddy Mississippi River water flows from the river into Lake Pontchartrain, and for varying periods of time upsets the balance of the ecosystem in the state’s largest lake.

What happens, the old timers have said, is that is takes the lake a couple of years to “get right” — in this case three full runs of the seasons — but when the ecosystem gets right, there’s a mushroom cloud-sized explosion of life in the lake. It’s happened before: The Bonnet Carre was opened in 2008, and 2010 turned out to be a banner year for specks and other species in the lake, notably a run-to-remember on flounder in October that year.

If that’s the explanation for the extraordinary number of crabs in the lake, and all the other fishes, this year, then it follows the trend, albeit a year later than the 2008 pattern, of building the microorganisms that it takes to start the food chain that eventually leads to bonus catches of redfish and other species.

Even last year, when fishermen reported taking giant blue catfish from The Causeway and the bridges spanning the five-mile gap between the south and north shores, there was evidence the return to a brackish-water system was lagging. Yet there was enough food around to keep the 20-40 pound blue cats in places where they could eat and survive.

Though the trout were on the small side for Pontchartrain trout, the mid-April through Mid-May run on specks should have been signal enough that the lake was ready to provide the kind of fish-catching action some anglers said was gone during the past two years.

For now, the reports note 16 to 21-inch long redfish around The Causeway. There are some 30-35 inch long reds showing up, especially along the south shore and farther east towards The Rigolets and Chef Pass.

“There are as many redfish as you want to catch in a day,” Covington angler Jeff Bruhl said after a Causeway trip last week.

Anglers need to remember that the daily redfish limit is five and the fish must measure a minimum of 16 inches long to go into the ice chest. And, among those five reds, none can be longer than 27 inches.

Two tournaments

David Cavell called to let bass fishermen know that Sunday’s Bass-n-Bucks tournament has been moved from Doiron’s in Stephensville to the Attakapas Landing on east side of Lake Verret. Take La. 401 west from Napoleonville to access the Attakapas Landing.

Wayne Tucker let the 55-and-older bass anglers know the Old Timers tournament is set for June 5 at Paizano’s at La. 70 and Belle River.