Are There Sharks in Lake Pontchartrain?

Shark in Lake Pontchartrain

Lake Pontchartrain, located in southeastern Louisiana, is an expansive estuarine system known for its brackish waters—a mix of freshwater from rivers and saltwater from the Gulf of Mexico. This unique environment supports a wide variety of aquatic life, including an unexpected predator: sharks.

Yes, there are sharks in Lake Pontchartrain, and their presence, while surprising to some, is entirely natural. The lake’s occasional influx of saltwater, especially during high tides, tropical storms, or periods of low river flow, allows certain salt-tolerant shark species to enter and inhabit the lake, even temporarily.

What Types of Sharks Are Found in Lake Pontchartrain?

1. Bull Shark (Carcharhinus leucas)

The most commonly encountered and most well-documented shark in Lake Pontchartrain is the bull shark. Known for their ability to thrive in both saltwater and freshwater, bull sharks are often found in rivers, bays, and estuaries worldwide. Their presence in Lake Pontchartrain is not new—there have been numerous documented sightings and catches dating back decades.

Bull sharks have a high tolerance for low salinity and can travel far inland, even up the Mississippi River. Juvenile bull sharks are especially likely to be found in Lake Pontchartrain, using the relatively protected and nutrient-rich waters as a nursery ground.

2. Occasional Visitors

While bull sharks are the primary species seen in the lake, other marine species such as blacktip sharks or spinner sharks may occasionally venture into the lake’s edges near the Rigolets or Chef Menteur Pass, where the lake connects to more saline waters. However, these species are rare and do not typically linger.

Why Are Sharks in the Lake?

Several natural conditions contribute to shark presence:

Brackish Water: Bull sharks have specialized kidneys and gland systems that allow them to survive in freshwater or brackish water for extended periods.

Food Availability: Lake Pontchartrain is home to abundant prey—mullet, croakers, catfish, and even small stingrays—making it an ideal hunting ground.

Nursery Habitat: Shallow, calm waters with rich food sources make the lake appealing for juvenile sharks, particularly in the warmer months.

Are Sharks in Lake Pontchartrain Dangerous?

While the idea of sharks in an inland lake may sound alarming, attacks on humans are extremely rare. Bull sharks are one of the few shark species that have been known to bite humans, but such incidents in Lake Pontchartrain are virtually nonexistent.

Most sightings involve small juveniles rather than large, aggressive adults. Still, caution should always be exercised, particularly during late summer when shark activity may increase near the Rigolets or other saltwater-connected areas.

Famous Shark Sightings in the Lake

In 2014, a boy caught a five-foot bull shark near Slidell.

A 2010 LSU marine biology study tagged several bull sharks in Lake Pontchartrain, confirming their regular seasonal presence.

In 2004, a shark was caught beneath the Causeway Bridge—an area with strong tidal currents ideal for larger marine predators.

These documented cases, while rare, reinforce the notion that Lake Pontchartrain’s ecosystem is more dynamic and connected to the Gulf than it might appear at first glance.

Conclusion

Yes, sharks—primarily bull sharks—do inhabit Lake Pontchartrain, especially during warmer months when saltwater levels rise. Their presence is a testament to the ecological complexity and connectivity of the lake to the Gulf of Mexico. While the idea might seem startling, these apex predators are a natural part of the lake’s food chain and pose minimal risk to humans.

Lake Pontchartrain remains a safe and vibrant environment for recreation, fishing, and wildlife observation—with the occasional shark visit just adding to its natural intrigue.