Lake Pontchartrain, spanning over 600 square miles in southeastern Louisiana, is not a traditional lake but a large, shallow estuarine embayment. This unique classification means the water is a dynamic blend of fresh and salt components, creating one of the most biologically diverse fishing environments on the Gulf Coast. Its direct connection to the Gulf of Mexico, coupled with significant freshwater inflow, supports a complex food web that includes species from both marine and inland habitats, providing anglers with a wide array of potential catches throughout the year.
The Unique Brackish Environment
The ecological conditions defining Lake Pontchartrain’s fish life stem from its geography and water chemistry. The term “brackish” describes the mix of salt and fresh water, with salinity levels fluctuating significantly based on season and weather. Saltwater enters primarily from the Gulf of Mexico through the Rigolets and the Chef Menteur Pass.
This salt intrusion can cause stratification, where denser saltwater settles on the bottom, sometimes leading to low dissolved oxygen levels that stress aquatic life. Conversely, a large volume of freshwater enters the lake from the north, supplied by rivers such as the Tangipahoa, Tchefuncte, and Amite. These rivers lower the overall salinity, creating a gradient from near-fresh conditions on the northern shore to more saline conditions near the eastern passes.
Primary Saltwater and Game Fish Residents
The most stable and sought-after fish populations are those highly tolerant of the lake’s fluctuating brackish conditions. Speckled Trout (Cynoscion nebulosus) are one of the most popular game species, often congregating around the extensive underwater structure provided by the Lake Pontchartrain Causeway and old railroad trestles. They primarily feed on smaller baitfish and shrimp, and their presence often signals healthy water conditions.
Red Drum (Sciaenops ocellatus) are another year-round resident, prized for their fighting ability and found throughout the lake, including the shallow grass flats near Goose Point. Juveniles are frequent catches, while larger “bull” reds occasionally enter the system from the Gulf. Black Drum (Pogonias cromis) also inhabit the lake, tolerating a wide range of salinity. Larger adults are often found near bridge pilings and deeper channels, especially during winter and early spring.
The Southern Flounder (Paralichthys lethostigma) is a flatfish that ambushes prey along the sandy bottom and near tidal inlets. Flounder fishing peaks in the fall as the fish migrate toward the Gulf of Mexico to spawn, moving through the eastern passes. Sheepshead (Archosargus probatocephalus) use specialized teeth to crush crustaceans around submerged structures. These species form the core of the lake’s dependable saltwater fishery.
Freshwater and Seasonal Visitors
The lake’s northern shore and areas near river mouths support populations of true freshwater species. Largemouth Bass (Micropterus salmoides) thrive in the marshy bayous and northern shallows, often found in the same areas as brackish species. This overlap allows anglers to target both saltwater and freshwater species within a short distance.
Various Catfish species (Ictalurus spp.), including Blue Catfish and Channel Catfish, are common in the lower-salinity zones. These bottom-dwelling fish are adaptable and can be found in many parts of the lake, offering a consistent opportunity for anglers.
The lake also hosts significant seasonal migrants and occasional visitors from the Gulf. These visitors include species like Jack Crevalle (Caranx hippos) during the warmer months and, notably, the Bull Shark (Carcharhinus leucas). Bull sharks are highly tolerant of low-salinity water and enter the estuary during the summer, often sighted near deep channels and bridge pilings. Gulf Menhaden (Brevoortia patronus) also enter seasonally, serving as an important forage fish for larger predators.
Fishing Regulations and Consumption Safety
All anglers fishing in Lake Pontchartrain must possess a valid Louisiana fishing license. Because the water body is officially recognized as a saltwater fishery, a saltwater license is also required for residents aged 18 and older. The Louisiana Department of Wildlife and Fisheries (LDWF) enforces strict size and possession limits that vary by species to ensure sustainable fishing, such as maximum size limits for Red Drum.
Fish consumption advisories are an important consideration for anyone planning to eat their catch. The Louisiana Office of Public Health issues warnings, primarily due to mercury contamination in certain species. Vulnerable populations, such as women of childbearing age and young children, are advised to limit or avoid consumption of species like largemouth bass and crappie. Anglers should consult current LDWF regulations and health advisories before fishing.