Redfish decline a product of our disappearing coastal marshes

Taylor Valois with a redfish caught sight fishing in the marsh.

Louisiana fishermen grabbed tape measures and the magic markers last November to change the fish-measuring marks on their ice chests and boat gunwales.

For more than 30 years, 25, 12-plus inch speckled trout per person could crowd the ice chest per day. Now, it’s 15 fish at 13-20 inches with only two fish over that 20-inch slot.

This summer, they’ll get out the ruler and the Sharpie again for redfish. Barring any legislative direction to revise the Wildlife and Fisheries Commission’s decision in March, the old five-fish, 16-27-inch, with one over-slot redfish rules are being replaced with a four-fish, 18–27-inch slot, with no retention of fish over the slot.

Biological data shows over the last three decades that too few redfish are escaping coastal marshes as mature, spawning-ready adults. The decline has been noted by population surveys by Wildlife and Fisheries as well as some, but not all, coastal anglers who’ve noticed it has become harder to find reds than it was 20-30 years ago.

Plenty of opinions and, at times, heated, personal attacks, rumors and conspiracies have been lobbed around at public meetings and on social media over the last four years as the inevitable, legally-required changes to Louisiana’s most iconic and pursued coastal fish were considered.

Disappointingly, not nearly enough of those heated exchanges about who or what is to blame centered on coastal habitat loss, which is the true culprit.

Marsh loss

More than 20 years ago, respected fisheries biologists, Mark Schexnayder and Rex Caffey, penned a paper for LSU Sea Grant titled “Fisheries Implications of Freshwater Reintroductions.” It examined the positive and negative effects of reconnecting the Mississippi River to the rapidly disappearing coastal marshes it once created and fed but were disconnected from by levees built during the late 19th and early 20th centuries.

The paper pointed out “The break-up of vegetated marsh causes a short-term increase in the ingress routes and edge habitat so vital for juvenile estuarine fish. Yet this sort of productivity may be short-lived. Indeed, geologic simulations indicate that Louisiana’s coastal land-water interface has recently begun to decline. This loss of habitat does not bode well for future fisheries production.”

That observation was made more than two decades ago. The marsh loss that did not “bode well for the future of Louisiana’s fisheries production” is precisely what the state is facing now, especially in the Barataria Basin where nearly a century of subsidence, canal dredging, saltwater intrusion and battering from cold fronts and hurricanes has caused the highest rate of marsh loss in the world.

The Mid-Barataria Sediment Diversion

The Mid-Barataria Sediment Diversion, an ambitious project already under construction to reconnect the river to Barataria Bay, is the best chance to stabilize Louisiana’s redfish population and help it recover. Redfish, particularly juveniles, thrive in low-salinity, grass-filled coastal estuaries, the exact habitat Louisiana has lost so much of and what the diversion aims to restore.

Most reading this have likely formed an opinion about the project and are aware of the political wranglings and the staggering nearly $3 billion price tag for construction and mitigation, a sum paid by penalties from the 2010 Deepwater Horizon oil spill.

Arguments against its construction have focused, in large part, on the negative consequences to fisheries, especially oysters. It is a 100 percent certainty oyster beds in the immediate outflow of the diversion will be killed. However, those arguments generally fail to mention many of those beds are in areas that were once low salinity marshes. They also ignore the dozens of square miles of empty water bottom in western Barataria Bay that will become prime oyster grounds with diversion operation.

What doesn’t enter the debate enough is the same studies that show oysters will die also show redfish will benefit from the reconnection to the river. What redfish like to eat, including crabs, white shrimp, pogeys and mullet, will benefit as well, and the diversity of food sources for redfish will increase dramatically. Redfish have no qualms about gorging themselves on freshwater forage like bream, crawfish and shad.

Keep the crown

The politics of diversions and coastal restoration don’t change the ecological reality of Louisiana. It’s the “Redfish Capital of the World” because of the Mississippi River.

Reconnect the river and the state can continue to wear that crown. Fail to take this opportunity to use oil spill penalties to reconnect the river to the Barataria Basin, and a decade from now Louisianans should plan to break out the rulers and markers and, again, fight about reducing limits.