Swamp Stomp
Volume 17, Issue 23
A colony of tiny bugs has taken up residence near the mouth of the Mississippi River and is killing large amounts of wetland grass that is needed to ensure the health of Louisiana’s coast. This incident is causing state and university scientists to quickly try to figure out how and why the pest, which could be a European or Asian import, got to south Louisiana, and how can they stop them from killing more of the wetland grass.
The wetlands in south Plaquemines Parish have experienced large-scale die-offs of Roseau cane. Roseau cane is a tall-growing grass that’s native to Louisiana and is the perfect habitat for fish and other wildlife. This has been going on since last fall. This grass is so important to the health of wetlands because its roots hold marshlands in place. Without this grass the already rapid erosion of the coastline will happen even quicker.
“Roseau cane is very, very important to the overall stability of our coastline,” state Agriculture Commissioner Mike Strain said. “This is happening at the mouth of the Mississippi, and that’s part of the economic lifeblood of the American economy. It’s important we deal with this.”
The invasive species is a type of scale, an aphid-like insect that feeds on plant sap. Scientists do not think it is native to North America. Louisiana entomologists are collaborating with others in Europe and Asia to identify the scale.
“At the moment, we don’t know the species name of the scale nor its origin,” said Rodrigo Diaz, a Louisiana State University entomologist. “We are working with taxonomists and ecologists to understand this problem. Because of the recent discovery of the problem, there are a lot of unknowns.”
The large-scale cane deaths were first reported to Department of Agriculture and Forestry by fishers and charter boat captains in October and November. In winter, the cane dies back naturally. By February, when department scientists inspected the affected areas, the marshes should have been green with regrowth.
“We went out in airboats, and the impact was obvious,” said Joey Breaux, an environmental specialist with the department’s soil and water office. “We were seeing regrowth of just 5 and 15 percent when it should have been 80 or 100 percent. And we’ve been back since then, and it’s lots worse.”
It is unknown how many acres are affected. Charter fishing captain Eric Newman guesses that thousands of acres near Venice have experienced partial or near-total die-off.
“These places were flush with cane in November,” he said. “Now they’re almost unrecognizable. These bugs have eaten almost all of it.”
The Agriculture Department has found cane death as far north as the Bohemia Spillway. The scale has caused the biggest problems around the river’s mouth, including the Pass a Loutre Wildlife Management Area. Breton Island has also been hit hard.
Scientists are trying to determine how the scale arrived and whether environmental factors, such as changes in climate, water chemistry and storm patterns, might have affected the scale’s spread.
Source: Baurick, Tristan. “Mystery Pest Wiping out Wetlands at the Mouth of the Mississippi River.” NOLA.com. Times-Picayune, 04 Apr. 2017. Web. 13 Apr. 2017.