nutria

1930s –



Imported from fur farms, nutria were released, either intentionally or accidentally, in the Louisiana marshes in the 1930s, and soon after, feral populations were established near the Gulf Coast. Nutria continued to expand their range from there as they were trapped and transplanted into marshes from Port Arthur, Texas to the Mississippi River in 1941. Later that year, a hurricane further dispersed nutria populations in southeast Texas and southwest Louisiana.



Late 1940s –



In the late 1940s, nutria were promoted as biological agents for controlling aquatic weeds, primarily water hyacinth, and were transplanted throughout southeastern Louisiana. Rapid population growth followed for several years thereafter. Annual pelt harvest records and damage reports were the primary source of information on population dynamics at that time.



Mid-1950s –



At this time, reports started coming in describing the damage done to marshes, rice and sugarcane fields, and levee systems, as nutria populations soared to 20 million animals. Biologists described areas where nutria had completely denuded natural levees at the mouth of the Mississippi River. The marsh had been weakened by severe over-grazing, and in 1957, Hurricane Audrey hit southwestern Louisiana. Its storm surge further weakened the marsh as a huge wave of seawater pushed thousands of nutria inland, accelerating the rate at which the animals spread. Soon after, reports of agricultural damage increased, and in 1958 nutria were taken off the list of protected wildlife.



1960s to 1980s –



As the state promoted nutria fur as a natural resource, efforts to manage nutria as a pest began to compete with the growing fur industry. In 1965, the nutria was returned to the protected wildlife list. From 1962 to 1982, 1.3 million nutria were harvested annually for their fur from the coastal marshes. Reports of nutria damage declined substantially, and periodic severe weather helped to reduce populations.