The Nutria in Louisiana: A Current and Historical Perspective

  • Charles E. Sasser
  • Guerry O. Holm
  • Elaine Evers-Hebert
  • Gary P. Shaffer
Part of the Estuaries of the World book series (EOTW)


Nutria is an exotic, aquatic rodent that was introduced to Louisiana wetlands during the early 1930s and can make coastal restoration more challenging. From 1960 to 1990, greater than 36-million nutria were taken when the fur market was lucrative. By 2000, the fur market had collapsed and nutria populations increased. Nutria reach sexual maturity at 4–8 months, may have 2–3 litters per year, and average 13.1 young per female per year. Nutria generally have a small home range in marsh habitats occurring primarily in fresh and intermediate marsh. The organic nature of these soils makes them particularly susceptible to destruction with grazing. Nutria are opportunistic feeders, with a broad diet comprising more than 60 plant species in Louisiana and they are attracted to wetlands that contain a reliable source of nutrient-rich fresh water, such as river diversions and assimilation wetlands. It is imperative that restoration projects that increase input of nutrient-rich fresh water into wetlands have a nutria control program in place. Nutria can consume large amounts of marsh biomass and in certain cases can cause the collapse of marsh locally. Scientific studies investigating effects of nutria on marsh habitats consistently conclude that nutria grazing is damaging to marsh and young forest vegetation. It is generally accepted that nutria damage – in addition to larger scale subsidence, sea level rise, and salinity intrusion – can create an accelerated deterioration of wetlands. Nutria grazing on baldcypress and water tupelo seedlings is extensive and remains a major factor in the inability of baldcypress-water tupelo forests to regenerate. Projects designed to restore coastal swamp forests should include a nutria control component and suitable protection of transplants should be used to minimize mortality from grazing. Eruptions of populations of nutria can cause severe wetland damage and loss. Some areas of the coast have persistent populations creating “Hot Spots” of severe damage, especially in freshwater-intermediate salinity areas of Terrebonne, Barataria, and Breton Sound basins. Nutria densities are relatively low in the Chenier Plain currently compared to historic observations and harvest records. The Coastwide Nutria Control Program (CNCP) was implemented in 2002–2003 by the LDWF, and since then there has been a reduction in 70,000 acres of marsh damage from 2003 to 2010. Approximately 446,000 nutria were harvested in 2010 in the CNCP, primarily in the deltaic plain. When considering the costs of creating new wetlands (approximately $50,000–$70,000 per acre), the CNCP is a successful wetland conservation program that has produced measureable reduction in marsh damage. Since 2002–2003, 2,571,480 nutria have been harvested. This program is a success and, from a resource management perspective, should be continued with improvement and expansion if possible. Nutrient enrichment of coastal landscapes may cause nutria population growth and habitat damage. Coastal restoration projects with areas receiving nutrient enrichment should include nutria control to ensure plant productivity, establishment, and expansion.


Invasive species Nutria Herbivory Wetland loss Population dynamics 



Several people were instrumental in helping us to pull together the information in this chapter. They were willing to discuss collected information as well as their understandings of the role of nutria in the Louisiana coastal area. We thank Edmond Mouton and Jillian Jordan (Louisiana Department of Wildlife and Fisheries) for providing information to help us understand the data collected through the Coastal Nutria Control Program. We also thank Greg Linscombe and Edmond Mouton, who have always been more than willing to share their wealth of knowledge about nutria and its habitat with us.


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Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  • Charles E. Sasser
    • 1
  • Guerry O. Holm
    • 2
  • Elaine Evers-Hebert
    • 1
  • Gary P. Shaffer
    • 3
  1. 1.Department of Oceanography and Coastal Sciences, College of the Coast and EnvironmentLouisiana State UniversityBaton RougeUSA
  2. 2.CH2MBaton RougeUSA
  3. 3.Department of Biological SciencesSoutheastern Louisiana UniversityHammondUSA

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