Changes in Living Resources

Changes in Living ResourcesApproximately 735 species of birds, finfish, shellfish, reptiles, amphibians, and mammals spend all or part of their life cycle in the estuary. Several of the species are either categorized as threatened or endangered. Many factors contribute to declines in animal populations.


Change in habitat is a significant factor for most of the organisms. Pollution can also have a negative impact on the health of species and their ability to reproduce. Additionally, over-harvesting by fishermen, hunters, and trappers can harm animal populations.

In spite of threats that face animal species throughout the Barataria and Terrebonne basins, data indicates that most have not experienced continuous declines in population over the past thirty years. This is true for all estuarine dependent finfish and shellfish and for most of the wading birds and raptors.

A significant number of species, such as alligator, show an increasing trend that can be attributed to recovery from recent over-harvesting. Birds, such as the American bald eagle and the brown pelican, also show signs of recovery following near extinction in this area due to reproductive failure caused by pesticides. Migratory waterfowl that winter in the region are also exhibiting increasing trends that track continental trends.  

Probable Causes

  • Historic habitat loss/modification 
  • Commercial fishing (over-fishing)
  • Historic wildlife hunting (over-harvesting)
  • Aquaculture
  • Water pollution (eutrophication, pathogens, toxins)
  • Conflicts between recreational and commercial fisheries
  • Introduction of exotic species

Probable Impacts

  • Decreases in sport and commercial fish and shellfish populations 
  • Changes in furbearing and waterfowl populations with sport and commercial value
  • Reduced recreation and commercial value of wetlands and estuaries
  • Decreased populations or extinction of some native species
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