Home > Biological Info > A Shrimp's Niche In Its Ecosystem

The shrimp fisheries in the Gulf of Mexico are some of the most valuable fisheries in the United States (Van Voorhees and Prichard 2004). Because temperature and salinity changes affect the life stages of each shrimp species in a slightly different manner, shrimp occupy many niches in Louisiana’s estuaries and in Gulf waters. Reproducing populations of several species of shrimp mature through the postlarval and subadult stages in Louisiana’s estuaries at slightly different times of the year, sometimes overlapping in habitat use, sometimes occupying different niches in state waters. The two shrimp species harvested by the state’s commercial shrimpers – the brown shrimp (Farfantepenaeus aztecus) and white shrimp (Litopenaeus setiforus) – represent 95 percent of all annual landings. Very small quantities of other shrimp species such as seabobs, pink shrimp, rock shrimp and royal reds have also been caught in Louisiana’s waters. Brown shrimp usually spawn earlier in the year, and are most abundantly harvested in May, June and July whereas white shrimp are most abundantly harvested in August, September, and October. However, some adults of both species are available throughout a large portion of the year. In Louisiana’s waters, 60-65 percent of white shrimp are harvested in coastal or bay waters, whereas the majority of brown shrimp in Louisiana are harvested in deeper, outside regions. This is different from other Gulf states, where shrimp harvests of all species tend to be higher offshore, outside of state waters.

Although commercial shrimpers harvest almost as many brown as white shrimp in a given year, white shrimp typically grow to a larger size before they are harvested. For example, in 2004, white shrimp accounted for 55 percent of the year’s landings, but nearly 70 percent of its value, according to the Louisiana Department of Wildlife and Fisheries. This size difference occurs because white shrimp remain longer in estuaries, responding only to very strong tidal changes that stimulate movement in and out of the estuaries. White shrimp also tend to migrate back through the passes into estuaries over winter.

In addition to their value to commercial fisheries, shrimp are important in estuarine and offshore food webs. The interactions of many different living, growing organisms with each other and the physical environment shape a shrimp’s niche (i.e., its role in the environment, the species it interacts with, and its environmental requirements for food and shelter). The continuous but changing characteristics of a shrimp’s niche can be seen by studying the major life stages of this important crustacean.

References

Muncy, R.J. 1984. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico)—White Shrimp. U.S. Fish and Wildlife Service, FWS/OBS-82/11.20. U.S. Army Corps of Engineers, TR EL-82-4. 19 pp.

Lassuy, D.R. 1983. Species Profiles: Life Histories and Environmental Requirements (Gulf of Mexico) – Brown shrimp. U.S. Fish and Wildlife Service, Division of Biological Services. FWS/OBS-82/11.1. U.S. Army Corps of Engineers, TR EL-82-4. 15 pp.

Van Voorhees, David and Elizabeth Prichard. October 2004. Fisheries of the United States 2003. Annual report of National Marine Fisheries Service, Office of Science and Technology, Fisheries Statistics Division. Published by U.S. Department of Commerce, National Marine Fisheries Service. Available online at http://www.st.nmfs.gov/st1/fus/fus03/2003_fws.pdf

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The following experts contributed information to this project and served as a review panel for this summary.

Mark Benfield, Don Baltz, Gary Peterson – all of LSU Coastal Fisheries Institute; John Fleeger – LSU Department of Biological Sciences; Dianne Lindstedt – Louisiana Sea Grant College Program; and Marty Bourgeois – Louisiana Department of Wildlife and Fisheries Division of Marine Fisheries.

Development of this portion of the Louisiana Sea Grant Fisheries Web site was funded by the Gulf & South Atlantic Fisheries Foundation, Inc. under NOAA cooperative agreement #NA16FM2817.
The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the Gulf & South Atlantic Fisheries Foundation, Inc., NOAA, or the Department of Commerce.