74 
National Marine 
Spencer F. Baird 
Fisheries Service 
Fishery BuHetin 
First U.S. Commissioner 
w 
NOAA 
ftf established in 1881 
of Fisheries and founder 
of Fishery Bulletin 
Population dynamics and secondary production 
of juvenile white shrimp iLitopmnaeus setiferus} 
along an estuarine salinity gradient 
Marvin M. Mace IIP 
Lawrence P. Rozas^ 
Email address for contact author: marvin.mace.iii@gmail.com 
Abstract — We used estimates of 
shrimp density, growth, mortality, 
and secondary production during an 
84-d sampling period to compare the 
value of nursery habitat for juvenile 
white shrimp {Litopenaeus setiferus) 
among 3 salinity zones (interme- 
diate, brackish, and saline zones) 
within Sabine Lake, an estuary of 
the northern Gulf of Mexico. Densi- 
ty, growth, mortality, and secondary 
production were generally higher 
in the saline or brackish zones and 
lowest in the intermediate zone. The 
saline and brackish zones appeared 
to provide the most important nurs- 
ery habitat on a per-area basis, but 
the intermediate zone also may con- 
tribute substantially to total shrimp 
production; although production in 
the intermediate zone was modest, 
this zone encompasses a relatively 
large portion (26%) of coastal wet- 
lands in Louisiana. The relative val- 
ue of nursery areas can be dynamic; 
variation occurs both spatially (e.g., 
within an estuary and among es- 
tuaries) and temporally (e.g., from 
year to year). We documented with- 
in-estuary differences (i.e., differ- 
ences among salinity zones within 
the estuary) in the value of nursery 
habitat for white shrimp in Sabine 
Lake and expect this value, espe- 
cially in the intermediate zone, to 
vary interannually. The dynamic na- 
ture of habitats should be considered 
when assessing the value of estua- 
rine nursery areas. 
Manuscript submitted 16 October 2015. 
Manuscript accepted 26 September 2016. 
Fish. Bull. 115:74-88 (2017). 
Online publication date: 22 November 2016. 
doi: 10.7755/FB.115.1.7 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
' Department of Biology 
University of Louisiana at Lafayette 
P.O. Box 42451 
Lafayette, Louisiana 70504 
^ Estuarine Habitats and Coastal Fisheries Center 
Southeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
646 Cajundome Boulevard 
Lafayette, Louisiana 70506 
Penaeid shrimps support several 
valuable commercial fisheries in the 
United States. Three species, brown 
shrimp {Farfantepenaeus aztecus), 
pink shrimp (F. duorarum), and 
white shrimp {Litopenaeus setiferus), 
within the family make up most of 
the landings in terms of weight and 
economic value (NMFS^). Most white 
shrimp are landed in the western 
Gulf of Mexico, specifically in Louisi- 
ana and Texas (NMFS^). 
The white shrimp is an estuarine- 
dependent species that occurs in- 
shore during the early phase of its 
life history. Spawning takes place off- 
shore from late spring to early fall, 
postlarvae migrate into estuarine 
habitat, and juvenile shrimp use this 
nursery habitat for -7-16 weeks be- 
fore returning offshore to complete 
their life cycle (Muncy, 1984; Baker 
et ah, 2014). The importance of es- 
tuarine nursery areas in support- 
ing populations of juvenile penaeid 
shrimps, such as white shrimp, is 
1 NMFS (National Marine Fisheries Ser- 
vice). 2015. Commercial fishery land- 
ings. [Available at website, accessed 
October 2015.] 
widely accepted, but the suitability 
of this habitat for penaeid shrimps 
often varies among and within es- 
tuaries (Vance et ah, 1998; Rozas 
and Minello, 2010, 2011; Palmer and 
Montagna, 2015). 
Vegetated aquatic habitats (e.g., 
tidal marshes, mangroves, and sea- 
grasses) within estuaries are thought 
to provide essential habitat for many 
species of fish and crustaceans 
(Kneib, 1997; Kathiresan and Bing- 
ham, 2001; Heck et al., 2003; Minello 
et al., 2003). Tidal marshes, in par- 
ticular, are believed to be important, 
especially for the young of commer- 
cially important species, including 
white shrimp (Boesch and Turner, 
1984; Kneib, 1997). In coastal Louisi- 
ana, tidal marshes are disappearing 
at a rapid rate because of a variety 
of natural and anthropogenic causes 
(Turner, 1990), and identifying areas 
that are important nurseries for fish- 
ery species should be a priority for 
conserving coastal habitats. 
The density (abundance) and vi- 
tal rates (growth and mortality) of 
juvenile white shrimp in estuaries 
may be useful indicators of habitat 
value and their contribution to adult 
