Environmental Biology of Fishes

, Volume 36, Issue 2, pp 109–126

Microhabitat use by marsh-edge fishes in a Louisiana estuary

  • Donald M. Baltz
  • Chet Rakocinski
  • John W. Fleeger
Article

DOI: 10.1007/BF00002790

Cite this article as:
Baltz, D.M., Rakocinski, C. & Fleeger, J.W. Environ Biol Fish (1993) 36: 109. doi:10.1007/BF00002790

Synopsis

We used a drop sampler to characterize use of the marsh-edge ecotone by small fishes along two transects running inland from the Gulf of Mexico for ca. 25 km in Louisiana's Barataria-Caminada Bay System. Monthly sampling was stratified among upper, middle, and lower reaches and within reaches to characterize fish responses to salinity, depth, distance from shore, substrate, dissolved oxygen concentration, temperature, turbidity, velocity, and emergent stem density. In 681 quantitative samples, covering 658 m2, collected between October 1987 and October 1989, we collected 57 fish species and 16 864 individuals, primarily larvae and juveniles. The 15 most abundant fishes, comprising 97.7% of all individuals, were concentrated near the marsh edge (i.e., 0 to 1.25 m distance). Some significant differences within species for seasonal variables (e.g., temperature and dissolved oxygen concentration) reflected the ephemeral duration of early life history stages. Other differences reflected ontogenetic microhabitat shifts (e.g., depth and distance from shore). Within ecological groups, characterized as demersal residents, nektonic transients, and demersal transients, spatial and temporal segregation reflected the particular habitat requirements of each species. In a principal component analysis of microhabitat use, the first three components were interpreted as seasonal, depth-and-distance, and salinity axes, respectively. The array of species and size classes in principal component space reflected the complex dimensionality of microhabitat use. The high density of fish larvae and juveniles near the marsh edge confirmed the importance of the marsh-edge ecotone as a nursery for many estuarine-dependent fishes.

Key words

Early life historyNursery habitatSpartina marsh

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • Donald M. Baltz
    • 1
    • 2
  • Chet Rakocinski
    • 1
  • John W. Fleeger
    • 3
  1. 1.Coastal Fisheries InstituteLouisiana State UniversityBaton RougeU.S.A.
  2. 2.Department of Oceanography and Coastal SciencesLouisiana State UniversityBaton RougeU.S.A.
  3. 3.Department of Zoology and PhysiologyLouisiana State UniversityBaton RougeU.S.A.
  4. 4.Gulf Coast Research LaboratoryOcean SpringsU.S.A.