Spatial Distribution Patterns of Planktonic Fish Eggs in Lower Mobile Bay, Alabama

Abstract

Abstract A 12-month survey of planktonic fish eggs in lower Mobile Bay yielded 110 samples containing over 105 eggs. Fourteen taxa were represented, of which eight were abundant enough for analysis. By normal and inverse schemes of numerical classification, two distinct assemblages (station groups), coastal and estuarine, were found. The coastal assemblage was influenced by high-salinity tidal intrusions, whereas the estuarine assemblage was influenced by low-salinity estuarine water and river discharge. The spawning location of adult fish, circulation patterns, and salinity gradients (due to river discharge) were responsible for delineating the two assemblages. There also were two species associations (species groups). Eggs of Anchoa mitchilli, Sciaenidae, and Symphurus sp. were ubiquitous in both the estuarine and coastal assemblages. The eggs of Harengula jaguana , Anchoa hepsetus, Anchoa sp., Chloroscombrus chrysurus, and Trinectes maculatus were found predominantly in the coastal assemblage. Month-to...