Spatial and Temporal Variability In Ichthyoplankton Communities Ingressing Through Two Adjacent Inlets Along the Southeastern US Atlantic Coast

Abstract

© 2017, Springer International Publishing Switzerland. Estuaries along the US east coast serve as essential nursery habitats for the early life history stages of many marine fishes. In the South Atlantic Bight (SAB), many studies have demonstrated the importance of these habitats for juveniles, but larval fish communities have received little attention, particularly around northeast Florida. To determine community structure, and seasonal distribution and abundance of larval fish in the Guana–Tolomato–Matanzas (GTM) estuary at its two inlets (St. Augustine and Matanzas), ichthyoplankton were sampled bi-weekly for one year at both inlets during nighttime spring flood tides. Samples were collected with a plankton net (1 m diameter, 1 mm mesh) suspended 1 m below the surface. Seventy-two taxa were collected, with four families comprising 85% of the collection: Sciaenidae (36.2%), Engraulidae (19.9%), Gobiidae (18.0%), and Gerreidae (10.7%). The two inlets differed in larval densities and taxonomic richness, although both were greatest during the summer. Spring and summer pulses in recruitment were observed for nearshore summer spawners. Marine offshore-spawned species exhibited peak recruitment in winter. The ichthyoplankton communities of the GTM estuary were most similar to those in southern SAB estuaries, and showed pronounced seasonal changes in composition, as is common in estuaries worldwide