Planktonic Copepods in a Sub-Tropical Estuary: Seasonal Patterns in the Abundance of Adults, Copepodites, Nauplii, and Eggs in the Sea Bed

The seasonal abundance of copepod eggs in the bottom sediments of the Apalachicola estuary was documented at bimonthly intervals between November 1989 and August 1990. Concentrations as high as 106 m-2 were noted. In addition, when bottom sediments from the estuary were incubated in the laboratory at ambient environmental conditions, large numbers of nauplii hatched, indicating that the eggs in the sediments constituted a large pool of potential recruits for the planktonic population. The eggs in the sediments and the nauplii that hatched were identified as Acartia tonsa, based upon morphology and the dominance of this species in the estuary. Therefore, the occurrence of copepod eggs in bottom sediments is not a phenomenon limited to temperateboreal coastal environments.