Effects of resuspension events on restructuring phytoplankton communities

PIs: Linda M. Goad and Matthew L. Julius

Objectives:

  1. Identify the species composition of plume event phytoplankton floras.
  2. Note floristic differences between spring and fall plume floras as well as assemblage composition outside of the plume.
  3. Isolate abiotic and biotic variables effecting species composition in plume floras.

Approach:

Results:
Pre-plume spring phytoplankton floras can be generalized as follows:

Plume event phytoplankton floras can be generalized as follows:

The pre-plume flora generally replaces the plume flora within 2 weeks of the plume events conclusion.

Sediment resuspension experiments in the laboratory indicate time may be the single most important factor. Aulacoseira islandica and A. italica always dominate the species composition in the initial phase of the resuspension experiment, regardless of modifications in light, temperature, and nutrients. Once the initial Aulacoseira spp. pulse has diminished, other species being increasingly abundant varying in relation predominately to differing light and temperature regimes.