The landward distribution of oceanic plankton and micronekton over the west Florida continental shelf as related to their vertical distribution

The landward distributions of 69 plankton and 92 micronekton species over the west Florida continental shelf were examined in relation to their vertical distribution in the eastern Gulf of Mexico. Using linear and power-curve regressions, it was found that extent of landward occurrence is significantly correlated with bottom topography in terms of bottom depth and distance from the open Gulf. Epipelagic plankton species were distributed considerable distances across the shelf whereas the mesopdagic shrimp and fish species were not found landward of slope stations. Possible factors affecting landward distribution, such as currents, vertical migration patterns, and predation, are discussed.