Rip current charactersitics and their role in the exchange of water and surf diatoms between the surf zone and nearshore

Surfzone hydrodynamics as a key determinant of spatial variation in rocky intertidal communities

“…Simulated zooplankters were transported into the surf zone over shoals, and they were concentrated in deeper rip channels before some returned seaward in offshore flow episodically with the arrival of wave groups. Prior to our study, diatoms that were specifically adapted to remaining in surf zones throughout their life cycles were known to be concentrated in surf zones [17], but it is now apparent that all zooplankters as well as passive particles may accumulate by recirculation in surf zones of rip-channelled shores [18,19].…”

Associations in ephemeral systems: the lack of trophic relationships between sandhoppers and beach wrack

“…Coupled with the stable isotope results, this suggests that, in general, sandhopper populations on the warm temperate South African coast have little direct dietary association with the material under which they live. As sandy shores, particularly dissipative beaches, are often regarded as semi-enclosed systems with a large input of primary production from the surf zone (McLachlan 1980), the trophic link could lie in blooms from the local surf-zone diatom Anaulus birostratus (Talbot & Bate 1987). Although A. birostratus commonly occurs within South African surf zones, the input from diatoms on the nearshore does not seem to contribute as much as detritus (Talbot & Bate 1987).…”

“…Sandy beaches are the most widely distributed transitional coastal systems and rely heavily on energy sources from both land and sea (McLachlan 1980, Talbot & Bate 1987, Brown & McLachlan 1990, van der Merwe & McLachlan 1991. The flux of material between land and sandy shores can be dynamic, with beaches transferring nutrients to terrestrial communities (e.g.…”

Variation in the abundance of Pseudo-nitzschia and domoic acid with surf zone type

“…This is likely how they become concentrated in rip current recirculation cells (Talbot and Bate, 1987a). Typical offshore phytoplankton taxa can be caught by bubbles rising through the water column (Krichnavaruck et al, 2007) and trapped cells might become concentrated in rip current eddies.…”