This dissertation develops themes at the interface between ecology and physical oceanography through the consideration of an important physical mechanism: internal tidal bores. Internal tidal bores are shown to account for a wide and disparate phenomenology. This dissertation demonstrates that nearshore physical phenomena that can be explained by internal-tidal bores include: 1) drops in surface water temperature lasting several days; 2) predictability in surface water temperature within the lunar cycle in spring and summer but not in winter and fall; and 3) the onshore translation of warm-water fronts and associated replacement of nearshore bodies of water at diurnal or semidiurnal periodicities. To explore whether large internal-tidal bores were a geographically widespread phenomenon, long time-series of surface water temperature were used; the evidence supports the idea that this phenomenon is common along the western United States. Evidence is presented regarding the biological consequences of internal tidal bores. Water column larvae inhabiting subsurface or thermocline water are transported onshore when subsurface cold water is advected by the internal bores. When the cold, denser water sinks and slides offshore, it is replaced by onshore-moving warmer water; warm-water fronts lead the warm water. It is shown that neustonic larvae are transported onshore in these fronts. Using an historical diatom time-series, some evidence was found for increased abundance of diatoms on the days of the lunar cycle when water is predictably coldest (due to internal tidal bores).

Another study focuses on the correlation between the transport and settlement of larvae and other factors influencing settlement rate. This study suggests that temporal variability in settlement rate at scales of 100 m are related to the larval pool and to physical transport processes, while spatial variability is associated with behavioral response and substrate availability. Evidence is also presented to support the idea that the proportion of unmetamorphosed larvae to total settlement is a periodic, semi-lunar (_ 14.7 days) phenomenon that is related to restricted immersion times.

Overall, this dissertation presents a parsimonious hypothesis for explaining a previously unrelated array of phenomena. The hypothesis describes a broadly predictable process with profound but largely unexplored implications for nearshore communities.