Editing Internal wave (section)

===Internal tidal bores===
Similarly to surface waves, internal waves change as they approach the shore. As the ratio of wave amplitude to water depth becomes such that the wave “feels the bottom,” water at the base of the wave slows down due to friction with the sea floor. This causes the wave to become asymmetrical and the face of the wave to steepen, and finally the wave will break, propagating forward as an internal bore.<ref>Defant A (1961) Physical Oceanography, 2nd edn. Pergamon Press, New York</ref><ref>Cairns JL (1967) Asymmetry of internal tidal waves in shallow coastal waters. Journal of Geophysical Research 72:3563–3565</ref> Internal waves are often formed as tides pass over a shelf break.<ref>Rattray MJ (1960) On coastal generation of internal tides. Tellus 12:54–62</ref> The largest of these waves are generated during [[spring tide|springtides]] and those of sufficient magnitude break and progress across the shelf as bores.<ref>Winant CD, Olson JR (1976) The vertical structure of coastal currents. Deep-Sea Research 23:925–936</ref><ref name="Winant CD 1980">Winant CD (1980) Downwelling over the Southern California shelf. Journal of Physical Oceanography 10:791–799</ref> These bores are evidenced by rapid, step-like changes in temperature and salinity with depth, the abrupt onset of upslope flows near the bottom and packets of high frequency internal waves following the fronts of the bores.<ref>Shanks AL (1995) Mechanisms of cross-shelf dispersal of larval invertebrates and fish. In: McEdward L (ed) Ecology of marine invertebrate larvae. CRC Press, Boca Raton, FL, p 323–336</ref>

The arrival of cool, formerly deep water associated with internal bores into warm, shallower waters corresponds with drastic increases in [[phytoplankton]] and [[zooplankton]] concentrations and changes in plankter species abundances.<ref name="Leichter JJ 1998">Leichter JJ, Shellenbarger G, Genovese SJ, Wing SR (1998) Breaking internal waves on a Florida (USA) coral reef: a plankton pump at work? Marine Ecology Progress Series 166:83–97</ref> Additionally, while both surface waters and those at depth tend to have relatively low primary productivity, [[thermocline]]s are often associated with a [[chlorophyll]] maximum layer. These layers in turn attract large aggregations of mobile zooplankton<ref name="Mann KH 1991">Mann KH, Lazier JRN (1991) Dynamics of marine ecosystems. Blackwell, Boston</ref> that internal bores subsequently push inshore. Many taxa can be almost absent in warm surface waters, yet plentiful in these internal bores.<ref name="Leichter JJ 1998"/>