Formation and collapse of surface films

Films that accumulate from lake water, coastal seawater, and Sargasso Sea water with low concentrations of added protein can collapse when subjected to increased surface pressure. Collapse is accompanied by the transformation of some film organic material to particulate material that cannot spread at the interface; these particles are formed from filter‐passing organic material previously in the bulk liquid. Film collapse and accompanying particle formation in nature may be a part of a process that, in some areas, removes filter‐passing surface‐active material from water and precipitates it as particles back into the water column. Such particles tend to sink and could provide particulate food to organisms in the surface waters and perhaps at greater depths.