Richard, It should also be mentioned that polychlorobiphenyls (PCBs) like the kinds once used in transformers, which have leaked into drainage and spent considerable time in direct sunlight become strongly photoactivated, and have been said to "glow" for a while after sunset.
The only reason this might be connected to an ocean setting, in particular like LA or especially Long Beach is the proximity to a large Naval Shipyard, which is notorious for PCBs and other toxins. I would be willing to bet that Long Beach is a problem area for this kind of thing, since it isone of the world's largest shipping ports and also has a large oilindustry and manufacturing infrastructure-- and a reputation for being lax in enforcement (probably as a result of being too close to LAX ;-)
