The presence of aluminum ions in sea water has long been an accepted fact, but there are few figures available on the concentrations in which the element exists and in particular under varying conditions….
Haendler, Helmut M., and Thomas G. Thompson. 1939. "The determination and occurrence of aluminum in sea water." Journal of Marine Research 2, (1). https://elischolar.library.yale.edu/journal_of_marine_research/541