Distributions of phosphorus and nitrogen in New England coastal waters at various times of year are described. In surface waters the nitrate-nitrogen content is sometimes completely exhausted, even though small concentrations (0.2-0.5µg-at/l) of phosphorus are always available. The ratio of concentrations by atoms, N:P, varies in surface waters from maximum values of about 10: 1 to values approaching zero as the nitrate is exhausted....
Ketchum, Bostwick H., Ralph F. Vaccaro, and Nathaniel Corwin. 1958. "The annual cycle of phosphorus and nitrogen in New England coastal waters." Journal of Marine Research 17, (1). https://elischolar.library.yale.edu/journal_of_marine_research/920