THE DISTRIBUTION OF AMMONIA IN THE WATERS OF THE GULF OF MAINE

¹ From the Woods Hole Oceanographic Institution and the Biological Laboratories, Harvard University

1. In the deeper basins of the Gulf of Maine in May ammonia occurred in minimal concentrations at the surface and at all depths below sixty meters; maximal concentrations varying up to 45 mg. N per cubic meter occurred in a definite stratum between 30 and 60 meters.

2. In September the concentration of ammonia was rather uniform at all depths and increased as the distance from the open sea increased, concentrations exceeding 50 mg. N per cubic meter occurring in the western basin.

3. In the tideways of the North and South Channels, ammonia is distributed uniformly with depth in both May and September.

4. In shallow waters its occurrence showed no regularity.

5. The occurrence of ammonia may be correlated in part with the distribution of organic phosphorus compounds, of nitrite, and of zoöplankton, so as to support the view that its distribution marks the place and the intensity of organic decomposition.