Observations were made of salinity, temperature, nitrate + nitrite, phosphate, silicate, total available nitrogen, and chlorophyll a in nine areas of the Alaskan Inside Passage during April of 1971. In general all properties indicated the water to be well mixed throughout this area. The conservative properties were particularly uniform. The greatest range in temperature from the surface to 200 m was only 1.1°C. The largest salinity range over the same depth was 2.0 ₀/₀₀ Spring phytoplankton blooms were just beginning to appear. Clarence Strait, in the southern part, presented the most evidence of biological activity. Values of chlorophyll a in this area were the highest observed (7.25 mg chl a/m³) outside of Auke Bay. This area also had the most density structure, probably due to stabilization brought on by warming. N:Si:P ratios for Clarence Strait indicate that silicate could become limiting in this area. The only other area, outside of Auke Bay, that had evidence (high chlorophyll a) of biological activity was Taku Inlet. The N:Si:P ratios for this area indicate that nitrate will probably be the limiting nutrient. Low oxygen values (2 ml/l) from the bottom of several deep basins indicate the possibility of anaerobic conditions developing as the water column stabilizes. Flow within the Inside Passage seems to be controlled by freshwater and saltwater inputs. Several major sources of both types of water are found. Tides and winds contribute to the circulation of the area but the mixing of saltwater and freshwater seems to be the predominant force. Local effects such as land runoff, glacial melt, input from hot springs and bottom topography are important in determining water conditions. Total available nitrogen may be a better indicator of photosynthesis than nitrate. TAN:P ratios tend to remain higher during photosynthesis than nitrate:P ratios. / Graduation date: 1972