Results:

While data has been collected in Commencement Bay by UWT since 2000, this results section will primarily focus on the data collected during the spring 2003 cruises (May 9, 2003 and May 16, 2003). A data repository has been created for all surveys, begining in 2000, and can be accessed on this website. The master cruise log, CTD data, and nutrient data can be obtained from the data repository for all available cruises (some cruise data has not yet been processed). In this section, a general presentatoin of the results obtained from the CTD and Surfer Sections, Secchi disk surveys, water sample analysis, and plankton sample analysis are presented. Please see Mitsuhiro Kawase's model for a display of surface salinity and temperature changes within Commencement Bay and the surrounding Puget Sound area.

CTD and Surfer Profiles:

Along the terminus transect (5/16/2003), from Thea Foss waterway to Hylebos waterway, the CTD profiles revealed that the Puyallup River delta is a transition zone in stratification. Looking at the density, salinity, temperature, and dissolved oxygen profiles obtained on May 16, 2003, stratification is relatively moderate from the mouth of the Thea Foss waterway to the Puyallup River delta. However, moving east from the Puyallup River delta to the mouth of the Hylebos waterway, a fresher, less dense, warmer, and more oxygen enriched layer of water was observed. The water column from the Puyallup River delta to the mouth of the Hylebos waterway is significantly more stratified than that which was observed between the mouth of the Thea Foss waterway and the Puyallup River delta. The salinity contour map displayed below characterizes the observations mentioned above.

Along the middle transect (5/16/2003), the salinity, density, temeperature, and dissolved oxygen profiles show that a fresher, less dense, and warmer layer of water was observed near the terminus of the bay. Moving out into the mouth of the bay along the middle transect, the water column becomes less stratified and generally denser, more saline, colder, and less oxygen enriched. The salinity contour map displayed below characterizes the observations mentioned above.

Along the mouth transect (5/16/2003), the salinity, density, temperature, and dissolved oxygen profiles show that a fresher, less dense, warmer, and more oxygen enriched layer of water was observed in the upper water column between the Mid Mouth station and the Brown's Point Station. Between the Asarco Station and the Mid Mouth Station, the upper water column was more saline, denser, coller, and less enriched with oxygen. The salinity contour map displayed below characterizes the observations mentioned above.

On May 9, 2003, only the mouth transect, plus two addition stations (CMB 003 and Hylebos) were able to be completed due to time constraints. The profiles of salinity, temperature, density, and dissolved oxygen along the mouth transect on May 9, 2003 show less stratification than that which was observed on May 16, 2003. The data collected at the CMB 003 and Hylebos Stations on May 9, 2003 also show less stratification than that which was observed on May 16, 2003.

Mouth Transect: From Asarco on Point Defiance to Brown's Point	Middle Transect: From Pier 5 at the terminus to the middle of the bay's mouth	Terminus Transect: From the mouth of the Thea Foss waterway to the mouth of the Hylebos waterway
May 16, 2003	May 16, 2003	May 16, 2003
Density	Density	Density
Salinity	Salinity	Salinity
Temperature	Temperature	Temperature
Dissolved Oxygen	Dissolved Oxygen	Dissolved Oxygen
May 9, 2003	May 9, 2003	May 9, 2003
Density	N/A	N/A
Salinity	N/A	N/A
Temperature	N/A	N/A
Dissolved Oxygen	N/A	N/A
Fluorescence	N/A	N/A

From the data obtained during the May 2003 surveys, salinities ranged from 25.6 to 29.6 PSU, densities ranged from 19.4 to 22.8 kg/m³, temperatures ranged from 9.1 to 10.7 C, and dissolved oxygen concentrations ranged from 4.4 to 6.3 mL/L within the bay. In May 2000, salinities ranged from 19.96 to 30.07 PSU, densities ranged from 15.15 to 23.30 kg/m³, temperatures ranged from 8.59 to 10.85 C, and dissolved oxygen concentrations ranged from 3.75 to 7.17 mL/L within the bay. In May 2002, salinities ranged from 27.00 to29.91 PSU, densities ranged from 20.60 to 23.16 kg/m³, temperatures ranged from 8.82 to 10.92 C, and dissolved oxygen concentrations ranged from 5.16 to 9.51 mL/L within the bay.

Secchi Disk Depths:

The Secchi Disk depths obtained from the May 9, 2003 and May 16, 2003 surveys show that the greatest depths were observed along the mouth and in the middle of the bay. Looking at the Secchi disk depths obtained from May 16, 2003 in the below graph, the depths were nearly 6 times greater along the mouth and within the center of the bay than they were at the terminus of the bay. The stations listed in the below graph are as follows; (1) Asarco, (2) Mid Mouth, (3) Brown's Point, (4) CMB 003, (5) Hylebos waterway, (6) Sewer Outfall, (7) Puyallup Delta, and (8) Thea Foss waterway. See the station map for the location of these stations.

Water Sample Analysis:

Nutrients:

Unfortunately, nutrient data was only available for the spring 2000 and fall 2002 surveys during the construction of this website. However, nutrient data for spring 2003 and winter 2003 have been added in the data repository, although the results of these nutrient samples are not discussed here. Although nutrient samples were collected during other surveys, these samples have yet to be processed. Therefore, the following ranges in nutrient concentrations observed within the bay only represent the data obtained from two sets of surveys. In these surveys, nutrient concentrations in the bay range from 0.46 to 2.90 umols/L phosphate, 30.08 to 67.53 umols/L silicate, 3.89 to 27.23 umols/L nitrate, 0.004 to 1.22 umols/L nitrite, and 0.00 to 3.80 umols/L ammonium.

Plankton Sample Analysis:

Plankton data was only available for the May 2002 and 2003 surveys. The results of phytoplankton and zooplankton density analysis can be seen in the below graphs. In general, the phytoplankton densities were considerably higher during the May 2002 surveys as compared to the May 2003 surveys. However, zooplankton densities were considerably lower during the May 2002 surveys as compared to the May 2003 surveys. The stations listed in the below graph are as follows; (1) Asarco, (2) Mid Mouth, (3) Brown's Point, (4) CMB 003, (5) Hylebos waterway, (6) Sewer Outfall, (7) Puyallup Delta, and (8) Thea Foss waterway. See the station map for the location of these stations.

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