2004 Cathlamet Marina Monitoring Data 

Description of Site

The Cathlamet Marina is located in Wahkiakum County in the lower Columbia River estuary in Washington. The marina in located in sheltered area off the Columbia River and is tidally influenced. In recent years, an infestation of the state-listed noxious freshwater weed Eurasian watermilfoil (Myriophyllum spicatum) and to a lesser extent native Canadian waterweed (Elodea canadensis) has been impacting navigation, recreation, and aesthetics in the marina.

The purpose of monitoring was to document the effect of the 2,4-D application on the dissolved oxygen concentrations in the Cathlamet marina and to determine herbicide concentrations 24 hours and five days after treatment.

Treatment

On July 13, 2004, 8 acres in the Cathlamet Marina were treated with the aquatic herbicide 2,4-D (DMA*4IVM™). The herbicide was applied by a state-licensed applicator using sub-surface injection. A total of 72 gallons was applied for a target concentration of 2-4 ppm. The application was timed to coincide with neap tides to increase the contact time between the herbicide and plants. A group of citizen volunteers monitored the marina for dissolved oxygen (DO), water temperature, and presence of distressed or dead fish for six days prior to the herbicide treatment and for seven days after the herbicide application. The aquatic plant management company who applied the herbicide developed the monitoring protocol, trained the volunteers in instrument calibration and monitoring techniques, and loaned them the monitoring equipment.

Sampling Protocols

Water: Three sampling stations were established in the marina. Station 1 was located at the middle of Dock A on the left side of the marina facing towards the Columbia River. Station 2 was located at the shoreline end of the Dock D on the right side of the boat launch. Station 3 was taken from the middle of Dock E on the right side of the boat launch (see site map below).

Dissolved oxygen and temperature were measured at each station on the high tide for six days before treatment and for seven days following the herbicide treatment. At each station, a water column profile was taken from the surface and at one foot intervals to the bottom. These measurements were taken with a YSI® digital DO/Temperature meter.

2,4-D Residue Sampling: Surface water samples for 2,4-D were taken by volunteers at Station 1 and Station 4, 24 hours and 5 days after treatment. The samples were stored on ice and delivered to an Ecology-accredited laboratory for analysis.

Fish: In addition to taking water measurements, the volunteers looked for dead or distressed fish. They were instructed to record the location of any dead or distressed fish, the number of fish observed, and the species (if known). In addition, they were asked to determine if the mortality was recent, to collect a sample, and to notify the applicator and the County.  

Results

Residues: The 2,4-D water concentrations were below the drinking water standard of 0.070 mg/L by five days after treatment at both sampling sites.

Station 24 hours 5 days
1 0.550 mg/L 0.014 mg/L
3 0.820 mg/L 0.022 mg/L

Temperature: Temperatures in the Calthlamet Marina varied little between the sampling stations. The temperatures increased over the 14-day sampling period, but this was expected since the weather was hot and sunny over this time period. The temperature in Calthlamet Marina in July always exceeded the Water Quality Standard for salmon core rearing areas (16 degrees C), both before and after the herbicide treatment. It is not likely that the herbicide treatment had any impact on water temperatures.

Dissolved oxygen: There appeared to be little impact of the herbicide treatment on dissolved oxygen at the sampling stations. The oxygen levels remained relatively high before and after treatment, although they were generally always below the minimum dissolved oxygen concentration for core salmon rearing (9.5 mg/L) both before and after herbicide treatment. Washington has set a Water Quality Standard for a minimum DO concentration for surface water of 9.5 mg/L for salmon core areas. Dissolved oxygen in July was generally below this standard in the marina even before the 2,4-D treatment.

Fish Observations: There were no distressed or dead fish observed during this two week period in the marina.

Summary of Dissolved Oxygen and Temperature Data

 Station 1 – Dissolved oxygen - ppm

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

7.93

7.65

8.03

7.41

7.54

7.41

7.15

7.14

7.33

7.51

7.85

7.75

8.04

2

7.88

6.96

7.44

6.79

7.12

7.81

7.31

8.19

7.67

8.12

7.62

7.06

8.05

3

7.81

6.87

7.55

6.93

7.54

7.59

7.36

7.99

8.28

8.5

6.84

7.6

8.01

4

7.79

6.8

7.5

6.75

7.33

7.55

6.99

7.92

8.18

7.25

6.38

7.42

7.68

5

7.77

6.61

7.01

6.51

6.83

6.99

6.72

7.56

7.64

 

6.73

7.21

6.92

6

8.06

5.9

 

5.61

 

 

 

7.17

7.55

 

5.46

6.8

6.01

7

8.05

 

 

 

           

 

   
8

6.86

                       

 Station 2 – Dissolved oxygen - ppm

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

7.97

7.16

7.34

6.81

8.4

8.2

7.68

7.64

7.48

6.88

6.88

7.73

7.23

2

7.32

6.35

7.07

6.56

7.73

8.33

7.67

7.64

7.77

7.49

6.22

7.52

7.3

3

7.4

6.41

6.38

6.75

7.71

7.79

7.51

7.18

7.56

7.64

6.51

7.97

7.13

4

7.44

6.46

6.51

6.74

7.68

8.06

7.1

7.37

8.06

7.67

5.81

8.59

8.15

5

7.1

6.71

6.31

6.02

7.13

8.01

7.13

6.73

7.49

7.6

6.06

8.65

8.07

6

7.28

6.43

6.1

5.77

7.26

8.29

6.24

7.01

7.65

8.15

6.07

8.5

8.01

7

7.32

5.49

5.83

5.23

7.43

7.81

6.8

7.45

6.87

7.38

5.79

7.89

8.13

8

6.88

6.16

5.56

5.18

7.63

7.17

6.29

6.89

6.46

7.22

5.38

7.84

7.16

9

7.1

5.67

5.96

5.4

8.14

6.82

7.21

6.98

7.31

6.82

6.35

6.62

6.57

10

7.29

5.57

6.33

5.25

7.62

6.62

6.35

7.06

7.31

4.85

4.27

6.04

6.3

11

7.15

6

                     

Station 3 - Dissolved Oxygen – ppm

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

8.21

7.66

7.51

6.94

7.37

7.78

7.33

7.08

7.15

7.49

7.17

7.06

7.28

2

7.6

7.7

7.12

7.21

7.51

7.67

7.46

7.96

7.78

8.06

6.55

7.66

7.77

3

7.63

7.11

7.18

7.29

7.27

7.76

7.71

8.17

8.42

7.46

6.55

8.06

7.35

4

8.04

7.2

6.39

6.94

7.07

7.54

7.92

8.35

7.57

8.43

6.92

8.05

7.56

5

8.28

7

7.66

7.38

6.79

6.73

7.75

7.87

8.09

8.35

7.31

6.91

7.2

6

7.37

7.29

7.03

6.69

5.92

7.69

7.24

7.86

8.13

6.83

6.24

7.16

7.6

7

8.02

7.35

7.03

6.25

6.54

7.21

6.64

8.02

7.61

7.26

7.13

7.47

6.93

8

7.12

7.27

6.84

6.28

6.57

7.01

6.75

7.64

6.03

6.81

6.97

7.62

7.38

9

6.8

7.23

6.55

6.65

6.01

6.64

6.78

7.36

6.15

5.15

5.29

6.57

7.17

10

7.28

7.28

6.99

 

5.78

5.9

5.71

7.53

 

3.92

2.79

4.88

6.56

11

 

7.49

                     

Station 1– Temperature

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

20.4

20.1

20.4

20.9

21.6

22.5

22.5

24

23.1

23.8

21.7

23.2

23

2

20.5

20.1

20.3

20.5

20.4

21.2

21.8

21.4

22.5

23.2

24.9

22.8

22.6

3

20.6

20.1

20.2

20.3

20.3

20.9

21.4

21.5

22.1

22.9

21.9

22.8

22.3

4

20.6

20.1

20.2

20.1

20.1

20.9

21

21.4

21.9

22.5

22

22.7

22.2

5

20.6

20.1

20.1

19.9

20.1

20.5

20.7

21.3

21.5

 

21.8

22.5

22.1

6

20.5

20.1

 

19.9

 

 

 

21.3

21.4

 

21.8

22.5

22.1

7

20.5

 

 

 

           

 

   
8

20.4

                       
9

 

                       

 Station 2 – Temperature

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

20.8

20.2

20.2

20.9

20.9

21.9

22.7

22.9

23.2

24.4

21.7

23.4

23.3

2

20.8

20.2

20.2

20.5

20.4

21.1

22.5

22.2

22.7

23.4

24.9

22.9

22.7

3

20.8

20.1

20.1

20.4

20.3

20.8

21.7

21.9

22.8

23

21.9

22.7

22.4

4

20.6

20.1

20.1

20.2

20.1

20.7

21.3

21.7

21.6

22.6

22

22.6

22.3

5

20.6

20.1

20

20.1

20.1

20.6

21

21.6

21.5

22.2

21.8

22.5

22.2

6

20.5

20

19.9

19.9

19.9

20.5

20.8

21.1

21.5

22

21.8

22.4

22.2

7

20.5

20

19.8

19.9

19.8

20.4

20.7

21.1

21.4

21.8

 

22.3

22.1

8

20.4

19.9

19.8

19.8

19.8

20.4

20.6

20.9

21.4

21.7

 

22.3

22

9

20.4

19.9

19.8

19.8

19.8

20.2

20.5

20.9

21.2

21.5

 

22.2

22

10

20.4

19

19.7

19.8

19.7

20.2

20.4

20.9

21.1

21

 

22

22

11

20.3

19.8

                     

Station 3 – Temperature

Before Treatment After Treatment
Feet 2d 3d 4d 5d 6d 7d 8d 9d 10d 11d 12d 13d 14d
1

20.6

20.4

20.6

20.8

21.7

22.2

22.2

22.5

22.7

23.5

21.5

23.3

22.8

2

20.6

20.3

20.3

20.5

20.8

21.3

21.7

22.2

22.3

23.3

21.8

23

22.6

3

20.5

20.3

20.3

20.3

20.4

20.9

21.8

21.9

21.9

22.8

21.8

22.9

22.4

4

20.5

20.2

20.1

20.2

20.3

20.7

20.9

21.7

21.8

22.5

21.8

22.7

22.3

5

20

20.1

20.1

20.1

20.1

20.5

20.8

21.6

21.5

22.1

21.8

22.5

22.2

6

4

20

20

19.9

20

20.5

20.5

21.1

21.3

21.8

21.7

22.3

22.1

7

20.4

19.9

19.9

19.8

20

20.4

20.4

21

21.2

21.7

21.7

22.2

22.1

8

20.4

19.9

19.8

19.8

19.8

20.3

20.4

20.9

21.1

21.5

21.6

22.1

22

9

20.3

19.8

19.7

19.8

19.7

20.2

20.3

20.9

21

21.1

21.3

22

22

10

20.3

19.8

19.7

 

19.7

20.1

20.2

20.9

 

20.7

20.7

21.7

22

11

 

19.8