USGS Scientific Investigations Report 2009–5078Assessment of Eutrophication in the Lower Yakima River Basin, Washington, 2004

Table 5. Periphyton biomass in the lower Yakima and Naches Rivers, Washington, 2005–07.

[Algal biomass data from the Bureau of Reclamation laboratory, Boise, Idaho. Median values are given where replicates were analyzed. Shading indicates chlorophyll a value that was above nuisance condition level. Abbreviations: Chl a, chlorophyll a; Pheo-a, pheophytin a; AFDM, ash-free dry mass; mg/m², milligram per square meter; g/m², gram per square meter; RM, river mile; USGS, U.S. Geological Survey; –, no data]

USGS site identification No.	Sampling location	RM	Date	Number of samples	Chl a (mg/m²)	Pheo-a (mg/m²)	AFDM (g/m²)
Naches Reach, 2007
12494450	Naches River at RM 12.2 near Naches	12.2	07-24	3	34	3	17
			08-07	3	70	5	23
12498690	Naches River above Diversion Dam near Yakima	3.5	08-23	3	41	7	15
			09-03	3	49	4	13
12498990	Naches River at 40th Avenue near Yakima	2.8	07-24	3	20	3	9
			08-07	3	46	5	15
Zillah Reach, 2005
1250532120	Yakima River at RM 90.9 near Zillah	90.9	06-28	1	83	119	26
1250532250	Yakima River at RM 90.1 near Zillah	90.1	06-28	1	93	88	28
1250532340	Yakima River at RM 89.5 near Zillah	89.5	06-28	1	92	236	47
Zillah Reach, 2006
12505045	Yakima River at RM 102.8 near Parker	102.8	07-11	2	255	48	63
12505060	Yakima River at RM 102.6 near Parker	102.6	07-11	2	168	18	42
12505085	Yakima River at RM 100.8 near Donald	100.8	07-11	2	214	31	48
12505090	Yakima River at RM 100.7 near Donald	100.7	07-11	2	82	10	29
1250532100	Yakima River below North Myers Road Bridge right bank near Zillah	91.0	07-12	2	340	26	58
1250532110	Yakima River below North Myers Road Bridge left bank near Zillah	91.0	07-12	2	178	26	61
1250532200	Yakima River at RM 90.4 near Zillah	90.4	07-12	2	144	27	56
1250532210	Yakima River at RM 90.3 near Zillah	90.3	07-12	2	305	67	103
1250532400	Yakima River 3 ft from right bank at RM 89 near Zillah	89.0	07-12	2	195	67	147
12505040	Yakima River at RM 103 near Wapato	103.0	08-14	3	67	19	22
12505100	Yakima River at Donald Road at RM 100.3, at Donald	100.3	08-14	3	57	5	16
12505310	Yakima River below Highway 22 near Toppenish	92.0	08-14	3	57	5	16
12505325	Yakima River at RM 88.1 near Toppenish	88.1	08-15	3	41	4	12
12505330	Yakima River above East Toppenish Drain near Granger	86.5	08-15	3	56	7	19
			09-21	3	243	15	–
12505040	Yakima River at RM 103 near Wapato	103.0	10-02	3	132	11	24
12505100	Yakima R at Donald Road at RM 100.3, at Donald	102.5	10-03	3	225	15	36
12505310	Yakima River below Highway 22 near Toppenish	92.0	10-03	3	225	15	36
12505325	Yakima River at RM 88.1 near Toppenish	88.1	10-03	3	155	27	31
12505330	Yakima River above East Toppenish Drain near Granger	86.5	10-03	3	168	27	30
Zillah Reach, 2007
12505040	Yakima River at RM 103 near Wapato	103.0	05-30	3	66	9	16
12505330	Yakima River above East Toppenish Drain near Granger	86.5	05-30	3	38	23	12
12505040	Yakima River at RM 103 near Wapato	103.0	06-12	3	76	2	22
			07-16	9	40	7	19
12505270	Yakima River at RM 94.4 near Buena	94.4	07-16	3	39	2	15
12505330	Yakima River above East Toppenish Drain near Granger	86.5	07-17	3	29	2	15
12505040	Yakima River at RM 103 near Wapato	103.0	07-31	9	54	5	25
12505270	Yakima River at RM 94.4 near Buena	94.4	07-31	6	31	3	21
12505330	Yakima River above East Toppenish Drain near Granger	86.5	07-31	3	30	2	20
12505040	Yakima River at RM 103 near Wapato	103.0	08-23	3	51	10	12
12505330	Yakima River above East Toppenish Drain near Granger	86.5	08-23	3	34	7	11
12505040	Yakima River at RM 103 near Wapato	103.0	09-03	3	72	8	20
12505330	Yakima River above East Toppenish Drain near Granger	86.5	09-03	3	77	6	16
Kiona Reach, 2007
12510500	Yakima River at Kiona	29.9	08-07	3	8	1	2

Assessment of Eutrophication in the Lower Yakima River Basin, Washington, 2004–07