Table 2. Phytoplankton biomass (Chl-a) and TSI of Ethiopian highland lakes based on the Carlson’s TSI

Trophic state indices	Lake
	Dendi	Wonchi	Ziqualla	Hayq	Ardibo	Tana
Chl-a (μg/L)	0.1	3.04	2.2	4.03	3.28	38
TSI (TP)	31.56	34.75	48.46	56.94	65.25	88.405
TSI (Chl-a)	11.31	41.95	38.20	51.46	41.5	58.23
TSI (Sec)	24.19	36.81	50.01	41.95	65.23	62.66
Mean TSI	22.37	37.84	45.56	43.16	57.33	69.77
Trophic state	Oligotrophic	Oligotrophic	Mesotrophic	Mesotrophic	Eutrophic	Eutrophic

TSI, Trophic State Index; TSI (TP), TSI referred to total phosphorus; TSI (Chl-a), TSI referred to chlorophyll-a; TSI (SD), TSI referred to Secchi depth.