Community characteristics of phytoplankton and eutrophication assessment in Tianjin section, downstream of Haihe River Basin

Figures & data

Figure 1. Map of sampling stations.

Table 1. Grading standards for freshwater trophic status.

Trophic status standards	Eutrophication assessment indices score	TN （mg·L^-1）	TP （mg·L^-1）	chl-a （µg·L^-1）	CODMn （mg·L^-1）
Oligotrophic $EI\leqq 20$	10	0.02	0.001	0.5	0.15
	20	0.05	0.004	1.0	0.40
Mesotrophic 20﹤EI$\leqq$50	30	0.10	0.010	2.0	1.00
	40	0.30	0.025	4.0	2.00
	50	0.50	0.050	10.0	4.00
Mild eutrophication 50﹤EI$\leqq$60	60	1.00	0.100	26.0	8.00
Moderate eutrophication 60﹤EI$\leqq$80	70	2.00	0.200	64.0	10.00
	80	6.00	0.600	160.0	25.00
Severe eutrophication 80﹤EI$\leqq$100	90	9.00	0.900	400.0	40.00
	100	16.00	1.300	1000.0	60.00

Table 2. Directory of dominant phytoplankton species.

Code	Species	May	July	September
P1	Cryptomonas erosa	+	+	+
P2	Merismopedia sp.	+	+	+
P3	Phormidlum tenue	+	+	+
P4	Oscillatoria sp.	+	+
P5	Nostoc sp.		+
P6	Dactylococcopsis sp.	+	+	+
P7	Merismopedia sp.		+	+
P8	Crucigenia sp.		+	+
P9	Chlorella vulgaris	+	+	+
P10	Scenedesmus quadricauda	+	+	+
P11	Oocystis sp.	+	+
P12	Cosmarium sp.	+	+
P13	Nitzschia sp.	+	+	+
P14	Cyclotella meneghiniana	+	+	+
P15	Phacus pleuronectes		+
P16	Ankistrodesmus sp.	+	+	+
P17	Phacus helicoides		+
P18	Phacus onyx		+
P19	Scenedesmus dimorphus	+	+	+
P20	Eutreptia sp.		+
P21	Closterium sp.		+	+
P22	Coelastrum sp.	+	+
P23	Spirulina platensis		+
P24	Strombomonas sp.		+
P25	Chroomonas acuta	+	+
P26	Actinastrum sp.	+	+
P27	Euglena acus		+
P28	Chlamydomonas globosa		+
P29	Euglena oxyuris	+		+
P30	Pseudoanabaena sp.			+
P31	Lyngbya sp.			+
P32	Synedra sp.	+		+
P33	Chroococcus minutus			+
P34	Gyrosigma sp.			+
P35	Nitzschiiella closterium	+		+
P36	Tetraselmis sp.			+
P37	Chromullina sp.			+
P38	Melosira sp.			+
P39	Microcystis aeruginosa			+
P40	Chlamydomonas reinhardti			+
P41	Scenedesmus obliquus	+		+
P42	Microcystis incerta			+
P43	Scenedesmus denticulatus			+
P44	Pesiastrum duplex	+
P45	Pinnularia sp.	+
P46	Cladophora aegagrophila	+
P47	Tetraedrom tumiduclum	+
P48	Navicula sp.	+
P49	Cryptomons ovata	+
P50	Schroederia sp.	+
P51	Nitzschia palea	+
P52	Pesiastrum simplex	+
P53	Dinobryon sp.	+

Table 3. Distribution characteristics of maximal abundance of dominant phytoplankton species in three surveys.

Phytoplankton species	Maximum abundance （×10^4 cells·L^-1）	Month with the maximum abundance	Station with the maximum abundance	Region
Cryptomonas erosa	417.11	July	19	Qilihai Wetland
Merismopedia sp.	577.11	September	20	Ji Canal
Phormidlum tenue	1155.20	May	22	Ji Canal
Dactylococcopsis sp.	493.87	July	2	Beidagang Wetland
Chlorella vulgaris	205.32	September	25	Yuqiao Reservoir
Scenedesmus quadricauda	645.60	May	12	Duliujian River
Nitzschia sp.	1068.21	September	27	New Chaobai River
Cyclotella meneghiniana	497.60	July	11	Duliujian River
Ankistrodesmus sp.	707.20	May	12	Duliujian River
Scenedesmus dimorphus	135.95	September	22	Ji Canal

Table 4. Biomass and abundance of the phytoplankton community in the survey area.

Region	Station	Biomass (mg·L^-1)			Annual average	Abundance (×10^4 cells·L^-1)			Annual average
		May	July	September		May	July	September
Beidagang Wetland	1	0.784	3.666	5.535	3.328	29.06	1519.52	873.98	807.52
	2	2.078	9.634	15.512	9.075	159.20	2104.96	832.37	1032.18
	3	3.431	22.532	9.760	11.908	65.60	2708.93	1442.78	1405.77
	4	0.529	8.705	6.159	5.131	92.00	5774.79	3630.05	3165.61
	5	1.487	18.163	24.116	14.589	80.80	1807.17	1353.06	1080.34
	6	2.503	20.745	6.634	9.961	155.20	2102.20	1233.74	1163.71
	7	0.705	1.281	21.203	7.730	68.80	99.86	617.80	262.15
	8	2.019	8.796	25.781	12.199	57.60	571.52	1291.11	640.08
	9	3.275	7.338	11.860	7.491	124.80	1419.66	1676.77	1073.74
Duliujian River	10	1.111	9.878	24.309	11.766	200.80	1361.40	998.83	853.68
	11	7.375	7.364	32.498	15.746	3472.00	828.66	1618.50	1973.05
	12	7.738	1.766	6.535	5.346	3449.60	261.72	920.23	1543.85
Haihe river mainstem city section	13	0.500	3.882	8.344	4.242	108.80	391.17	2100.31	866.76
	14	0.624	11.398	9.107	7.043	94.40	1083.90	1267.05	815.12
	15	3.247	3.880	2.364	3.164	247.20	1234.60	1267.05	916.28
	16	0.443	2.263	3.364	2.023	43.20	368.98	672.38	361.52
Qilihai Wetland	17	23.051	12.423	8.574	14.683	492.00	568.76	624.28	561.68
	18	21.491	11.702	4.573	12.589	3147.20	1869.15	1512.15	2176.17
	19	7.784	4.214	3.390	5.129	904.80	675.13	1657.35	1079.09
Ji canal	20	4.732	10.489	3.736	6.319	244.00	820.33	600.25	554.86
	21	2.358	11.123	2.614	5.365	261.60	865.65	272.82	466.69
	22	5.522	25.030	5.138	11.897	388.80	1645.30	546.59	860.23
Yuqiao Reservoir	23	0.083	3.571	2.307	1.987	51.20	470.70	806.48	442.79
	24	0.015	2.592	1.782	1.463	1.90	577.07	617.79	398.92
	25	0.007	2.492	0.723	1.074	0.94	779.62	544.75	441.77
New Chaobai River	26	1.545	4.825	10.885	5.752	258.40	624.26	512.37	465.01
	27	1.707	16.454	15.991	11.384	164.80	1042.31	7924.17	3043.76
	28	4.383	17.002	9.917	10.434	0.40	984.01	1567.62	850.68

Table 5. Species richness index d and biodiversity index H of the phytoplankton community in the survey area.

Region	Station	Margalef richness index d			Annual average	Shannon-Wiener diversity index H			Annual average
		May	July	September		May	July	September
Beidagang Wetland	1	5.342	3.139	2.215	3.565	2.481	2.227	1.727	2.145
	2	4.931	3.270	1.338	3.180	2.781	2.482	1.949	2.404
	3	3.824	3.289	1.925	3.013	2.712	2.504	2.036	2.417
	4	3.760	2.309	1.342	2.470	2.640	1.532	1.508	1.893
	5	4.781	2.741	1.248	2.923	2.893	2.532	1.948	2.458
	6	2.379	2.483	1.545	2.136	1.735	2.520	1.726	1.994
	7	3.781	2.389	1.089	2.420	2.619	2.117	1.458	2.065
	8	2.960	3.623	2.373	2.985	2.296	2.866	2.154	2.439
	9	4.972	3.322	3.098	3.797	2.851	2.631	2.443	2.642
Duliujian River	10	2.075	3.464	1.307	2.282	2.203	2.598	1.744	2.182
	11	1.595	2.083	2.165	1.948	2.139	1.609	1.874	1.874
	12	1.841	3.054	1.465	2.120	2.089	2.411	1.153	1.884
Haihe river mainstem city section	13	5.118	3.686	2.353	3.719	2.490	2.361	1.690	2.180
	14	4.618	3.439	2.379	3.479	2.794	2.815	2.086	2.565
	15	4.174	4.074	1.120	3.123	2.604	1.678	1.219	1.834
	16	3.187	2.538	0.956	2.227	2.294	1.884	1.382	1.853
Qilihai Wetland	17	4.184	3.279	2.032	3.165	2.651	2.759	2.130	2.513
	18	3.952	2.836	2.538	3.109	2.568	2.435	2.601	2.535
	19	3.689	3.844	1.070	2.868	2.640	3.020	1.199	2.286
Ji canal	20	2.056	2.920	1.214	2.063	2.105	2.249	1.814	2.056
	21	2.259	2.680	1.088	2.009	1.395	2.614	1.308	1.772
	22	1.490	3.223	1.366	2.026	1.520	2.823	1.925	2.089
Yuqiao Reservoir	23	1.270	4.062	1.345	2.226	0.870	2.859	1.396	1.708
	24	–	2.112	1.428	1.770	1.598	1.555	1.654	1.602
	25	14.020	3.146	2.334	6.500	1.318	1.743	1.985	1.682
New Chaobai River	26	3.785	3.628	0.544	2.652	2.277	2.837	1.107	2.074
	27	3.526	4.029	0.557	2.704	2.414	2.757	0.494	1.888
	28	2.520	3.418	2.244	2.727	2.093	2.518	2.297	2.303

TABLE 6. Spatial distribution of TN and TP in the survey area.

Region	Station	TN (mg·L^-1)			Annual average	TP (mg·L^-1)			Annual average
		May	July	September		May	July	September
Beidagang Wetland	1	0.82	1.74	1.06	1.21	0.590	0.044	0.062	0.232
	2	4.23	2.12	5.03	3.79	0.031	0.042	0.128	0.067
	3	1.96	3.82	1.97	2.58	0.015	0.034	0.067	0.039
	4	1.97	2.55	2.33	2.28	0.031	0.091	0.092	0.071
	5	1.95	4.98	2.63	3.19	0.052	0.075	0.080	0.069
	6	1.95	1.71	1.89	1.85	0.133	0.040	0.100	0.091
	7	1.24	4.53	1.77	2.51	0.045	0.046	0.107	0.066
	8	1.22	1.48	1.58	1.43	0.023	0.026	0.054	0.034
	9	1.23	1.58	1.96	1.59	0.042	0.029	0.075	0.049
Duliujian River	10	8.67	3.58	1.97	4.74	0.290	0.147	0.094	0.177
	11	13.50	9.14	3.85	8.83	0.190	0.141	0.480	0.270
	12	10.60	8.29	4.53	7.81	0.222	0.072	0.368	0.221
Haihe river mainstem city section	13	4.80	5.56	2.23	4.20	0.194	0.044	0.058	0.099
	14	4.77	10.80	3.26	6.28	0.235	0.082	0.594	0.304
	15	5.87	5.97	6.35	6.06	0.480	0.110	0.102	0.231
	16	7.50	6.18	3.15	5.61	1.018	0.065	0.216	0.433
Qilihai Wetland	17	5.42	6.40	2.40	4.74	0.146	0.092	0.122	0.120
	18	4.69	3.34	3.82	3.95	0.221	0.059	0.092	0.124
	19	3.57	4.34	4.28	4.06	0.408	0.264	0.096	0.256
Ji canal	20	3.08	5.04	2.94	3.69	0.208	0.181	0.174	0.188
	21	4.63	5.29	2.36	4.09	1.217	0.118	0.703	0.679
	22	6.40	7.52	2.33	5.42	0.704	0.159	0.635	0.499
Yuqiao Reservoir	23	6.87	9.37	2.59	6.28	0.030	0.031	0.033	0.031
	24	4.21	4.59	2.46	3.75	0.017	0.028	0.039	0.028
	25	4.56	3.85	3.24	3.88	–	0.026	0.035	0.031
New Chaobai River	26	9.42	9.12	5.98	8.17	1.156	0.610	0.432	0.733
	27	7.90	5.68	5.60	6.39	1.208	0.988	1.430	1.209
	28	7.56	4.39	3.09	5.01	0.002	0.374	1.080	0.485

TABLE 7. Spatial distribution of Chl-a and COD_Mn in the survey area.

Region	Station	Chl-a (μg·L^-1)			Annual average	CODMn (mg·L^-1)			Annual average
		May	July	September		May	July	September
Beidagang Wetland	1	4.820	5.778	12.184	7.594	9.48	11.16	9.50	10.05
	2	9.230	15.233	27.429	17.297	24.28	26.30	25.44	25.34
	3	7.260	17.070	20.351	14.894	19.63	19.92	20.84	20.13
	4	15.380	46.132	29.292	30.268	19.77	20.79	20.04	20.20
	5	9.710	38.884	22.500	23.698	18.39	29.43	18.89	22.24
	6	26.330	29.788	30.655	28.924	18.66	18.77	11.72	16.38
	7	7.670	37.097	36.598	27.122	10.42	15.76	12.60	12.93
	8	2.720	9.948	28.915	13.861	12.80	12.82	13.37	13.00
	9	10.860	6.312	34.793	17.322	14.00	14.95	14.83	14.59
Duliujian River	10	74.850	107.352	121.626	101.276	17.54	18.04	14.42	16.67
	11	105.960	36.397	455.767	199.375	20.02	12.16	23.39	18.52
	12	61.300	18.154	179.009	86.154	21.29	6.00	15.34	14.21
Haihe river mainstem city section	13	40.160	20.733	56.637	39.177	7.99	7.81	8.04	7.95
	14	10.090	37.202	48.330	31.874	9.22	9.00	8.89	9.04
	15	42.040	108.774	508.700	219.838	8.45	13.58	27.02	16.35
	16	8.520	21.285	39.027	22.944	9.96	6.96	12.40	9.77
Qilihai Wetland	17	346.840	90.241	82.242	173.108	25.70	16.52	18.52	20.25
	18	47.550	52.799	60.996	53.782	19.33	14.28	18.64	17.42
	19	218.980	83.176	134.874	145.677	34.96	13.00	21.59	23.18
Ji canal	20	36.350	86.986	82.045	68.460	10.53	13.28	15.80	13.20
	21	60.170	108.980	52.718	73.956	16.41	17.24	14.84	16.16
	22	183.320	211.655	39.907	144.961	16.76	17.76	14.29	16.27
Yuqiao Reservoir	23	20.800	18.957	10.184	16.647	4.19	6.61	8.96	6.59
	24	2.270	12.934	16.392	10.532	4.95	7.42	8.44	6.94
	25	2.720	15.004	17.509	11.744	5.11	7.31	8.89	7.10
New Chaobai River	26	120.220	89.859	31.381	80.487	18.41	12.29	17.06	15.92
	27	75.120	327.895	465.047	289.354	17.98	18.36	30.14	22.16
	28	83.760	71.717	294.001	149.826	19.07	22.18	18.33	19.86

Table 8. Linear regression equation fitted by assessment indices and fixed score.

Assessment indices	Fixed score	Linear regression equation	R-Squared	Significance
TP	E1	E1=56.678 × TP + 36.72	0.738	P﹤0.01
TN	E2	E2=4.717 × TN + 38.505	0.691	P﹤0.01
chl-a	E3	E3=70.002 × chl-a + 43.327	0.542	P﹤0.05
CODMn	E4	E4=1.827 × CODMn+35.62	0.752	P﹤0.01

Table 9. Spatial distribution characteristics of EI in the survey area.

Region	Station	EI			Annual average
		May	July	September
Beidagang Wetland	1	51.06	44.96	43.99	46.67
	2	51.99	50.42	55.00	52.47
	3	47.56	50.29	48.93	48.93
	4	47.99	50.39	49.60	49.33
	5	47.72	55.68	49.30	50.90
	6	49.24	47.74	46.55	47.84
	7	44.18	50.31	46.89	47.13
	8	44.52	45.01	46.03	45.19
	9	45.33	45.79	47.35	46.16
Duliujian River	10	59.88	52.59	49.02	53.83
	11	65.50	55.92	65.44	62.29
	12	62.16	51.64	57.22	57.01
Haihe river mainstem city section	13	50.28	48.65	45.62	48.18
	14	50.69	56.04	54.56	53.76
	15	55.77	53.47	65.12	58.12
	16	65.22	49.41	50.04	54.89
Qilihai Wetland	17	61.39	54.34	50.55	55.43
	18	54.31	48.89	51.47	51.56
	19	63.66	53.09	54.31	57.02
Ji canal	20	49.20	52.90	51.04	51.05
	21	67.63	53.96	57.03	59.54
	22	64.72	59.14	55.63	59.83
Yuqiao Reservoir	23	48.83	52.54	45.18	48.85
	24	45.43	47.02	45.05	45.83
	25	48.58	46.12	46.08	46.93
New Chaobai River	26	74.11	63.52	57.80	65.14
	27	72.13	70.95	83.30	75.46
	28	55.14	57.46	68.58	60.39

Figure 2. Pearson correlation between the phytoplankton community parameters and the eutrophication assessment indices.

Figure 3. Ordination plot between the abundance of phytoplankton dominant species and the eutrophication assessment indices.

Data availability statement

The data that support the findings of this study are available from the first author, upon reasonable request.