The use of biological indices and morphology of diatoms for the environmental assessment of streams

Costa, Ana Paula Tavares; Martins, André Ribeiro; Perazzo, Giselle Xavier; Schneck, Fabiana

doi:10.1590/S2179-975X3124

home Sumário navigate_before Anterior Atual Seguinte navigate_next

home Sumário

Original Articles • Acta Limnol. Bras. 37 • 2025 • https://doi.org/10.1590/S2179-975X3124 linkcopy

The use of biological indices and morphology of diatoms for the environmental assessment of streams

O uso de índices biológicos e da morfologia de diatomáceas na avaliação ambiental de riachos

Authorship SCIMAGO INSTITUTIONS RANKINGS

Abstract:

Aim Our aim was to verify whether morphological diatom metrics performed as effectively as diversity metrics and diatom indices for ecological assessments in streams in the Brazilian Pampa biome.

Methods We sampled physical and chemical variables along with benthic diatom communities from 15 Pampean streams. These streams are inserted along a gradient of agricultural land use. We calculated species richness, and three common diatom indices used for stream ecological assessment. In addition, we quantified the percentage of deformed valves in the communities and analyzed the shape of Achnanthidium minutissimum s.l. through geometric morphometrics. All biological responses were evaluated in relation to physical and chemical variables summarized through Principal Component Analysis (PCA).

Results We found that the Pampean Diatom Index was positively related to turbidity and velocity and negatively related to total nitrogen and pH. On the other hand, the percentage of deformed diatom valves and the different shapes of A. minutissimum s.l. were associated with total phosphorus, depth and total dissolved solids.

Conclusions Our study is one of the first to investigate morphological biomarkers in diatoms for ecological assessments in the Brazilian Pampa biome. We found that morphological diatom metrics were more effective in assessing the effects of the land use gradient is streams compared to taxonomic metrics. However, we highlight the importance of replicating this study with a larger sample size and across lotic environments influenced by diverse impacts. This will improve the understanding of the utility of different metrics for ecological assessments and biomonitoring in streams.

Keywords:
diatom index; teratology; Achnanthidium minutissimum; geometric morphometrics; Pampa biome

Stream	pH	DO	Cond	TDS	Turbidity	TP	TN	Vel	Width	Depth
Stream	pH	(mg L^-1)	(µS cm^-1)	(g L⁻¹)	(NTU)	(µg L^-1)	(mg L^-1)	(cm s^-1)	(m)	(cm)
1	7.8	11.1	0.22	0.14	24.14	72.6	0.77	<1.0	5.2	49.1
2	7.4	5.6	0.10	0.07	41.32	52.1	0.60	<1.0	5.9	49.8
3	6.9	7.3	0.04	0.02	29.16	94.1	0.84	<1.0	2.5	23.9
4	7.2	7.9	0.06	0.03	20.98	38.8	0.63	<1.0	1.9	25.5
5	7.5	7.8	0.03	0.02	6.38	134.4	0.92	<1.0	1.2	20.2
6	7.3	6.6	0.15	0.09	21.75	43.0	0.44	21.0	1.1	17.5
7	7.9	7.9	0.07	0.04	18.79	47.1	0.60	23.9	3.0	14.6
8	7.1	8.0	0.04	0.02	32.20	30.6	0.52	66.4	2.2	21.9
9	7.5	6.2	0.08	0.06	29.28	49.6	0.74	<1.0	1.0	9.5
10	7.6	7.6	0.04	0.03	18.20	11.4	0.56	<1.0	5.5	5.4
11	7.4	7.0	0.06	0.04	18.27	25.7	0.60	9.7	4.1	16.8
12	8.4	7.8	0.12	0.08	9.14	29.0	0.81	<1.0	1.3	9.8
13	7.5	6.4	0.11	0.07	19.94	27.3	0.81	<1.0	1.9	39.8
14	7.5	8.0	0.07	0.05	23.67	33.1	0.74	30.5	4.1	7.3
15	7.3	6.7	0.07	0.04	32.72	96.5	0.60	38.5	4.7	11.1

Stream	S	IDP	IPS	TDI	DVD (%)
1	76	2.16	12.63	63.18	2.2
2	69	1.99	14.42	48.99	2.8
3	67	2.52	14.10	32.49	1.0
4	48	2.03	14.13	37.24	2.6
5	37	1.48	17.40	31.08	2.0
6	81	2.58	11.76	49.86	0.6
7	79	2.55	11.13	67.30	1.4
8	66	2.29	14.60	46.01	0.6
9	78	2.22	12.10	51.30	1.6
10	54	2.07	15.63	44.34	0.2
11	67	2.41	10.77	64.88	0.2
12	71	1.97	14.63	51.16	0
13	55	1.69	16.44	44.23	0.2
14	70	2.59	13.57	59.87	0
15	72	2.99	12.37	65.13	0

	Estimate	SE	t-value	P-value	adjusted R²
Richness
Intercept	65.067	3.128	20.799	<0.001
PCA axis 1	2.834	2.058	1.377	0.192	0.06
Intercept	65.066	3.342	19.47	<0.001
PCA axis 2	-0.557	2.426	-0.23	0.822	-0.07

TDI
Intercept	50.477	3.034	16.639	<0.001
PCA axis 1	1.981	1.995	0.993	0.339	-0.001
Intercept	50.476	3.146	16.044	<0.001
PCA axis 2	-0.104	2.283	-0.046	0.964	-0.07

IPS
Intercept	13.715	0.466	29.383	<0.001
PCA axis 1	-0.521	0.307	-1.699	0.113	0.11
Intercept	13.715	0.515	26.581	<0.001
PCA axis 2	-0.015	0.374	-0.041	0.968	-0.07

IDP
Intercept	2.241	0.079	28.122	<0.001
PCA axis 1	0.157	0.052	3.003	0.010	0.36
Intercept	2.241	0.102	21.842	<0.001
PCA axis 2	0.039	0.074	0.532	0.604	-0.05

Deformities
Intercept	1.026	0.267	3.837	<0.001
PCA axis 1	-0.030	1.795	-0.172	0.866	-0.07
Intercept	1.026	0.216	4.733	<0.001
PCA axis 2	-0.411	0.0157	-2.611	0.020	0.29

A. minutissimum shape
Intercept	0.0007	0.003	0.205	0.841
PCA axis 1	0.003	0.002	1.310	0.213	0.04
Intercept	-0.001	0.003	-0.369	0.718
PCA axis 2	-0.006	0.002	2.530	0.020	0.27

vertical_align_top show_chart

more_horiz close
- image
- translate
- link
- article
- vertical_align_top
- file_download
- show_chart
- image
- translate
- link
- article

location_on

Associação Brasileira de Limnologia Av. 24 A, 1515, CEP: 13506-900 , Tel.:+55 (19) 3526-4225 - Rio Claro - SP - Brazil
E-mail: actalimno@gmail.com

rss_feed Acompanhe os números deste periódico no seu leitor de RSS

[1] Cond = electrical conductivity; DO = dissolved oxygen; TDS = total dissolved solids; TP = total phosphorus; TN = total nitrogen; Vel = current velocity.