Macrobenthic community responses to multiple environmental stressors in a subtropical estuary

Fernanda M Souza; Eliandro R Gilbert; Kalina M Brauko; Luciano Lorenzi; Eunice Machado; Mauricio G Camargo

doi:10.7717/peerj.12427

Macrobenthic community responses to multiple environmental stressors in a subtropical estuary

PeerJ. 2021 Dec 7:9:e12427. doi: 10.7717/peerj.12427. eCollection 2021.

Authors

Fernanda M Souza^{1

2}, Eliandro R Gilbert³, Kalina M Brauko⁴, Luciano Lorenzi⁵, Eunice Machado⁶, Mauricio G Camargo⁶

Affiliations

¹ University of Amapá State-UEAP, Macapá, AP, Brazil.
² Centro de Estudos do Mar, Universidade Federal do Paraná, Pontal do Paraná, Paraná, Brazil.
³ Instituto Brasileiro de Geografia e Estatística-IBGE, Macapá, AP, Brazil.
⁴ Coordenadoria Especial de Oceanografia, Universidade Federal de Santa Catarina-UFSC, Florianópolis, SC, Brazil.
⁵ Department of Biology, University of Joinville Region-UNIVILLE, São Francisco do Sul, SC, Brazil.
⁶ Programa de Pós-Graduação em Saúde e Meio Ambiente, Institute of Oceanography, Federal University of Rio Grande-FURG, Rio Grande, RS, Brazil.

Abstract

We assessed how multi- and univariate models reflect marine environmental health based on macrobenthic community responses to three environmental stressor categories: hydrodynamics, organic enrichment and metal contamination. We then compared the models with the benthic index AMBI (AZTI Marine Biotic Index). Macrobenthic community and physicochemical variables were sampled at 35 sites along Babitonga Bay, a subtropical estuary in Southern Brazil. Distance-based linear modelling identified depth, grain size and organic matter as well as Cu and Zn as key stressors affecting the macrobenthos. Using canonical analysis of principal coordinates (CAP), we developed three multivariate models based on the variability in community composition, creating stress gradients. The metal gradient showed better correlation with the benthic community. Sediment quality indices (Geoaccumulation Index and Contamination Factor) showed a low to moderate contamination status, with higher concentrations for Cr, Ni and Zn at the inner areas of the bay. According to AMBI, Babitonga Bay has a "good" environmental health status, and the AMBI values show stronger correlations with the hydrodynamic and organic enrichment gradients (r = 0.50 and r = 0.47) rather than the metal gradient (r = 0.29). Lumbrineridae polychaetes (not included in the AMBI list) and Scoloplos sp. were negatively related to the metal contamination gradient and were considered sensitive, while Sigambra sp., Magelona papillicornis, the gastropod Heleobia australis and species of the crustacean order Mysida were positively related to the gradient and considered tolerant to higher concentrations of metals in the sediment. Despite the inconsistency in the ecological classification provided by AMBI and its relationship with the metal gradient, our results suggest that the environmental quality was satisfactory for the studied gradients. The metal gradient showed the weakest correlation to AMBI. In such cases, the ecological classification of taxa by the index should be evaluated under the perspective of the action of inorganic genotoxic contaminants represented by metals.

Keywords: AMBI; Babitonga Bay; Environmental health; Estuarine gradient; Macrofauna; Metal contamination; Organic enrichment; Pollution effects; Sediments.

Grants and funding

This work was supported by Conselho Nacional de Pesquisa e Desenvolvimento CNPq (n° 478424/2013-2), Fundação Araucária (Project 209610/2014-11) and Paranaguá Pilots. Fernanda M. Souza was supported by Brazilian Ministry of Education CAPES scholarship at the Ocean and Coastal Systems Graduate Program (PGSISCO). Kalina M. Brauko were supported by Brazilian Ministry of Education CAPES scholarship at the Graduate Program in Oceanography (PPGOCEANO). Luciano Lorenzi was supported by Fundo de Apoio à Pesquisa - Universidade da Região de Joinville (FAP- UNIVILLE). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.