Interrogating pollution sources in a mangrove food web using multiple stable isotopes

Abstract

Anthropogenic activities including metal contamination create well-known problems in coastal mangrove ecosystems but understanding and linking specific pollution sources to distinct trophic levels within these environments is challenging. This study evaluated anthropogenic impacts on two contrasting mangrove food webs, by using stable isotopes (δC, δN, Sr/Sr, Pb/Pb and Pb/Pb) measured in sediments, mangrove trees (Rhizophora mangle, Laguncularia racemosa, Avicennia schaueriana), plankton, shrimps (Macrobranchium sp.), crabs (Aratus sp.), oysters (Crassostrea rhizophorae) and fish (Centropomus parallelus) from both areas. Strontium and Pb isotopes were also analysed in water and atmospheric particulate matter (PM). δN indicated that crab, shrimp and oyster are at intermediate levels within the local food web and fish, in this case C. parallelus, was confirmed at the highest trophic level. δN also indicates different anthropogenic pressures between both estuaries; Vitória Bay, close to intensive human activities, showed higher δN across the food web, apparently influenced by sewage. The ratioSr/Sr showed the primary influence of marine water throughout the entire food web. Pb isotope ratios suggest that PM is primarily influenced by metallurgical activities, with some secondary influence on mangrove plants and crabs sampled in the area adjacent to the smelting works. To our knowledge, this is the first demonstration of the effect of anthropogenic pollution (probable sewage pollution) on the isotopic fingerprint of estuarine-mangrove systems located close to a city compared to less impacted estuarine mangroves. The influence of industrial metallurgical activity detected using Pb isotopic analysis of PM and mangrove plants close to such an impacted area is also notable and illustrates the value of isotopic analysis in tracing the impact and species affected by atmospheric pollution.

Incorporation of PVDF Nanofibre Multilayers into Functional Structure for Filtration Applications

“…Air and water pollution has become a major environmental concern due to the growing global population, increasing economic expansion, and amount of consumption. Many developing countries face an increase in particulate matter (PM) as an air pollutant and amounts wastewater [ 1 , 2 , 3 , 4 ]. One of the greatest challenges to the sustainability of modern society is an inadequate supply of clean air and water.…”

Atmospheric particulate matter from an industrial area as a source of metal nanoparticle contamination in aquatic ecosystems

“…All these metals are used in new metal alloys for the growing electronics, light alloys and anticorrosive steel. These rare elements dispersed in the atmosphere contaminate not only the air but also the aquatic environment and, passively, be incorporated by the local biota (Souza et al 2018b, Souza et al 2019.…”

Responses of nitrogen stable isotopes in fish to phosphorus limitation in freshwater wetlands

“…Therefore, the increasing pattern of d 15 N ratios along the nutrient gradient may also be caused by increases in wastewater loading. Enriched d 15 N of various flora and fauna has been used as an indicator for sewage influence in the freshwater and coastal marine environments (Cole et al, 2004;Rožič et al, 2014;Souza et al, 2018;de Carvalho et al, 2019). There have been no reports of any significant wastewater contributions from human or animal sources to the Everglades.…”

“…The use of d 15 N as an indicator of aquatic eutrophication is based on the fact that increases in ecosystem productivity controlled by nutrient enrichments will lead to decreases in isotope fractionation by primary producers and the transfers of organic matter from one trophic level to another will result in predictable isotope enrichment along food chain (Post, 2002;Vander Zanden et al, 2015). At present, the use of consumer d 15 N largely focuses on the source of nitrogen contaminations (Lake et al, 2001;Vander Zanden et al, 2005;Schlacher et al, 2005;Robinson et al, 2016;Souza et al, 2018) and trophic interactions (Post, 2002;Vander Zanden et al, 2015;Wang et al, 2018). Very few studies link consumer isotope composition to primary productivity in freshwater ecosystems (Woodland et al, 2012;Hou et al, 2013).…”