Fish track wastewater pollution to estuaries

摘要: Excess nitrogen is a forceful agent of ecological change in coastal waters, and wastewater prominent source nitrogen. In catchments where multiple sources pollution co-exist, biological indicators are needed to gauge the degree which wastewater-N can propagate through receiving food webs. The purpose this study was test whether estuarine fish suitable as sewage-N pollution. Fish were analysed from three estuaries within 100-km strip on Australian East Coast. differ substantially loading: (1) Maroochy Estuary receives large fraction local shire’s treated sewage, (2) Mooloolah has no licensed outfalls but marinas/harbours stormwater may contribute nitrogen, (3) Noosa neither discharges nor suspected loads. Sampling for included both high rainfall (‘wet’ season) low (‘dry’ periods. Muscle-δ15N variable predicted respond loading, reflecting relative enrichment 15N resulting treatment process distinguishing it alternative N such fertiliser natural inputs (both 15N-depleted). Of 19 species occurring all estuaries, those had significantly elevated δ15N values (up 9.9‰), inter-estuarine differences fish-δ15N consistent across seasons. Furthermore, not only did estuary carry very distinctive tissue signal, enriched muscle-δ15N also evident sampled one sewage contamination previously (i.e. Estuary: 0.2–4.8‰ over reference system). Thus, indicator systems that receive loads, detection more subtle inputs. Arguably, be preferred because they: integrate long time periods, have an element ‘ecological relevance’ reflect movement chain, assessments usually based evidence species.