Icefish (Salangidae) as an Indicator of Anthropogenic Pollution in Freshwater Systems Using Nitrogen Isotope Analysis

Abstract

We investigated differences in delta(15)N of seston and icefishes from seven freshwater ecosystems with different trophic states in China. An increase of seston delta(15)N values was accompanied by an increase of total nitrogen and phosphorus concentrations. Significantly positive correlations were observed between delta(15)N of icefishes and delta(15)N of seston, total nitrogen and phosphorus concentrations. This study demonstrated that icefishes could be preferred indicators of anthropogenic contamination in test systems because they integrated waste inputs over long time periods and reflected the movement of waste through the pelagic food chain.

Primary consumers as bioindicator of nitrogen pollution in lake planktonic and benthic food webs

“…Hence, the assessment of anthropogenic pollution in aquatic ecosystems with the ı 15 N isotopic method has been widely tested on organisms of different trophic levels as biological indicators in aquatic ecosystems, including plants, invertebrates, and fishes (Lake et al, 2001;Cole et al, 2004;Schlacher et al, 2005;Xu et al, 2007). In addition the elevated ı 15 N signatures in aquatic biota are known to be correlated with increased exposure to human septic or sewage waste (Cole et Oligochaete Chironomus …”

“…Further, different nitrogen integration periods across multiple organisms can offer a selection of complementary vantage points for evaluating anthropogenic waste input at various spatial and temporal scales, which can help give focus on nutrient management (Gustafson et al, 2007;Wen et al, 2010). Meanwhile, the elevated ı 15 N signatures in primary consumers in aquatic ecosystems with anthropogenic nitrogen input will be further recorded by consumers higher up the food chain, such as fish, and result in elevated ı 15 N signatures of aquatic systems (Lake et al, 2001;Schlacher et al, 2005;Xu et al, 2007;Bergfur et al, 2009).…”

“…Thus, many studies have correlated increases in the ı 15 N values in aquatic systems to the extent of anthropogenic activity in watersheds and the input of wastewater (e.g. Cabana and Rasmussen, 1996;Vander Zanden et al, 2005;Xu et al, 2007).…”

Habitat-specific variation in stable C and N isotope ratios of pond smelt (Hypomesus nipponensis)

“…N sources from human and animal waste usually have higher d 15 N than other N sources (McClelland et al 1997;McClelland and Valiela 1998). In our study, the higher pond smelt d 15 N values in Lake Youngrang and Lake Mae compared to Lake Hwajinpo might be due to differences in N sources from the watersheds (Cabana and Rasmussen 1996;Choi et al 2007;Xu et al 2010). Lake Youngrang and Lake Mae receive N inputs from sources such as waste water and agricultural runoff, but not in Lake Hwajinpo.…”

“…Some studies have successfully used 15 N measurements of fish tissue to identify N sources to aquatic ecosystems. Xu et al (2010) showed that the d 15 N of icefish (Salangidae) could be used as an indicator to assess anthropogenic nutrient inputs based on the positive correlation between icefish d 15 N values and seston d 15 N values in freshwater ecosystems. Schlacher et al (2005) also found that fish tissue d 15 N values can be an excellent indicator of anthropogenic N in estuaries.…”