Impacts of contaminant sources on marine fish abundance and species richness: a review and meta-analysis of evidence from the field

We conducted a systematic review and meta-analysis of the in situ effects of contaminant sources on fish abundance and species richness. We discuss these effects and examine the role of contaminant sources, habitats, and study systems. We also highlight the role of fish ecology in determining contaminant impacts, mechanisms of impact, and areas for future research. A total of 45 papers were analyzed in the meta-analysis, which revealed that the average change in abundance at contaminated sites was +103x (fish farms), +40% (sewage studies), -52% (industrial effluent), and -65% (run-off). This analysis suggested that the abundance of fish assemblages in coral reefs was negatively impacted by contaminants and that these reefs are more sensitive than other habitats. Weak trends were observed for species richness, which may suggest that contamination is not having an impact on fish diversity. Some sources of contamination that are also sources of food are having sizeable effects on abundance and richness and are likely to be of commercial and environmental significance. Further research is warranted, particularly where contamination may act as an additional stressor in impacted communities.