Mercury is a potent neurotoxin with no physiological function in organisms. Biomagnification (an increase in contaminant concentration observed with increasing trophic level) of mercury has been documented for many systems, and often top piscivores in aquatic systems contain the highest mercury levels. All the Great Lake states have issued fish consumption advisories related to mercury contamination in top predator fish species. Researchers affiliated with the GLC are trying to further understand the dynamics of mercury movement through ecosystems by examining the movement of mercury from aquatic to terrestrial habitats.
Riparian zone spiders (Larinioides sclopetarius) build their webs on structures adjacent to aquatic habitats and feed on emerged aquatic insects. This study examined the mercury content of riparian spiders and their midge prey from areas within the Buffalo River Area of Concern (AOC) and from an upstream area. Spiders contained significantly more mercury than their midge prey, and surprisingly, spiders upstream from the AOC held more mercury than those within the AOC. Researchers are continuing to investigate why the upstream area had higher mercury levels.
