| dc.description.abstract | Methyl mercury (MeHg) is a highly toxic contaminant found in water bodies throughout the world because of the widespread atmospheric deposition of inorganic mercury (Hg). In aquatic ecosystems, bacteria convert Hg into MeHg. Organisms at the base of the food web such as algae concentrate MeHg directly from the water and consumers are exposed to MeHg through their diets. Historically, studies of MeHg contamination of foodwebs have focused on aquatic organisms, but recent studies have found that a terrestrial spider living along the shorelines of ponds, the long jawed orb weaver (Tetragnatha sp.), can be contaminated with high levels of MeHg. The purpose of the present study was to determine the level of Hg contamination in other families of spiders associated with the shorelines of ponds. The study was conducted at the Eagle Mountain fish hatchery near Fort Worth, TX. We collected shoreline spiders on six dates between June and September 2015 using sweep nets and by hand and preserved them in 95% ethanol. A total of 4,671 spiders were collected representing six families; Lynx Spiders (Oxyopidae), Long Jawed Orb Weavers (Tetragnathidae), Orb Weavers (Araneidae), Crab Spiders (Thomisidae), Fishing Spiders (Pisauridae), and Jumping Spiders (Salticidae). Mercury analysis was conducted with a Milestone DMA-80 direct Hg analyzer. Methyl mercury concentration varied between taxa of spider, and some taxa contained high enough concentrations of MeHg that they may be toxic to nestling birds. | |
