title: Water striders (family Gerridae): mercury sentinels in small freshwater ecosystems.
abstract: To circumvent some of the previous limitations associated with contaminant-monitoring programs, we tested the suitability of the water strider (Hemiptera: Gerridae) as a mercury sentinel by comparing total mercury concentrations in water striders and brook trout (Salvelinus fontinalis) from a variety of stream sites in New Brunswick, Canada. There was a strong association between the two variables across sites (r(2)=0.81, P<0.001) in systems where both atmospheric deposition and a point source (an abandoned gold mine) were likely contributing to ambient mercury levels. In a small stream draining the gold mine tailings pile, water striders had mercury concentrations an order of magnitude higher than those from reference locations. Temporal variation at three southern New Brunswick stream sites was non-significant. These results suggest that water strider mercury levels accurately quantify food chain entry of the element. The use of sentinel species holds great potential for expanding contaminant-monitoring programs.
authors.affiliation: Canadian Rivers Institute, University of New Brunswick, Fredericton, New Brunswick, Canada. tim.jardine@unb.ca
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Jardine
authors.forename: Tom A
authors.initials: TA
authors.lastname: Al
authors.forename: Kerry T B
authors.initials: KT
authors.lastname: MacQuarrie
authors.forename: Charles D
authors.initials: CD
authors.lastname: Ritchie
authors.forename: Paul A
authors.initials: PA
authors.lastname: Arp
authors.forename: Antu
authors.initials: A
authors.lastname: Maprani
authors.forename: Richard A
authors.initials: RA
authors.lastname: Cunjak
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D020387:Food Chain; D005618:Fresh Water; D006430:Hemiptera / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury