Bioaccumulation of Mercury and the effects on Wildlife

Bioaccumulation of Mercury and the effects on WildlifeBy: Adam Ware

•Levels in prey and piscivorous fish

•Bioaccumulation in birds

•What does this mean for the top of the food chain?

Levels in prey fish•Canadian study, eh?

•Country-wide undertaking focusing on Hg levels in the Yellow Perch

Why Yellow Perch?•Common prey for piscivores•Very tolerant of pH, temperature, and

dissolved O2

•Specimens around 12cm in length were selected for study

The Pinnacle of the Gilled Piscivores

Findings

How do you measure Mercury levels?

•Two common ways:

▫Old, expensive method – Gas Spectrometer

▫New, efficient, and cheaper way – Nano-velcro!

Obligate Piscivore

Loons and other birds at risk, not just water-dwelling birds!•Blood levels (Loons)

▫Concentrations of Hg in adults ranged from 0.12 to 7.80 μg/g (parts per million)

▫Levels in offspring <6 weeks of age ranged from 0.03 to 0.78 μg/g

Mercury accumulated in Feathers•Relatively large amount built up in

feathers.•Even with yearly molting, levels are

rising.

Say what?!

Song birds are sensitive too!•Blood levels above only 0.7 ppm – 10%

reduction in hatchability•> 1.7 ppm – over 30% decrease

Hg’s Effects at the higher trophic levels•Reproductive impairment

▫Birds have trouble hitting certain notes•Reduced hatchability in water and land-

based birds.•Deformation of fetus during early

development period.

Questions?