Biomagnification of mercury in an Antarctic marine coastal food web during 1989-1991

Twenty samples of surface sediment (the top 3.0 cm) were taken on soft bottoms
(from 20 to 300 m depth) with a stainless steel box corer. Phytoplankon and
zooplankton were sampled with conical nylon nets (1m in diameter, 50 and 500 mm
mesh size, respectively), towed just below the surface. Krill samples were
collected in the Ross Sea with a plankton sampler (EZNET BIONESS) equipped with
10 nets of 250 and 500 mm mesh size at a depth raging from 10 to 100 m. Benthic
organisms were obtain with a Van Veen grab or by dredging on hard bottoms. Fish
specimens were caught with a trammel net or baited long lines. On the coast
around Terra Nova Bay, eggs, primary feathers, chick plumage and guano samples
were gathered when possible in abandoned nests of sea birds (both plankton and
fish eating). Samples of stomach contents were taken from 5 Adelie penguins
(Pigoshelis adeliae). Various internal organs and tissues were obtained from an
Adelie penguins and an adult female Weddell Seal (Leptonychotes weddellii).
Samples were frozen for storage and transport to Italy.

In the laboratory, both sediments and biological material was decomposed with
HNO3 (Merck Suprapur) in Teflon vessels under pressure at 120 degrees C for 8
hrs. Mercury was determined in the digested solution by Flow Injection Atomic
Absorption Spectrometry (FIAAS) using a Perkin Elmer FIMS 400.