Assessing the impact of contaminated sediments on hard-substrate Antarctic marine communities

The toxicity of aqueous metals and metal-contaminated resuspended sediment to the spirorbid polychaete Spirorbis nordenskjoldi Ehlers, 1900 was assessed in assays conducted during the 2005/6 and 2006/7 field seasons. A more detailed description of the design of experiments and the methods used can be found in Hill et al, 2009. Spirorbids were exposed to aqueous solutions of copper, lead and zinc singularly, and in mixtures.

Spirorbids were also exposed to resuspended metal-spiked sediments. Spirorbids attached to the brown alga Desmarestia sp were collected from Beall Island, Windmill Islands, East Antarctica, a clean site located approximately 2 km from Casey Station. Algae and animals were kept in the aquarium facility on station, in seawater maintained at 1 C and a 12-h light:dark photoperiod.

Seawater was constantly aerated and changed every 5 to 6 d. Spirorbids were used within two weeks of their collection and fed once per week with plankton. Spirorbids were removed from the surface of algal blades 24 h before the start of a test, and allowed to recover in a constant-temperature chamber (CTC) at 0.5 C. Immediately before the start of tests, spirorbids were examined, and only healthy individuals were selected for tests.

Spirorbids were determined to be healthy if their tentacular crown (fan) was extended and retracted quickly in response to stimuli. The download file contains further information on the data.