Response of Antarctic benthic communties to disturbance: first results from the artificial Benthic Disturbance Experiment on the eastern Weddell Sea Shelf, Antarctica.

• Main Authors: Gerdes, Dieter, Isla, Enrique, Knust, Rainer, Mintenbeck, Katja, Rossi, S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2008
• Subjects: Antarc*; Antarctic; Antarctica; Iceberg*; Polar Biology; Weddell Sea
• Online Access: https://epic.awi.de/id/eprint/34001/; https://hdl.handle.net/10013/epic.42277

The long-term benthic disturbance experiment (BENDEX) was started on the eastern Weddell Sea shelf off Austasen during ´Polarstern cruise ANT XXI in Dec. 2003 to simulate the impact of grounding icebergs on the seabed and follow the steps and timescales of recovery of disturbed benthos and demersal fish. Here we report the basic approach and first results for this experimental field study. Before the disturbance event and 11 days after it, the seafloor communitied were sampled (invertebrate assemblages by multibox corers, the fish fauna by trawl hauls) and comparatively analyzed.Sediment texture and chemistry was not significantly altered by the heavy disturbance inflicted by repeated trawling, whereas the fauna was negatively affected. Invertebrate benthic biomass was drastically reduced by a factor of 10, while mean abundances were only slightly reduced. Demersal fish biomass and abundance were slightly but not significantly smaller after the disturbance. Efects of disturbance became more evident in the composition of the fish fauna, with Trematomus pennelli and T. hansoni being more dominant at disturbed sites, whereas Chionodraco myseri was the dominant species in trawl catches from undisturbed stations