| Popis: |
The sediment communities — with particular reference to polychaete functions—were studied at four stations at depths between 7 and 26 m in a slightly sewage-polluted North Norwegian sill fjord basin with recorded sub-zero temperatures six months a year. The sampled macro-fauna (> 1 mm sieve) included ca. 53300 individuals and 152 taxa, of which the polychaetes comprised ca. 49000 individuals and 69 taxa. The total abundance increased from 5721 individuals m-2 at the 7 m station to 20653 individuals m-2 at the 26 m station. Similarly, the maldanid polychaete abundance — comprising deep subsurface head-down feeding detrivores (mainly Maldane sarsi) — increased with depth from 483 individuals m-2 to 12510 individuals m-2. Based on literature data, a maldanid-driven sediment turnover rate of up to ca. 4500 1 m-2 year-1 was calculated. It is suggested that the maldanids, through feeding at some depth in the sediment and faecal deposition at the sediment surface, may greatly contribute to maintain a ye... |
