Midwater biomass profiles over the Madeira Abyssal Plain and the contribution of copepods
Roe, H.S.J. (1988). Midwater biomass profiles over the Madeira Abyssal Plain and the contribution of copepods, in: Boxshall, G.A. et al. Biology of copepods: Proceedings of the third international conference on Copepoda. Developments in Hydrobiology, 47: pp. 169-181. http://dx.doi.org/10.1007/978-94-009-3103-9_15 In: Boxshall, G.A.; Schminke, H.K. (Ed.) (1988). Biology of copepods: Proceedings of the third international conference on Copepoda. Developments in Hydrobiology, 47. Kluwer Academic Publishers: Dordrecht/Boston/London. ISBN 978-94-010-7895-5; e-ISBN 978-94-009-3103-9. XII, 639 pp. https://dx.doi.org/10.1007/978-94-009-3103-9, more In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more |
| Keywords | Population characteristics > Biomass
Copepoda [WoRMS]
Marine/Coastal | | Author keywords | Midwater; Bathypelagic; Benthopelagic; Copepods |
| Abstract | Biomass profiles for plankton and micronekton throughout the water column at a site on the Madeira Abyssal Plain, position 31° 17’ N 25° 24’ W, depth 5440 m, arc described. Biomass declined exponentially with depth. >80% of the plankton and >95% of micronekton occured between 0–1000 m. The total biomass was low, ca 2 g dry weight below each m2 of sea surface but this situation is probably not abnormal and reflects the paucity of biota at abyssal depths. Plankton and micronekton profiles were strikingly similar at depths below 1700 m. In contrast to previous observations there was no dramatic increase in biomass just above the bottom. Comparisons with previous data suggest that the processes controlling the distribution of biomass in the deep oceans arc similar despite differences in overlying surface production. The most numerous planktonic group were copepods and the plankton biomass profiles mirror their abundance profiles. The proportion of dead: living copepods has been estimated for depths > 1500 m: the relative constancy of the proportions in midwater may be attributable to detritivory. Immediately above the bottom the proportion of carcases increased and the proportion of non calanoid copepods also increased. Total numbers of copepods increased markedly in a haul which hit the bottom, this may be due to a specialised population living very close to the sea bed. |
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