Nematode biomass spectra as descriptors of functional changes due to human and natural impact
Vanaverbeke, J.; Steyaert, M.; Vanreusel, A.; Vincx, M. (2003). Nematode biomass spectra as descriptors of functional changes due to human and natural impact. Mar. Ecol. Prog. Ser. 249: 157-170. dx.doi.org/10.3354/meps249157
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, more
| |
Keywords |
Aquatic communities > Plankton > Phytoplankton Depletion > Oxygen depletion Ecosystem disturbance Population characteristics > Biomass Population characteristics > Population structure > Size distribution Sedimentation Nematoda [WoRMS] ANE, Belgium [Marine Regions] Marine/Coastal |
Author keywords |
nematodes; biomass; size spectra; physical disturbance; oxygen stress; phytoplankton sedimentation |
Abstract |
Nematode biomass spectra (NBS) for different nematode communities—subject to different forms of stress and enrichment—from the Belgian continental shelf have been constructed and analysed. These analyses showed that non-normalised NBS yield better results for comparisons of nematode assemblages than normalised NBS (in which the biomass in a weight class is divided by its corresponding weight interval) since the ecologically relevant information is retained. Normalising the spectra caused elevated biomass values and peaks to disappear, introducing bias when interpreting the distribution of biomass over spectra. Cumulative nematode biomass spectra proved to be useful in evaluating statistical differences, using the slope of the regression line of the cumulative biomass to the nominal value of a log2-based size class. Interpreting Pareto-type graphs and regressions was not straightforward. We suggest a combined use of both NBS and the regression approach for the analysis of NBS. NBS and cumulative NBS constructed for nematode communities from undisturbed sediments proved to be conservative: no differences in size distribution were found for communities from different locations. Physical disturbance, introduced by sand extraction, did not affect the regression slopes of cumulative NBS. However, a shift in peak biomass values towards lower size classes was observed in the regular NBS. This was attributed to an alteration of the nematode communities due to the frequent physical disturbance of the sediments. At an oxygen-stressed site, we observed a single class biomass peak, due to the presence of a single nematode species well adapted to the impoverished sediment quality. Phytoplankton sedimentation during a spring bloom corresponded to shifts in peaks in NBS due to a change in age structure of the nematode communities. Biomass values probably increased as a result of a higher food supply to the benthos. |
Datasets (4) |
- PODOI: Vanaverbeke, J. & Steyaert, M. (1994). Length and width measurements of nematodes from coastal stations on the Belgian Continental Shelf. Ghent University, Department of Biology, Marine Biology Section (MARBIOL), Belgium., more
- Vanaverbeke, J. (1998). Length, width and biomass measurements of nematodes from sandbanks on the Belgian Continental Shelf. Ghent University, Department of Biology, Marine Biology Section (MARBIOL), Belgium., more
- Vanaverbeke, J. et al., Meiobenthos of subtidal sandbanks on the Belgian Continental Shelf. Manuela Database, Universiteit Gent; Faculteit Wetenschappen; Vakgroep Biologie; Afdeling Mariene Biologie, Ghent, Belgium., more
- Vanaverbeke, J., Deprez, T. & Vincx, M. (2006). Meiobenthos of subtidal sandbanks on the Belgian Continental Shelf. Ghent University, Department of Biology, Marine Biology Section (MARBIOL), Belgium., more
|
|