Path analyses of the influence of substrate composition on nematode numbers and on decomposition of stranded seaweed at an Antarctic coast
Alkemade, R.; Van Rijswijk, P. (1993). Path analyses of the influence of substrate composition on nematode numbers and on decomposition of stranded seaweed at an Antarctic coast. Neth. J. Sea Res. 31(1): 63-70
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Authors | | Top |
- Alkemade, R.
- Van Rijswijk, P., more
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| Abstract |
Large amounts of seaweed are deposited along the coast of Admiralty Bay, King George Island, Antarctica. The stranded seaweed partly decomposes on the beach and supports populations of meiofauna species, mostly nematodes. The factors determining the number of nematodes found in the seaweed packages were studied. Seaweed/sediment samples were collected from different locations, along the coast near Arctowski station, covering gradients of salinity, elevation and proximity of Penguin rookeries. On the same locations decomposition rate was determined by means of permeable containers with seaweed material. Models, including the relations between location, seaweed and sediment characteristics, number of nematodes and decomposition rates, were postulated and verified using path analysis. The most plausible and significant models are presented. The number of nematodes was directly correlated with the height of the location, the carbon-to-nitrogen ratio, and the salinity of the sample. Nematode numbers were apparently indirectly dependent on sediment composition and water content. We hypothesize that the different influences of melt water and tidal water, which affect both salinity and water content of the deposits, are important phenomena underlying these results. Analysis of the relation between decomposition rate and abiotic, location-related characteristics showed that decomposition rate was dependent on the water content of the stranded seaweed and sediment composition. Decomposition rates were high on locations where water content of the deposits was high. There the running water from melt water run-off or from the surf probably increased weight losses of seaweed. |
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