Kinetics and Trophic Role of Bacterial Degradation of Macro-Algae in Antarctic Coastal Waters
Aerobic formation of detritus from debris of the Antarctic Kelp, Himantothallus grandifolius, yielded amounts of carbon and nitrogen 2 and 4 times higher, respectively, than fresh algae, and a concomitant decrease of the carbon:nitrogen ratio from 19 to approximately 10. These changes were achieved only in the presence of the indigenous Antarctic bacterio-flora. During formation of detritus from the Antarctic red alga, Leptosomia simplex, C:N ratios may drop even below the Redfield ratio reported for phytoplankton. The increases in the C and N contents of the debris and its colonization by epiphytic bacteria were characterized by saturation kinetics, which showed an initial lag, subsequent steep increment, and a final stationary phase. During its exponential phase, rates of bacterial colonization of debris from brown and red algae were comparable to those calculated for kelp in areas of temperate climates. There is preliminary evidence that some of the enzymes, which participate in the decomposition of the particulate detrital matter, are optimally adapted to the temperature regime of a permanently cold environment. The results obtained favour the idea that the formation of macro-algal detritus in Antarctic coastal waters is as efficient as in temperate regions. Preliminary assessments indicated that partly degraded thalli from both the brown and red algae were preferred over fresh thalli, as a food source, by intertidal amphipods.
KeywordsBiomass Phytoplankton Immobilization Biodegradation Beach
Unable to display preview. Download preview PDF.
- Baross JA, Morita RY (1978) Microbial life at low temperatures: Ecological aspects. In: Kushner DJ (ed) Microbial life in extreme environments. Academic, London, p 9–71Google Scholar
- Bird KT, Habig C, DeBusk T (1982) Nitrogen allocation and storage patterns in Gracilaria tikvahiae (Rhodophyta). J Phycol 18:344–348Google Scholar
- Christian RR, Wetzel RL (1978) Interaction between substrate, microbes and consumers of Spartina detritus in estuaries. In: Wiley ML (ed) Estuarine Interactions. Academic, New York pp 93–144Google Scholar
- Dieckmann G, Reichardt W, Zielinski K (1985) Growth and production of the seaweed, Himantothallus grandifolius, at King George Island. In: Siegfried WR, Condy PR, Laws RM (eds) Antarctic nutrient cycles and food webs (Proceedings of the 4th SCAR symposium on Antarctic Biology). Springer, Berlin Heidelberg New YorkGoogle Scholar
- Lucas MI, Newell RC, Velimirov B (1981) Heterotrophic utilisation of mucilage released during fragmentation of kelp (Ecklonia maxima and Laminaria pallida). II. Mar Ecol Progr Ser 4: 43–55Google Scholar
- Newell RC, Lucas MI (1981) The quantitative significance of dissolved and particulate organic matter released during fragmentation of kelp in coastal waters. Kieler Meeresforsch Sonderh 5: 336–369Google Scholar
- Stuart V (1982) Limitations of ATP as a measure of microbial biomass. S Afr Tydskr Dierkd 17: 93–95Google Scholar
- Velimirov B, Ott JA, Novak R (1981) Microorganisms on macrophyte debris. Kieler Meeresforsch Sonderh 5: 333–344Google Scholar