Formation and potential trophic significance of marine foam near kelp beds in the benguela upwelling system
✍ Scribed by B. Velimirov
- Book ID
- 104752188
- Publisher
- Springer-Verlag
- Year
- 1980
- Tongue
- English
- Weight
- 847 KB
- Volume
- 58
- Category
- Article
- ISSN
- 0025-3162
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✦ Synopsis
The present study investigates the importance of foam in nearshore waters on the west coast of the Cape Peninsula (South Africa) as a possible food resource for consumer organisms. A bacterial density of 3.45 x 109 cells m1-1 foam suspension was recorded. Calorific values of up to 15.39 kJ g-1 ash-free dry weight were noted, and a biochemical analysis of the drained foam suspension gave a composition of 22.85% protein, 10.76% lipid and 3.07% carbohydrates. Field data showed a correlation between peaks of phytoplankton up to 510 mg C m -3 water temperatures and days of intense foam formation during periods of strong onshore winds. Experimental foam formation in the laboratory indicates that kelp mucilage and phytoplankton contain surface-active agents. An additional feature of kelp mucilage is its capability to improve foam stability. The comparison of the chemical composition of 12 and 120 h-old foam suspension indicates a loss of easily metabolizable components such as trichloroacetic-acid precipitated protein and neutral lipid with time. It is hypothesised that the losses are due to utilisation of these components by consumers.