Differential response of varying temperature and salinity regimes on nutrient uptake of drifting fragments of Kappaphycus alvarezii: implication on survival and growth

• Published in: Journal of applied phycology Vol. 27; no. 4; pp. 1571 - 1581
• Main Authors: Mandal, Subir Kumar, Ajay, G., Monisha, N., Malarvizhi, J., Temkar, Ganesh, Mantri, Vaibhav A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-08-2015; Springer Nature B.V
• Subjects: Algae; Bioavailability; Biomedical and Life Sciences; Cultivation; Developing countries; Ecology; Freshwater & Marine Ecology; Kappaphycus alvarezii; LDCs; Life Sciences; Nutrient uptake; Plant Physiology; Plant Sciences; Rhodophyta; Salinity; Bioinvasion; Drifting fragments; Nutrients and survival efficiency
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-014-0469-1

Commercial cultivation of seaweeds has improved the livelihood of coastal fishermen in several developing countries. Along with success story of the commercial cultivation of popular carragenophyte
Kappaphycus alvarezii
(Rhodophyta), there have been concerns about its invasive tendencies. Substantial quantities of algal fragments disperse during farm maintenance, specifically during harvesting. It is believed that the drifting fragments eventually die on the sea bottom. In the present investigation, drifting fragments (live, semi-bleached, and bleached) were incubated under different salinity (20, 25, 30, 35, and 40 ‰) and temperature (15, 20, 25, 30, and 35 °C) regimes to record daily growth rate (DGR). NO
3
-N, PO
4
-P, and SiO
3
-Si uptake was evaluated for live fragments under similar culture conditions at 72 h interval in case of live fragments. The highest uptake (99 %) was recorded for NO
3
-N at 30 °C in 30 ‰, while the lowest (62 %) was recorded for SiO
3
-Si at 35 °C in 20 ‰. After 30 days of laboratory incubation, culture fragments were outplanted into the open sea to evaluate their survival efficacy and growth. The highest DGR (7.116 %) was observed in fragments which were priorly incubated at 20 °C in 20 ‰ salinity followed by a DGR of 4.85 % at 30 °C in 30 ‰. The overall findings reveal that conducive temperature and salinity, along with survival efficiency due to bioavailability of required nutrients and regeneration capacity of drifting fragments, play crucial role in determining the establishment of
K. alvarezii
population in the wild.