Impact of Large Scale Cultivation of Seaweeds along the Coastal Environment of India
The Project
Commercial cultivation of Kappaphycus alvarezii originated in the Philippines in 1960 and since then, countries like Japan, Indonesia, Tanzania, Fiji, Kiribati, Hawaii and South Africa have been cultivating this species on a large scale. K. alvarezii was introduced in India during 1994 by Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Bhavnagar, from Japan. After the initial laboratory culture and experimental farming along the coast of Saurashtra, the species was introduced into Gulf of Mannar (GoM) for promoting commercial farming and later extended to Mandapam area of Palk Bay during 1995–1997. Since then, Kappaphycus cultivation has spread to several Indian coastal areas and results indicate the feasibility of large-scale Kappaphycus commercial cultivation in Indian waters as an alternative livelihood income generation for the coastal community.
As farming operations expanded, apprehensions over their impact on the coastal environment, on native species and on biodiversity started to emerge. The spread of K. alvarezii in the sub-tidal area of the Mandapam region triggered the need for assessing the impact of its spread and preventing its further spread in Gulf of Mannar Marine National Park (GoMMNP). K. alvarezii has been reported to have established in the reefs of the Krusadai Island of GoMMNP. There are conflicting reports on the invasive impact of Kappaphycus on the coral reef of GoM. The current study was undertaken to assess the extent of reefs affected by the introduced red alga and assess the potential role of its long-term commercial cultivation in Palk Bay for their spread in GoM.
Aim
The aim of the study was to assess the extent of reefs affected by the introduced red alga and assess the potential role of its long-term commercial cultivation in Palk Bay for their spread in Gulf of Mannar
Objectives
Key Findings
- The long-term cultivation of alvarezii, since more than a decade, has not caused any significant impact on the water quality of Palk Bay
- The impact of seaweed cultivation on the coastal environment is believed to be less when the rafts are laid perpendicular to the coast rather than in parallel orientation.
- Preliminary studies reveal that alvarezii cultivated in rafts laid in vertical orientation had a significantly higher daily growth rate (5.01%) and single plant biomass (76.67 ± 16.65g) than their counterparts grown in horizontal orientation (1.87%; 28.54 ± 11.12g respectively).
The drivers determining the spread of Kappaphycus in Gulf of Mannar