Regulatory ecosystem services through large-scale commercial farming of Kappaphycus alvarezii: Pan-India potential estimates

For more than a billion years, seaweeds have been a segment of marine primary productivity this fact must be contemplated while considering emerging conceptual frameworks such as the “blue economy”. This sector not only has the potential to provide renewable feedstock but its cultivation and processing ticks an important box for sustainable development. Seaweed cultivation in India is gaining momentum and great attention is being given to developing the infrastructure. A flagship program ‘Pradhan Mantri Matsya Sampada Yojana (PMMSY)’ has provided adequate budgetary allocation to achieve a production of 11.2 Mt (fresh) feedstock. However, the scheme seems to focus only on material benefits (product development) and the ecosystem services, especially regulatory services have seldom been taken into consideration. Thus, the present article tries to address the estimation of potential regulatory ecosystem services [capture carbon, uptake nutrients and heavy metals (Cr, Co, Cd)] met through Kappaphycus alvarezii farming, at the Pan-India level. The estimates were made for both tube net and raft cultivation methods separately. The farm cover was estimated to be around 700,000 ha supporting approximately 780,000 farmers for tube net, while it was 56,000 ha supporting ~ 1.25 million farmers for raft cultivation. A total number of tube nets that would be put to use would be 140 million and 56 million in the case of rafts. Once the target is achieved India would have gained the ability to annually capture approximately 600,000 t of carbon, 22,000 t of nitrogen, and 2000 t of phosphorous and absorb more than 1000 t of heavy metals cumulatively. Nevertheless, a monetary valuation of ecosystem services is needed to arrive at rational decisions by policy-makers and resource managers.