Title: Towards development of a promising community-based polyaquaculture involving sea cucumber (Holothuria scabra) seaweed (Kappaphycus alvarezii) and corals in Madagascar

Authors: Lavitra T.1*, Pascal F3, Pascal B4, Razanakoto I.3, Eeckhaut I.1,2, Todinanahary G.1,2

1 Polyaquaculture Research Unit, Fishery and Marine Science Institute (IH.SM) of the University of Toliara, 601 – Toliara, Madagascar 2 Biology of Marine Organisms and Biomimetism, University of Mons, 7000 – Mons, Belgium 3 Ocean Farmers SA, 601 – Toliara, Madagascar 4 Indian Ocean Trepang SA, 601 – Toliara, Madagascar

Lavitra T. [email protected] (*Corresponding and presenting author); Pascal F. fred@ocean- farmers.com ; Pascal B. [email protected] ; Razanakoto I. [email protected] ; Eeckhaut I. [email protected] ; Todinanahary G. [email protected]

Abstract: Aquaculture is becoming a popular alternative source of income for coastal communities in Southwest Madagascar.More than 40 villages off the ~300 km coastline are currently farming sea cucumber (Holothuria scabra) and/or seaweed (Kappaphycus alvarezii) for commercial purpose. Since community-based farming trials in 2008, sea cucumber farmers increased to 172; their trepang production reached 327kg (2018). Farmers buy 15 – 20 g juveniles from a private nursery (Indian Ocean Trepang) and grow them during 10 to 16 months in sea pens provided by NGOs. 1,800 households are also involved in seaweed farming reaching a production of 1,100 dry tons in 2017. Various off-bottom and semi- floating farming methods are used, with all materials and technical support supplied for free by a private company (Ocean Farmers) providing farmers fulfill sustainability farming requirements. In both activities, farmers sell the final products to the supporting private company. Moreover, NGOs are involved with social organization and public institutions oversee administrative (Fishery Administration) and research (IH.SM) aspects. However, if it was expected that aquaculture would to reduce fishing pressure on coral reefs, a wild development of monoculture combined with suitable spaces saturation could also increase pressure on ecosystems. Diversification of cultivated species thereby becomes key to sustainable aquaculture. Several projects targeting environmental and social sustainability are being developed and implemented by the broad range of stakeholders involved to consolidate the existing production system and avoid unwanted impacts. Since 2013, fFeasibility of coral farming within the area was proven through experimental projects launched in 2013. Today, several programs including coral nurseries, coral gardens, and artificial reefs are undertaken with farmers to raise community awareness. Moreover, community-based polyaquaculture development is driven by a multi-stakeholder model following relational governance principles, with all actors from communities, private sector, civil society and public institutions coordinating through regular meetings and discussion platform, After 10 years, this model remains the most promising alternative to declining coastal fishery and the better tool for coastal communities resilience to climate change.

Keywords: Community-based Polyquaculture, Seaweed, Sea Cucumber, Coral, Southwest Madagascar, Relational Governance

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