Browsing by Author "Mmochi, Aviti"

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    Mariculture
    (southwest Madagascar, 2000) Mmochi, Aviti
    Aquaculture is the cultivation of aquatic animals and plants in natural or controlled marine or freshwater environments, whereas mariculture is restricted to marine and estuarine (brackish) waters. On a worldwide scale, aquaculture is a fast-growing industry, showing a 12-fold increase between 1980 and 2010, or average annual growth of 8.8 per cent (FAO 2012). Recent statistics show that growth has slowed, with food fish annual production rates decreasing from 9.5 per cent (1990-2000) to 6.2 per cent (2000-2012) (FAO 2014). World production through aquaculture increased to 90.4 million tonnes in 2012 (66.6 million tonnes food fish and 23.8 million tonnes aquatic plants; FAO 2014) with about 50 per cent of production originating from mariculture (Figure 22.1). This is in stark contrast with the global levelling off in harvests from capture fisheries, at about 80 million tonnes per year since the mid 1990’s (FAO 2014).
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    Mariculture in the WIO region
    (WIOMSA, 2009) Troell, Max; Hecht, Tom; Beveridge, Malcolm; Stead, Selina; Bryceson, Ian; Kautsky, Nils; Ollevier, Frans; Mmochi, Aviti
    Today aquatic products provide nearly 3 billion people with at least 15% of their animal protein intake and fish constitute the dominant source of animal protein in many island states and low income, food deficient countries (FAO, 2009; Smith et al., 2010). The world’s growing population consumes more and more fish and stagnating catches from our oceans cannot keep up (Pauly et al., 2003; FAO 2009). The rapid development of aquaculture has to some extent enabled us to meet this growing demand and currently the aquaculture sector provides half of all fish destined for human consumption (FAO, 2009). However, the gap between demand and supply is increasing and so the pressure on aquaculture to meet this shortfall has led to development of the sector rising up political agendas worldwide. The aquaculture industry is the fastest growing animal production sector but the question is whether it can double in a sustainable manner (Soto et al., 2008; Tacon & Metain, 2008) by 2020 to meet expected demand for fish products (Jacquet et al., 2009). Another interesting question is what role Africa will play in future development of aquaculture, in particular to what extent can the expansion of marine aquaculture offer alternative or supplementary livelihoods to fishery dependent communities?
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    Marine Pollution Bulletin
    (Elsevier, 2012) Moynihan, Molly; Baker, David; Mmochi, Aviti
    a b s t r a c t In Stone Town, Zanzibar, sewage treatment is minimal, with a biological oxygen demand reduction to 60% and no removal of bacteria or nutrients. Here, Stone Town’s sewage pollution was studied by measuring Enterococci and NHþ4 concentrations in seawater and d15N of benthic organisms; samples were collected along the Stone Town shoreline and from offshore coral reefs. Public perceptions of sewage pollution were investigated via interviews. Enterococci from the Stone Town shoreline exceeded USEPA guidelines for recreational use. Benthic organisms from two of the four reefs were relatively enriched (d15N > 10‰), indicative of sewage derived N. d15N values of organisms from Stone Town exceeded 16‰. A strong correlation was found between Enterococci and d15N across sites, while step-wise regression indicated rainfall and tidal stage as important predictors for bacterial concentrations. These data provide an important impact assessment from which the efficacy of future policy and management change can be assessed. 2012 Elsevier Ltd. All rights reserved