Impact of environmental changes on farmed seaweed and farmers: the case of Songo Songo Island, Tanzania

Growth performance of the sea cucumber Holothuria scabra and the seaweed Eucheuma denticulatum: integrated mariculture and effects on sediment organic characteristics

“…The optimization of seaweed-sea cucumber integrated systems requires establishment of stocking densities that can yield optimum growth of culture species and best utilise potential nutrient flow synergies between species (Agudo 2006, Li & Qi 2010. Following the design of a previous study that integrated K. striatum and H. scabra in Zanzibar (Beltran-Gutierrez et al 2014), the current study extends research knowledge to the use of Eucheuma denticulatum, a much more widespread seaweed species in Zanzibar and apparently more resistant to environmental conditions than Kappaphycus (Hayashi et al 2010, Msuya 2011b, Msuya & Porter 2014. A wide range of stocking densities (without sea cucumbers, low, medium, high) is applied in order to better understand trade-offs and limiting capacities with different densities and effects on organic matter content in sediments.…”

“…Apparently, seaweed quality is declining, leading to abandonment of the activity by some farmers and switching to other livelihood options (Msuya & Porter 2014). Integrated farming of seaweed and other aquatic organisms in Zanzibar, Tanzania, and the Western Indian Ocean, rather than traditional monoculture of seaweed, has been investigated and recommended by several authors (Hayashi et al 2010, Eklöf et al 2012, Msuya 2013b.…”

Health problems related to algal bloom among seaweed farmers in coastal areas of Tanzania

“…Nevertheless, most of respondents reported that seaweed farming was their main income generating activity for their livelihood in all the study sites. This is probably due to the fact that fishing activity has now become a problem for the coastal people and they are turning into seaweed farming as the alternative livelihood activity especially in Songosongo (Msuya and Porter, 2014) and Zanzibar Islands.…”

Farming of seaweeds

“…Msuya and Porter (2014) describe the impact of negative environmental conditions, particularly high water temperature, to off-bottom seaweed farming in Tanzania. The effects of abiotic stressors can be direct, promoting a variety of undesirable responses, including complete disintegration of the crop, or indirect, by triggering or favoring pathogenicity, like with ice-ice, a bacterial disease favored by nonoptimal environmental conditions.…”

“…In contrast, production in African countries is either stable or declining as farm profit margins shrink due to the spread of seaweed die-offs (Msuya and Porter, 2014) and the impact of lower prices (Valderrama et al, 2015). Given the positive results achieved in eastern Indonesia over the last decade, the Indonesian government has embraced the industry as a key driver of economic development and has set ambitious production targets for the next few years (The Economist, 2013).…”