Seaweed farming in Africa: current status and future potential

Koushul Narrain,John Bolton,Fred Pascal,Betty Nyonje,Elizabeth J Cottier-Cook,Flower E Msuya

doi:10.1007/s10811-021-02676-w

Abstract

Global demand for seaweed and its products has increased exponentially over the last 25 years. Equally, the continent of Africa and its offshore islands have considerable potential for seaweed production to contribute to world demand. Compared with China and the rest of Asia, Africa lags behind in seaweed production and utilisation. However, for red eucheumatoid seaweeds, Africa is the third-largest producer in the world, producing about 120,000 t (FW) annually. Details are provided for 13 African countries that are currently involved in seaweed farming and harvesting, commercially or experimentally, for export or domestic utilisation. Eucheuma spp. and Kappaphycus spp. in Tanzania represent 92% and in Madagascar 4.7% of continental production, and Ulva spp. and Gracilaria spp. in South Africa represent 1.5%. Over 2000 species of seaweed have been recorded in Africa, some of which are already successfully cultivated in other parts of the world. The environmental conditions across the continent range from warm, tropical waters to the cooler, nutrient-rich waters of the southwest, enabling the cultivation of seaweeds from the tropical, carrageenan-producing eucheumatoids to temperate kelp species. Seaweed aquaculture production in Africa, led predominantly by women, has improved the livelihoods of its coastal people. Challenges through disease and pest outbreaks, as a result of climate change, and the low prices paid to farmers are highlighted as major constraints on the development of this industry. Through scaling up and expanding current efforts in production and utilisation of seaweeds, Africa has the potential to join China and Southeast Asia as a global leader in producing, processing and consuming a wide variety of seaweeds.

Highlights

African coasts have a considerable diversity of seaweed species with many distinct biogeographical regions, each with their own seaweed-dominated communities in coastal seas (Bolton et al 2003)
In Namibia, the importance of seaweed production has been recognised since the 1980s, when seaweeds were harvested during the 1980s and 1990s and used to produce the gel agar (Molloy and Bolton 1995; Molloy 1998) and trial farming was done in the 1990s (Dawes 1995)
Coastal African countries are rich in seaweed species and many have suitable areas that can be used for cultivating and processing many types of seaweeds

Summary

Introduction

African coasts have a considerable diversity of seaweed species with many distinct biogeographical regions, each with their own seaweed-dominated communities in coastal seas (Bolton et al 2003). These include many species or their close relatives, which are commercially harvested and/ or cultivated in other continents worldwide. For example Tanzania and Kenya, recognised the economic potential of seaweed in the 1930s, when it was collected from the wild and exported to Europe (Mshigeni 1973; Msuya et al 2014; Bolton et al 2016). Several other African countries, recognising the potential of cultivated seaweeds re-initiated production as early as 1989 in Tanzania (Msuya 2010, 2020; Msuya and Hurtado 2017), and Mozambique, Madagascar, Kenya and South Africa, amongst others, have developed their industries over the last two decades (Wakibia et al 2006, 2011; Msuya et al 2014)

Methods

Findings

Conclusion