Knowledge gaps and management recommendations for future paths of sustainable seaweed farming in the Western Indian Ocean

Abstract

Farming of eucheumatoid seaweeds is a widespread, promising activity and an important livelihood option in many tropical coastal areas as for example in East Africa, Western Indian Ocean (WIO). Compared to other types of aquaculture, seaweed farming has generally low impact on the environment. Nonetheless, there are potential direct or indirect negative effects of seaweed farming, such as introduction of alien species and changes in local environmental conditions. Although farming has been practiced in this region during several decades, the knowledge concerning the actual environmental impacts from faming non-native eucheumatoid haplotypes and consequently how to manage farming activities to mitigate those is highly limited. In this review, we provide a summary of the current scientific knowledge of potential direct and indirect negative environmental effects linked to eucheumatoid seaweed farming such as alterations of benthic macrophyte habitats and loss of native biodiversity. Furthermore, we highlight knowledge gaps that are of importance to address in the near future, e.g., large-scale ecosystem effects and farms as potential vectors of pathogens. We also provide a number of feasible management recommendations to be implemented for a continued development of environmentally sustainable seaweed farming practices in the WIO region, which includes spatial planning of farms to avoid sensitive areas and farming of native haplotypes of eucheumatoids instead of introduced specimens.

Exploring, harnessing and conserving marine genetic resources towards a sustainable seaweed aquaculture

“…It should be emphasised that agriculture and non-native species are major drivers of species extinction on land (Bellard et al, 2016). Therefore, the scale at which the global seaweed cultivation progresses and its integration with other human activities arguably calls for a careful assessment of its potential long-term impacts on coastal ecosystems and their possible mitigation (Eggertsen & Halling, 2020). The specific characteristics of seaweeds, such as their complex life histories, would need to be fully considered when performing risk assessments for invasiveness (Krueger-Hadfield, 2019).…”

Investigating the need for environmental risk assessment of chemical crop protection practices in seaweed

“…Source : Campbell et al, 2019. Compared to other types of aquaculture, seaweed farming has a generally low impact on the environment. Nonetheless, there are potential direct or indirect negative effects of especially largescale seaweed farming, such as introduction of alien species and changes in local environmental conditions (Eggertsen and Halling, 2020). Other risks stemming from non-chemical sources are inherently associated with large scale commercial seaweed farming.…”

Seaweed Aquaculture in Indonesia Contributes to Social and Economic Aspects of Livelihoods and Community Wellbeing

“…This evidence is evaluated in the context of a sustainability science approach to Indonesian seaweed farming, which provides a framework to assess the sustainability of either individual aquaculture industries or production systems incorporating: (i) definition of sustainability issues; (ii) sustainability assessment; (iii) detailed risk analysis; (iv) plan to ameliorate identified impacts; and (v) plan for communicating the evolution of operations towards greater stewardship and sustainability [21]. In adopting this approach, we note that there are several recently-published reviews of the environmental aspects of tropical seaweed aquaculture [22][23][24][25][26][27], as well as seaweed farming more broadly, including the provision of ecosystem services [28][29][30][31][32]. Rather than repeat the conclusions of these reviews, in this paper we augment the scientific literature's focus on the environmental aspects of tropical seaweed mariculture by focusing on social and economic aspects.…”