Example of Sargassum washed ashore in the Dominican Republic
Image taken by Ulises Jauregui, Playa Nigua, Dominican Republic (May 2020)
Massive strandings of the pelagic brown seaweeds Sargassum natansand fluitansbring every year millions of tonnes of fresh biomass to the shores of the Caribbean and western Africa, where theyhave major negative environmental, health, and socio-economic impacts, in particular for the most vulnerable communities.
However, this abundant seaweed biomass represents an interesting feedstock that should be valorised for the benefit of the affected countries. Indeed, in different parts of the world, brown seaweeds are harvested from wild populations or farmed to provide valuable products, including texturing agents for the food industry, bioenergy, fertilisers, animal feed, nutraceuticals, and cosmeceuticals. Therefore, existing commercial applications of other brown algae indicate that it is possible to turn the pelagic Sargassumpollution into valuable resources, as part of the equitable resilience strategy implemented within the SARTRAC project.
In this context, WP3 will assessthe biological, political, social, and economic aspects to inform potential valorisation routes for the Sargassumfeedstock. It is articulated around four main topics:
- Determination of Sargassumbiomass consistency in Jamaica. This is an important aspect to be considered when foreseeing development of commercial applications of any feedstock. In-depth characterisation of the biochemical composition of the Sargassumharvested mainly in Jamaica, and also from Ghana, will be provided to assess potential changes related to seasonality and storage.
- Assessment of Sargassumfor production of energy by bio-digestion. Anaerobic mono-and co-digestion (with pig-slurry) of seaweeds in bio-digesters of different scales for the production of gas and electricity at the single family and community level will be investigated. This process will also generate useful by-products that are compost/fertilizer (from the slurry or sludge), and irrigation water (from the final treated effluent).
- Evaluation of Sargassumfor soil amelioration in the context of food production and environmental applications. Composts containing different proportions of Sargassumwill be included in farming methods to study influence on the growth of crop and vegetable seedlings. The opportunity to consider Sargassum-based compost for restoration of mangroves will also be explored.
- Integration of interdisciplinary data to identify opportunities and barriers for the management and valorisation of Sargassumin Ghana and the Caribbean. This will involve analysing and combining knowledge gained through the four WP’s of the project. It will support establishment of an efficient strategy for harvesting Sargassum, and implementation of transformational adaptation opportunities within the vulnerable communities in Jamaica and Ghana.
It is expected that, at the end of the project, knowledge gained and applications developed in the context of this Work Package will be extended to several Caribbean and western Africa countries affected by recurrent Sargassuminundations.
This work package is led by Prof Mona Kay Webber, Dr Thierry Tonon and Dr Carla Botelho Machado
Outputs from this work package :