Technical challenges for offshore cultivation of kelp species: lessons learned and future directions

Abstract

Traditional kelp farming methods require a high amount of labor and are limited in geographic distribution – occurring mainly in nearshore, sheltered sites. To address growing global demand for sustainable biomass, the continued expansion of kelp cultivation will most likely have to move further offshore. Although many offshore cultivation trials have been done over the last 50 years, few were sufficiently robust to be viable in exposed and deep-water areas. In the North Atlantic Ocean, a Faroese company developed and tested a structural farm design that has survived in open-ocean conditions since 2010. The durable structure has withstood harsh weather events common in the Faroe Islands and thereby presents a potential strategy and method for moving kelp farming further offshore. This paper describes the primary challenges of offshore kelp farming and provides an overview of work previously done. Ultimately, the improved productivity, system survivability and scalability the MacroAlgal Cultivation Rig (Faroe Islands) and the BioArchitecture Lab cultivation grid (Chile) represent state-of-the-art and powerfully transformative strategies to pursue large-scale offshore farming to support mass production of kelp in the near future.

Engineering A Low-Cost Kelp Aquaculture System for Community-Scale Seaweed Farming at Nearshore Exposed Sites via User-Focused Design Process

“…Innovations in engineering for seaweed farms have been occurring since the 1970s when the concept of biofuel production via offshore cultivation of Sargassum spp. was proposed (Bak et al, 2020), and more recently via the specter of colocation with offshore wind installations (Harkell, 2021), and furthermore via a reemergence of the biofuel concept (Harris et al, 2021). The design and testing of offshore and exposed seaweed cultivation platforms has been reviewed by Roesijadi et al (2008), Langan and Buck (2017), and most recently by Bak et al (2020).…”

“…was proposed (Bak et al, 2020), and more recently via the specter of colocation with offshore wind installations (Harkell, 2021), and furthermore via a reemergence of the biofuel concept (Harris et al, 2021). The design and testing of offshore and exposed seaweed cultivation platforms has been reviewed by Roesijadi et al (2008), Langan and Buck (2017), and most recently by Bak et al (2020). Commonplace among these assessments is complexity of design, high capital cost necessitating the need for scaling to achieve profitability, and the need to develop specialized mechanization and production flow processes specific to the husbandry platform.…”

Seaweeds and microalgae: an overview for unlocking their potential in global aquaculture development

“…However, seaweed cultivation in the open ocean faces the challenges of technical feasibility (e.g. strong cultivars are needed to withstand strong waves; novel farming systems, such as the tube net for Kappaphycus/Eucheuma cultivation, are needed to protect seaweeds from strong waves; new skills, such as swimming, are needed to operate in deep-water farm sites; and enhanced management capacity is needed to safeguard and monitor the operation), economic viability, and the general lack of regulations on offshore aquaculture (Msuya, 2013;van den Burg et al, 2016;Liu et al, 2019;Bak, Gregersen and Infante, 2020).…”

Landing facilities for processing of cultivated seaweed biomass: a Norwegian perspective with strategic considerations for the European seaweed industry

“…It is therefore important to define the roles and functions of such a facility and to consider regional specificities where LFCS are most pertinent when, for example, industrial buyers of seaweed biomass, technology suppliers as well as potential competitors are locally present. The future expansion of seaweed cultivation to industrial levels is expected to move further offshore to avoid the potential conflicts and limitations in coastal areas (Bak et al 2020). In this case, effective procedures and technology must be developed to harvest, stabilize and further process large amounts of biomass for large-scale industrial applications.…”