The SeaCoRe system for large scale kelp aquaculture: a plug-and-play, compatible, open-source system for the propagation and transport of clonal gametophyte cultures

The future of large-scale kelp aquaculture is standing at a crossroad, with the diverging paths being characterized by two fundamentally different cultivation methods that differ on how well gametophyte reproduction can be controlled. The cultivation method that does not directly control gametophyte reproduction is more widely utilized at the moment, but interest in better controlling gametophyte reproduction is growing steadily. Here, we validate a bioreactor system that overcomes a number of implementation challenges for this controlled reproductive method, expanding the possibility of clonal gametophyte cultivation outside of expensive laboratory settings. The main goals of this system include (i) the maintenance of clean gametophyte clonal cultures in non-sterile environments over prolonged periods of time, (ii) the production of large numbers of juvenile sporophytes, and (iii) effective transportation of gametophytes and sporophytes. The “SeaCoRe system” consists out of three parts that correspond to these three challenges: (1) clone-reactors, (2) a clone-inducer, and (3) a transporter. The validation of the system showed that delayed Saccharina latissima and Alaria esculenta gametophytes can grow reliably for 75 days in the clone-reactors. Initial gametophyte densities of 0.4 mg DW and 0.6 mg DW gametophtyes mL⁻¹ were optimal for S. latissima and A. esculenta, resulting in reproductive successes of 604 and 422 sporophytes mL⁻¹, respectively. Lastly, gametophyte transport was simulated, with high reproductive success still achieved within 19 days in ~ 20 °C environments. The SeaCoRe system helps unlock the full potential of large-scale kelp cultivation using multiannual delayed clonal.