Assessing the economic viability of mussel on-bottom culture: a comparative analysis of wild and aquaculture seeds in Denmark

Mussel on-bottom culture, involving the relocation and transplantation of mussel seed to designated seabed areas, is a relatively recent practice in Denmark and has been proposed as a management approach to address pressures such as overfishing and eutrophication. While ecological and biological benefits are well documented, the economic feasibility of this practice remains largely unexplored. This study provides the first economic evaluation of mussel on-bottom culture under alternative seed-sourcing and organizational arrangements, using primary data from Limfjorden, Denmark. A cost–benefit analysis is conducted from both a societal and a fishermen-specific (financial) perspective to compare alternative seed-sourcing strategies, including wild seed and aquaculture-derived seed. Wild seed sourcing is examined under two organizational arrangements: seed collection by individual fishermen with centralized transport and relaying, and a fully centralized system managing both collection and relaying. Baseline results, assuming a relative biomass production (RBP) of 0.5, show that on-bottom culture is economically viable when wild seed is used, particularly under centralized management, while aquaculture-derived seed is not viable from a societal perspective. Because fishermen obtain aquaculture seed through a profit-sharing arrangement rather than an up-front purchase, this option is comparatively more attractive to them at low productivity and less so as productivity rises. Sensitivity analyses indicate that all options become economically viable at higher productivity levels (RBP > 1). The results highlight productivity, organizational structure, and seed sourcing as key determinants of economic feasibility.