State of the Art and Challenges for Offshore Integrated Multi-Trophic Aquaculture (IMTA)

Abstract

By moving away from coastal waters and hence reducing pressure on nearshore ecosystems, offshore aquaculture can be seen as a possible step towards the large-scale expansion of marine food production. Integrated multi-trophic aquaculture (IMTA) in nearshore water bodies has received increasing attention and could therefore play a role in the transfer of aquaculture operations to offshore areas. IMTA holds scope for multi-use of offshore areas and can bring environmental benefits from making use of waste products and transforming these into valuable co-products. Furthermore, they may act as alternative marine production systems and provide scope for alternative income options for coastal communities, e.g., by acting as nodes for farm operation and maintenance requirements. This paper summarizes the current state of knowledge on the implications of the exposed nature of offshore and open ocean sites on the biological, technological and socio-economic performance of IMTA. Of particular interest is improving knowledge about resource flows between integrated species in hydrodynamic challenging conditions that characterize offshore waters.

Biofouling in marine aquaculture: a review of recent research and developments

“…For example, exposed sites are linked with reduced levels of biofouling for the cultured kelps Undaria pinnatifida, Saccharina latissima and Laminaria digitata (Andersen et al 2011;Peteiro and Freire 2013;Rolin et al 2017) and increased water movement with less siltation is recommended for the cultivated red alga Kappaphycus alvarezii (Hurtado et al 2006). In contrast, softer-bodied seaweeds such as the red alga Gracilaria chilensis may lose biomass when cultured at exposed locations (reviewed in Buck et al 2018). However, cultivating seaweeds at exposed sites may also present other environmental challenges as severe storms can damage seaweeds and displace aquaculture structures, leading to reductions in biomass and farm productivity (Rolin et al 2017).…”

Valuation of Ecosystem Services to promote sustainable aquaculture practices

“…Regarding production systems design, Integrated Multi-Trophic Aquaculture (IMTA) has been endorsed by scientists as a more sustainable mode of aquaculture than intensive monocultures, as that practice is capable of enhancing multiple ES (Chopin et al 2012;Granada et al 2016;Marques et al 2017;Buck et al 2018). In IMTA, nutrients wasted on artificially fed cultures (e.g.…”

Using systems thinking and open innovation to strengthen aquaculture policy for the United Nations Sustainable Development Goals

“…Many biologists and aquaculture producers specialise in understanding or growing one particular species, with little regard for the opportunities and synergies that might arise from growing multiple organisms together. Similarly, there has been much debate in Europe about the potential for co‐location of aquaculture facilities, among offshore wind‐turbines (Buck et al , ), but this has often come to nothing or had limited success. The lack of systems thinking and in particular concerns about insurance, access, regulations, risk or governance issues (Christie et al , ; Krause & Stead, ) is constraining the positive effect aquaculture could have on people and the aquatic environment.…”