Marine sponges: an eco-friendly and profitable by-product of Integrated Multitrophic Aquaculture (IMTA)

Coastal fish farming plants can have a significant environmental impact due to the release of organic wastes from farmed organisms and feed residues, causing an overall increase in organic matter, nutrients, harmful particles (e.g., bacteria, viruses, and also fecal pellets) including potentially pathogenic or antibiotic-resistant bacterial load in the water body. In this sense, Integrated Multi-Trophic Aquaculture (IMTA) systems improve water quality and promise a high economic return. Among the extractive organisms, filter-feeders and in particular Porifera seem to be among the most promising. However, despite their proven capacity for biofiltration, ecosystem restoration and the problem of biomass supply for the industries concerned (for use as cosmetics, pharmaceuticals or ornamental aquarium species), few integrated multi‐trophic aquaculture systems incorporate these invertebrates in their facilities. Therefore, this work aims to highlight the suitability and benefits of marine sponges in IMTA systems in a circular blue economy framework by discussing their profitability and eco-economic potential.