Integrated Multitrophic Aquaculture (IMTA)
Sea cucumber, green macroalgae and fish culture in extensive systems (“esteros”)
The farming in Cádiz Bay is based on extensive fish aquaculture, allowing the entry of natural recruitment with tides, and later closing the “esteros” for fish fattening, with periodical water renewal through floodgates equipped with nets to prevent the fish escapes. Fish grow fed exclusively on natural benthos, being caught at the end of autumn or early winter. The main commercial species produced in this polyculture system are mugilids, seabream, seabass and sole, plus eels, crabs and shrimps.
The fish production in these systems should be improved to increase its profitability through an adequate management, but also with investments for innovation focused on diversification of target species and development of polycultures and/or Integrated Multi-Trophic Aquaculture (IMTA) systems. Sea cucumber, as deposit-feeders and species with high commercial value in Asian markets, are optimal candidates to be used in IMTA systems. Dr. Wangüemert already tested and demonstrated during her work as Principal Investigator in CCMAR (University of Algarve, https://ccmar.ualg.pt/users/mwanguemert) the high growth, productivity and economical profit of co-culture systems including the sea cucumbers Holothuria arguinensis and Holothuria mammata, the macroalgae Ulva lactuca, and the sea urchin Paracentrotus lividus.
Under this framework, WANGUMAQUA SLU is starting a project on fattening of sea cucumber juveniles in co-culture with green macroalgae and seabream/seabass, being all them common species in this geographical region and “esteros”. This project is located in “Molino Santa Cruz estero” and “San Enrique” salterns in Cádiz (South Spain).
Fattening of juveniles and pre-adults of sea cucumber linked with fish cages production
There are some concerns linked to intensive aquaculture such as production of nutrient-rich waste, that could cause eutrophication, alteration of the physical and chemical features of water, and changes on the benthic communities.
Integrated multi-trophic aquaculture (IMTA) promotes the re-use of waste by including different trophic groups and improving the sustainability of feeding. It is mainly useful as a tool for bio-mitigation of negative impacts, improving and diversifying the productivity, reducing infrastructural cost and increasing profits.
WANGUMAQUA SLU is developing an IMTA system including several extractive aquaculture species, such as seaweed (green and red macroalgae) and deposit feeders (sea cucumber) that recapture the inorganic and organic nutrients from feed aquaculture used to growth the main target species (seabream and seabass) with commercial value. These projects will be developed in Canary islands (NE Atlantic) and SE Spain (Mediterranean Sea).
