An Innovative IMTA System: Polychaetes, Sponges and Macroalgae Co-Cultured in a Southern Italian In-Shore Mariculture Plant (Ionian Sea)

Abstract

In this paper, we report data from the first year of rearing of a set of filter feeder bioremediator organisms: macrobenthic invertebrates (sabellid polychaetes and sponges), coupled with macroalgae, realized in a mariculture fish farm. This innovative integrated multi-trophic aquaculture (IMTA) system was realized at a preindustrial level in the Gulf of Taranto (southern Italy, northern Ionian Sea), within the framework of the EU Remedia Life project. Long lines containing different collector typologies were placed around the fish breeding cages. Vertical collectors were utilized for both polychaetes and sponges, whilst macroalgae were cultivated in horizontal collectors. Data on the growth and mortality of the target species after the first year of rearing and cultivation are given together with their biomass estimation. Polychaete biomass was obtained from natural settlement on ropes previously hung in the system, while sponges and macroalgae were derived from explants and/or inocules inserted in the collectors. The description of the successional pattern occurring on collectors used for settling until reaching a “stable” point is also described, with indications of additional filter feeder macroinvertebrates other than polychaetes and sponges that are easily obtainable and useful in the system as bioremediators as well. The results demonstrate an easy, natural obtaining of large biomass of sabellid polychaetes settling especially from about a 4 to 10 m depth. Sponges and macroalgae need to be periodically cleaned from the fouling covering. The macroalgae cycle was different from that of invertebrates and requires the cultivation of two different species with about a 6-month cycle for each one. The present study represents one of the first attempts at IMTA in the Mediterranean area where invertebrates and macroalgae are co-cultured in an inshore fish farm. Possible utilization of the produced biomass is also suggested.

Filtering Activity and Nutrient Release by the Keratose Sponge Sarcotragus spinosulus Schmidt, 1862 (Porifera, Demospongiae) at the Laboratory Scale

“…In conclusion, we provided evidence that S. spinosulus is able to remove the inoculated V. parahaemolythicus from seawater in test tanks at different concentrations, showing better performance at the higher concentration, with a contribution to the nutrient load. The promising survival and growth performance already obtained by this species in a Mediterranean IMTA system [49] highlights the ability of this sponge species to withstand the environmental conditions of an aquaculture facility. In addition, the biomass obtained [49] appears to be sufficient to implement the rearing system over time, thus avoid-ing ethical problems due to the depletion of wild stocks.…”

“…The promising survival and growth performance already obtained by this species in a Mediterranean IMTA system [49] highlights the ability of this sponge species to withstand the environmental conditions of an aquaculture facility. In addition, the biomass obtained [49] appears to be sufficient to implement the rearing system over time, thus avoid-ing ethical problems due to the depletion of wild stocks. S. spinosulus represents an effective mediator and bioremediator in integrated multitrophic aquaculture systems.…”

“…In the case of invertebrate animal species, while overcoming ethical issues, further criticism, such as the availability of the appropriate amount of biomass to obtain a valuable result, management of the zoo-remediator biomasses, survival skills in critical conditions, and excessive collection efforts on wild populations, needed to be addressed [17,48]. To find sustainable solutions to these issues, recently an in situ innovative integrated multitrophic aquaculture (IMTA) system in a Mediterranean fish farm, in which explants of the keratose sponge Sarcotragus spinosulus Schmidt 1862 (Porifera, Demospongiae) were co-cultured, showed promising survival and growth performances with a doubling of the sponge biomass after one year of rearing [49]. To date, no studies are available on the filtering performance and nutrient release [15,25], despite representing a deeply studied species in the research of basic and applied biology (e.g., microbiology, mariculture and the extraction of bioactive compounds) [50][51][52].…”

The multifunctional role of marine sponges in multi-trophic mariculture systems : towards sustainable use of sponges in polluted marine waters

“…There has been a renewed interest in farming of sponges in situ due to the outstanding filtering abilities of sponges and to replenish natural populations of bath sponge stocks . The ecosystem services provided by sponges in diverse marine habitats, together with their ability to contain and accumulate biomaterials have raised interest in the inclusion of these animals in integrated multitrophic aquaculture (IMTA) applications and in use of treatment of waste water streams (Cebrian et al 2003;Page et al 2005Longo et al 2016;Gokalp et al 2019Gokalp et al , 2020aGiangrande et al 2020). In this integrated farming approach, sponges consume dissolved and particulate nutrients available in the water column without the need for additional feeding providing a triplet benefit: 1) enhanced production of sponge biomass, 2) prevention of overexploitation from natural stocks and 3) purified water, whether the organic particle load is from suspended fish farm activities or urban runoff .…”

“…A series of long-lasting culture trials revealed several factors that determine the prosperity and sustainability of the culture. These include biotic factors such as predation by marine organisms, diseases and fouling, species-related factors such as broodstock selection and repeated cloning, as well as abiotic factors including water temperature, seasonality/time of seeding and external factors such as storms, wave action, marine traffic and vandalism (Barthel and Theede 1986;Duckworth and Battershill 2003;Page et al 2005Giangrande et al 2020).…”