Recovering wasted nutrients from shrimp farming through the combined culture of polychaetes and halophytes

Abstract

The bioremediation and biomass production of organic extractive organisms (polychaetes Arenicola marina, Hediste diversicolor and halophyte Salicornia ramosissima) was assessed in an integrated multi-trophic aquaculture (IMTA) framework. Culture trials were performed outdoors using the nutient rich effluent from a shrimp farm employing recirculated aquaculture systems. Similar bioremediation efficiencies were obtained in cultures using a single polyculture tank (1 T) or two trophic levels separated tanks (2 T; ≈ 0.3 and 0.6 m2 operational area, respectively), with a reduction of 74–87% for particulate organic matter (POM), 56–64% for dissolved inorganic nitrogen (DIN) and 60–65% for dissolved inorganic phosphorus (DIP). Hediste diversicolor adapted well to culture conditions, reaching densities up to 5.000 ind. m−2 (≈ 78–98 g m−2). Arenicola marina failed to cope with water temperature that exceeded the species thermal limits, displaying a survival < 10% (20 °C often pointed as the maximum thermal threshold for this species). Productivity of S. ramosissima with 1 T was about twice that obtained with 2 T (≈ 150–170 and ≈ 60–90 g FW m−2 edible aboveground biomass, respectively). The yellowish coloration of cultured plants was likely due to the chemical oxidation and rapid sand filtration pre-treatment applied to the brackish groundwater used in the aquaculture facility, that removed iron (and probably other essential elements). Overall, 1 T design combining H. diversicolor and S. ramosissima displayed the best bioremediation performance and biomass production, while also allowing reducing in half the operational area required to implement this IMTA framework.

Effects of dietary various oil sources on zootechnical performance, sexual maturation, whole‐body proximate composition and fatty acid profile of Hediste diversicolor

“…In another polychaete such as P. aibuhitensis (Lv et al, 2017), Diopatra neapolitana , Sabella cf. pavonina and Terebella lapidaria (Jerónimo et al, 2021), palmitic acid was pinpointed as primary FA with maximum concentration. There was a usual process between 18 carbon FA (oleic, linoleic and linolenic acid) and 20 carbon FA (longer‐chain PUFAs, such as 20:4n6, ARA, C20:3n‐3, EPA and 22:6n3, DHA) composition of the test diets and body composition of H. diversicolor .…”

Evaluating the Bioremediation Capacity of the Polychaete Perinereis gualpensis (Jeldes, 1963) for Atlantic Salmon Aquaculture Sludge

“…The salmon aquaculture sludge used in this study fulfilled the nutritional requirements of P. gualpensis. The high survival and positive growth rates obtained in bioremediation trials with polychaetes indicate that the organic matter used as food was nutritionally suitable and highlight the bioremediation potential of the species [10,11].…”

“…The management practices in aquaculture systems can influence the amount of feed left unconsumed by the fish, which can range from 3% to 20%, and some of the nutrients provided in the feed may not be fully digested, ending up in the sludge [9]. Some of these nutrients have high nutritional value, particularly protein and lipids, which are essential components of animal feed, making their release to the environment also a significant loss of valuable components [10].…”

“…Many of these studies reported organic matter removal by the Nereididae and Arenicolidae families, which are the most commonly studied for this purpose. For example, Hediste diversicolor was found to effectively remove total organic matter (TOM) from fish and shrimp effluents, also exhibiting notable growth and survival rates in several investigations [9,10,16,19]. Similarly, Perinereis aibuhitensis and Abarenicola pusilla reduce carbon and nitrogen levels by consuming organic matter from fish sludge [20][21][22].…”

The carrying capacity of the seas and oceans for future sustainable food production: Current scientific knowledge gaps

“…The high level of polyunsaturated fatty acids measured in several polychaete species (Brown et al, 2011; Nederlof et al, 2019) makes it interesting to explore the feasibility of using polychaetes to convert waste from fish farms into alternative sources for fish diets and thus reduce pressure on wild fish stocks for animal feed. Polychaetes are already used together with shrimps in a multi‐trophic aquaculture setting (Jerónimo et al, 2021).…”