The role of polychaeteNereis diversicolorin bioremediation of wastewater and its growth performance and fatty acid composition in an integrated culture system withHuso huso(Linnaeus, 1758)

Abstract

This study was undertaken to evaluate the role of polychaete Nereis diversicolor in bioremediation of waste water and its growth performance and fatty acid composition in an integrated culture system with great sturgeon, Huso huso. Three treatments consisting of N. diversicolor fed with H. huso waste (FNW), N. diversicolor fed with fish feed waste (NW), and fish waste without the worm (FW) were considered at water temperature of 23°C for 8 weeks. The obtained results demonstrated that N. diversicolor in the flow‐through system could grow via feeding with the fish waste water. The pure production and survival rate of harvested Nereis in NW treatment were significantly higher than those of FNW treatment (p < .05). However, no significant difference was observed in specific growth rate and weight gain between these two treatments (p > .05). The highest removal efficiency of waste water including total nitrogen (56%), total phosphorus (53%), NO2‐N (91%), NH3‐N (35%), PO4‐P (47%), BOD5 (60%) were seen in FNW treatment. Also, the highest additional efficiency of NO3‐N occurred in FW (37%) treatment. Certain fatty acids specifically 20:5 ω3 (eicosapentaenoic acid [EPA]) and 22:6 ω6 (docosahexaenoic acid [DHA]) were also abundant in Nereis, and analysis revealed some differences due to the diet. These results demonstrated that the promotion of growth by cultured Nereis can enhance the decomposition rate of organic matter in enriched sediment and minimize negative effects in fish farms. These results also suggest that the use of N. diversicolor is an excellent potential candidate for an integrated aquaculture and nutrient recycling including the removal of organic wastes.

Effects of rearing density on growth, fatty acid profile and bioremediation ability of polychaeteNereis diversicolorin an integrated aquaculture system with rainbow trout (Oncorhynchus mykiss)

“…The removal rates of these metabolic substances were generally recorded higher than 50% in the outlet water of all worm storage tanks, and the highest removal rates were observed in T 4 with the highest worm population. These values are higher than those reported previously for N. diversicolor in an integrated culture system with Huso huso (Pajand et al, ), but in line with those reported previously for Capitella sp. worms (Heilskov & Holmer, ; Kinoshita et al, ).…”

“…For instance, growth indices (SR, SGR and WG) of N. diversicolor fed with O. mykiss faeces and uneaten feed were significantly higher in T 1 treatment. Support for these results have come from the study reported by Pajand et al () in which N. diversicolor fed with Huso huso faeces and gained a specific growth rate of 3.40%/day in the course of an eight week experiment. Likewise, specific growth rate of 3% per day was gained when Nereis virens was fed with halibut faeces during a 71‐day experiment (Brown, Eddy, & Plaud, ).…”

“…Filters were weighed to calculate the dry weight (DW) and placed into an oven at 500°C for 6 hr and then weighed again to determine the ash‐free dry weight (AFDW). Percentage of total organic matter (TOM) was calculated using equation %TOM = (DW – AFDW)/DW) × 100 (Pajand et al, ).…”

“…Polychaetes play a profound function in transferring organic matters and nutrients from the water column into sediments and vice‐versa (i.e., bioturbation) (Batista, e Costa, Matias, et al, ; García‐Alonso, Müller, & Hardege, ). Literature suggests Nereis diversicolor as an excellent potential candidate to be used in an integrated aquaculture for nutrient recycling and removal of organic wastes originating from fish farms (Batista, e Costa, Matias, et al, ; Heilskov & Holmer, ; Pajand, Soltani, Bahmani, & Kamali, ). Ragworms (e.g., N. diversicolor ) recycle feed nutrients in an integrated recirculating aquaculture system (Bischoff, Fink, & Waller, ).…”

Abarenicola pusilla (Quatrefages, 1866): A novel species for fish waste bioremediation from marine recirculating aquaculture systems

“…Species of marine polychaetes such as Sabella spallanzanii (Pierri, Fanelli, & Giangrande, 2006), Capitella sp. (Kinoshita et al, 2008), Nereis diversicolor (Pajand, Soltani, Bahmani, & Kamali, 2017), Nereis virens (Brown, Eddy, & Plaud, 2011), Perinereis nuntia (Palmer, 2010) (Weston, Penry, & Gulmann, 2000). During the 28 days of trials, the total ammonia nitrogen (TAN, Nessler method), nitrite-nitrogen (NO À 2 , diazotization method), nitrate-nitrogen (NO À 3 , cadmium reduction method) were measured daily by analytical methods for dissolved inorganic nutrients using a spectrophotometer (Hach DR-3900) to determinate concentration and excretion rate by the polychaetes.…”