Periphyton For Biofiltration And Fish Feeding in An Integrated Multi-Trophic Aquaculture System: A Case Study in The Gulf of Aqaba

Abstract

The environmental footprint of mariculture is a major obstacle towards expansion of this agro-industry. Additional economic constraints are the high costs of effluent treatment and expensive, non-sustainable ingredients in aquafeeds. Both Ulva and periphyton reveal great potential in nitrogen removal in mariculture effluent. To overcome the relatively minor uptake of nitrate by Ulva, a periphyton-based biofilter can be used either as a stand-alone biofiltration unit or as a polishing unit in an integrated Ulvaperiphyton biofilter. The biomass produced is rich in protein and is suitable for feeding of marine fish, served fresh on the plastic net substrate or included in pelleted aquafeeds to replace fishmeal.

Fishmeal replacement by periphyton reduces the fish in fish out ratio and alimentation cost in gilthead sea bream Sparus aurata

“…This is particularly due to the low content of fish oil, only 0.25%, in that experimental diet 15 which is significant as compared to all other examined diets. Although not addressed in the current study, a significant reduction in fish oil content may also be achieved with the use of marine periphyton, which contain high levels of essential fatty acids 46 . An interesting outcome from the present study was the relatively protein-rich (59%) but lipid-poor (23%) fish flesh when fed with the fishmeal-free diet with high periphyton content.…”

“…This is in addition to its other advantages in water oxygenation and pH balancing 29 , 47 . In earlier studies, periphyton in culture ponds reduced the amount of commercial aquafeeds required 36 , 42 , 46 but the potential of this edible biomass in replacing dietary fishmeal has not been reported until now. Therefore, the current study is novel in its evaluation of the feasibility of having marine periphyton from a biofilter for fishpond effluent treatment also serve as a protein source to minimize fishmeal content in pelleted diets and enhance the circular economy concept.…”

“…Marine periphyton from an IMTA biofilter system plays a valuable role in the removal of excess nitrogen and phosphorus from fishpond effluent and assimilating them into edible biomass for further use 44 – 46 . This is in addition to its other advantages in water oxygenation and pH balancing 29 , 47 .…”

Sustainable Aquafeed with Marine Periphyton to Reduce Production Costs of Grey Mullet, Mugil cephalus

“…However, knowledge concerning the feasibility of periphyton as a source of macro-and micro-nutrients in aquafeeds is relatively negligible. The harvested biomass contains 20-40% crude protein in its dry weight [17,24,25] and is wasted unless employed for other applications. In a recent study, periphyton from a biofilter for mariculture effluents efficiently substituted for FM in the diet of gilthead seabream (Sparus aurata) [26].…”

Avaliação quantitativa e bioatividade de um biofilme perifítico oriundo de piscicultura

“…Foram obtidos uma quantificação maior que 99% de bactérias em relação a fungos no biofilme desenvolvido durante o cultivo de tilápia, sendo evidenciado essa diferença nos resultados encontrados na presente pesquisa. Essa dominância quantitativa dos componentes bacterianos já foi vista em outras pesquisas (SILVA et al 2016, GUTTMAN 2019 Os biofilmes são descritos tipicamente como consórcio de microrganismos fixos em superfícies, mas eles também podem formar agregados suspensos, tapetes microbianos, e flocos, onde todos os arranjos utilizam alguma mistura das substâncias poliméricas extracelulares para agregação, estrutura, e manutenção do estilo de vida da comunidade (FLEMMING & WINGENDER 2010, BILLINGS et al 2015. Comunidades microbianas frequentemente tem uma capacidade maior de executar determinada atividade que os indivíduos que vivem de forma livre (JAMES et al 1995).…”