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19.1 Introduction

5 months ago

8 min read

Aquaponics is an integrated closed-loop multi-trophic food production system that combines elements of a recirculating aquaculture system (RAS) and hydroponics (Endut et al. 2011; Goddek et al. 2015; Graber and Junge 2009). Aquaponics is therefore discussed as a sustainable eco-friendly food production system, where nutrient-enriched water from fish tanks is recirculated and used to fertilize vegetable production beds, thus making good use of the valuable nutrients that in conventional aquaculture systems are discarded (Shafahi and Woolston 2014) and presents a potential solution to an environmental problem usually referred to as eutrophication of aquatic ecosystems.

Organic agriculture is also based on natural principles of recirculation and resource minimization as defined by the International Federation of Organic Agriculture Movements (IFOAM 2005):

Organic Agriculture is a production system that sustains the health of soils, ecosystems and people. It relies on ecological processes, biodiversity and cycles adapted to local conditions, rather than the use of inputs with adverse effects. Organic Agriculture combines tradition, innovation and science to benefit the shared environment and promote fair relationships and a good quality of life for all involved.

Due to the cyclic or systemic nature of both production systems, obtaining organic certification could appear to be a natural step for a researcher, system designer or commercially oriented aquaponics producer to engage in. On the other hand, the underlying principles of aquaponics and organic production differ considerably. From a research perspective, one could argue that the discussion on aquaponics being organic or not demonstrates an interesting case between two poles of agro-food-systems-thinking, namely, agro-industrial (conventional) and agro-ecological (organic). Somehow aquaponics needs to find its place in this continuum.

The aim of this chapter is to shed light on the current status quo regarding the barriers of certifying aquaponics as organic food production, and to discuss the underlying principles, contradictions and views upon its sustainability. It will also discuss possible future scenarios emerging out of the links between the rationales and implementations of the two production systems. We can consider both organic farming and aquaponics as food production systems, because both farmers and aquaponics producers are faced with complex decision-making situations involving the balancing of interconnected and interrelated inputs, external factors (environment, markets, value chains, etc.) and management procedures in order to produce food.

19.1.1 Aquaponic Production Systems and the Technology Applied

Present-day aquaponic production systems are generally categorized according to the type of technology applied to the plant production part, and whether the integration is coupled into one single loop between the plants and the fish or decoupled into separate loops. The most common technologies applied in the plant production are: (1) The Deep Water Culture (DWC) or in the literature often called UVI because originally developed at the University of Virgin Island, (2) NFT (Nutrient Fluid Technology) and (3) 'Flood and Ebb'. The DWC and NFT are the most common or 'classic' technologies applied to the plant production, and often the fish and plant production are connected into one dependent loop of water and nutrient flow. This singular connection and interdependency of the whole system is a factor that increases risks tremendously, and is a prime barrier to establishing large-scale commercial production.

The main differences between the first two systems are related to how the plants are grown.

In the DWC system, the plant bed is the floating system where plants are grown on RAFTs (usually polystyrene) floating in long tanks of variable width, acting both as an extensive biofilter and a water buffer, regulating temperature and pH fluctuations.

In the NFT system, plants are grown in hydroponic plastic pipes, well known from modern horticulture. A thin layer of nutrient water supplied to the pipes feeds the plants. In both cases of the NFT and DWC, the holes for the plants are fixed, which constrains the producer as to what kind of plants can be produced. In some aquaponics systems, both plant-growing technologies from the DWC and NFT are applied at the same time giving more flexibility and security while running a singular aquaponics loop (Kledal and Thorarinssdottir 2018).

In the third category, 'Flood and Ebb', plants are grown in pots placed on (often moveable) plant tables, and then fed two or three times a day by flooding the tables for 5—10 min. The plant tables provide the option of producer with flexibility in the choice of plants grown and the size of the pots, as well as the prospect of using soil and this opening up the possibility of organic certification.

In recent years, decoupled aquaponics is starting to emerge as the production system applicable to large-scale commercial aquaponics production (Fig. 19.1). In decoupled aquaponics the fish and plant production, each has their own loop of water supply, but is also connected to each other via a fertilizer tank supplying nutrient deficiencies to the plants. In this way, the dependency between the fish and plant production has been removed, but the symbiotic benefits are kept allowing for investment in large-scale commercial production. There is currently some debate about the advantages of circulating, or coupled vs. decoupled aquaponics (Goddek et al. 2016). However, there is not yet a consensus about the status of decoupled systems since they could be considered as just another plant nutrient supply method, as long as the water does not circulate back to the fish (Junge et al. 2017).

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Fig. 19.1 (a) coupled (b) decoupled aquaponics system. (Adapted from Peterhans 2015)

Aquaponics is in general receiving increased interest globally as a sustainable food production method, and with the prospects of promoting aquaponics on a commercial scale, there is an equivalent interest in receiving organic certification with its related price premiums on the produce. According to Kledal and Thorarinssdottir (2018) and König et al. (2018), the commercially available systems of aquaponics are mainly based on the research carried out by Rakocy and his co-workers (Rakocy 1999a, b, 2002, 2009; Rakocy et al. 2001, 2004, 2006, 2009), as previously described (the classic production technologies 1 and 2 above) where plants and fish are connected in a singular dependent loop. Likewise, most production systems, whether they are based on DWC, NFT or moveable plant tables with 'Flood and Ebb', are not using an organic growth media, hence already excluding themselves from obtaining an organic certification for the horticultural part. Regarding aquaponics production, access to organic fish feed is in general only available for a few commercial freshwater fish species. So, aside from the various input factors, there are constraints to starting an organic aquaponics production on a commercial scale.

So we can see that despite the growing interest in marketing aquaponics as an environmental-friendly food production system the present organic legislation regime in the EU and USA prohibits aquaponics from being recognized as such (NOSB 2017). However, the discussion is not finalized, and while it is ongoing, some private certification agencies in the US allow for the certification of the vegetables as organic (Friendly Aquaponics 2018).

19.1.2 Aquaponics and the EU Organic Regulation Regime

In the EU, the present regulatory framework for organic fish and horticultural production is regulated by the Council Regulation (EC) No. 834/2007, whereas more detailed rules are regulated by the Commission Regulations (EC) No. 889/2008 and (EC) no. 710/2009. However, the EU organic regulatory regime does not have any standards or regulations for certifying aquaponics as organic. The organic regulation is based on the aims and principles of recognizing organic farming as a natural resource-based food production (Lockeretz 2007; Aeberhardt and Rist 2008). This is backed up in the implementing regulation annex by the exclusion of inputs not allowed for organic farming. Consequently, aquaponics farming systems using the RAS technology and soilless vegetable production (hydroponics) cannot be certified as organic under the present EU organic regulation.

However, among aquaponics practitioners, there is continuous discussion about aquaponics and organic certification. First of all, the rapid industrial developments within fish farming and the market diversification and demand for organic products make it economically desirable to qualify for the organic price premium as one way to reimburse the high capital investments required for commercial aquaponics. Second, it appears only natural to link an environmental-friendly food production such as aquaponics, to already well-established certification labels and consumer perceptions of a sustainable food production rather than engaging in the high transaction costs of creating a whole new food label.

In view of the current discussions on limited resources for food production, animal welfare, the increasing pressure on the sustainability of the aquatic environment, paralleled with the ongoing technological progress within aquaponics, this article asks why aquaponics cannot be certified organic.

In the following paragraph, the organic rules and regulations under the EU regime creating barriers to aquaponics will be examined.