IMTA: the back-to-front food chain
It was a while ago when we both got involved in an Integrated Multi-Trophic Aquaculture* project with NUI Galway and decided to write a book chapter on the topic.
The IMTA concept is based on a ‘back-to-front food chain’. Where food chains usually describe energy transfer from the bottom-up (i.e. producer – herbivore – carnivore – top predator), here, we focus on energy transfer from the top-down (fish waste – shellfish/other invertebrates – seaweeds).
This ensures that the best use possible is made of the energy — in the form of food input to the system. In this way, we are working with natural ecological processes to enable cleaner production systems, and ideally, trying to improve the quality and quantity of what is produced.
The interesting part of the project was interviewing stakeholders in the aquaculture industry along with the general public.
We aimed to define the number of facilities that had some IMTA experience, and to evaluate if people were aware of the concept. If they were, we wanted to understand how it was perceived.
Identifying facilities
More than ten years later, we are midway in the Project: INTEGRATE (2017-2020), which is now on a bigger scale, including the Atlantic Area (Ireland, U.K., France, Spain, Portugal).
As before, the project aims to identify existing IMTA facilities, and discuss and facilitate the development of this concept in the different countries and regions involved. You can read more about it here.
We have found several more projects working with the IMTA concept, and greater experimentation with species and systems.
In Ireland there are two commercial facilities that are also case studies for this project. Bord na Mona’s facility in Mount Lucas, Co Offaly, is a freshwater recirculating system where perch and common duckweed are being cultured in linked ponds/raceways; and the Bantry Marine Research Station (BMRS) in Gearies, Co Cork — an offshore marine system where Alaria esculenta is being cultured next to a salmon farm.
Awkward acronym
During our research we noticed some confusion as to what exactly is meant by IMTA. While the acronym has become widely used in academic and aquaculture circles, and to some extent has been accepted by the industry, it means little to other stakeholder groups – particularly the wider public.
As we know, scientists are not always the best communicators, and here, with our awkward acronym, IMTA, we appear to have a case in point. If we wish to broaden knowledge about sustainable aquaculture practices we need to find tools and language that are intuitive.
Interestingly too, this point was raised at our recent ‘IMTA social best-practices workshop’ in NUI Galway. A lot of work remains to be done, but if nobody knows what we are talking about, we are likely to struggle!
In the ‘best-practices’ workshop we had other ideas for what IMTA might be called: Integrated Aquaculture; Connected Aquaculture; Circular Aquaculture; AquaFarm; Paired system.
Anna Soler-Vila & Jessica Ratcliff
