INTEGRATE fosters cooperation for industrial transition towards Integrated Multi-Trophic Aquaculture (IMTA) in the Atlantic Area

Final results webinar Session 2: understanding IMTA best-practice in the Atlantic Area

The results of the pilot actions developed by INTEGRATE were also released. The project had eight case studies distributed in three pilot actions in Spain, Portugal, France, and Ireland to develop specific technology and production processes for Atlantic IMTA. The results of this work are useful not only at a production level, but also at a legislative and environmental level.

Starting off the Pilot Actionpresentations, Anna Soler from the Irish Seaweed Consultancy, spoke about “Cultivation of Himanthalia elongata (Sea Spaghetti): First trials on an IMTA farm in Ireland”. The aim of this pilot action was to test new eco-friendly technologies and high-value seaweeds applied to IMTA. This species was selected since it was one of the first 10 seaweed species authorised by France in 1990, as the first country in Europe to do so. Only minimal previous work has been done on cultivation of this species on a large-scale, and new in this sense also for ISC before starting these pilot action activities.  Starting with a description (with photos) of the interesting growth stages of the Himanthalia elongata, starting with button-like growth and finalising in the long spaghetti-like strands, that lend this species its common name, Anna presented their process of selecting the ideal substrate for cultivation and finally, their experience of cultivating the species at sea to test the methodology they were developing. They brought the selected substrate (scallop shells) to Lehenagh IMTA farm in Connemara, Co. Galway, managed by the Marine Institute and a great location to test these methodologies. Although throughout the growth stages epiphytes were always present, they did not seem to overgrow the Himanthalia elongata, but they do clearly compete for space. After a list of conclusions and observations, ISC is happy to conclude that it is a very pleasant species to work with and that they have a successful proof of concept for IMTA with this species and will continue with their studies and testing in order to render cultivation of this species to become commercially available.

Jessica Ratcliff from NUIG continued with a presentation of pilot action 1 activities describing their trials of lumpsuckers and Ulva spp. in a pilot-scale recirculating IMTA system. The lumpsuckers are particularly pleasant to work with and, as is the case also for Ulva spp., they have an economic value and are locally available. NUIG has lumpsuckers in their local hatchery, due to their interest in using them as a biological control of sea lice on farmed salmon. In the case of Ulva spp., it is not only of economic value but also has a high potential growth rate and, therefore, good remediation potential, also very important in this case and in IMTA in general. The initial questions on which the study was based were: What are the nutrient dynamics of the system? Does the Ulva effectively use the nutrients provided by the fish and does this impact growth rate and seaweed composition in terms of carbon and nitrogen? Do the two morphologies behave the same and is there an interaction between them when they are co-cultivated? And how is the alga growth and productivity affected by altering certain environmental parameters in the system? After describing the methodologies in more detail, the main conclusions are that, first of all and in general, the systems worked. It seems that the laminar Ulva was more suitable than the tubular and reasons for poor Ulva growth rates require further testing, but may be that it is not the best species, the photoperiod may be too short or the temperature and nutrient concentrations too low or the biofilter too big.

The final pilot action 1 presentation was given by project partner Rémy Luthringer from Agrocampus Ouest in Brittany France, where they tested the cultivation of oysters, sea cucumbers and seaweed in a land-based IMTA system in Beg Meil in southern Brittany. The main objective of this activity was to monitor and assess the performance of a land-based IMTA system. As species for their pilot action they chose oysters as the excretive component, expected to enrich the water with nutrients, and sea cucumber and seaweed (Palmaria palmata or Ulva spp.) as the extractive species, primary producers. They performed 2 experiments with the seaweeds, one with each of the aforementioned species. Both can be found locally, which is an important factor in the pilot actions. They also all have an economic value. The main difference between the 2 different experiments was the water flow, the first being a flow-through system, using Palmaria palmata and the second a recirculating system, using Ulva spp. In order to feed the oysters, they used phytoplankton, using the same concentration and the same number of oysters. Full details of the results are described in the presentation video. The main conclusions of this pilot action are that the non-domesticated animals like the sea cucumber H. forskali, is a good candidate as a benthic species for IMTA in Europe (good economic value potential; feeding on detritus). It is very important when setting up an IMTA experiment to consider seasonality, bioremediation capacity and economic value when choosing the species, for example, Palmaria palmata is more suitable during the winter and Ulva spp. more suitable for the summer the future it would be interesting to dig deeper into the study of different animal densities, also for the seaweed. Furthermore, an important next step would be to scale up the system to obtain a more precise idea of the economic value of such a system.

Following the INTEGRATE project presentations, a talk was given by Damien Toner from BIM, Ireland’s Seafood Development Agency and an associated partner of the INTEGRATE project. His external testimonial about the AQUAMONA freshwater project was entitled: “A perch, trout and duckweed outdoor recirculating IMTA system in Ireland”. The project is based on cutaway peatland in Ireland. The area was traditionally used for peat harvesting for heating homes and electricity generation, but are now being converted into environmentally sustainable projects. Their greatest challenge at the moment is to maintain the system balance between algae, duckweed, bacteria and cyanobacteria.

Starting off the Pilot Action 2 presentations, Bertrand Jacquemin from CEVA in Brittany spoke about their case study about combining oysters and nori in an IMTA system, how oyster farmers could domesticate a high value seaweed, naturally recruiting on oyster pockets. They used Porphyra purporea (aka nori) naturally recruiting in different farms (7 farms identified) to obtain a strain collection. They then artificially seeded oyster pockets that were subsequently transferred to oyster farms. They then tested different harvesting techniques that can be easily reproduced in the context of the farm. This case study allowed them to explore the production process from the early stages to the harvest and different scenarios were discussed on a case by case basis for each oyster farm.

As previously, we also had an external testimonial presentation here to conclude the pilot action 2 context. In her presentation, Cynthia Carpentier from CREAA talked about the potentiality of macroalgae culture in Nouvelle-Aquitaine – a Study applied to Porphyra sp. In their study they monitored the three following environments: foreshore, marsh and deep water – longline. After their study the can conclude that the foreshore environment is the most suitable for cultivation of Porphyra sp. and they are now further defining the best culture course on the foreshore, which can secure a potential new seaweed production in the Nouvelle-Aquitaine region.


In order to introduce the particular environment in which the pilot action 3 studies were located, we started off the presentations with our external testimonial by Macarena Algarín, co-founder of the company Estero Natural S.L. in Andalusia, Spain, mainly dedicated to oyster cultivation and eco-tourism, on “IMTA in the southern European Atlantic area: Advantages of its implementation”, according to Estero Natural’s point of view. Most of the aquaculture facilities in their area are land-based, due to the local sea conditions, divided into esteros and others. She continued by explaining what esteros are, namely former salt production areas that were transformed into marine fish cultivation areas after the 1970s salt industry crisis, presenting “opportunities during times of crisis”. Esteros use marine water, which flows into the ponds through sluice gates, then flowing from pond to pond by gravity. This process is completely influenced by the local tides, producing water in- and outflow, which is crucial for implementing IMTA. In the spring when water flows in, it also brings fish, which then grow in a natural way, without the use of pumps or external feeding. Esteros host a lot of biodiversity, fish species, bird species, some of which are threatened. It is most likely that in order to stop the deterioration of the local environment sustainable productive activity is essential. But what is the current productive situation in esteros? Many companies have realised that extensive fish farming is not profitable and many companies are not allowed to implement a different type of aquaculture, since they are located within protected areas. Estero Natural is convinced that they need a diversification strategy for their company, which is where IMTA can play an important role.

Starting off the INTEGRATE Pilot Action 3 presentations, Gabriela Oliveira from IPMA, Portugal, spoke about the southern Portuguese case study in the combined pilot action with southern Spain, entitled: “Towards a standard model for land-based IMTA mariculture – Two cases from southern Spain and southern Portugal: semi-extensive and semi-intensive production”. As Macarena explained in the previous presentation, most of the aquaculture in these areas is located in earthen ponds (esteros) within protected areas, so IMTA can be an appropriate sustainable approach, simulating natural systems. The advantage is that it is a land-based system where species compartment flows can be controlled. In order to develop a started model for land-based IMTA, a semi-extensive and semi-intensive case studies were implemented in earthen pond systems in southern Atlantic area of Portugal and Spain. At IPMA they used the following species: meagre, white seabream, flathead mullet, oysters and sea lettuce. They can conclude that the high-density system showed higher final results, and higher trophic level species had higher production in the high-density system and lower trophic level species in the low-density system. The densities in this IMTA system presented problems, i.e. parasite outbreaks.

Erik Malta from CTAQUA subsequently presented the southern Spanish part of pilot action 3, giving an overview of the IMTA pilot implementation in a functioning aquaculture company in the Salina de Belén, Puerto Real, Spain, hosted by the company Estero Natural, as previously presented by Macarena Algarín. In the CTAQUA case, they had to make slight modifications to the design in order to guarantee continuous water flow through the compartments and also a constant minimum water depth, which is very important for the seaweed. This modification basically consisted in managing the sluices so that at high tide and spring tide they could store a lot of water in the storage basins. The experiment itself consisted of 2 compartments, one with fish and oysters and the other, downstream, with seaweeds. The fish were fed with a standard commercial feed. CTAQUA concludes that these esteros, i.e. former salt evaporation ponds, show potential for IMTA, because they have different compartments, they’re relatively easy to manage, there’s a good water flow, which is assisted by the tides and therefore energy saving. At least for the oysters there is a very high production capacity, whereas the seaweed systems need to be improved and are being tested in a different project. Preliminary results of the marker-analyses and nutrient concentrations indicate trophic connection between the compartments. The standard model guideline can be found on the INTEGRATE project website.

Following the pilot action presentations, Emília Cunha from IPMA, Portugal, presented IMTA’s environmental contribution, i.e. the development of the conceptual model and the results of the life cycle assessments (LCAs) of semi-intensive and semi-extensive pilot actions. Since there were various pilot actions being tested within the INTEGRATE project, they started be developing a conceptual model to incorporate the pilot actions. The conceptual compartment model was basically a model of saltwater pond IMTA and the environmental performance of the system being carried out was evaluated through an LCA. The could conclude that the assessment carried out is an estimate representing the range of potential impacts of semi-extensive and semi-intensive pond IMTA; feed is the largest single contributor to all environmental impacts associated with pond IMTA production; the metrics “feed:gain” and “water renovation:energy consumption” explains most variation regarding the environmental impacts of pond IMTA; downstream macroalgae production decreased eutrophication impact. They suggest the following improvements in the environmental impact: on farm improvements in “feed:gain” for all impacts, water renovation – energy use, global warming, acidification as the base impacts, improvement of feed composition and management, improvement of energy consumption, and increase in downstream production of macroalgae.