[CANTABRIA ECONÓMICA  march 2017] Fish waste to feed the algae.

A Cantabrian consortium would like to introduce algae culture in fish farms.

March 2017- “Three Cantabrian companies, ECOHYDROS, Investalga and Rodecan, have joined forces to study how the waste from a fish farm can be used as food for algae grown in the same facilities. The fish farm would then convert a waste, whose purification entails a cost, into the nutrient to obtain another commercially growing species such as algae. The pilot plant will be made in Rodecan and the same technology could be applied to the cultivation of other species”.

The first quarter of 2017, key in the development of the AMTI system.


April 2017 – The months of January, February and March have been particulary important for the desingn  abd full deployment of the AMTI pilot unit.

The site selected for the installation of the AMTI pilot plant is located outside the Rodecan aquaculture plant, on a concrete slab bordering the coastal area in the Fonfría inlet, Ruiloba.

It has been in this period when the assembly of culture tanks, filters, pipes and aeration system, pumping and impulsion systems to storage tanks, tank drains and general drains has been completed, thus reaching one of the milestones of the ALGACULTURA   project, the construction of the AMTI unit.

The whole system is running at full capacity and all that remains is to determine which algae species can be grown more profitably than all those that occur naturally in our waters.

Work for the deployment of the AMTI system

Identificadas genéticamente las especies de Ulva utilizadas en el sistema AMTI en el marco del proyecto Algacultura.

June 2018- The species of the genus Ulva present a high phenotypic plasticity and a fast morphological response to environmental changes which makes the identification of the species’ visu particularly difficult. Therefore, a genetic characterization is necessary for species-level determination.

Preparations of the different species analyzed arranged according to their morphological differences: Laminar, tubular and filamentary.


During the first year, in collaboration with IBBTEC, the algae under study were analysed at molecular level in order to determine their genotype and with a view to subsequently identifying those regions related to specific morphological or physiological characteristics that could be varied with a view to optimising their production or their bioremediation capacity.

In this second year, this task has been continued, but this time using more than one molecular marker, given that the identification linked to one is not entirely reliable, as one that mutates with the frequency necessary to be able to discern accurately between species has not yet been found. With new markers, samples of previously identified species have been re-analyzed in order to corroborate their identity and obtain more information regarding their genetic structure.


Detail of a specimen of Ulva compressa (previously identified as Ulva flexuosa) in which the variety can be appreciated.

of the different morphologies adopted by the thallus.


The results of this new round of analysis corroborate, assuming an identity of at least 99% in 98% of the sequence of the four molecular markers.

the identity of the Ulva laminar species as Ulva rigida, and group the two species previously identified as Ulva flexuosa and Ulva compressa in a single, Ulva compressa, which presents at least 3 different morphologies.


Generation of a spore database of Ulvales species within the framework of the Algacultura Project.

July 2018- One of the objectives of the ALGACULTURA project is the creation of a germplasm bank of Ulva species of interest that can be counted on as viable seed independent of the biomass existing in the natural environment, so that pure crops can be started and maintained at any time of the year, and the conditions that determine the growth and composition of each strain can be studied in a specific way. The creation of one’s own germplasm bank would ensure the conservation of plant material and the ability to permanently dispose of material with which to work.

Fragmentation of the thallus of Ulva spp. is one of the steps used in the process of provoking sporulation.


Within the framework of the second annuity, the experiments initiated during the first annuity have continued, testing different conditions of induction to sporulation in order to obtain a sufficient quantity of spores for their subsequent conservation and germination. These experiments have been carried out in the facilities of IBBTEC, an institute with which INVESTALGA AHTI signed a collaboration agreement within the framework of the ALGACULTURA project.


Detail of the thallus of Ulva rigida to the microscope (40x) in which it can be appreciated as the chloroplasts move towards the extremes

of cells, first sign of induction to reproduction in algal tissue.


Although it has been possible to provoke the change from vegetative to reproductive state with several species under controlled conditions, the experiments carried out have not been successful in unleashing a massive release of the spores that allows their collection and conservation. So far, not enough material has been obtained to establish a first spore bank of the selected Ulva species.


Completed the taking of measures in the cultures of algae with the auto-analyzer of nutrients.

September 2018 – From the first laboratory analyses, it was confirmed that the inorganic nitrogenous and phosphorous nutrients that the algae take for growth follow a very variable dynamic over time, and that even on the same day there are great differences in concentration in the influent of the treatment tanks, due to the fact that the starting culture system (turbot) presents peaks as a consequence of the established feeding patterns and the physiological activity of the fish.

However, it was vital for the experiments to have the ability to correctly delimit and describe these nutrient dynamics. For this reason, it was decided to focus efforts related to the monitoring of algae macronutrients on developing a nutrient autoanalyzer.

This equipment (EcoLABII) allows in situ and unattended (pre-programmed) analysis of the four main macronutrients (nitrates, nitrites, ammonium and phosphates).

By means of a syringe pump, the equipment mixes precise volumes of sample, standard solution and reagents that are connected to a rotary valve, for later analysis by means of high precision colorimeters. In essence, the EcoLAB is a submersible “chemical robot”.

Throughout the execution of the project, several high-frequency monitoring sessions have been programmed, during representative periods of each stage of development and of each test, alternating between the different culture tanks.

The data obtained in this deployment will also support the calibration of simulation models, in addition to serving for the calibration of equipment and establishment of nutrient dynamics for algae.


In situ nutrient autoanalyzer (left). In situ measurements with the EcolabII (right).

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