Improving the mineral content in microalgal biomass for aquaculture

The intensification of aquaculture is inevitable in an ever increasing population. Fish feed plays a major role in this industry where there is a demand for more sustainable food sources. This research project aims to increase the amount of biominerals in microalgae whilst ensuring they are bioavailable for the fish.


There has been an increasing interest in fish feed optimization in terms of sustainability and nutrient availability in an ever growing aquaculture industry. Aquafeed consists of a variety of ingredients ranging from animal to vegetable sources, i.e. plant based protein and oil. However, these ingredients do not all contain the right classes of lipids, or sufficient amount of amino acids or minerals which lead to the need for supplementation. 


Current commercially available supplementation is based on inorganic mineral mixes, which result in a low uptake efficiency by fishes. Algae are a good candidate to help tackle this bioavailability challenge as an aqua feed micro ingredient. Additionally, marine microalgae already have an important role in the ocean food chain as primary producers of fatty acids and carotenoids. The project “Improving the mineral content in microalgal biomass for aquaculture” will be undertaken over the course of 4 years and will aim at researching the uptake of minerals by microalgae and their bioavailability within fish feed.


GAIN (Green Aquaculture Intensification in Europe) aims to rectify the gap between production and demand in aquaculture by meeting the current annual growth in aquatic product volume whilst focusing on more sustainable methods. This will be achieved by improving the feed composition, by-product utilisation and policy that selects for more sustainable practices in aquaculture.

The aim of this PhD project is to utilise microalgae as a fish feed component and increase the amount of minerals to positively impact the fish health, by strengthening the immune system and reducing the likelihood of diseases.


The approach will consist of ensuring the incorporation of biomineral-containing algae, understanding algal mineral toxicity and mechanisms of uptake. The bioavailability of the incorporated minerals will be assessed through fish trials and a techno-economic model will be produced based on pilot scale production results.

Thesis project

There are different topics available for BSc or MSc thesis within the GAIN project. If you are interested, feel free to contact Barbara Guimaraes.