Stage

Internship opportunity at Nofima, Norway

Investigating organic load and microparticle accumulation potential in recirculating aquaculture systems
Internship at Nofima in Sunndalsøra
Duration: 5 months, starting in November ’18

Background

Recirculation aquaculture systems (RAS) are becoming a new industry standard in salmonid production. RAS allow for an increased production of fish at a lower water intake than traditional flow-through systems, independent of season. Furthermore, RAS offer full control over the production environment (e.g. temperature, light), increase biosecurity by disinfecting water at the intake and in the production loop, prevent escapees and offer the possibility to efficiently treat the farm effluents. However, with the recirculation of water, organic material accumulates within the system, which can impair fish and biofilter performance. Degradable organic matter in the system hampers nitrification efficiency and the accumulation of microparticles (< 30 μm) can impair fish welfare.

Problem definition

The main origin of organic material in RAS is faecal waste, and there is a considerable lack of knowledge how
faecal waste composition affects system performance. Besides ensuring operational stability in RAS, this is
especially relevant for feed development and the inclusion of novel feed ingredients, as this will change faecal
waste properties. Most research focuses only on describing water quality in RAS, often ignoring the causal
relationship between feed, faeces and water quality. Thus, there is an evident need to understand the effect
of feed composition on water quality in RAS.

Objectives

In this project, we want to follow the water quality changes with increasing fish density in RAS stocked with
Atlantic Salmon and investigate the effects of feed composition on water quality. Furthermore, you will be
involved in the development of a bench-scale test to estimate the potential for organic load and microparticle
accumulation in RAS. This project will help to move on from a descriptive approach to a predictive approach
when assessing the organic load in RAS, thus providing a valuable tool for the salmon industry.

Material and Methods

This work is part of a larger experiment to investigate the effect of light quality and intensity on the
performance and welfare of salmon post-smolts in cooperation with partners from research and industry.
During a period of 4 months, salmon post-smolts will be grown from ~90 to 900 g in RAS with brackish water.
Towards the end of the experiment, we will switch feeds and assess the impact on water quality and system
performance. You will be responsible for water quality measurements, data analysis and assisting in the
development of a small scale experimental system to predict the impact of feces composition on RAS
performance. Furthermore, you will be involved in day-to-day operations in the commercial-scale RAS
research facility of Nofima in Sunndalsøra. You will be working with different analytical methods to measure
water quality and to accurately describe solid and dissolved organic matter. Mass balance models will help
to put the obtained results into context for commercial RAS conditions.

About Nofima

The Nofima Centre for Recirculation in Aquaculture is unique in Norway as
the only research facility of approximate commercial size (1750 m²). The
centre features six experimental sections and has a total breeding volume of
1100 m³. The centre has access to both freshwater and seawater. The
research plant is ideal for testing out equipment, methods and operational
routines in collaboration with the industry. Nofima wants to contribute to
developing competence in this field for the industry and society in general.
Nofima will provide supervision, accommodation on-site and access to labs
and experimental facilities for the successful intern.

Are you interested in this internship?

Please contact Ep Eding: