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SWEMARC's PhD projects

PhD student Ida Hedén, Department of Biological and Environmental Sciences

The focus of my research is on new alternative feed sources for fish farming in closed re-circulating aquaculture systems without affecting the welfare of the fish. The project investigates underlying physiological mechanisms for effects on growth, appetite, health, and intestinal nutrient uptake.

I am involved in several studies and I work on different fish species such as wolffish (Anarhichas lupus och minor), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss) och African catfish (Clarias gariepinus).

To ensure that the new alternative feed sources do not negatively affect the growth and welfare of the fish, several physiological measurements can be used. My belief is that if you ensure the welfare of the fish, the final product to the consumer will also be of the highest quality.

There has been a relatively large amount of research on land-based products such as wheat, corn and soybean as replacements for fish meal and fish oil, and today these are common ingredients in commercial fish feed. My focus is instead on marine products such as micro / macro algae, sea squirts and side-stream products from the shrimp-, herring- and mussel industry. Products from the ocean have usually a beneficial nutritional composition of amino acids and fatty acids that contribute to rapid growth and maintained health of the fish, but also a desirable nutritional content of the final product for human consumption.


PhD student Jonas Nilsson, Department of Law

The doctoral thesis is written in the subject of public law. The purpose of the thesis is to analyse whether aquaculture should be regulated within the realm of the general environmental regulation, or whether it is motivated to have special regulation, to achieve sustainable aquaculture in Sweden. The research is conducted through a comparative study of the Swedish regulation of aquaculture in comparison to the regulation in other countries and for other activities.



PhD student Matthew Hargrave, Department of Marine Sciences

The focus of my research area is multi-trophic aquaculture involving extractive, or non-fed, species. Multi-trophic aquaculture is a method of food production whereby species from different trophic levels are grown in association with each other. The aim of this is to increase the yields of the system via the recycling of nutrients between species, resulting in more efficient growth as well as a decrease in the release of potentially harmful nutrients.

Whilst most aquaculture systems tend to focus on a species that requires feeding, such as salmon, my aim is to research the potential for co-cultivating non-fed species in a multi-trophic system. At present, I am working to co-cultivate the blue mussel (Mytilus edulis), an important aquaculture species in Sweden, with seaweeds such as the sugar kelp (Saccharina latissima) and the sea lettuce (Ulva lactuca).

Filter feeding species such as the blue mussel acquire their food from naturally occurring organic particles and phytoplankton in the water column and so do not require an extra source of feed. However, whilst they feed efficiently on natural particles, they also release nutrients such as ammonium and phosphate. They nutrients are crucial in the growth of seaweeds and in some circumstances can be limiting factors in seaweed growth. As such, there is potential for growing seaweeds in association with mussels or other filter feeding species to capitalize on this valuable nutrient source, and to prevent the accumulation of ammonium in the coastal marine environment which can potentially contribute to local eutrophication.

To explore this area I am using a combination of field and laboratory studies to determine the interaction between these species and the potential to develop this into a larger scale food production system.


Page Manager: Webbredaktionen|Last update: 7/10/2018

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