Growth in Pearlside – a new fisheries resource

Would you like to learn how scientists measure and study growth in mesopelagic fish, a new and perhaps a valuable future food resource from the ocean?


Project background 

Fig. 1. Photo: Anne Gro Vea Salvanes

Deep west Norwegian fjords and the Norwegian Trench house large populations of previously unexploited and understudied mesopelagic fish species.  These fish are distributed in open oceans around the world. Recent studies estimates the biomass to be in size order of 10 billon tonnes globally, and mesopelagic fish thus represent a marine resource that potentially in future could become food from the ocean for the growing human population, if managed sustainably and according to the UN sustainable goal SDG14: “Life below water”.  This has led studies on mesopelagic fish becoming a hot research topic in Norway.

Two species dominate in Norwegian waters; the Pearlside to the left and the Lanternfish to the right on Figure 1.

Very little is known about these fishes. Sustainable management of this new resource require that we know basic biology and ecology. Growth studies are essential components of this.

The Department of Biological Sciences has received samples catches taken by the fishing vessel “LIBAS” during a pilot fishery in the North Sea area in 2019. This material is now available as bioSPIRE projects. As a bioSPIRE student you will contribute to important research on Pearlside.



Fig. 2. Photo: Julie Skadal

You will measure the standard length and weigh the whole fish and liver tissue, and try sex individuals. You will also dissect out fish otoliths (ear-stone; Figure 2).  The otolith has growth rings and will give important information of how fast individuals grow. Each fish you measure, and its otolith will be given a unique ID-Number. All measures you take you will transfer to formatted Excel work sheets.


The project involves: labwork.

Starting date/period: all year long.


Experience/skills to be acquired:

You will learn how scientists in marine biology and fisheries biology work when they collect fish data to study growth. Growth is important to know for management of fish species that are harvested for human consumption.  You will also learn to organise data into spread sheets. The skills you learn are relevant for those aiming for master studies in marine sciences.

Involvement: approx. 30 hours (max 40 hours). Work periods of 4-6 hours recommended. Work in groups of 2 students is recommended.

Interested by this project? Need more info? Contact Julie Skadal (

Project number: 029

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