Arild Folkvord

Larval fish ecology, dr. scient.

University of Bergen, 1993

Cod larva in Sarsia

Phone: (+47) 55 58 44 56

Cod otolith (lapillus)


Mobile: (+47) 413 00 147



Fax:     (+47) 55 58 44 50




Short CV






    Publication list


Recent and ongoing projects


   KILO (Kunnskapsinnhenting i Barentshavet, Lofoten og Vesterålen)

   Landnemi (turbot in Iceland)

   Calcification by Marine Organisms (CalMarO)

   The occurrence of skipped spawning and its importance for population dynamics in Northeast Arctic gadoids

   Meltzer project (High latitude climate variability and its effect on human settlement and fishery resources as revealed by fossil otoliths)


Teaching and training


   NMA (Nordic Marine Academy)


   BIO 338 Larval Fish Ecology

   BIO 300 Biological data analysis and research design

   BIO 240 Fisheries Ecology


   Student supervision at BIO


   Master’s programme in Fisheries Biology and Management


   Recent PhD’s in Fisheries Biology

Research profile

The focus of my research is on growth and survival mechanisms in the early life of fishes. The research is experimentally oriented, and covers aspects of marine juvenile production and process oriented recruitment studies.

Size-selective mortality in cultured fish is often due to aggression and cannibalism. A large effort has been made to elucidate factors promoting cannibalism in captive cod (e.g. hunger level, size, size differences etc.). Size- and temperature dependent growth in juvenile flatfish and cod has also been studied with the aim of determining the growth potential under culture conditions. The growth process is very dynamic during the early life stages, and controlled laboratory experiments are carried out to calibrate methods used for growth characterization (e.g. RNA:DNA analysis, otolith microstructure analysis, fatty acid analysis).

The age of field caught fish larvae is often difficult to assess. Fortunately, growth increments are usually formed on a daily basis in the ear stones (otoliths) of fish larvae. It is thus possible to estimate the larval age in days in a similar manner as one determines the age of older fish by counting yearly zones in the otoliths and scales. The growth pattern in the otolith also reflects the previous growth history of the larva, and can be used to determine where, and under what conditions, the larva grew up. The otolith has therefore often been referred to as the "black box" in fish. An important part of the ageing research is related to the accuracy and precision of the age estimation. Knowledge in this field is of great importance in process studies and fisheries management.

Selected publications

Hufthammer AK, H Høie, A Folkvord, AJ Geffen, CA Andersson & US Ninnemann. 2010.  Seasonality of human site occupation based on stable oxygen isotope ratios of cod otoliths. Journal of Archaeological Science 37: 78-83.

Folkvord A, Ø Fiksen, H Høie, A Johannessen, E Otterlei, KW Vollset. 2009. What can size distributions within cohorts tell us about ecological processes in fish larvae. Scientia Marina 73 S1: 119-130.

Folkvord A, H Høie, A Johannessen, T Solbakken. 2009. Effects of prey density, light regime and parental origin on growth and survival of herring larvae under controlled experimental conditions . ICES Journal of Marine Science 66: 1702-1709.

Folkvord A. 2005. Comparison of size-at-age of larval cod (Gadus morhua L.) from different populations based on size- and temperature-dependent models. Canadian Journal of Fisheries and Aquatic Sciences 62: 1037-1052.

Folkvord A, A Johannessen, E Moksness. 2004. Temperature dependent otolith growth in herring (Clupea harengus) larvae. Sarsia 89: 297-310.


Skajaa K, A Fernö, A Folkvord. 2003. Swimming, feeding and predator avoidance in cod larvae (Gadus morhua L.): trade-offs between hunger and predation risk. In H Browman & AB Skiftesvik (Editors). The Big Fish Bang: Proceedings of the 26th Annual Larval Fish Conference. Pp. 105-121.

Department of Biology - Last update:  October 17, 2012 AF