Sigurd Heiberg Espeland

My scientific work can mainly be divided in three areas or themes:

Connectivity and population structure of coastal cod populations. The area includes different approaches like field sampling, genetics and analysis of tagging data as well as historical data. My work here has focused on how local populations of coastal cod are structured and exchange individuals and genes.

Mapping of spawning areas. This theme has a great overlap with the first theme. This theme relates to partly my responsibility of mapping spawning areas of coastal cod in the project “National program for mapping marine naturtypes”, a responsibility I have had since 2008. This work focuses mainly on dynamics of spawning areas interpreted from sampling of newly spawned cod eggs. Currently I’m leading a program for mapping spawning areas for other important species in the coastal zone as well. This includes other codfish like haddock, saith, pollock and whiting as well as different flatfish.

Effects of marine protected areas. I started working on this theme based on my relevant experience with ecology of coastal cod, but my work here includes studies of lobsters in marine protected areas in Skagerrak as well. My focus here have been on studying the effect of fishery on marine populations and documenting effects of removing fishery.

Espeland, S. H., Gundersen, A. F., Olsen, E. M., Knutsen, H., Gjosaeter, J. and Stenseth, N. C. (2007). Home range and elevated egg densities within an inshore spawning ground of coastal cod. ICES Journal of Marine Science 64 (5): 920-928.

Knutsen, H., Olsen, E. M., Ciannelli, L., Espeland, S. H., Knutsen, J. A., Simonsen, J. H., Skreslet, S. and Stenseth, N. C. (2007). Egg distribution, bottom topography and small-scale cod population structure in a coastal marine system. Marine Ecology Progress Series 333: 249-255.

Jorde, P. E., Knutsen, H., Espeland, S. H. and Stenseth, N. C. (2007). Spatial scale of genetic structuring in coastal cod Gadus morhua and geographic extent of local populations. Marine ecology progress series 343: 229-237.

Espeland, S. H., Olsen, E. M., Knutsen, H., Gjøsæter, J., Danielssen, D. and Stenseth, N. C. (2008). New perspectives on fish movement: kernel and GAM smoothers applied to a century of tagging data on coastal cod. Marine ecology progress series 372; 231-241.

Espeland, S. H., Thoresen A. G., Olsen, E. M., Stige, L. C., Knutsen, H. and Stenseth, N. C. (2010.). Diel vertical migration patterns in juvenile cod from the Skagerrak coast. Marine ecology progress series 405: 29-37.

Cianelli, L., Knutsen, H., Olsen, E. M., Espeland, S. H., Asplin, L., Jelmert, A., Knutsen, J. A. and Stenseth. N. C. (2010).  Maintenance of small-scale population structure in a marine population in relation to water circulation and egg characteristics). Ecology 9: 2918-2930.

Lund, M. B. Olsen, E. M., Espeland, S. H. and Stenseth, N. C. (2011) Life-history of fjord cod from Skagerrak in 1905 compared to the early 2000’s. Marine ecology progress series 424: 169-17.

Knutsen, H., Olsen, E. M., Jorde, P. E., Espeland, S. H. and Stenseth, N. C. (2011) Are low but statistical significant levels of genetic differentiation in marine fishes “biologically meaningful”? A case study of coastal Atlantic cod. Molecular Ecology 20(4): 768-783.

Bekkby, T., Moy, F.E., Olsen, H., Rinde, E., Bodvin, T, Bøe, R., Steen, H., Grefsrud, E.S., Espeland, S.H., Pedersen, A., Jørgensen, N.M. (2012). The Norwegian Program for Mapping of Marine Habitats – Providing Knowledge and Maps for ICZMP. Chapter 2, page 21-30 in: Moksness, E., Dahl, E. and Støttrup, J. (Eds.) Global Challenges in Integrated Coastal Zone Management. Wiley-Blackwell Ltd. ISBN ISBN: 978-0-470-65756-0.

Moland E, Olsen EM, Knutsen H, Garrigou P, Espeland SH, Kleiven AR, Andre´ C, Knutsen JA. (2013). Lobster and cod benefit from small-scale northern marine protected areas: inference from an empirical before–after control-impact study. Proc R Soc B 280(1754) DOI:10.1098/rspb.2012.2679

Fernández-Chacón A, Moland E, Espeland SH, Olsen EM (2015). Demographic effects of full vs. partial protection from harvesting: inference from an empirical before–after control-impact study on Atlantic cod. Journal of applied ecology doi: 10.1111/1365-2664.12477.

Espeland, S. H., Albretsen J, Olsen EM, Bodvin T (2015). Modelling drift of pelagic offspring: the importance of egg surveys in providing a realistic model initialization. ICES journal of marine science doi:10.1093/icesjms/fsv134

Kleiven, A. R., Fernandez-Chacon, A., Nordahl, J. H. Moland, E., Espeland, S. H., Knutsen, H., Olsen, E. M. (2016). Harvest Pressure on Coastal Atlantic Cod (Gadus morhua) from Recreational Fishing Relative to Commercial Fishing Assessed from Tag-Recovery Data. PLOS ONE  11 (3)  DOI: 10.1371/journal.pone.0149595

Fernández-Chacón A, Moland E, Espeland S. H., Kleiven A. R. Olsen E. M. (2016). Cause of mortality in depleted populations of Atlantic cod estimated from multi-event modeling of mark-recapture and recovery data. Canadian journal of Fisheries and Aquatic Science, july.

Halvorsen, K. T, Sørdalen, T. K., Vøllestad, L. A., Skiftesvik, A. B., Espeland, S. H., Olsen, E. M. (2016), Sex- and size-selective harvesting of corkwing wrasse (Symphodus melops) — a cleaner fish used in salmonid aquaculture. ICES journal of marine science doi: 10.1093/icesjms/fsw221

Espeland, S. H. and Sannæs H. (2017). Estimating cod egg developmental stage based on DNA concentration. ICES Journal of Marine Science, doi.org/10.1093/icesjms/fsx172