Research interests

• Fish behaviour: migration and population separation mechanisms [pdf, pdf2]
• Analysis of life history using otolith information
• Exploitation patterns and historic development of fish stocks
• Fisheries management in a political context [pdf1, pdf2]

Current research

My studies are mostly focused on the behavioural ecology of demersal fish stocks. Secondly, I find the interplay between marine resources and the society most interesting.

In the beginning of my studies on the Swedish west coast, I and my colleagues found a profound decline for the entire inshore demersal fish community. In contrast, the coastal areas still functioned as nursery habitats for juvenile fish. It has previously been suggested that juvenile cod might be recruited from offshore spawning areas in the North Sea, from which they had been passively transported. My archival tagging studies indicated pronounced differences in cod migratory behaviour between tagging locations in the Skagerrak-Kattegat area. A large and over time increasing proportion of the tagged cod along the Skagerrak coast moved to the west at liberty.

Taken together, these findings clearly suggested a strong behavioural component in the distribution pattern of cod in the eastern North Sea region, as cod tagged at different localities showed non-random, directional movements in agreement with the hypothesis that the cod population in this region comprises a mixture of resident and migratory stocks. I therefore suggested that this migratory behaviour is compatible to natal homing based upon individual “decision-making” of the fish.

More work will be done concerning the vertical migratory behaviour of cod using obtained records from archival tags. The growth and temperature strategies have been evaluated in concert with other nation tagging programmes within the project CODYSSEY.

In an otolith chemistry study the hypothesis of natal homing was confronted by combining migratory trajectories with analysis of the trace elements in the otolith core, using Micro Particle Induced X-ray Emission analysis facilities at Lund University. Moreover, further and even more elaborated studies on migration and genetics is currently carried out, combining genetic information with individual migratory trajectories.

Historical records, mostly originating from previous scientific trawl surveys, have been updated back to 1901. In addition, we are at the moment analysing landing statistics from Swedish longline fisheries from 1859 and on. These records give us the opportunity to reconstruct former stock structures and abundance and is the basis for the project Waking the Deads.

Participation in ICES advisory processes (at the moment):

SIMWG (Stock Identification Methods Working Group)

WGNSSK (Working Group North Sea and Skagerrak)

Networks

HMI (I was employed as a scientific coordinator for two years at Havsmiljöinstitutet (HMI)/Swedish Institute for the Marine Environment

CODYSSEY (Former cod tagging research project)

EELIAD (Eel tagging project)

HMAP (History of Marine Animal Populations)

CV

Link to CV

Recent publications

Svedäng, H. & Gipperth, L. 2012. Will regionalisation improve fisheries management in EU? – An analysis of the Swedish eel management plan reflects difficulties. Marine Policy 36: 801–808. doi:10.1016/j.marpol.2011.11.011

Cardinale, M., Svedäng, H., Bartolino, V., Maiorano, L., Casini, M., Linderholm, H.W. 2012. Spatial and temporal depletion of haddock and pollack during the last century in the Kattegat- Skagerrak. Journal of Applied Ichthyology 28: 1–9. doi: 10.1111/j.1439-0426.2012.01937.x

Bartolino, V., Cardinale, M., Svedäng, H., Linderholm, H.W. & Grimwall, A. 2012. Historical spatiotemporal dynamics of eastern North Sea cod. Canadian Journal of Fisheries and Aquatic Sciences 69: 833–841. doi:10.1139/F2012-028

Cardinale, M. & Svedäng, H. 2011. The beauty of simplicity in science: the Baltic cod stock improves rapidly in a “cod hostile” ecosystem state. Marine Ecology Progress Series 426: 297-301.

Svedäng, H., Cardinale, M. & André, C. 2011. Recovery of former fish productivity: philopatric behaviors put depleted stocks in an unforeseen deadlock. pp. 232-247. In Ecosystem Based Management for Marine Fisheries: an evolving perspective. (Editors: Belgrano, A., Fowler, C.W.). Cambridge University Press.

Righton, D.A., Andersen, K.H., Neat, F., Thorsteinsson, V., Steingrund, P., Svedäng, H., Michalsen, K., Hinrichsen, H.H., Bendall, V., Neuenfeldt, S., Wright, P., Jonsson, P., Huse, G., van der Kooij, J., Mosegaard, H., Hüssy, K. & Metcalfe, J. 2010. Thermal niche of Atlantic cod Gadus morhua: limits, tolerance and optima. Marine Ecology Progress Series 420: 1-13. Feature article.

Svedäng, H., André, C., Jonsson, P., Elfman, M. & Limburg, K. 2010. Homing behaviour and otolith chemistry suggest fine-scale sub-population structure within a genetically homogenous Atlantic cod population. Environmental Biology of Fishes 89: 383–397.

Svedäng, H., Stål, J., Sterner, T. & Cardinale, M. 2010. Subpopulation structure in cod (Gadus morhua) puts strain on the management toolbox. Reviews in Fisheries Science 18: 139–150.

Cardinale, M., Hagberg, J., Svedäng, H., Bartolino, V., Gedamke, T., Hjelm, J., Börjesson, P. & Norén, F. 2009. Fishing through time: population dynamics of plaice (Pleuronectes platessa) in the Kattegat-Skagerrak over a century. Population Ecology 52: 251–262.

Cardinale, M. & Svedäng, H. 2008. Mismanagement of fisheries: policy or science? Fisheries Research 93: 244–247.

Lilly, G.R., Wieland, K., Rothschild, B., Sundby, S., Drinkwater, K.,Brander, K., Ottersen, G., Budgell, P., Carscadden, J., Stenson, G., Chouinard, G., Swain, D., Daan, N., Enberg, K., Hammill, M., Aqqalu, R.-A., Svedäng, H., & Vázquez, A. 2008. Decline and recovery of Atlantic cod (Gadus morhua) stocks throughout the North Atlantic. Resiliency of Gadid Stocks to Fishing and Climate Change pp. 39-66. Alaska Sea Grant College Program, AK-Sg-08-01, 2008.

Vitale, F., Börjesson, P., Svedäng, H. & Casini, M. 2008. The spatial distribution of cod (Gadus morhua L.) spawning grounds in the Kattegat, eastern North Sea. Fisheries Research 90: 36-44. doi: 10.1016/j.fishres.2007.09.02

Cardinale, M. & Svedäng, H. 2008. To have a fling on the ling. Fisheries Research 89: 305–306. doi:10.1016/j.fishres.2007.09.033

Svedäng, H., Righton, D. & Jonsson, P. 2007a. Migratory behaviour of Atlantic cod Gadus morhua: natal homing is the prime stock-separating mechanism. Marine Ecology Progress Series 345: 1-12. Feature article.

Svedäng, H., Righton, D. & Jonsson, P. 2007b. Defining ‘natal homing’ in marine fish populations; need for inference in fishery science: reply to Bradbury & Laurel (2007). Marine Ecology Progress Series 347: 309-310.

Westerberg, H., Lagenfelt, I., & Svedäng, H. 2007. Silver eel migration in the Baltic. ICES Journal of Marine Science 64: 1457-1462.

van der Kooij1, J, Righton, D., Strand, E., Michalsen, K., Thorsteinsson, W., Svedäng, H., Neat, F. & Neuenfeldt, S. 2007. Life under pressure: insights from electronic data-storage tags into cod swimbladder function. ICES Journal of Marine Science 64: 1293-1301.