PhD defense: International fisheries management under changing climate

On Friday 9 November 2012 Xiaozi Liu will hold a trial lecture on a prescribed topic, and defend her thesis for the PhD degree at NHH.

02.11.2012 - Hallvard Lyssand

Ocean temperatures are rising due to climate change, e.g., mean annual surface temperatures in the North Sea are predicted to increase by 1.0--2.5°C by 2050. This has a range of impacts, one of which is fish stocks moving northwards. For example, in 2012 northeast Arctic cod was recorded further north than ever before.

Almost all fish stocks that are commercially important in Norway are currently shared based on semi-permanent agreements, which typically assume a static fish distribution. The changing stock distribution may lead to a breach of existing agreements, hence imposes risks of stock depletion.

This thesis composes of four papers on fisheries economics. Liu first elaborates on the strategic behaviours under dynamic stock distribution. This theoretical study suggests that the distributional shift changes the most prominent feature of a non-cooperative harvesting game under static distribution, namely that the major player is more conservation oriented than the minor player.

The thesis proceeds with an empirical study focusing on the distribution-dependent sharing rule. The finding confirms that a minor owner behaves more responsibly in a dynamic environment. Unit effort cost is a key parameter in determining how the joint benefits should be allocated, and the degree of cost asymmetry affects positively the stability of the grand coalition.

The other topic this thesis tackles is about the problem of managing multiple species. Effort regulation has been advocated for being more effective than catch quota in managing mixed-species fisheries. By studying the interactions among fishers, fish and the market, Liu concludes that effort regulation alone is not sufficient to save less abundant species.

All papers in the thesis emphasize the importance of spatial heterogeneity; that is accounting for fish schooling behaviours and variation of fish density in different zones. This has enabled the thesis to bring more biological realism into economic decision model.

Xiaozi Liu (b. 1973) is from Zhejiang in China. She has her education from Sun Yat-sen University, China and Lund University, Sweden. She has been a PhD student at The Department of Finance and Management Science, NHH.

Prescribed topic for the trial lecture:
Lessons from game theory for management of shared fish stocks

Time of the trial lecture:
10:15-11:00, Karl Borch's Auditorium, NHH

Title of the thesis:
Essays on economic optimization: bridging fisheries economics and fisheries biology.

Time and place for the defense:
12:15 in Karl Borch's Auditorium, NHH

Supervisors:
Professor, Leif Kristoffer Sandal, NHH (hovedveileder)
Professor Stein Ivar Steinshamn, NHH
Professor Gunnar Eskeland, NHH

Evaluation committee:
Professor Rögnvaldur Hannesson, NHH (chairperson)
Professor Claire Armstrong, University of Tromsø
Assistant Professor Linda Nøstbakken, University of Alberta