Blar i Bergen Open Research Archive på forfatter "Zimmermann, Fabian"
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Bioeconomic consequences of fishing-induced evolution: a model predicts limited impact on net present value
Zimmermann, Fabian; Jørgensen, Christian (Peer reviewed; Journal article, 2015-04)Fishing reduces stock size and shifts demographics, and selective mortality may also lead to evolutionary changes. Previous studies suggest that traits may change evolutionarily because of fishing on decadal time scales. ... -
Can less be more? Effects of reduced frequency of surveys and stock assessments
Zimmermann, Fabian; Enberg, Katja (Peer reviewed; Journal article, 2016)Uncertain and inaccurate estimates are a prevailing problem in stock assessment, despite increasingly sophisticated estimation methods and substantial usage of scientific and financial resources. Annual scientific surveys ... -
Common trends in recruitment dynamics of north-east Atlantic fish stocks and their links to environment, ecology and management
Zimmermann, Fabian; Claireaux, Marion; Enberg, Katja (Peer reviewed; Journal article, 2019-03-13)Recruitment dynamics are challenging to assess or predict because of the many underlying drivers that vary in their relevance over time and space. Stock size, demographic and trait composition, condition and distribution ... -
Density regulation in Northeast Atlantic fish populations: Density dependence is stronger in recruitment than in somatic growth
Zimmermann, Fabian; Ricard, Daniel; Heino, Mikko Petteri (Peer reviewed; Journal article, 2018-05)Population regulation is a central concept in ecology, yet in many cases its presence and the underlying mechanisms are difficult to demonstrate. The current paradigm maintains that marine fish populations are predominantly ... -
Density-independent mortality at early life stages increases the probability of overlooking an underlying stock-recruitment relationship
Zimmermann, Fabian; Enberg, Katja; Mangel, Marc (Journal article; Peer reviewed, 2021)Abstract Beverton and Holt’s (1957) monograph contributed a widely used stock–recruitment relationship (BH-SRR) to fisheries science. However, because of variation around a presumed relationship between spawning biomass ... -
Does size matter? A bioeconomic perspective on optimal harvesting when price is size-dependent
Zimmermann, Fabian; Heino, Mikko; Steinshamn, Stein Ivar (Peer reviewed; Journal article, 2011-09-09)Body size is a key parameter influencing demographic characteristics of fish populations as well as market value of landed catch. Yet in bioeconomic modelling body size is often an overlooked biological and economic ... -
The value of size. Bioeconomic consequences of size-dependent pricing and fishing-induced evolution
Zimmermann, Fabian (Doctoral thesis, 2011-09-02)The influence of fishing on the dynamics of fish stocks is a core element in fisheries management. One of the most notable characteristics in this context is the sizestructure of a fish stock, composed by the individual ...