Browsing Bergen Open Research Archive by Author "Zimmermann, Fabian"
Now showing items 1-10 of 10
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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 ... -
Considerations for management strategy evaluation for small pelagic fishes
Siple, Margaret; Koehn, Laura; Johnson, Kelli F; Punt, André E.; Canales, T. Mariella; Carpi, Piera; de Moor, Carryn L.; De Oliveira, José A.A.; Gao, Jin; Jacobsen, Nis S.; Lam, Mimi Elizabeth; Licandeo, Roberto; Lindgren, Martin; Ma, Shuyang; Óskarsson, Gudmundur Jóhann; Sanchez-Maroño, Sonia; Smolinski, Szymon; Surma, Szymon; Tian, Yongjun; Tommasi, Desiree; Gutierrez T., Mariano; Trenkel, Verena; Zador, Stephani; Zimmermann, Fabian (Journal article; Peer reviewed, 2021)Management strategy evaluation (MSE) is the state-of-the-art approach for testing and comparing management strategies in a way that accounts for multiple sources of uncertainty (e.g. monitoring, estimation, and implementation). ... -
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 ... -
Environmental drivers of herring growth and how the perception shifts with time series length
Claireaux, Marion; Zimmermann, Fabian; Ernande, Bruno; Heino, Mikko Petteri; Enberg, Katja (Journal article; Peer reviewed, 2022)Growth is a key component of population dynamics and, thus, fisheries management, yet drivers of its variations are often poorly understood. Using individual data collected over 80 years, we explored how environmental ... -
Pre-catch and discard mortality in Northeast Atlantic herring and mackerel fisheries: consequences for stock estimates and advice
Tenningen, Maria; Zimmermann, Fabian; Enberg, Katja (Journal article; Peer reviewed, 2021)Unaccounted mortality caused by discarding or pre-catch losses is a major challenge for fisheries management. In pelagic fisheries, a considerable proportion of catches may be lost due to intentional release of unwanted ... -
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 ...