Consulta: creatorFacets:"Kempf, Alexander"
Registros recuperados: 5
Data/hora: 26/07/2024 22:47:20

Achieving maximum sustainable yield in mixed fisheries: a management approach for the North Sea demersal fisheries
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan-jaap; Rindorf, Anna.
Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example of an issue that is generic across most demersal fisheries worldwide, with the diversity of species and fisheries inducing numerous biological and technical interactions. Building on a rich knowledge base for the understanding and quantification of these interactions, new approaches have emerged. Recent paths towards operationalizing MSY at the regional scale have suggested the expansion of the concept into a desirable area of “pretty good yield”, implemented...
Tipo: Text
Palavras-chave: Choke species; Common Fisheries Policy; Fleet modelling; FMSY ranges; Landing obligation; Management plan; Pretty good yield.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00347/45834/45922.pdf

Emergence of a new predator in the North Sea: evaluation of potential trophic impacts focused on hake, saithe, and Norway pout
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cormon, Xochitl; Kempf, Alexander; Vermard, Youen; Vinther, Morten; Marchal, Paul.
During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direct impacts may affect forage fish through modified predator–prey interactions, and indirect impacts may materialize through competition with other resident predators. For instance, North Sea saithe (Pollachius virens) spatial overlap with hake has increased while saithe spawning-stock biomass has decreased recently notwithstanding a sustainable exploitation. In this context, we investigated the range of potential impacts resulting from most recent hake emergence in...
Tipo: Text
Palavras-chave: Hake; Interspecific competition; Maximum sustainable yield; Multispecies stock assessment; Norway pout; Predator-prey interactions; Saithe; Simple foodweb; SMS.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00327/43794/45917.pdf

Inclusion of ecological, economic, social, and institutional considerations when setting targets and limits for multispecies fisheries
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rindorf, Anna; Dichmont, Catherine M.; Thorson, James; Charles, Anthony; Clausen, Lotte Worsoe; Degnbol, Poul; Garcia, Dorleta; Hintzen, Niels T.; Kempf, Alexander; Levin, Phillip; Mace, Pamela; Maravelias, Christos; Minto, Coilin; Mumford, John; Pascoe, Sean; Prellezo, Raul; Punt, Andre E.; Reid, David G.; Roeckmann, Christine; Stephenson, Robert L.; Thebaud, Olivier; Tserpes, George; Voss, Ruediger.
Targets and limits for long-term management are used in fisheries advice to operationalize the way management reflects societal priorities on ecological, economic, social and institutional aspects. This study reflects on the available published literature as well as new research presented at the international ICES/Myfish symposium on targets and limits for long term fisheries management. We examine the inclusion of ecological, economic, social and institutional objectives in fisheries management, with the aim of progressing towards including all four objectives when setting management targets or limits, or both, for multispecies fisheries. The topics covered include ecological, economic, social and governance objectives in fisheries management, consistent...
Tipo: Text
Palavras-chave: Ecosystem-based fisheries management; Multiple objectives; Reference points; Sustainability; Variability.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00381/49262/49838.pdf

North Sea saithe Pollachius virens growth in relation to food availability, density dependence and temperature
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cormon, Xochitl; Ernande, Bruno; Kempf, Alexander; Vermard, Youen; Marchal, Paul.
North Sea saithe Pollachius virens, a major top predator in the area, supports the fishery economy of several European countries. However, recent stock assessments suggested a decrease in spawning stock biomass along with a decline in saithe mean weight-at-ages. In this context, we investigated North Sea saithe growth characteristics at the population level. First, saithe annual weight increments and age-length relationships were studied. Modelling of saithe age-length relationships was carried out using (1) the traditional von Bertalanffy growth function model, (2) the Verhulst logistic model and (3) an empirical linear model. Second, the effects of environmental factors on saithe growth were investigated. Explanatory environmental factors included food...
Tipo: Text
Palavras-chave: Bottom-up processes; Von Bertalanffy growth function; Logistic growth; Norway pout; Prey availability effects; Density-dependence; Predator-prey interactions; Resource limitation; Competition.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00314/42499/41875.pdf

Projecting changes in the distribution and productivity of living marine resources: A critical review of the suite of modeling approaches used in the large European project VECTORS
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Peck, Myron A.; Arvanitidis, Christos; Butenschon, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahevas, Stephanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sebastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-trolet, Morgane; Van De Wolfshaar, Karen E.
We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by...
Tipo: Text
Palavras-chave: Distribution; Modelling; Habitat; Resources; Man-induced effects.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00337/44845/44436.pdf