|
|
|
|
|
Hoffle, Hannes; Van Damme, Cindy J. G.; Fox, Clive; Lelievre, Stephanie; Loots, Christophe; Nash, Richard D. M.; Vaz, Sandrine; Wright, Peter J.; Munk, Peter. |
Previous studies have shown that four commercially important demersal species, namely cod (Gadus morhua), haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus) and plaice (Pleuronectes platessa) spawn in distinct areas across the North Sea. Based on two comprehensive ichthyoplankton surveys in 2004 and 2009, the present study uses Generalized Additive Mixed Models (GAMMs) to delimit these spawning grounds using the distribution of recently spawned eggs, investigates their relationship to specific environmental conditions and examines egg dispersal during their development. Results indicate that presence/absence of early stage eggs is more related to temporal and topographic variables, while egg densities are closely linked with hydrography.... |
Tipo: Text |
|
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00385/49641/50157.pdf |
| |
|
|
Dickey-collas, Mark; Payne, Mark R.; Trenkel, Verena M.; Nash, Richard D. M.. |
The use of modelling approaches in marine science, and in particular fisheries science, is explored. We highlight that the choice of model used for an analysis should account for the question being posed or the context of the management problem. We examine a model-classification scheme based on Richard Levins' 1966 work suggesting that models can only achieve two of three desirable model attributes: realism, precision, and generality. Model creation, therefore, requires trading-off of one of these attributes in favour of the other two: however, this is often in conflict with the desires of end-users (i.e. mangers or policy developers). The combination of attributes leads to models that are considered to have empirical, mechanistic, or analytical... |
Tipo: Text |
Palavras-chave: Climate; Fisheries; GAM; Management; Prediction; Projection; Recruitment; Time-series analysis. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00222/33371/32179.pdf |
| |
|
|
Dickey-collas, Mark; Mcquatters-gollop, Abigail; Bresnan, Eileen; Kraberg, Alexandra C.; Manderson, John P.; Nash, Richard D. M.; Otto, Saskia A.; Sell, Anne F.; Tweddle, Jacqueline F.; Trenkel, Verena. |
Marine environmental legislation is increasingly expressing a need to consider the quality of pelagic habitats. This paper uses the European Union marine strategy framework to explore the concept of good environmental status (GES) of pelagic habitat with the aim to build a wider understanding of the issue. Pelagic ecosystems have static, persistent and ephemeral features, with manageable human activities primarily impacting the persistent features. The paper explores defining the meaning of "good", setting boundaries to assess pelagic habitat and the challenges of considering habitat biodiversity in a moving medium. It concludes that for pelagic habitats to be in GES and able to provide goods and services to humans, three conditions should be met: (i) all... |
Tipo: Text |
Palavras-chave: Marine strategy framework directive; MPA; Pelagic habitats; Plankton; Seascape. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00414/52596/53551.pdf |
| |
|
|
|