Achieving a more sustainable skates and rays stock management in the Greater North Sea by analysing age determination methods, length frequency discard surveydata, and current management of Raja brachyura and Raja clavata
the analysis of growth bands in vertebrae and length measurements ofdiscard survey catch data from central and southern North Sea (division 4.band 4.c) of Raja brachyura and Raja clavataAchieving a more sustainable skates and rays stock management in the Greater North Sea by analysing age determination methods, length frequency discard surveydata, and current management of Raja brachyura and Raja clavata
the analysis of growth bands in vertebrae and length measurements ofdiscard survey catch data from central and southern North Sea (division 4.band 4.c) of Raja brachyura and Raja clavataSamenvatting
The species blonde ray (Raja brachyura) and thornback ray (Raja clavata) have been selected for the 2.1 InnoRays project, to get more insight about the status of these stocks in the Greater North Sea. Unstained and stained age determination methods were tested and LFQ data analysis are conducted for Raja brachyura and Raja clavata samples to determine the age. The age determination method was done on the individuals that were labeled for the DNA-research of the 2.1 InnoRays project. The sampling was carried out on the 1st of October and consisted of 36 Raja brachyura and 120 Raja clavata. Unstained and stained sagittal sections images were obtained from individual vertebra and have been analyzed for visible growth bands to determine the age of the individuals. The main results was, that tested age determination methods cannot be used for age determination of the species.
Organisatie | Van Hall Larenstein |
Afdeling | Kust en Zee Management |
Partner | Wageningen University & Research |
Datum | 2019-04-03 |
Type | Bachelor |
Taal | Engels |