Determination of Plaice Lifetime Movements in the North Sea by Linking Natural and electronic data records (PLAICELIFELINE)

Background

Previously otolith studies have provided exceptionally accurate age data, now recent studies have shown that it is also possible to determine the environment in which a fish has lived by the chemical signals laid down in the otoliths (ear stones) as the fish grows.

 The project studied the data collected from 80 Data Storage Tag (DST)-tagged plaice (Pleuronectes platessa) in the North Sea.  Using Cefas’ newly developed DST it is possible to record a fish’s movement over a period of time and combine these with new techniques in chemical analysis of the otoliths.  The project allowed the migrations of the plaice to be observed in a much greater resolution, previously not possible.

Objectives

• Trace element analysis of juvenile plaice otoliths from known nursery areas using the Cefas state of the art micromill and oxygen isotope analysis.
• Otolith examination of aquarium-grown plaice and DST-tagged plaice
• Identification of the migratory patterns of the DST-tagged plaice and determination of their time and source of recruitment.

Policy development

The project has developed new methods for reading otoliths of commercially exploited fish and greatly improved the methods used in migration studies and modelling and will therefore feed directly into management advice designed to promote sustainability, thereby contributing to the social and economic well-being of the EU’s fishing regions.

In addition the project, as an intra-European fellowship allowed a proven researcher to refine and develop existing techniques to the forefront of the field.