SGS Product & Process Certification - Marine Stewardship Council

1. THE ASSESSED FISHERY
2.1 Biology of the target species
Distribution
Sea bass are distributed in Northeast Atlantic shelf waters from southern Norway, through the
North Sea, Irish Sea, Celtic Sea, Bay of Biscay and Mediterranean, to Northwest Africa.
Tagging studies around England, Wales and Ireland (Pawson, Kelly and Pickett, 1987; Pawson
et al., 2007a), together with studies on geographical and seasonal patterns of feeding,
condition and gonad development (Pawson and Pickett, 1996), have demonstrated that adult
sea bass migrate between well-defined feeding areas and pre-spawning and spawning areas
which tend to be offshore to the south and west. First-year sea bass are found in estuaries and
harbours, and along the adjacent coastline, where the juveniles may remain for up to 5 years
before recruiting to the adult population.
Figure 1.Sea bass
Stock identity
Tagging and genetic studies indicate considerable mixing throughout the North-west European
bass population (Castilho & McAndrew, 1998; Naciri et al., 1999; Frisch et al., 2006; Pawson et
al, 2007a), and assessments of the dynamics of sea bass populations around the coasts of
England and Wales show common features regarding year-class strength over large parts of
the species‘ range (Pawson et al., 2007b). This suggests that the abundance of sea bass may
be controlled by large-scale environmental patterns. However, the assessment areas proposed
by ICES (2005), within which fishery and biological data could be used in assessments and for
which management advice may be given, are based on a consideration of both the current
patterns of seasonal movements of sea bass in the exploited populations (i.e., fish larger than
the 36 cm minimum landing size – MLS, total length used throughout), as indicated by tag
recaptures, and the characteristics of the fisheries taking them (Figure 2, Pawson et al.,
2007a). The bass population in the North Sea (ICES Divisions IVa,b,c) is considered to be a
single management unit, although there is some movement of both juvenile and adult sea bass
between the North Sea and the English Channel (see below). The main area of exploitation of
this ―stock‖ is in ICES Divisions IVc (southern North Sea) and VIId (eastern English Channel).
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