Sardine spawning off the European Atlantic coast: Characterization of and spatio-temporal variability in spawning habitat

摘要: Abstract Data on the occurrence of sardine (Sardina pilchardus) eggs from 42 national ichthyoplankton surveys along European Atlantic coast were collated in order to describe spawning habitat and distribution recent decades (1985–2005). A modification existing characterisation techniques a newly developed method compare probability egg presence across carried out with different sampling gears used. Results showed that off is mainly restricted shelf area, main geographical range being between Strait Gibraltar (the southern limit data available for this analysis) middle part Armorican (latitude around 47.5° North), temperature 12–17 °C. Spawning grounds within these limits show nearly continuous distribution, covering large proportion Iberian peninsula adjacent waters, except for: (1) persistent gap at north west corner peninsula, (2) small secondary break Spanish–French border inner Bay Biscay (3) south where there narrowing width. These discontinuities used separate into four nuclei changes time series. The relative importance each nucleus degree separation varies years, exception permanent northwest which throughout Year year potential actually occurred, changing 60% before mid 1990s 40% thereafter, did not any relationship stock biomass. Evolution occupation over shows larger variability than observed percentages ranging 30% up 80% years (within limitations relatively sparse region).