Distribution and abundance of sardine (Sardina pilchardus) eggs in the English Channel from Continuous Plankton Recorder sampling, 1958-1980

Continuous Plankton Recorder (CPR) samples from the English Channel and adajacent Celtic shelf, taken over the period 1958-1980, were analysed for sardine (Sardina pilchardus) eggs. Results showed the progression of sardine spawning along the English Channel from west to east from March to August and a return From cast to west from September to November. This corresponds with the two seasonal peaks of sardine egg abundance in the western Channel: We main summer peak being in May/June, with a smaller autumn peak in October/November. Long-term changes in sardine egg abundance in CPR samples showed a decline in summer spawning from the late 1960s, but no clear trend in autumn-spawned egg abundance. Similar patterns were observed in the numbers of sardine eggs sampled by conventional plankton net tows at be time-series Station L5 off Plymouth. This supports the use of the longer time-series or sardine egg data at L5 as being representative of a wider area and emphasizes the importance in continuation of the L5 time-series.