Ecological evidence from live–dead comparisons of benthic foraminiferal faunas off Cape Blanc (Northwest Africa)

A comparison of live and dead benthic foraminiferal faunas in a five-station sample transect off Cape Blanc suggests that interspecific differences in living/dead (L/D) ratios are to a large extent determined by seasonal differences in reproduction. It is proposed that many epifaunal and superficial infaunal species show a highly opportunistic behaviour, with a majority of the foraminifera being produced in a relatively short period of the year. The density of deeper infaunal taxa, on the contrary, would be much more stable over time. Sites with large contrasts in L/D ratios between deep/intermediate infaunal and epifaunal/shallow infaunal taxa should be subject to important seasonal variations in the downward flux of organic matter. This study suggests that important ecological information can be gained from live–dead comparisons.