[1] High concentrations of one species of Quinqueloculina within the Celtic Sea are interpreted as a seasonal indicator of strong vertical mixing in that water body.

In an experiment, trends in diversity, abundance and taxonomic composition of live foraminiferal assemblages were analyzed to replicate corer samples collected at the Porcupine Abyssal Plain over a thirteen-year period.

was virtually absent in multicore samples from 1989 to 1994, peaked in September 1996 (22%) when degraded phytodetritus was present on core surfaces, was less common in March 1997, and thereafter was relatively uncommon.

However, horizontally sliced box-core samples revealed that large specimens were more abundant in March 1997, and also were concentrated in deeper sediment layers, than in September 1996.

Overall, the abyssal time-series revealed decadal-scale changes among shallow-infaunal foraminifera, more or less coincident with changes in the megafauna, as well as indications of shorter-term events related to seasonally-pulsed phytodetrital inputs.