EVIDENCE OF BENTHIC PELAGIC COUPLING AT A STATION OFF THE NORTHUMBERLAND COAST

The total numbers of benthic individuals and the numbers of a suite of dominant species are considered in conjunction with year-to-year variability of phytoplankton abundance as measured by the Continuous Plankton Recorder net colour index over the 20 years 1973-1982. Taking net colour as the independent variable in regression analyses, it has been established that phytoplankton abundance can explain between 55 and 84% of year-to-year variance in numbers of benthic species, after allowing an apparent 2-year lapse between change in phytoplankton and change in numbers. It is argued that one of the two years of the time-lapse is more apparent than real and is dependent on the timing of the sampling of the benthos in March of each year, whereas the phytoplankton index is calculated from the whole year. A 1-year time-lapse would seem more realistic.