Testing for correlation of the spatial distribution between plankton (zooplankton and phytoplankton) and selected parameters

Abstract

Abstract by author:

The correlation of the spatial distribution between plankton (zooplankton and phytoplankton) and selected parameters were investigated in the southern Benguela on the line 23° South of the Namibian coast. Upwelling along the west coast results in large, abundant phytoplankton inshore and decreasing offshore. Zooplankton abundance is affected by both the phytoplankton and the physical environment, and hence also decreases in size and abundance offshore to the front. Namibian monitoring for physical parameters and plankton is carried out on a monthly basis along this 23° S latitude line. The line was therefore selected so that the meteorological results can be compared with the equivalent Namibian long-term data from this line. Zooplankton abundance was high at the inshore and midshore regions but very low in the offshore region (60 - 70 nm). Eggs and nauplii (mainly from euphausiids) were found in the 2 to 10 nm region. Gelatinous zooplanktons were also more abundant in this area. The concentration of chlorophyll-a was high inshore, especially between 9 and 10nm station with values up to 9ug/l. However, overall, chlorophyll-a concentrations over the entire shelf were very low. Fluorometer readings indicate higher chlorophyll-a concentrations for the inshore stations (5nm-10nm) and values ranged between 1600*10 3 um 3/ml and 1000*10 3 um3 /ml. In comparison, the offshore stations (30-70nm) had values of less than 600*10 um3/ml