PHYTOPLANKTON-ZOOPLANKTON RELATIONSHIP IN THE NERiTIC WATER OFFALEXANDRL4

PHYTOPLANKTON-ZOOPLANKTON RELATIONSHIP IN THE

NERiTIC WATER OFFALEXANDRL4

y
SAMTA K MIKHAIL *
*National Institute ojOceanography & Fisheries. Alexandria (Egypt)
Key words: Phytoplankton-zooplankton relationship, Alexandria
ABSTRACT
PI,,-vtoplankron and zooplankton quantizatfl’e and qualizath’e
estimations are continuously variable in the ewrophic neritic ll’QTerS
off Alexandria Their relationship apparently was under /11ullijactorial control llflh remperature, salinir)’ being rhe mosr important
factors. phosphate and grazing at times Three different patterns oj
co-e:risrence of phyro-zooplankton were distingUished The POSili\’e
top-hollom relarionship was obser.ed at inlennirrent periods dW7ng
rhe dtfferenr seasons. and ll’ith diaram predominance. n,e negatil’e
op-bo{{om partem seems to be strongly inj/uenced by spectfrc
phJ’roplan/aon community SrrllCfllre and or diatom composition. The
parai/eleJ increasing phyto-::ooplank1on pallern occurred at rimes.
ll’irh lasr growing diaram ::,pecies. Zooplankton gra::ing pressure
afftcts the relaril’e abundance oj Ihe phytoplan/aon com/11unit)’
srl1lc!ure and species composilion. offering some adl’Qntage ro nondiatom species /0 dominate. Meaml’hz!e. reduced grazing has been
implicated as p17lnmy phytoplankton bloom Digger.