We presentastudyontheprotozooplankton 45 mm andcopepodslargerthan50 mm ataseriesof
contrastingstationsacrosstheSouthernIndianOcean(SIO).Numerically,over80%ofthecopepod
communityacrossthetransectwaslessthan650 mm insize,dominatedbynauplii,andsmaller
copepods,while80%ofthebiomass(asmgCm3) waslargerthan1300 mm inbodylength.Predation
by thecarnivorouscopepod Corycaeus sp. wasestimatedtobeabletoremoveupto2%d1 of the
copepods o1000 mm insize.Bythehelpofgrazingmodelsweestimatedthatprimaryproducerswere
mainly grazeduponbyciliatesandheterotrophicdinoflagellates(40–80%d1 combined)intemperate
waters butappendiculariansbecameincreasinglyimportantinthetropicalwatersgrazingabout40%of
the biomassperday.Despitetheirhighabundanceandbiomass,copepodscontributedlessthan20%of
the grazingatmoststations.Secondaryproductionwaslow(carbonspecificeggproduction
o0.14 d1) buttypicalforfoodlimitedoligotrophicoceans