al ▁factors , ▁such ▁as ▁pred ator ▁avoid ance ▁are ▁also ▁important . ▁F resh water ▁inputs ▁play ▁a ▁key ▁role ▁in ▁mer op l ank ton ▁species ▁composition ▁in ▁est u ar ine ▁environments . ▁Effect s ▁of ▁t ides ▁contribute ▁greatly ▁to ▁mer op l ank ton ▁species ▁distribution . ▁One ▁study ▁conducted ▁in ▁a ▁Pat agon ian ▁F j ord ▁found ▁that ▁species ▁composition ▁of ▁the ▁mer op l ank ton ▁community ▁dep ended ▁on ▁the ▁season ally ▁varying ▁input ▁levels ▁from ▁the ▁Baker ▁river ▁as ▁well ▁as ▁vertical ▁and ▁horizontal ▁strat ification ▁of ▁the ▁water ▁column . ▁Events ▁such ▁as ▁wind ▁driven ▁up well ing ▁and ▁down well ing ▁also ▁affect ▁mer op l ank ton ▁species ▁distribution . ▁Most ▁species ▁are ▁swe pt ▁in ▁the ▁direction ▁of ▁the ▁flow ▁of ▁water , ▁either ▁off ▁shore ▁during ▁an ▁up well ing ▁or ▁near ▁shore ▁during ▁a ▁down well ing . ▁Some ▁species , ▁such ▁as ▁b ival ve ▁lar va e , ▁have ▁the ▁ability ▁to ▁maintain ▁their ▁near sh ore ▁position ▁during ▁these ▁events . ▁ ▁Dis pers al ▁Sur v ival ▁rate ▁of ▁Mer op l ank ton ▁is ▁critical ▁to ▁successful ▁development ▁of ▁adult ▁organ isms . ▁Low ▁surv ival ▁rates ▁of ▁mer op l ank ton ▁will ▁result ▁in ▁reduction ▁in ▁adult ▁population ▁numbers . ▁One ▁factor ▁which ▁often ▁determ ines ▁mer op l ank ton ▁surv ival ▁is ▁lar val ▁dispers al . ▁Most ▁species ▁within ▁the ▁mer op l ank ton ▁community ▁rely