off ▁of ▁the ▁contin ental ▁sh elf , ▁approximately ▁ ▁in ▁depth . ▁From ▁the ▁point ▁of ▁view ▁of ▁marine ▁bi ology ▁it ▁forms ▁a ▁relatively ▁stable ▁and ▁well - ill umin ated ▁environment ▁for ▁marine ▁life , ▁from ▁pl ank ton ▁up ▁to ▁large ▁fish ▁and ▁cor als , ▁while ▁physical ▁ocean ography ▁sees ▁it ▁as ▁where ▁the ▁ocean ic ▁system ▁interact s ▁with ▁the ▁coast . ▁ ▁Definition ▁( marine ▁bi ology ), ▁context , ▁extra ▁termin ology ▁ ▁In ▁marine ▁bi ology , ▁the ▁ner it ic ▁zone , ▁also ▁called ▁coast al ▁waters , ▁the ▁coast al ▁ocean ▁or ▁the ▁sub l itt oral ▁zone , ▁refers ▁to ▁that ▁zone ▁of ▁the ▁ocean ▁where ▁sun light ▁reaches ▁the ▁ocean ▁floor , ▁that ▁is , ▁where ▁the ▁water ▁is ▁never ▁so ▁deep ▁as ▁to ▁take ▁it ▁out ▁of ▁the ▁phot ic ▁zone . ▁ ▁It ▁extends ▁from ▁the ▁low ▁t ide ▁mark ▁to ▁the ▁edge ▁of ▁the ▁contin ental ▁sh elf , ▁with ▁a ▁relatively ▁shall ow ▁depth ▁extending ▁to ▁about ▁ 2 0 0 ▁meters ▁( 6 6 0 ▁feet ). ▁A bove ▁the ▁ner it ic ▁zone ▁lie ▁the ▁inter tid al ▁( or ▁e ul itt oral ) ▁and ▁su pr al itt oral ▁zones ; ▁below ▁it ▁the ▁contin ental ▁slope ▁begins , ▁desc ending ▁from ▁the ▁contin ental ▁sh elf ▁to ▁the ▁aby ss al ▁plain ▁and ▁the ▁pel ag ic ▁zone . ▁ ▁Within ▁the ▁ner it ic , ▁marine ▁bi olog ists ▁also