▁P onds . ▁ ▁Po pp on ess et ▁Bay ▁has ▁experienced ▁problems ▁with ▁e ut roph ic ation ▁from ▁high ▁nit ro gen ▁loads ▁in ▁the ▁ground water ▁and ▁run off ▁from ▁the ▁waters h eds . ▁ ▁The ▁present ▁bay ▁results ▁from ▁tid al ▁flo oding ▁of ▁d rown ed ▁river ▁valle ys ▁formed ▁primarily ▁by ▁the ▁M ash pe e ▁and ▁Sant uit ▁R ivers ▁as ▁a ▁result ▁of ▁a ▁ris en ▁sea ▁level . ▁The ▁Bay ▁is ▁separated ▁from ▁N ant uck et ▁Sound ▁by ▁Po pp on ess et ▁Pen ins ula , ▁a ▁bar rier ▁sp it ▁which ▁extends ▁from ▁the ▁south western ▁shore ▁and ▁is ▁mostly ▁occupied ▁by ▁Po pp on ess et ▁Beach . ▁Po pp on ess et ▁Beach ▁is ▁known ▁to ▁the ▁loc als ▁as ▁simply ▁" The ▁Sp it ." ▁ ▁Po pp on ess et ▁Bay ▁has ▁a ▁second ▁beach ▁in ▁the ▁form ▁of ▁a ▁sand ▁bar ▁in ▁the ▁middle ▁of ▁the ▁bay , ▁which ▁is ▁subm ers ed ▁during ▁high ▁t ide . ▁This ▁island ▁is ▁known ▁as ▁Low ▁T ide ▁Island . ▁ ▁The ▁bay ▁ex changes ▁tid al ▁water ▁with ▁N ant uck et ▁Sound ▁through ▁a ▁single ▁maintained ▁in let . ▁The ▁shore ▁to ▁the ▁north ▁of ▁the ▁in let ▁has ▁been ▁stabil ized ▁with ▁rip rap ▁as ▁has ▁the ▁heavily ▁resident ial ▁southern ▁portion ▁of ▁Po pp on ess et ▁Beach . ▁The ▁current ▁sp it ▁is ▁significantly ▁shorter ▁than ▁seen ▁in ▁the ▁ 1 8