▁and ▁is ▁known ▁for ▁its ▁population ▁of ▁av oc ets ▁and ▁t ern s . ▁It ▁is ▁part ▁of ▁the ▁e colog ically ▁important ▁Al de - O re ▁Est u ary ▁and ▁has ▁protected ▁conservation ▁status ▁as ▁part ▁of ▁a ▁national ▁nature ▁reserve , ▁S SS I , ▁S AC , ▁S PA , ▁R ams ar ▁Site ▁and ▁is ▁also ▁a ▁part ▁of ▁the ▁Su ff olk ▁Coast ▁and ▁He ath s ▁A ON B . ▁ ▁The ▁island , ▁which ▁is ▁ ▁long ▁and ▁ ▁across ▁at ▁its ▁wid est ▁point ▁and ▁covers ▁, ▁lies ▁in ▁the ▁Ald er ▁and ▁O re ▁est u ary ▁and ▁is ▁protected ▁from ▁the ▁North ▁Sea ▁by ▁the ▁sh ing le ▁sp it ▁of ▁Or ford ▁N ess . ▁It ▁is ▁bounded ▁by ▁the ▁river ▁channels ▁known ▁locally ▁as ▁The ▁G ull , ▁Lower ▁G ull ▁and ▁The ▁N arrow s . ▁ ▁E col ogy ▁ ▁Ha ver gate ▁Island ▁compr ises ▁six ▁salt ▁water ▁l ago ons ▁covering ▁ 6 0 ▁hect ares , ▁surrounded ▁by ▁ear then ▁banks . ▁There ▁are ▁also ▁ 4 0 ▁hect ares ▁of ▁salt ▁mar sh ▁and ▁four ▁hect ares ▁of ▁veget ated ▁sh ing le . ▁There ▁are ▁also ▁areas ▁of ▁gra zing ▁mar sh ▁and ▁mud ▁fl ats , ▁and ▁the ▁site ▁provides ▁important ▁habitat ▁for ▁rare ▁g ull s , ▁w ading ▁birds ▁and ▁other ▁species . ▁ ▁The ▁island ▁is ▁an ▁important ▁bre eding , ▁ro ost ing ▁and ▁feed ing ▁site