▁an atom ists <0x0A> </s> ▁The ▁Crist ina ▁Island ▁mar sh es ▁( Mar ism as ▁de ▁Is la ▁Crist ina ) ▁are ▁located ▁at ▁the ▁mouth ▁of ▁the ▁river ▁Car rer as ▁in ▁the ▁province ▁of ▁H uel va , ▁And alus ia , ▁in ▁southern ▁Spain . ▁Cre ated ▁in ▁ 1 9 8 9 ▁( L aw ▁ 2 / 8 9 ▁of ▁the ▁invent ory ▁of ▁the ▁Prote cted ▁Natural ▁Sp aces ▁of ▁And alus ia ), ▁the ▁natural ▁park ▁has ▁a ▁surface ▁area ▁of ▁, ▁shared ▁between ▁the ▁municipal ities ▁of ▁Ay am onte ▁and ▁Is la ▁Crist ina . ▁ ▁Str ucture ▁▁ ▁The ▁mar sh es ▁are ▁shared ▁between ▁the ▁municipal ities ▁of ▁Is la ▁Crist ina ▁for ▁ ▁and ▁Ay am onte ▁for ▁some ▁. ▁ ▁Marsh es ▁in ▁general ▁are ▁hum id ▁areas , ▁low - lying , ▁sw amp y ▁terra ins ▁that ▁are ▁flo oded ▁by ▁sea ▁water ▁during ▁high ▁t ide . ▁They ▁usually ▁lay ▁in ▁est u aries ▁areas , ▁such ▁as ▁here . ▁ ▁The ▁tid al ▁dependence ▁of ▁these ▁e cos ystem s ▁gives ▁them ▁an ▁almost ▁total ▁absence ▁of ▁season ality . ▁From ▁the ▁landscape ▁point ▁of ▁view ▁one ▁can ▁differenti ate ▁between ▁the ▁mar sh es , ▁those ▁areas ▁in ▁which ▁man ' s ▁inter vention ▁has ▁transformed ▁the ▁e cos ystem ▁for ▁its ▁own ▁use ▁and ▁the ▁other ▁better ▁preserved ▁areas . ▁ ▁Where ▁the ▁mar sh es ▁have ▁been ▁transformed , ▁among ▁others ▁for