aging , ▁leading ▁to ▁dist urban ces ▁in ▁the ▁e cos ystem ▁and ▁food ▁chain . ▁Organ ic ▁materials ▁naturally ▁found ▁on ▁be aches , ▁also ▁known ▁as ▁wra ck , ▁provide ▁critical ▁nut ri ents ▁and ▁compose ▁the ▁foundation ▁of ▁the ▁food ▁chain . ▁The ▁elim ination ▁of ▁this ▁food ▁source ▁impact s ▁organ isms ▁r anging ▁from ▁me io fa una ▁to ▁pred ator ▁birds , ▁resulting ▁in ▁a ▁loss ▁of ▁b iod iversity ▁and ▁a ▁decrease ▁in ▁species ▁abund ance . ▁For ▁example , ▁D ug an ▁et ▁al . ▁studied ▁the ▁relationship ▁between ▁wra ck ▁abund ance ▁and ▁the ▁rich ness , ▁abund ance , ▁and ▁bi om ass ▁of ▁macro fa una ▁of ▁fifteen ▁sand y ▁be aches ▁in ▁Southern ▁California ▁and ▁found ▁that ▁ung room ed ▁be aches ▁with ▁relatively ▁low ▁levels ▁of ▁wra ck ▁had ▁a ▁mean ▁abund ance ▁of ▁macro fa una ▁that ▁th rive ▁in ▁the ▁presence ▁of ▁wra ck ▁that ▁was ▁almost ▁nine ▁times ▁greater ▁than ▁gro omed ▁be aches . ▁Additionally , ▁ung room ed ▁be aches ▁with ▁relatively ▁large ▁amounts ▁of ▁wra ck ▁supported ▁more ▁than ▁th ir teen ▁species ▁of ▁macro fa una ▁that ▁live ▁in ▁and ▁around ▁wra ck ▁while ▁gro omed ▁be aches ▁supported ▁less ▁than ▁three . ▁Furthermore , ▁the ▁presence ▁of ▁two ▁shore bird s ▁was ▁posit ively ▁correl ated ▁with ▁the ▁presence ▁of ▁wra ck - associ ated ▁macro fa una , ▁indicating ▁that ▁be aches ▁with ▁more ▁extensive ▁wra ck ▁cover ▁support ▁verte br