, ▁e colog ical , ▁and ▁commercial ▁ext inction . ▁Most ▁large ▁marine ▁animal ▁species ▁still ▁exist , ▁such ▁that ▁the ▁size ▁distribution ▁of ▁global ▁species ▁ass embl ages ▁has ▁changed ▁little ▁since ▁the ▁Ple ist oc ene , ▁but ▁individuals ▁of ▁each ▁species ▁are ▁smaller ▁on ▁average , ▁and ▁over f ishing ▁has ▁caused ▁redu ctions ▁in ▁gen etic ▁divers ity . ▁Most ▁ext in ctions ▁and ▁population ▁decl ines ▁to ▁date ▁have ▁been ▁driven ▁by ▁human ▁over exp lo itation . ▁ ▁Con sequ ences ▁Marine ▁def a un ation ▁has ▁a ▁wide ▁array ▁of ▁effects ▁on ▁e cos ystem ▁structure ▁and ▁function . ▁The ▁loss ▁of ▁animals ▁can ▁have ▁both ▁top - down ▁( c asc ading ) ▁and ▁bottom - up ▁effects , ▁as ▁well ▁as ▁consequences ▁for ▁bi oge och em ical ▁cy cling ▁and ▁e cos ystem ▁stability . ▁ ▁Two ▁of ▁the ▁most ▁important ▁e cos ystem ▁services ▁threatened ▁by ▁marine ▁def a un ation ▁are ▁the ▁provision ▁of ▁food ▁and ▁coast al ▁storm ▁protection . ▁ ▁See ▁also ▁Anth rop oc ene ▁Anth rop oc entr ism ▁Bush me at ▁Hol oc ene ▁ext inction ▁Human ▁impact ▁on ▁the ▁environment ▁Human ▁over pop ulation ▁In sect ▁population ▁decl ine ▁ ▁References ▁ ▁Further ▁reading ▁ ▁External ▁links ▁ ▁Mong ob ay . com ▁: ▁Def a un ation , ▁like ▁def or est ation , ▁threat ens ▁global ▁b iod iversity : ▁Inter view ▁with ▁Rod ol fo ▁Dir zo ▁ ▁Category : E col