( ( ( ( ( Reducing ( organic pollution ) ) ( from ( sewage ( treatment plants ) ) ) ) ( has ( ( increased ( dissolved oxygen ) ) ( in ( many ( of ( ( the ( Region 's ) ) surface ) ) ) ) ) ) ) ( ( waters , ) ( ( a factor ) ( that ( has ( contributed ( to ( healthier ecosystems ) ) ) ) ) ) ) ) . )
(ROOT (SINV (VP (VBG Reducing) (NP (JJ organic) (NN pollution)) (PP (IN from) (NP (NN sewage) (NN treatment) (NNS plants)))) (VP (VBZ has) (VP (VBN increased) (NP (JJ dissolved) (NN oxygen)) (PP (IN in) (NP (NP (JJ many)) (PP (IN of) (NP (NP (DT the) (NNP Region) (POS 's)) (NN surface))))))) (NP (NP (NNS waters)) (, ,) (NP (NP (DT a) (NN factor)) (SBAR (WHNP (WDT that)) (S (VP (VBZ has) (VP (VBN contributed) (PP (TO to) (NP (JJ healthier) (NNS ecosystems))))))))) (. .)))
Reducing organic pollution from sewage treatment plants has increased dissolved oxygen in many of the Region's surface waters, a factor that has contributed to healthier ecosystems.
(ROOT (S (NP (NNS Plants)) (VP (CONJP (RB not) (JJ only)) (VP (VBP contribute) (NP (NN food))) (CC but) (VP (VBD oxygen) (PP (IN for) (NP (NNS organisms))))) (. .)))