( ( In ( warmer ( water areas ) ) ) ( ( these ( low-oxygen zones ) ) ( often ( ( ( ( ( start ( 200 meters ) ) ( below ( the surface ) ) ) and ) ( ( extend ( in ( the ( water column ) ) ) ) ( down ( to ( ( about 1,000 ) meters ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (JJR warmer) (NN water) (NNS areas))) (NP (DT these) (JJ low-oxygen) (NNS zones)) (ADVP (RB often)) (VP (VP (VB start) (NP (CD 200) (NNS meters)) (PP (IN below) (NP (DT the) (NN surface)))) (CC and) (VP (VB extend) (PP (IN in) (NP (DT the) (NN water) (NN column))) (ADVP (RB down) (PP (TO to) (NP (QP (RB about) (CD 1,000)) (NNS meters)))))) (. .)))
In warmer water areas these low-oxygen zones often start 200 meters below the surface and extend in the water column down to about 1,000 meters.
(ROOT (S (NP (DT The) (JJ photic) (NN zone)) (VP (VBZ extends) (ADJP (NP (CD 200) (NNS meters)) (JJ deep))) (. .)))
The photic zone extends 200 meters deep.