( ( If ( ( such ( flow obstructions ) ) ( result ( in ( ( odor ( plume characteristics ) ) ( which ( interfere ( with ( mate ( ( finding or ) predation ) ) ) ) ) ) ) ) ) ) ( , ( ( ( then ( the presence ) ) ( of ( such obstructions ) ) ) ( ( may ( help ( to ( explain ( ( habitat preferences ) ( exhibited ( by ( many ( marine animals ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (JJ such) (NN flow) (NNS obstructions)) (VP (VBP result) (PP (IN in) (NP (NP (NN odor) (NN plume) (NNS characteristics)) (SBAR (WHNP (WDT which)) (S (VP (VBP interfere) (PP (IN with) (NP (NN mate) (NN finding) (CC or) (NN predation))))))))))) (, ,) (NP (NP (RB then) (DT the) (NN presence)) (PP (IN of) (NP (JJ such) (NNS obstructions)))) (VP (MD may) (VP (VB help) (S (VP (TO to) (VP (VB explain) (NP (NP (NN habitat) (NNS preferences)) (VP (VBN exhibited) (PP (IN by) (NP (JJ many) (JJ marine) (NNS animals)))))))))) (. .)))
If such flow obstructions result in odor plume characteristics which interfere with mate finding or predation, then the presence of such obstructions  may help to explain habitat preferences exhibited by many marine animals.
(ROOT (S (NP (JJ Strong) (NN odor)) (VP (VBZ helps) (S (NP (DT some) (NNS animals)) (VP (VB defend) (NP (PRP themselves)) (PP (IN against) (NP (NNS predators)))))) (. .)))
Strong odor helps some animals defend themselves against predators.