(S (S (NP (BASENP (NN Research)) (PP (IN by) (NP (BASENP (DT a) (NN team)) (PP (IN from) (BASENP (NNP Canada)))))) (VP (VBP have) (VP (VP (VP (VBN published) (BASENP (DT a) (NN report))) (PP (IN in) (BASENP (DT the) (NN magazine) (NNP Science)))) (S (VP (VBG stating) (SBAR (IN that) (S (BASENP (NNS seabirds)) (VP (VBP are) (NP (BASENP (DT the) (JJ main) (NNS carriers)) (PP (IN of) (NP (BASENP (NN pollution)) (PP (IN in) (NP (BASENP (JJ coastal) (NNS ponds)) (PP (IN in) (BASENP (DT the) (NNP Arctic)))))))))))))))) (PERIOD .))