( ( ( primary consumers ) ( -LRB- ( ( herbivorous zooplankton ) -RRB- ) ) ) ( second ( trophic level ) ) )
(ROOT (NP (NP (JJ primary) (NNS consumers)) (PRN (-LRB- -LRB-) (NP (JJ herbivorous) (NN zooplankton)) (-RRB- -RRB-)) (NP (JJ second) (JJ trophic) (NN level))))
primary consumers (herbivorous zooplankton) second trophic level
(ROOT (S (NP (NP (JJ Secondary) (NNS consumers)) (PRN (-LRB- -LRB-) (SBAR (WHNP (WDT which)) (S (VP (VBP eat) (NP (JJ primary) (NNS consumers))))) (-RRB- -RRB-))) (VP (VBP are) (VP (VBN considered) (S (VP (TO to) (VP (VB be) (ADJP (JJ trophic) (NP (NN level) (CD 3)))))))) (. .)))