A couple of people survey the sea for wildlife.
The people study sea animals and are wearing snorkels.
Just because the people are surveying the sea for wildlife mean that they study sea animals or that they are wearing snorkels.
exists e1 x1 x2 x3 x4.(n_sea(x3) & Theme(e1,x3) & Actor(e1,x1) & v_survey(e1) & for(x3,x4) & n_wildlife(x4) & of(x1,x2) & n_people(x2) & n_couple(x1))
exists e1 x1 x2 x3 x4.(n_people(x1) & a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_wear(e1) & n_snorkel(x4) & (x1 = x3) & n_study(x1) & n_animal(x1) & Time(x1,x2) & n_sea(x2))