4 But yelling mews, with seagulls hoarse and base,
But > Except mew > {The common gull, Larus canus, which has a mewing cry} seagulls > (Probably denoting the larger species, such as herring gull, Larus argentatus, great black-backed gull, L. marinus, etc., which have deeper cries) base > (Because gulls are associated with deception; or: bass, of their voices)
5 And cormorants, with birds of ravenous race,
cormorant > (Phalacrocorax sp., the sea-raven, noted for its greed) ravenous > {Ravenous; given to ravin or robbery; also, perhaps, punningly: raven-like}
6 Which still sat waiting on that wasteful cliff,
still > continuously waiting > keeping watch wasteful > desolate
7 For spoil of wretches, whose unhappy case,
spoil > plunder, booty
8 After lost credit and consumed thrift,
thrift > prosperity; savings