Complete digestive tracts were removed during necropsies and
the prey remains were immediately filtered and fixed (formalin or
ethanol) for diet analyses. Esophagus, stomachs and intestines
were fully inspected in order to detect PD, ulcerations and obstructions.
Plastic debris found were counted, measured and classified
by type and source. Two main sources of plastic debris were identified:
fishing-related items (monofilament lines, ropes, net fragments)
and packaging debris (plastic rubber bands, cellophane,
plastic bags, etc.). Other remains (hard plastic fragments) were
not assigned to these categories, and considered of unknown
source.