MARINE DEBRIS - Marine Pollution: What Everyone Needs to Know - page 49

averaged 13%, suggesting that the Sargassum habitat comes
with a risk of ingesting much debris. A study of fishes from
the general region of the North Atlantic gyre found exten-
sive marine debris ingestion in seven species with 58% in
one species ( Lampris sp., small-eye). Of all sampled individu-
als, 19% contained some debris, mostly plastic or fishing line.
Surprisingly, species that ingested the most debris are ones
considered to live in intermediate depths rather than near the
surface and therefore unlikely to come into contact with sur-
face debris, suggesting that there is more debris below the sur-
face than we thought.
It is difficult to prove that a dead animal died from ingest-
ing debris, however. In 2008 two sperm whales were stranded
along the California coast with large amounts of fishing net
scraps, rope, and other plastic debris in their stomachs. Plastic
debris that becomes lodged in digestive tracts, blocking the
passage of food, can cause death through starvation. A sperm
whale that beached itself in 2012 in Spain had a large amount
of garbage blocking its stomach, including some 36 square
yards of plastic canvas, a dozen meters of plastic rope, plastic
sheeting used on the outside of greenhouses, plastic sheeting
used inside, and even two flower pots. The whale was emaci-
ated because its intestines were totally blocked by the plas-
tic debris. A Risso's dolphin in the Hudson River in May 2013
likely starved to death because of four plastic bags lodged in
its stomach. The dolphin, which was 10 feet long and weighed
600 pounds, had four intact plastic bags in its stomach. The
largest bag was 4 feet by 2 feet and was rolled into a sphere,
about 8 inches in diameter, blocking its stomach.
Debris is also ingested by marine birds, which may starve or
become strangled if an object becomes lodged in their throats
or digestive tracts. Ingested marine debris is commonly found
in dead birds, turtles, and other animals, although one can-
not assume the debris caused the death (Figure 3.2). Scientists
quantified the stomach contents of 67 Northern Fulmars from
beaches in the eastern North Pacific in 2009-2010 and found