Figure 9.8 Types of material found in the “Great Pacific Garbage
Patch”The “garbage patch” formed gradually as a result of marine pollution
gathered by oceanic currents. The gyre’s rotational pattern draws in waste
material from across the North Pacific Ocean, including coastal waters off North
America and Japan. As materials are captured in the currents, wind-driven
surface currents gradually move floating debris toward the center, trapping it in
the region. Plastics and other plastic-like substances (such as nylon from fishing
nets) can entangle fish, sea turtles, and marine mammals, causing injury and
death. Certain types of plastic can break down into extremely small particles and
become ingested far into the future.
As the plastic photodegrades into smaller and smaller pieces, it remains as
plastic polymers leaching toxic chemicals into the upper water column. As the
plastic further disintegrates, it becomes small enough to be ingested by aquatic
organisms and birds near the ocean’s surface and eventually enters the marine
food chain. The floating debris can also absorb organic pollutants from seawater,
which, through bioaccumulation, distributes these toxins throughout the food
chain.
Marine plastics also facilitate the spread of invasive species that attach to
floating plastic. On the macroscopic level, the plastic kills birds and sea turtles
as the animals’ digestion systems cannot break down the plastic inside their
stomachs. Furthermore, the large amount of debris makes it much more difficult
for animals to see and detect their normal sources of food through the water
column.