The most apparent way in which wild animals can be harmed by marine debris is through strangling（Laist 1997）. As plastic debris is durable and long-lasting, once wild animals have become entangled in it, it causes them great suffering.
Strangling by plastic debris has been already reported for 344 species of animal, including seabirds, sea turtles, and whales（Kühn et al. 2015）.
Furthermore, 25% of all seabird species, that is, 103 species out of 406 species, are known to have been harmed by strangling by marine debris（Kühn et al. 2015）.
Most seabirds, such as the brown booby, use natural resources such as seaweed to make their nests. However, artificial debris such as plastic ropes and fishing nets are also often used as nesting material（Lavers et al. 2013, Votier et al. 2011, Verlis et al. 2014, Bond et al. 2012）.
During the mating season, adult male brown boobys and northern gannets collect marine debris, especially certain items such as discarded fishing gear, which they favor because it makes their nests stand out（Bond et al. 2012）.
Then, as the chicks are raised in a nest constructed with plastic, they end up becoming entangled with the plastics.
In the northwest Atlantic Ocean, almost all brown booby nests have been found to contain marine debris, most of which was originally used in the fishing industry（Montevecchi 1991）.
According to research conducted on brown booby nests on the Great Barrier Reef in Australia, about 60% of the 98 nests checked were found to contain plastic debris（Verlis et al. 2014）.
When there is an active gill net fishery close to seabird nesting grounds, the birds tend to more frequently use fishing gear for their nest. One study has reported that around 75% of brown booby nests were made with fishing gear（Bond et al. 2012）.
When such marine debris is used in the construction of nests, the risk of getting strangled increases for both adult birds and chicks（Laist 1997, Kühn et al. 2015）, and many cases have been reported of seabirds being strangled to death by their own nests（Laist 1997, Parker & Blomme 2007, Votier et al. 2011）.