At present 663 species of animals in the oceans are in contact with marine rubbish (CBD 2012). Of these approximately half the species of animals (some 370) are affected by ingesting it or being entangled by it. That is an increase in the impact on aquatic animals by over 40% compared with a study from 1997 which found this for 247 species. At least 43% of the species of whales, all species of turtles, some 44% of all species of seabirds worldwide and many species of fish have been described as having ingested marine rubbish. Six of seven species of turtle, 51 of the 312 species of seabird worldwide and 32 marine mammals are described as being affected by getting entangled with such rubbish, like lost nets, lines and fishing lines. Of the 120 marine mammals on the IUCN list 54 species (45%) are found to ingest marine rubbish or be entangled by it. 15% of these species are on the IUCN Red List(1)(3). The extent of the impact on animals by marine rubbish is probably a lot higher as in the statistics not all consequences of marine rubbish on the life of these animals are described. As an example, rubbish on the beaches can have a negative effect on the capability of young turtles to reach the water quickly after hatching out. (2) Or the temperature of the sandy beach changes due to the presence of plastic which can have negative influences on the breeding nature or eating behaviour of animals on the sandy beach.
When marine animals eat marine rubbish and cannot excrete it, a sense of satiation can set in so that the animals starve. Plastic parts can harm the digestive organs mechanically or obstruct them. Very small bits of micro plastic can be transported through the digestive system into bodily tissue and lead to inflammation and immune defence reactions. Toxics attached to micro particles can enter the animals’ metabolism after being swallowed.
Getting caught in marine rubbish, especially in nets and lines can lead to drowning for mammals and birds; fish can suffocate in it. Animals caught in lines or packing tape can get badly cut by them which cause inflammation. If birds use plastic lines in nest building, the young birds get caught in them and strangle themselves.
Animals but also for example pathogenic bacteria can travel large distances on floating plastic rubbish and act as invasive species with hegative impact on regions. (4)
1)WSPA Untangled. Marine Debris: a global picture of the impact of animal welfare and of animal focused solutions. Report
4) „Plastic rubbish – ready to board“ in Spektrum der Wissenschaft http://www.spektrum.de/suche/#!/q/Plastikm%C3%BCll%20Fertig%20zum%20Entern!