After the 1950s, fishing gear and land-based disposables were increasingly being produced with plastic and other synthetic materials.These materials, when lost or abandoned, become entanglement threats for many marine species. A global study found records for entanglement for 136 marine species around the world. Entanglement leads to decreased swimming ability, disruption in feeding, life-threatening injuries, and death. Both land-based pollution and loss by the maritime industry are considered significant sources. The latter has been addressed through Annex V to MARPOL, which prohibits the discharge of garbage into the sea, although the overall effectiveness is debatable. There have been further actions taken since the 1980s, but entanglement continues to be a serious issue.