The California sea lion is a protected species throughout its range, but the population continues to flourish despite ongoing conflicts with commercial and sport fisheries for species such as anchovy and herring. Sea lions are known to damage fishing gear and steal or destroy fish in the nets. As a result some California sea lions are illegally shot or drown in the nets. Some animals manage to escape from gill nets, but many of these animals are left with small pieces of net filament around their necks. These fragments of nets and other pieces of plastic debris eventually kills many sea lions by cutting deep into tissue as the animals grow around the constricting material. The increase of environmental toxins may also have a negative effect on sea lion populations.

An example of how net filaments can be harmful to sea lions. (Photo Credit: Schusterman; Long Marine Laboratory, UCSC)

A sea lion with a net filament wrapped around its neck (Photo Credit: Schusterman; Long Marine Laboratory, UCSC).