Ghost Gear and Fishery-sourced Plastics

Derelict fishing gear, also called ghost gear, is gear that is no longer actively fishing. Ghost gear can still passively fish, or capture other animals as bycatch, including seabirds. The most visible aspect of this is marine animal entanglement in recreational fishing monofilament line. In one study, Paijmans & Stewart (2016) mined the South African national bird banding (ringing) database for band recoveries of birds found dead or alive entangled in monofilament line. They reported 387 individuals of 49 species found, including 24 species listed in our database (the remaining 25 species were not seabirds).

Ghost gear can impact seabirds in less visible ways, too. Danckwerts (2014) found monofilament in the stomachs of the poorly-understood Barau’s Petrel Pterodroma baraui, one of many studies to find fishing-related gear in the gut contents of seabirds. Thiebot et. al (2018) recorded longline fishing gear in 55% of nests of the locally-endangered Short-tailed Albatross Phoebastria albatrus, risking entanglement of both adults and chicks. Gillnets can continue to passively fish after they are broken or separated from the vessel, drowning many air-breating species such as seabirds.

Battisti et al (2019) conducted a global review of plastics impacts on birds broken down by category and guild has a wealth of information on this topic and serves as an excellent introduction to ghost gear issues impacting seabirds. Ryan (2018) conducted an analysis of the specific issue of plastics entanglement in seabirds.

In response to the issue of ghost gear, the Global Ghost Gear Initiative was founded in 2015 in order to understand and mitigate ghost gear impacts. In addition, the Marine Pollution Bulletin journal frequently has analyses specific to seabirds mortality caused by ghost gear.

Albatrosses and petrels are perhaps the best known seabird species groups that are impacted by plastics ingestion. This association between albatrosses, petrels, and plastics allows scientists to track plastics output from vessels (Phillips and Waluda 2020).

References:

Battisti, C., E. Staffieri, G. Poeta, A. Sorace, L. Luiselli, and G. Amori. 2019. Interactions between anthropogenic litter and birds: A global review with a ‘black-list’ of species. Marine Pollution Bulletin 138:93-114.

Danckwerts, D.K. 2014. The trophic ecology of the endangered endemic Barau’s petrel (Pterodroma baraui) from Reunion Island, south-western Indian Ocean (MSc). Rhodes University.

Paijmans, D.M. and M. Stewart. 2016. African Black Oystercatcher fatality as a result of fishing line. Biodiversity Observations, Vol. 7(27):1-3.

Phillips, R.A. and C.M. Waluda. 2020. Albatrosses and petrels at South Georgia as sentinels of marine debris input from vessels in the southwest Atlantic Ocean. Environment International 136 (2020): 105443.

Ryan, P.G. 2018. Entanglement of birds in plastics and other materials. Marine Pollution Bulletin 135:1590164.

Thiebot, J.B., B. Nishizawa, F. Sato, N. Tomita, Y. Watanuki. 2018. Albatross chicks reveal interactions of adults with artisanal longline fisheries in a short range. Journal of Ornithology, 159(4):935-944.