Editing Seabird (section)

=== Seabirds and fisheries ===
Seabirds have had a long association with both [[fishery|fisheries]] and [[sailor]]s, and both have drawn benefits and disadvantages from the relationship.

Fishermen have traditionally used seabirds as indicators of both [[Shoaling and schooling|fish shoals]],<ref name="AU" /> underwater [[bank (topography)|banks]] that might indicate fish stocks, and of potential landfall. In fact, the known association of seabirds with land was instrumental in allowing the [[Polynesia]]ns to locate tiny landmasses in the Pacific.<ref name="Burger" /> Seabirds have provided food for fishermen away from home, as well as bait. Famously, tethered cormorants have been used to catch fish directly. Indirectly, fisheries have also benefited from [[guano]] from colonies of seabirds acting as [[fertilizer]] for the surrounding seas.<ref name="Perkins">{{cite web |url=https://www.science.org/content/article/bird-poop-brings-38-million-metric-tons-nitrogen-out-sea-each-year |url-access=limited |title=Bird poop brings 3.8 million metric tons of nitrogen out of the sea each year|last=Perkins |first=Sid |date=January 23, 2018 |website=Science Magazine |publisher=American Association for the Advancement of Science |access-date=March 26, 2021 |url-status=live |archive-url=https://web.archive.org/web/20220607193721/https://www.science.org/content/article/bird-poop-brings-38-million-metric-tons-nitrogen-out-sea-each-year |archive-date= Jun 7, 2022 }}</ref>

Negative effects on fisheries are mostly restricted to raiding by birds on [[aquaculture]],<ref>{{cite report|last1=Collis|first1= K.|last2= Adamany|first2= S. |last3 = Roby|first3 = D. D.|last4 =Craig|first4= D. P.|last5= Lyons|first5= D. E.|date =2000|url = http://www.govdocs.aquake.org/cgi/reprint/2004/915/9150520.pdf |archive-url = https://web.archive.org/web/20060831053949/http://www.govdocs.aquake.org/cgi/reprint/2004/915/9150520.pdf |archive-date = 31 August 2006|url-status = dead |title = Avian Predation on Juvenile Salmonids in the Lower Columbia River|publisher = Bonneville Power Administration|location = Portland, OR}}</ref> although [[long-line fishing|long-lining]] fisheries also have to deal with [[bait (luring substance)|bait]] stealing. There have been claims of prey depletion by seabirds of fishery stocks, and while there is some evidence of this, the effects of seabirds are considered smaller than that of [[marine mammal]]s and predatory fish (like [[tuna]]).<ref name="Burger" />

[[File:Seabirds longlinersm.jpg|thumb|right|Seabirds (mostly northern fulmars) flocking at a long-lining vessel]]Some seabird species have benefited from fisheries, particularly from discarded fish and [[offal]]. These discards compose 30% of the food of seabirds in the [[North Sea]], for example, and compose up to 70% of the total food of some seabird populations.<ref>{{cite journal|author1=Oro, D. |author2=Ruiz, X. |author3=Pedrocchi, V. |author4=Gonzalez-Solis, J. |year=1997|title=Diet and adult time budgets of Audouin's Gull ''Larus audouinii'' in response to changes in commercial fisheries|journal=Ibis |volume=139|pages= 631–637|doi=10.1111/j.1474-919X.1997.tb04685.x|issue=4}}</ref> This can have other impacts; for example, the spread of the [[northern fulmar]] through the [[United Kingdom]] is attributed in part to the availability of discards.<ref>Thompson, P. M. (2004). [http://www.abdn.ac.uk/lighthouse/documents/Thompson_fulmars.pdf Identifying drivers of change; did fisheries play a role in the spread of North Atlantic fulmars?] {{webarchive|url=https://web.archive.org/web/20081217092738/http://www.abdn.ac.uk/lighthouse/documents/Thompson_fulmars.pdf |date=December 17, 2008 }} in '' Management of marine ecosystems: monitoring change in upper trophic levels''. Cambridge: Cambridge University Press</ref> Discards generally benefit surface feeders, such as gannets and petrels, to the detriment of pursuit divers like penguins and guillemots, which can get entangled in the nets.<ref name="Brooke197">{{cite book |last=Brooke |first=Michael |date=2018 |title=Far From Land: The Mysterious Lives of Seabirds |location=Princeton |publisher=Princeton University Press |page=197 |isbn=978-0-691-17418-1}}</ref>

Fisheries also have negative effects on seabirds, and these effects, particularly on the long-lived and slow-breeding albatrosses, are a source of increasing concern to conservationists. The bycatch of seabirds entangled in nets or hooked on fishing lines has had a big impact on seabird numbers; for example, an estimated 100,000 albatrosses are hooked and drown each year on tuna lines set out by long-line fisheries.<ref>{{cite web |publisher=BirdLife International/RSPB |year=2005 |url=http://www.savethealbatross.net/the_problem.asp |title=Save the Albatross: The Problem |access-date=May 4, 2006 |archive-date=June 23, 2013 |archive-url=https://web.archive.org/web/20130623234319/http://www.rspb.org.uk/supporting/campaigns/albatross/ |url-status=dead }}</ref><ref>{{cite journal|year= 1991|title=Albatross mortality and associated bait loss in the Japanese longline fishery in the southern ocean|journal=Biological Conservation |volume=55|pages= 255–268|doi=10.1016/0006-3207(91)90031-4|issue=3|last1=Brothers|first1=Nigel|bibcode=1991BCons..55..255B }}</ref>{{Update inline|date=April 2021|reason=Likely a different number now}} Overall, many hundreds of thousands of birds are trapped and killed each year, a source of concern for some of the rarest species (for example, only about 2,000 [[short-tailed albatross]]es are known to still exist). Seabirds are also thought to suffer when overfishing occurs.<ref name="Cury">{{cite journal |last1=Cury |first1=P. M. |last2=Boyd |first2=I. L. |last3=Bonhommeau |first3=S. |last4=Anker-Nilssen |first4=T. |last5=Crawford |first5=R. J. M. |last6=Furness |first6=R. W. |last7=Mills |first7=J. A. |last8=Murphy |first8=E. J. |last9=Osterblom |first9=H. |last10=Paleczny |first10=M. |last11=Piatt |first11=J. F. |last12=Roux |first12=J.-P. |last13=Shannon |first13=L. |last14=Sydeman |first14=W. J. |title=Global seabird response to forage fish depletion—one-third for the birds |journal=Science |date=December 23, 2011 |volume=334 |issue=6063 |pages=1703–1706 |doi=10.1126/science.1212928 |jstor=41352310 |pmid=22194577 |bibcode=2011Sci...334.1703C |s2cid=1855657 |url=https://www.jstor.org/stable/pdf/41352310.pdf}}</ref> Changes to the marine ecosystems caused by dredging, which alters the biodiversity of the seafloor, can also have a negative impact.<ref>{{cite journal |last1=King |first1=Sd |last2=Harper |first2=Ga |last3=Wright |first3=Jb |last4=McInnes |first4=Jc |last5=van der Lubbe |first5=Je |last6=Dobbins |first6=Ml |last7=Murray |first7=Sj |title=Site-specific reproductive failure and decline of a population of the Endangered yellow-eyed penguin: a case for foraging habitat quality |journal=Marine Ecology Progress Series |date=October 25, 2012 |volume=467 |pages=233–244 |doi=10.3354/meps09969|bibcode=2012MEPS..467..233K |doi-access=free }}</ref>