Editing Bycatch (section)

===Shrimp trawling===
[[File:Trawer Hauling Nets.jpg|thumb|right|Double-rigged shrimp [[fishing trawler|trawler]] hauling in [[Fishing net|nets]]|alt=Photo of boat moving forward at sea. On each side, the boat has one pole pointing away from boat with nets attached]] 
[[File:Shrimp bycatch.jpg|thumb|right|[[Shrimp]] bycatch|alt=Photo of hundreds of dead fish lying on ship deck]]

The highest rates of [[incidental catch]] of non-target species are associated with tropical [[shrimp]] [[trawling]]. In 1997, the [[FAO|Food and Agriculture Organization of the United Nations]] (FAO) documented the estimated bycatch and [[Discards|discard]] levels from shrimp fisheries around the world. They found discard rates (bycatch to catch ratios) as high as 20:1 with a world average of 5.7:1.<ref>{{cite book|last=Clucas |first=Ivor|year=1997|url=http://www.fao.org/docrep/W6602E/w6602E09.htm|title=Discards and bycatch in shrimp trawl fisheries
|publisher=[[FAO]] Fisheries Circular|issue= 928 FIIU/C928}}</ref>

Shrimp trawl fisheries catch two percent of the world total catch of all fish by weight, but produce more than one-third of the world total bycatch. US shrimp trawlers produce bycatch ratios between 3:1 (3 bycatch:1 shrimp) and 15:1 (15 bycatch:1 shrimp).<ref name=Hall>{{cite journal|last1=Hall |first1=M |last2=Alverson |first2=DL |last3=Metuzals |first3=KI|year=2000
|title=By-catch: problems and solutions|journal=Marine Pollution Bulletin|volume=41|issue=1–6|pages=204–219 |doi=10.1016/S0025-326X(00)00111-9|bibcode=2000MarPB..41..204H }}</ref>

[[Trawling|Trawl nets]] in general, and shrimp trawls in particular, have been identified as sources of mortality for [[cetacea]]n and [[finfish]] species.<ref name="SAFMC">SAFMC (2004){{Full citation needed|date=June 2021}}</ref> When bycatch is discarded (returned to the sea), it is often dead or dying.<ref>{{cite book|last1=Morgan |first1=LE |last2=Chuenpagdee |first2=R
|year=2003|title=Shifting Gears. Addressing the Collateral Impacts of Fishing Methods in U.S. Waters}}</ref>

Tropical shrimp trawlers often make trips of several months without coming to port. A typical haul may last four hours after which the net is pulled in. Just before it is pulled on board the net is washed by zigzagging at full speed. The contents are then dumped on deck and are sorted. An average of 5.7:1 means that for every [[kilogram]] of shrimp there are 5.7&nbsp;kg of bycatch. In tropical inshore waters the bycatch usually consists of small fish. The shrimps are frozen and stored on board; the bycatch is discarded.<ref>{{cite book|editor=Clucas, I. |editor2=Teutscher, F. |title=FAO/DFID Expert Consultation on Bycatch Utilization in Tropical Fisheries. Beijing (China), 21–28 September 1998|year=1999|publisher=University of Greenwich, NRI|isbn=978-0-85954-504-4|page=333}}</ref>

Recent sampling in the South Atlantic [[Sicyonia brevirostris|rock shrimp]] fishery found 166 species of finfish, 37 [[crustacean]] species, and 29 other species of [[invertebrate]] among the bycatch in the trawls.<ref name="SAFMC"/> Another sampling of the same fishery over a two-year period found that rock shrimp amounted to only 10% of total catch weight. Iridescent swimming crab, dusky flounder, inshore [[lizardfish]], spot, [[Crangon crangon|brown shrimp]], longspine swimming crabs, and other bycatch made up the rest.<ref name="SAFMC"/>

Despite the use of [[bycatch reduction device]]s, the shrimp fishery in the Gulf of Mexico removes about 25–45 million [[Lutjanus|red snapper]] annually as bycatch, nearly one-half the amount taken in recreational and commercial snapper fisheries.<ref name="GMFMC (2006)"/><ref>{{cite book|publisher=Southeast Data, Assessment, and Review (SEDAR) Stock Assessment Report of SEDAR
|issue=7|year=2005|url=http://www.sefsc.noaa.gov/sedar/download/S7SAR_FINALreduce.pdf?id=DOCUMENT|title=Gulf of Mexico Red Snapper: Assessment Summary Report}}</ref>