Editing Bycatch (section)

{{Short description|Fish or other marine species caught unintentionally}}
[[File:Carcharhinus isodon in net.JPG|alt=Shark entangled in a net on board a fishing vessel|thumb|A [[finetooth shark]] (''Carcharhinus isodon'') caught as bycatch by a fishing vessel]]
'''Bycatch''' (or '''by-catch'''), in the [[fishing industry]], is a [[fish]] or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or [[Juvenile (organism)|juvenile]]s of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non-[[marine life|marine]] species ([[freshwater fish]] not [[saltwater fish]]) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as [[rough fish]] (mainly US) or [[coarse fishing|coarse fish]] (mainly UK).

In 1997, the [[OECD|Organisation for Economic Co-operation and Development]] (OECD) defined bycatch as "total fishing [[Mortality rate|mortality]], excluding that accounted directly by the retained catch of target species".<ref>OECD (1997) Towards sustainable fisheries: economic aspects of the management of living marine resources. OECD Paris.</ref> Bycatch contributes to fishery decline and is a mechanism of [[overfishing]] for unintentional catch.<ref>C. Michael Hogan. 2010. [https://editors.eol.org/eoearth/wiki/Overfishing ''Overfishing''. Encyclopedia of Earth. National Council for Science and the Environment]. eds. Sidney Draggan and C. Cleveland. Washington DC.</ref>

The average annual bycatch rate of [[pinniped]]s and [[cetacea]]ns in the US from 1990 to 1999 was estimated at 6215 animals with a [[standard error]] of 448.<ref>{{cite journal|last1=Read|first1=Andrew J.|last2=Drinker|first2=Phebe|last3=Northridge|first3=Simon|title=Bycatch of Marine Mammals in U.S. and Global Fisheries|journal=Conservation Biology|date=February 2006|volume=20|issue=1|pages=163–169|doi=10.1111/j.1523-1739.2006.00338.x|pmid=16909669|bibcode=2006ConBi..20..163R |s2cid=157350 }}</ref>

Bycatch issues originated with the "mortality of dolphins in tuna nets in the 1960s".<ref name=Hall/>

There are at least four different ways the word "bycatch" is used in fisheries:<ref>{{cite book|author1=Alverson D L |author2=Freeberg M K |author3=Murawski S A |author4=Pope J G |year=1994|title=A global assessment of fisheries bycatch and discards|publisher=FAO|location=Rome}}</ref>
* Catch which is retained and sold but which is not the target species for the fishery {{Citation needed|date=October 2023}}
* Species/sizes/sexes of fish which [[fisherman|fishers]] discard<ref>A definition used particularly in the northeast and western [[Pacific]] and in US legislation</ref>
* Non-target fish, whether retained and sold or discarded<ref>{{cite journal|last=Hall |first=M A |year=1996|title=On bycatches|journal=Reviews in Fish Biology and Fisheries |volume=6
|issue=3|pages=319–352 |doi=10.1007/BF00122585|bibcode=1996RFBF....6..319H |s2cid=25760363 }}</ref>
* Unwanted [[invertebrate]] species, such as [[echinoderm]]s and non-commercial [[crustacean]]s, and various vulnerable species groups, including seabirds, sea turtles, marine mammals and elasmobranchs (sharks and their relatives).<ref>{{Cite journal |last1=Blom |first1=Wilma |last2=Webber |first2=Richard |last3=Shultz |first3=Thomas |date=2009-06-01 |title=Invertebrate bycatch from bottom trawls in the New Zealand EEZ |url=https://tuhinga.arphahub.com/article/34177/ |journal=Tuhinga |language=en |volume=20 |pages=33–40 |doi=10.3897/tuhinga.20.e34177 |doi-access=free |issn=2253-5861}}</ref>

Additionally, the term "deliberate bycatch" is used to refer to bycatch as a source of [[illegal wildlife trade]] (IWT) in several areas throughout the world.<ref>{{Cite journal |last1=Ermolin |first1=Ilya |last2=Svolkinas |first2=Linas |date=January 2018 |title=Assessment of the sturgeon catches and seal bycatches in an IUU fishery in the Caspian Sea |journal=[[Marine Policy]] |volume=87 |issue=87 |pages=284–290 |doi=10.1016/j.marpol.2017.09.022 |url=https://www.researchgate.net/publication/321289096 }}</ref>

There are several tools to estimate bycatch limits—the maximum number of animals that could be sustainably removed from a population impacted by bycatch.
These include the 'potential biological removal' (PBR) and the 'sustainable anthropogenic mortality in stochastic environments' (SAMSE), which incorporates [[stochastic]] factors to determine sustainable limits to bycatch and other human-caused mortality of wildlife.<ref>{{cite journal|last1=Manlik|first1=Oliver|last2=Lacy|first2=Robert C.|last3=Sherwin|first3=William B.|last4=Finn|first4=Hugh|last5=Loneragan|first5=Neil |last6=Allen|first6=Simon C.|title=A stochastic model for estimating sustainable limits to wildlife mortality in a changing world|journal=Conservation Biology|date=2022|volume=36 |issue=4 |pages=e13897|doi=10.1111/cobi.13897|pmid=35122329|pmc=9542519 |bibcode=2022ConBi..36E3897M }}</ref>