What does bycatch mean?
Bycatch refers to fish, marine mammals, seabirds, and other creatures that are unintentionally caught during commercial fishing operations aimed at a different target species. Because much of this non-target catch is unmarketable, undersized, or legally protected, it is typically discarded overboard — frequently dead or mortally injured. The term originated in fisheries management and has become widely familiar through environmental journalism, since bycatch is considered one of the most serious threats to ocean biodiversity: dolphins entangled in tuna nets and turtles caught in shrimp trawls became emblematic cases that drove public campaigns. The word functions as an uncountable noun and often appears in phrases such as 'reduce bycatch' or 'bycatch reduction devices', reflecting ongoing efforts to make fishing gear more selective. Its connotations are strongly negative, evoking waste, collateral damage, and the unintended costs of industrial-scale harvesting.
nounFish or other marine creatures unintentionally caught while fishing for a different target species, typically discarded because they are unwanted, unmarketable, or protected.
- Unintended fish and marine animals (and sometimes seabirds or turtles) captured during commercial fishing and usually thrown back, often dead or dying.
"Shrimp trawlers once discarded enormous quantities of bycatch, including sea turtles and juvenile fish."
"The new nets include escape panels that allow turtles to avoid becoming bycatch."
"Regulators now require fleets to report their bycatch so scientists can assess the wider impact of fishing."
Bycatch is treated as uncountable; quantities are expressed as amounts rather than plurals.
"The fleet's annual bycatch amounted to thousands of tonnes of discarded fish."
An estimated millions of tonnes of marine life — including dolphins, turtles, and seabirds — are thrown back dead each year simply as bycatch, making it one of the biggest threats to ocean wildlife.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bycatch
Bycatch is a compound formed from the preposition 'by' plus 'catch', following the pattern of terms like 'by-product' to mean something obtained or encountered incidentally alongside a main result. It arose within twentieth-century fisheries science and regulation as industrial trawling made incidental capture a measurable problem, and it spread into everyday environmental vocabulary as concerns about discarding grew.
How bycatch is actually used
A technical term from fisheries science that has entered general usage through environmental reporting; it carries strong negative connotations of waste and ecological harm. It is an uncountable noun used attributively in compounds such as 'bycatch reduction'.
Easily confused with bycatch
A by-product is a secondary product made incidentally during a process, while bycatch is unwanted marine life accidentally caught during fishing.