Estimated bycatch

This page shows the proportion of catch and bycatch estimated from data collected by government observers. 

When a fishing vessel goes to sea it has a specific catch plan for key QMS species - this is the ‘target’ catch.  For each fishing event, the estimated target catch is reported by the vessel (“reported target”). 

‘Bycatch’ refers to catching a fish or other marine species that is not the target species. Bycatch can be:

  • commercially valuable species managed under the quota management system (QMS species)
  • non-QMS species, most of which will not be commercially valuable. 

The proportion of target and bycatch shown in the charts below is over two time periods: 

  1. All available data (annual average) - depending on the target fishery being reported on, this is based on data from 1991 to at least 2006 (up to 2013, depending on when each target fishery data were last analysed).
  2. Last five years available data (annual average) - this is from the last five years of analysed data, ranging from the five years ending in 2006, to the five years ending in 2013 (depending on when the target fishery was last analysed).

The charts below represent a generalised summary of the available data.  There can be slight differences in methodologies used for analysis across fisheries, so see full publications for full details. 

Across all years available data, for every kilogram of reported target catch, nearly 0.2kg of bycatch is estimated to be caught.  On average, less bycatch has been caught in the most recent five years of available data.

The charts also show that most (around 80% in recent years) of the estimated bycatch is of QMS species, which are more likely to be retained and reported. 

Reported target and estimated bycatch for six key deepwater fisheries

Last five years available data (average annual catch)

All available data (average annual catch)

Reported target catch and estimated bycatch for six key deepwater fisheries - specific target species 

Last five years available data (average annual catch)

All available data (average annual catch)

More on this topic 

This page is part of a section on deepwater bycatch and discards. 

Mixed species bycatch on a deepwater trawler. [MPI]