Aquatic Environment and Biodiversity Annual Review 2012

AEBAR 2012: Non-protected bycatch
6.3. State of knowledge in New Zealand
Estimation of annual bycatch and discard levels of non-protected species in selected New Zealand
fisheries have been undertaken at regular intervals since 1998 (Table 6.1).
Table 6.1: Summary of research into bycatch in New Zealand fisheries
Fishery Report
Arrow squid Anderson et al. (2000)
Anderson (2004b)
Ballara and Anderson (2009)
Anderson (In Press)
Ling bottom longline Anderson et al. (2000)
Anderson (2008)
Hoki trawl Clark et al. (2000)
Anderson et al. (2001)
Anderson and Smith (2005)
Ballara et al. (2010)
Hake trawl Ballara et al. (2010)
Ling trawl Ballara et al. (2010)
Jack mackerel trawl Anderson et al. (2000)
Anderson (2004b)
Anderson (2007)
Southern blue whiting trawl Clark et al. (2000)
Anderson (2004a)
Anderson (2009b)
Orange roughy Clark et al. (2000)
Anderson et al. (2001)
Anderson (2009a)
Anderson (2011)
Oreo trawl Clark et al. (2000)
Anderson (2004a)
Anderson (2011)
Scampi trawl Anderson (2004b)
Ballara and Anderson (2009)
Tuna longline Francis et al. (1999a, 1999b)
Ayers et al. (2004)
Francis et al. (2004)
Griggs et al. (2007)
Griggs et al. (2008)
Griggs & Baird (In Press)
Albacore troll fishery Griggs et al. (In Press)
Skipjack purse seine fishery Griggs (unpublished data)
The estimation process uses rates of bycatch and discards in various categories (in most cases “all
QMS species combined”, “all non-QMS species combined”, “all invertebrate species combined”) and
fishery strata in the observed fraction of the fishery, and effort statistics from the wider fishery, to
calculate annual bycatch and discard levels. This ratio-based approach calculates precision by
incorporating a multi-step bootstrap algorithm which takes into account the effect of correlation
between trawls in the same observed trip and stratum. Estimates of the annual bycatch of a wide range
of individual species were also made in the most recent analysis of the arrow squid fishery (Anderson
In Press).
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