Aquatic Environment and Biodiversity Annual Review 2012

AEBAR 2012: Non-protected bycatch
Figure 6.7: Annual estimates of fish bycatch in the target hoki, hake and ling trawl fishery, calculated for
commercial species, non-commercial species, and overall for 2000–01 to 2006–07 (black). Also shown (in
light grey) are the equivalent bycatch estimates calculated for 1990–91 to 1998–99 by Anderson et al.
(2001), and for the years 1990–91, 1994–95, 1998–99 and 1999–2000 to 2002–03 by Anderson and Smith
(2004), (in dark grey). Error bars show the 95% confidence intervals.
Total annual discard estimates for 2000–01 to 2006–07 ranged from about 5500 to 29 000 t per year
with the main species being discarded including spiny dogfish, rattails, javelinfish, hoki, and
shovelnose dogfish. Total annual discards for 1990–91 to 1998–99 were between 6600 t and 17 900 t,
and overall there has been no obvious trend in total discards (Figure 6.8). The target species (hoki,
hake, and ling) made up 9.7% of total observed discards. Discard rates were strongly influenced by
the use of meal plants on fishing vessels; discards of non-commercial species on factory vessels
without meal plants was up to twice the level of discards for vessels with meal plants. The use of meal
plants, especially for species such as javelinfish and other rattails, has become more prevalent in
recent years.
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