Aquatic Environment and Biodiversity Annual Review 2012

AEBAR 2012: Benthic impacts
Baird et al. (2011) used reported tows on small topographic features that are a focus for orange
roughy and cardinalfish fisheries by defining polygons for these tows as radii around the reported start
position with the area swept estimated from the reported duration and speed of the tow. These short
tows do not appear to contribute substantially to broad-scale plots like Figure 7.7, yet can represent
intense fishing effort on particular, small seamount features (e.g. Rowden et al. 2005, O’Driscoll and
Clark 2005).
Figure 7.8: Broad-scale distribution from Baird et al. 2011 of bottom trawl effort reported on CELRs (left) and on
CELRs and TCEPRs combined (right), for all fishing years 1989–90 to 2004–05. Updates for deepwater trawl
fisheries (but not inshore fisheries reporting on TCER) are expected in 2013.
After the peak of over 140 000 reported trawl tows in 1996/97 and 1997/98 (Figure 7.9) when slightly
over half of all tows were reported on TCEPRs, overall trawling effort declined to less than 100 000
tows per year by 2006/07. The reported number of trawl tows has remained relatively stable at about
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