At-sea observation of the stout whiting fishery 2009–10

Abstract

The stout whiting observer program was developed to collect accurate and detailed catch and effort information on T4 fishing operations, target species, by-product and bycatch (including protected species) in the northern and southern areas using the two gear types. This will be used to inform management decisions consistent with the ‘driven by knowledge’ guiding principle of the Queensland Fisheries Strategy 2009–14.
Participation in an at-sea observer program was presented as a key permit condition to gain access to these southern grounds in the fishery. Subsequently, largely funded by industry itself, an experienced observer was employed full time to work exclusively in the stout whiting fishery from November 2009 to December 2010. Over this period, 110 days of at-sea observation were attained across all permit holders.
The main points arising from the stout whiting observer program were:
• Catch rates of stout whiting were observed to be similar in the two fishing areas for both gear types where direct monthly comparisons could be made—no comparative data were available for otter trawl gear from April through to October 2010.
• Danish seine gear was observed to be more efficient in capturing the target species.
• Relatively few interactions with species of recreational importance were observed using otter trawl, though generally higher rates occurred in the NRA. However, trawling was not observed in the STEA during the winter months when these species might be more available to capture.
• The Danish seine operator had very little interaction with recreationally important species during the months observed (June to November).
• Relatively few prawns were caught, especially when using Danish seine gear. Of the various prawn species observed in each of the two areas using the different gear types, king prawns captured in otter trawl nets operating in the STEA had the highest percentage of total catch (by weight).
• Compared to prawns, the observed interactions (by weight) with crabs were an order of magnitude higher but still relatively low. Blue swimmer crabs and threespotted crabs were the two main species captured irrespective of gear type; both species represented higher percentages of the total observed catch (by weight) in the STEA compared to the NRA.
• The species composition of the bycatch varied between gear types and areas. A less diverse species assemblage was observed in the STEA, making it the ‘cleaner’ fishing area.
• Two permitted species, squids and yellowtail scad, were sometimes observed to be discarded dead because trip limits had been reached.
• Seasnakes and syngnathids (pipehorses only) were the only species of conservation interest (SOCI) observed. They were observed in low numbers and predominantly with otter trawl.
• Compared to otter trawl, the Danish seine gear caught much higher numbers of rays, especially eastern shovelnose rays and common stingarees. Examination of individual trip data showed this to be largely attributable to the occasional capture of large aggregations rather than to consistently higher interaction rates.
• Some 17 interactions with ‘monster’ sharks and rays were observed with the Danish seine gear, though 14 of these individuals were released alive. Only a single ‘monster’ interaction was observed on the otter trawlers, which, unlike the Danish seine, operate with a turtle exclusion device (TED).
• The new T4 discard logbook was not an effective tool for fishers to provide quality bycatch data.
The observer program has provided detailed catch information that fisheries managers can use in making decisions about continued future access to the southern extension area.