Proposed northern Australia water developments pertinent to the Northern Prawn Fishery: collation and review
Assessing data poor resources: developing a management strategy for byproduct species in the Northern Prawn Fishery
Declines in world prawn prices and rising fuel costs are contributing to a shift in fishing practices in the NPF and an increase in targetting of valuable byprduct groups such as bugs and squid. Little research has been done on byproduct in the NPF or in other tropical prawn trawl fisheries. The 2002 catch of byproduct was almost 250 t (AFMA) and comprised of four main groups (squid, cuttlefish, bugs and scallops) of at least eight species. However, the catch of squid alone has been over 400 t in some years (AFMA). The impacts of trawl catch on these groups have never been assessed. This situation is common among many Australian fisheries, where despite the value of byproduct being substantial, they lack sufficient data to undertake specific assessments or even to evaluate options for their management. Thus, there is a need for methods to help identify management options for groups that are data poor like byproduct species in the NPF. New approaches developed in this project will be of value to other Australian trawl fisheries especially the Torres Strait Trawl, East Coast Trawl and Western Australian prawn trawl fisheries. Operational advice from this project would contribute to at least two possible management strategies: the first would be to control fishing on byproduct through species-specific stock assessments. The second would be to control effort on byproduct through spatial and temporal closures, by identifying the key areas and seasons when these byproduct groups are most vulnerable. The most efficient approach to assess the relative merits of alternative management options is to adapt existing trawl impact assessment scenario models to account for non-target catch in their strategy evaluations.
Final report
Effects of trawling subprogram: An investigation of two methods to reduce the benthic impact of prawn trawling
Due to highly publicised concern about the impact of prawn trawling to the benthos, particularly pertaining to the GBR region, there is a critical need to minimise the intensity of seabed impact and demonstrate that the residual impact does not constitute a threat to biodiversity. This is consistent with the goals and strategies set by QFIRAC in their Strategic R&D Plan: 2002 – 2006. Specifically this need relates to QFIRAC’s key R&D areas titled, “Effect of Fishing/Cleaner Production” and the underlying goal, “Environmentally friendly fishing practices and technologies in place, which reduce to a minimum the impact of fishing on the environment”. The stated strategies of QFIRAC with respect to this goal are to support the quantification of the impact of trawling on the benthos and the development of innovations that minimise this impact. This project seeks to contribute to the latter strategy by quantifying the relative benthic impact of modified trawl gear with respect to a set of standard contemporary trawl gear.
The R&D plans and strategies of all advisory bodies to the FRDC contain high priority goals to reduce the impact of fishing on the environment. For example, the priority research areas identified by NORMAC includes; “improved efficiency in fishing gear and techniques in order to reduce bycatch and discarding, increased survivorship of bycatch and environmental impacts on the benthos”. This demonstrates that the proposed work has widespread relevance in terms of its potential application. The proposed work directly relates to trawling operations occurring in the GBR, which is a world heritage area and a national icon. This certainly makes the work of national significance.
Correspondingly there is also a need to determine the effects of the proposed modifications on the operating efficiency of trawl gear (operating efficiency can be thought of as a relative measure of the catching and engineering performance of trawl gear). This recognises that it is not only important to develop fishing technology that has improved environmental performance, but also it must maintain or improve the economic viability of fishing enterprises otherwise the technology is of low value to the industry and the community. This is consistent with FRDC’s Industry Development goal (planned outcome) that, “The commercial sector of the Australian fishing industry is profitable, internationally competitive and socially resilient”. The prototype devices to be investigated have been designed with the intention of maintaining or improving the catching and engineering performance of the trawl gear. The project will quantify these relative performances for the modified trawl gear with respect to standard contemporary gear.