Impact of reducing investment disincentives on the sustainability of the Moreton Bay prawn trawl fishery

• On average Moreton Bay prawn trawl fishery is economically unsustainable.
• Economic performance could be improved with investment in fewer, larger, vessels.
• Concerns exist that this would result in increased effort and reduced sustainability.
• Increasing vessel size results in less than proportional increases in catch.
• The existing hull unit capacity cap appears sufficient to maintain sustainability.

The Moreton Bay prawn trawl fishery is one of Queensland’s oldest commercial fisheries, but is currently economically unsustainable. The fishery is characterized by a mix of large and small vessels, with the small vessels facing different licensing and boat replacement restrictions to the large. Industry have proposed the removal of the current two-for-one boat replacement policy that affects the smaller vessels to encourage investment and replacement by larger vessels, although there is concern by managers about the impact of this on total fishing effort and sustainability of the stocks, despite the existence of a total cap in vessel capacity units. We estimate the impact of removing the boat replacement policy for the smaller vessels on fleet performance and total fishing effort, and find that removing the boat replacement policy is unlikely to result in a substantial increase in fishing effort due to the existence of a vessel unitization scheme.