The main objectives for managing the marron fishery are to:
preserve a sustainable recreational wild marron fishery;
support the production of high-quality marron by the aquaculture industry; and
maintain research programs for selective breeding and conservation genetics.
Marron are endemic to Western Australia. Due to environmental and fishing pressures, commercial wild harvest of marron was banned in the 1950s and the wild fishery became wholly recreational.
However, ongoing changes to natural marron habitat, such as declining water quality and quantity, meant even greater levels of protection were needed to keep the fishery sustainable. Over time this has involved reducing the recreational fishing ‘effort’ (the amount of fishing) for marron.
In 1987, after marron catches collapsed due to overfishing and drought, the fishery was closed for two years then reopened with much stricter fishing rules.
We manage recreational marron fishing through seasonal and area closures; size, bag and possession limits; and restrictions on the type of fishing gear used. In addition, recreational fishers require a licence to take marron.
In 2004 the season was shortened to only 16 days but it has now been extended to one month.
Monitoring, assessment and research
Detailed research on the marron stocks in south-west rivers has been carried out since the 1970s.
Currently, we monitor stock levels before the opening of the fishing season, when our researchers carry out an annual stock assessment survey by trapping marron in many locations throughout the south-west.
This survey provides data on abundance and biological characteristics for key marron populations. In addition, we survey in-season catches of licensed fishers.
The data collected is used to monitor trends in stock levels, enabling researchers to recommend management adjustments when necessary. Current breeding stock levels are assessed as adequate.
In 2011 the total catch was below the maximum target set, and total effort was estimated from phone surveys at about 21,500 days, slightly less than the 2010 season. Fishing effort has been assessed as acceptable.
2011 marron catches and status
| WA marron fishery |
96,000–136,000 |
74,400 (estimate) |
Adequate |
Acceptable |
|---|
The Shannon River is closed to fishing to provide a representative river system where researchers can assess the role of environmental factors on marron populations. In 2011 it was decided this closure should continue.
We are also studying the Margaret River hairy marron, found only in the Margaret River. The more widespread ‘smooth’ marron, the basis of the recreational fishery, is outcompeting the hairy marron within the Margaret River, and the hairy marron is now listed as critically endangered.
We are leading the hairy marron recovery program and our researchers are now focused on genetic research to test the purity of the hairy marron’s genes. Animals identified as being genetically pure form the basis of the breeding population established at our Pemberton Freshwater Research Centre (PFRC).
Our researchers have also worked with the marron aquaculture industry to develop best farming practices. They have bred a strain of marron with the most desirable characteristics for aquaculture purposes, such as a fast growth rate and large size. The marron from our selective breeding research program can grow twice as fast as those stocked on most commercial farms, doubling production levels. We are maintaining a population of this faster-growing marron strain at the PFRC.