Earlier this year, the Victorian Murray Cod Reference Group was invited to comment on a range of changes that DEPI (Department of Environment and Primary Industries) is currently seeking public comment on. These changes are a dramatic departure from historic management methods, and to some people, may seem totally foreign.

While I was not part of the reference group, I did have the opportunity to ask Anthony Forster (Manager – Inland Fisheries) from Fisheries Victoria a range of questions about the proposed changes. I will say before you read this that after listening to the answers I am an advocate for these changes. I see it as a sensible use of available science to improve regulations to enhance fish populations and give those wanting to take a cod an opportunity to do just that. So let’s learn more about what’s proposed.

Q: Anthony, can you provide our readers with a list of the proposed changes?

A:

Currently in Victoria, recreational fishers can take Murray cod above a minimum size of 60cm and below a maximum size of 100cm. A bag limit of 2 Murray cod per day applies.

Fisheries Victoria is proposing to introduce a revised minimum size for Murray cod of 50cm and a maximum size of 70cm, in all waters. We are also proposing a bag limit of two cod per day for lakes and impoundments and 1 cod per day in rivers.

Q: Dropping the size limit to 50cm seems like a big departure from all the fuss made about protecting the ability of a fish to breed once when the size limit was raised to 60cm. Can you elaborate on this please?

A:

You’re right Stephen. For a long time, fisheries managers set minimum sizes that would afford a young Murray cod the opportunity to breed at least once before it could be harvested. That’s why, as we learned more about size and age at maturity, the minimum size for Murray cod increased a number of times e.g. in 1975 (50cm minimum size) and in 2009 (60cm minimum size). This approach assumes early maturing Murray cod (e.g. under 60cm) successfully breed in their first season however this may not be the case.

From hatchery experience, we know that Murray cod greater than 70cm are more effective breeders because they are more experienced and yield more and larger eggs. For example, a first maturing female Murray cod of 53 cm will produce around 10,000 eggs, compared with 90,000 eggs for a 100cm fish. For wild stocks of many fish species around the world, it’s now been shown that the large, older females contribute proportionally the most to raising the next generation.

Q: A slot limit is an interesting management tool, how did you arrive at a slot limit of 50-70cm?

A:

During 2012, in collaboration with researchers at the Arthur Rylah Institute and the University of Florida, Fisheries Victoria gathered together decades of Murray cod population data and tested a number of bag and size limit scenarios using two independent Murray cod fish population models. The results clearly showed that narrower slot limits e.g. 50 to 70cm, were far superior in protecting breeding fish and rebuilding Murray cod numbers than current size limits.

We have also had feedback from recreational fishers that they were more comfortable in taking a smaller, immature Murray cod for the table than a larger, more important breeding fish. Also, smaller Murray cod are less fatty and more palatable than larger Murray cod.

Q: Reducing river bag limits to 1 fish will create some waves within the river fishing community that likes to keep a couple of fish. How was the proposal to reduce the bag limit in rivers reached?

A:

Recreational fishing pressure has altered the natural size distribution of Murray cod, such that there is a peak in the abundance of cod just below the legal size of 60cm. Although few fishers currently take their bag limit of 2 Murray cod a day, there was concern that a pulse of fish between 50 and 60cm could be harvested soon after the introduction of a new 50 to 70cm slot limit. A bag limit of 1 Murray cod a day will moderate this initial take and, in the longer term, improve Murray cod breeding success in rivers. Recreational fishers we spoke to felt that, because Murray cod of 50 to 70cm are likely to weigh between 2 and 7 kilograms, this represents a reasonable daily take for the purposes of a meal.

Q: You talk about scientific modelling and how these proposed changes will improve outcomes for Murray cod populations, what exactly do you mean by improve outcomes?

A:

The results of our fish modelling analyses strongly indicated that over a 15 year time-frame, by adopting the 50-70cm slot limit scenario, we might look forward to a 42% increase in Murray cod sustainability, a 146% increase in the number of trophy fish and a 12% increase in the number of fish available to harvest.

Q: So your modelling suggests there will be more Murray cod, does this mean anglers, in years to come, can expect to see more Murray cod on their line?

A:

The modelling predicts recreational fishers will catch more Murray cod with a lot more larger Murray cod being encounter (and released) in the future.

Q: I note that the bag limit in lakes remains the same, why is that?

A:

Because Murray cod are less likely to breed in lakes than in rivers. Victorian lakes and impoundments are primarily managed as stocked fisheries. For example, one million Murray cod were stocked into Lake Eildon over a recent three year period.

Q: So stocked fish are there to be taken by anglers, while wild fish are more protected? Can you elaborate further on this?

A:

Yes. While we encourage Murray cod fishing in rivers and lakes, rivers experience more fishing pressure and these Murray cod are more vulnerable to harvest. By developing strong and viable lake fisheries, we are also diverting fishing pressure away from critical breeding populations of Murray cod in rivers.

Q: The reference group were briefed on the proposed changes and given access to some of the science behind the decisions. What did they think of the proposals?

A:

The Murray cod reference group included some of Australia’s most experienced Murray cod fishers and advocates. After a detailed explanation of the science behind the proposal the group was supportive of the proposed changes.

Q: Traditionally, reference groups are made up of government friendly advocates, but this focus group was different. Can you explain how participants were selected?

A:

Because we wanted to road test the science with recreational fishers, we invited a wide cross section of representative and independent fishers who brought to the table a variety of fishing methods, opinions and perspectives. We also invited a few fishing journalists who write about cod fishing to help us communicate our messages to the wider fisher audience.

So with all of that information, I hope you can come up with some of your own thoughts on the proposals. There is a limited time in which you can have your say due to our publication deadlines, however, as you read this there will be around five weeks left to comment. I know I’ll be commenting and I hope you will too.

I love fishing for Murray cod and regulations that might allow me the chance to tangle with more cod, keep one that will not impact on the population too much and know that all those big beautiful green fish are protected, seems like a good choice. Ultimately we recreational anglers will sway decisions by input, so now’s the time to let Fisheries Victoria know what you think.