What will, hopefully, turn out at long last to be drought-breaking rains across NSW and Queensland may also throw a lifeline to Australia’s largest freshwater fish – the Murray cod – and those who like to fish for it. This iconic species of the Murray Darling Basin has taken a hammering during what has been, if not the worst drought ever, one of the most severe and widespread droughts in Australia’s history.
As inflows fell progressively to the stage where the Darling River was reduced to a mere trickle in places, water clarity improved dramatically.
This has made the mighty cod a bit like the proverbial ‘sitting duck’ for an increasing number of anglers hooked on lure fishing and armed with such effective cod magnets as ‘aeropolane spinners’ and ‘stump jumpers’.
Over the last couple of years, plenty of big fish have been taken on lure right across NSW, Victoria and further downstream through South Australia.
This has led to concerns from fisheries authorities in South Australia that, with so many large fish being removed from the river, the species may suffer permanent damage.
A moratorium was suggested, but the possibility of an indefinite ban on the taking of cod until environmental conditions improved raised the hackles of the recreational freshwater fishing fraternity and the battle lines were drawn.
One of those stepping up to fight in defence of recreational cod fishers’ rights has been long-time cod enthusiast, Rod MacKenzie, who has chased cod as well as callop – otherwise known as ‘yellow belly’ – in the Murray, Darling and Murrumbidgee Rivers since he was a young man.
“The information on which these scientists have been basing talk of a moratorium is akin to guess work because, over the years, so little money or effort has been put towards researching fish stocks in the Murray.”
MacKenzie says that over the last few years he’s never known cod to be so plentiful and his opinion is backed-up by South Australia’s recreational fishing advisory body, SARFAC. Its executive officer, Trevor Watts puts this down to the removal of professional fishing for cod and other native species.
“Every year since commercial fishing ended in 2003, around 20 tonnes of cod has effectively remained in the river. That’s now getting well up towards the 100-tonne mark and these are fish that would otherwise have been harvested,” says Watts.
SARFAC’s Victorian equivalent, VR Fish has also been campaigning against any fishing ban.
BEST IN DECADES
Spokesman Rob Loats backs the claim that cod fishing is the best it’s been for decades and insists that the recreational sector is being treated as a soft target now the professionals are out of the river.
“I’ve been fishing the Murray for cod for over 40 years and presently we’re seeing really good catches from the Murray and many of its tributaries,” he said.
Loats says any moratorium in southern waters, either now or in the future, would also dramatically impact on the other river states.
“Fishing pressure in Victoria, for example, would inevitably increase as anglers simply moved across the border to chase cod. We already have enough problems in our own backyard, with an increasing number of areas being closed to fishing and we absolutely reject any such move,” says Loats.
Some believe more would be gained for the river by tightening up on what they see as regulatory loop holes, which allow some antiquated fishing practices to continue. Rod MacKenzie points to NSW where, he says, in some parts the use of set lines is still permitted.
“This is patently ridiculous,” says MacKenzie. “There’s nothing about this practice that fits the generally accepted modern day concept of fishing being an active recreational pastime. These set lines are left out overnight. By the time they’re pulled, any fish hooked has most likely drowned and that includes any undersize fish.”
THE SA ARGUMENT
South Australia’s fisheries manager, Alice Fistr says Australia’s largest and longest-living fresh water fish has been under pressure like never before and is likely to take several years to recover numbers.
It is, of course, in South Australia, at the bottom end of the river, where this recovery is likely to take the longest, once good seasons return.
Fistr says, while cod do breed each year regardless of environmental conditions, it requires good years of high flows and preferably a good old-fashioned flood, to form relatively strong socalled ‘year classes’.
“High rivers in spring are important to high survival rates of Murray cod larvae as they create an explosion of zooplankton, the tiny aquatic insects that are critical food for newly-hatched cod and other native river species,” says Fistr.
The real concern is that, given several years now with extremely poor inflows into the Murray Darling, there is a high risk that stock may decline significantly unless strong year classes can be added.
What chance then a high river?
In stark contrast to the press coverage of the Christmas floods at Condobolin and Coonamble in NSW, water levels in the Murray Darling Basin generally remain low. Figures on inflows during the drought show, only too clearly, how far the river has fallen and how much ground there is to recover.
At the height of the big dry, figures show that, during the six months from June to November 2006, inflows to the Murray Darling fell to just 610 gigalitres, or in everyday language, 610 billion litres. That’s just seven per cent of the long-term average for the same period and a little over half the previous lowest figure recorded in 1902.
During the two-year period to the end of November 2007, inflows to the Murray Darling system were the lowest ever recorded.
The worry is that the very latest predictions – as at February this year – point to little improvement, at least for southern parts of the Murray Darling Basin.
While the Weather Bureau expects improved rainfall over the next few months, it’s at the wrong time of the year, with high evaporation limiting its value to the river system compared to if it had fallen during the usual winter/spring period.
In the very latest outlook report, there is now considered to be a three-in-four chance of less water being available at June this year than was the case in June of 2007. The report says that, as a result, further contingency measures aimed at cutting back on consumption are likely.
Victorians proudly point to a major re-stocking program as justification that they are doing their bit and that regulations should stay as they are.
In the last few years, millions of cod fingerlings have been released into the Murray Darling system from a hatchery at Snobs Creek in Victoria’s northeast. This program has now been extended to a trial release of year-old cod at Kerang Lakes, near Swan Hill.
But South Australia is approaching the issue in a vastly different manner. In rejecting calls – including from its own recreational angling body – to extend the restocking program to South Australia, it, instead, is following a policy of ‘natural recruitment’.
Fisheries manager, Fistr explains that this involves managing and restoring river flow and habitat, removing barriers to fish migration and regulating for sustainable exploitation.
“We have removed commercial fishing for all native species from the Murray and, in its place, instigated a fishery for the noxious species, European carp. We are also restoring migratory pathways through locks and weirs for native fish as part of the Hume Dam to Sea Fishway Program,” she says.
While deciding not to move on a moratorium for the time being, South Australia has, instead, significantly tightened regulations to further protect the cod. These measures include lifting the minimum legal size by ten centimetres to 60 centimetres to accord with the age cod reach sexual maturity. A maximum size limit of 100 centimetres continues to apply.
Bag and boat limits have been cut in half – the bag limit down to one fish per person per day – while the boat limit drops from six to three.
South Australia has also extended the cod closed season by one month to five months. This now applies from the start of August until the end of December.
If worst comes to the worst and things don’t improve much for the river, a moratorium may be seen as the only answer. And there is a precedent for such a ban. The cod fishery – professional and recreational – was closed for three years from early 1990.
That was aimed at countering what was seen as a dramatic downturn in cod numbers blamed on commercial fishing in the 1950s, when the annual cod catch peaked at 140 tonnes.
Only time – and careful monitoring of the fishery – will tell what the future has in store for the old man of the river.
THE COD CHRONICLES
The Murray cod – scientific name Maccullochella Peelii Peelii – is Australia’s largest freshwater fish, and by a considerable margin.
The largest cod officially recorded weighed in at 113 kilograms. It measured 183 centimetres and probably had lived close to the cod’s known maximum age of 48 years.
There have been unsubstantiated claims of even larger fish being caught and scientists believe the species may actually live much longer, possibly up to a century.
This would enable them to outlast prolonged periods of drought and to capitalise on exceptional conditions for spawning and recruitment.
But really large fish are seldom caught these days and to land a cod weighing in at more than 30 kilograms is considered uncommon.
For this reason, cod have joined the ranks of Threatened Australian Species of National Significance.
The Murray cod was once widespread throughout the entire Murray Darling system. The exceptions were a few small tributaries and the alpine headwaters of some southern rivers within the Murray Darling basin, which itself covers more that one million square kilometres or one seventh of the Australian continent.
Wild cod stocks are now estimated to be less than ten per cent of what they were at the time of European settlement.
They have, in fact, become locally extinct in many small tributaries in which they were once prolific.
As for its preferred habitat, the cod is extremely territorial and is found in deep holes with cover in the form of large rocks, fallen trees and overhanging vegetation.
A re-snagging program being coordinated by the Murray Darling Basin Commission is aimed at reinstating the preferred habitat of native fish, including the cod.
Much clearing of the river has been done over the years to facilitate navigation, with little consideration at the time of how this would impact on native fish species.
An aggressive and opportunistic predator, cod will feed on pretty much anything that its cavernous mouth can accommodate, ranging from spiny freshwater crayfish and freshwater mussels to frogs, tortoises, small mammals and even water fowl.
Maccullochella Peelii Peelii is, indeed, a fish that has shown itself to be a great survivor.
Fossils unearthed in NSW date the Murray cod back to the very origins of the Murray Darling basin, around 26 million years ago.