Solutions to cod deaths in Lake Yerrabi There has been a good response to the call for solutions to the problem of Murray cod dying in Lake Yerrabi. Some anglers think it's worth the risk and would prefer to see the lake stocked again with cod, arguing that it has happened only once in 20 years. Others argued that we should spend hard-earned money for stocking of golden perch only, given the success of that program throughout the ACT and in Googong Reservoir. The possible use of solar-powered aerators, such as those being tried out on Lake Burley Griffin to control blue-green algal blooms, was a popular option to help keep oxygen in the water. But much more information is needed about their effectiveness, including size, cost, noise, protection against vandalism and the area a unit can treat. Murray cod season opens on December 1 and new size limits apply. Only fish in the range of 55-75cm can be retained, others must be returned to the water immediately. Catch-and-release enables the fish to grow larger and provide a better trophy later on. The Cod Classic will be held at Lake Mulwala on December 6-7, with $150,000 worth of prizes. For information contact Tony Bennett at codclassic@bigpond.com. Mystery Bass I wrote recently about the mystery of a bass caught in Lake Burley Griffin, given they are not native to the region. One suggestion is that bass stocked in private farm dams in NSW, specifically in the Googong area, have been washed down to Lake Burley Griffin during floods. It's entirely tenable and hard to police or control. People do some silly things, often without thinking through the consequences and can stock fish without permission. In the past we've seen European carp thriving in farm dams draining into Googong Reservoir. Luckily they were detected and killed before they got into the reservoir. Murray cod stocked in private dams upstream from Googong also were known to have been washed downstream to the reservoir during a flood event. Another suggestion is somebody is surreptitiously stocking the lake with the fish, which can be purchased from several hatcheries in NSW. This is undesirable, illegal and disruptive to ACT and NSW Government programs. The fact another bass was found in Lake Ginninderra, on a separate drainage system to Burley Griffin, two years ago, supports this possibility. Given that bass cannot breed in fresh water and seem to be able to survive Canberra's cold winters, Government may wish to consider stocking them as a recreational species. Similar programs in Victoria, NSW and Queensland have been highly successful and welcomed by anglers but before this could be undertaken it would need to be carefully evaluated by the ACT government fisheries ecologists. Trollers succeed Fishing was hard at Eucumbene for bait and fly anglers, but trollers reported some good catches, mostly on Tasmanian Devils. One boat came back from a morning session with 11 fish then backed up in the afternoon for another five. Most of the fish were browns around 1kg. Bryan Pratt is a Canberra ecologist.