Heavy snowfalls, sub-zero temperatures and icy winds are testing the big crowds fishing the run of prespawning brown trout in the Thredbo and Eucumbene rivers, and only the lure of an outsized trophy fish is keeping anglers on station.

The season closes at midnight on June 8 and after that the fish will be left in peace to complete their run upriver to the spawning beds. The rivers will reopen to fishing on the October long weekend.

In the interim anglers are working hard to catch a trophy fish on the traditional Glo Bug and nymph combination and are allowed to keep one fish per day if it is over 50cm in length.

Areas with the largest crowds included Paddys Corner on the Thredbo River and Dennison on the Eucumbene, and some nice fish were caught. Most anglers landed at least one big fish each day and some of the better anglers got up to 15.

Most fish were around the 2kg mark but occasional specimens up to 7kg were recorded. The vast majority of the fish were released.

Anglers recognise the value of the fish in repopulating the streams and feeder lakes and also realise that the fish are unsuitable for the table whilst in their prespawning or spawning mode. Spawning hormones make the flesh soft, flabby and unpalatable.

A few anglers hoping to avoid the crowds made more long treks into the rough upstream sections of the big rivers, but to little avail. Two walked all the way from Sawyers Hut carpark to the Eucumbene Gorge, only to find the river covered by thick ice. They saw one huge fish, which they hooked but lost when the hook pulled.

Despite the large numbers of browns on the spawning runs some good specimens and some rainbows were caught on bait, lure and fly in the mountain lakes.

The most fish came from Tantangara, where anglers braved bitter night temperatures but sunny days for some medium-sized browns and rainbows on brown nymph, Power Bait and scrub worms. In Eucumbene the best catches came from Frying Pan, Yens Bay and Cemetery Point. East Jindabyne and Waste Point were the top spots in Jindabyne.

At the coast most estuary fishing was surprisingly quiet, with only small catches of bream, flathead and whiting reported from Tuross, St Georges Basin and the Clyde River. Coila was one brighter spot, with some big bream reported from the upper reaches and a few nice flathead came from the Bega River. A big kill of fish in Cuttagee Lake, near Bermagui, is being investigated.

Salmon have been the mainstay of rock and beach angling, with plenty of fish showing around Bermagui, Narooma and Ulladulla.

Offshore, kingfish have been taking jigs and bait at Montague Island and trollers have caught plenty of bonito, striped tuna and frigate mackerel.

Bottom bouncers have done well on medium-sized flathead, snapper and morwong, but beating the leatherjackets has been hard.

Out wide marlin are still around and there are plenty of small mahi mahi and occasional albacore. A few yellowfin have shown off Narooma but game anglers are watching for a big school, reported south of Bermagui by pro boats, to move to within boating range in the next few days.