A recent trip to PNG made me realise that shut-down fish are possible even in the most remote locations, and not just in the heavily-fished urban regions.

Shutdowns can happen for a number of reasons. A flush of cold water from either rain or currents; barometric pressure systems; de-oxygenated water and I’m sure a whole heap of other reasons we don’t even know about.

Shutdowns mystify me. Are the fish still down there and simply not feeding or have they cleared out of the system altogether?

I find it hard to believe that all the different species just 'up and leave'. On the other hand, out of a school of, say, 200 or so trevally, even during the worst shutdown you'd expect at least a few to be hungry enough to accept an easy feed.

Regardless, days can slip by without even losing a bait. During a bad shutdown, even the species usually considered to be pests, like cockney bream and pike, are off the chew.

Shutdowns are typically more common in the colder months but can occur at any time of year.

Lure fishos are usually the first to suffer and while the most common and successful solution is to switch to bait, certain changes in lure tactics can occasionally turn the tide.

Specifically, downsizing lures dramatically and working them deep and slow can produce surprising results during shutdowns, even after bait has failed.

Here are a few hints that might help to turn the tough days around.

In Winter, most of the fish in the upper reaches of a waterway will turn right off. The upper reaches, being shallower and influenced by influxes of very cold freshwater, cool down earlier than the lower reaches.

The temperature down around the mouth of the various waterways is more influenced by the ocean, which generally takes much longer to cool.

So better fishing will be found down around the lower reaches and in the deep, flooded-valley waterways around Sydney.

Best results in this situation will be had on the incoming tide, which brings warmer ocean water and stimulates feeding. The outgoing tide will bring cold water from upstream, with opposite results.

In Summer the opposite occurs – the upper reaches will be warmer than the ocean. We often get dodgy cold currents in late Spring and early Summer that can have devastating results in the lower reaches, including fish kills.

A few seasons back we had one of these events and the results were very interesting. Dolphins, as well as fish, died as water dropped dramatically from 22° to 14°. Fishing was a complete shutdown and we couldn’t even find squid, which usually don’t mind the cold.

A lot of pelagic fish found refuge in the upper reaches, way beyond where you would normally find them, and stayed there until the cold current backed out.

We had a huge influx of a variety of fish forced upstream and held there by a natural, but invisible, barrier of cold water. I find my temperature gauge as invaluable as my sounder.

Overall, an outgoing tide bringing sun-warmed water downstream is a likely trigger for shut-down fish in summer.

Hydrographical temperature charts and a temp gauge on your sounder should always get plenty of attention, particularly so in a shutdown.

Use only the best baits; this means ultra-fresh or live. Buy packet bait from outlets with a large bait turnover, minimising your chances of getting a packet that has been sitting in the bottom of the freezer since Christmas.

Specialist bait outlets usually carry a supply of live baits, such as yabbies, prawns and nippers. At this time of year they are well worth the investment.

Slimy mackerel and squid are prevalent through Winter and make excellent cut or live baits.

Fish a variety of baits. You’ve got to work hard to get a feed and this includes sampling the area to see what species are on the chew. It’s no good fishing exclusively for trevally, for example, with top quality peeled prawns if the trevally are absent or shut down.

There could be six big john dory cruising around down there, but they won't take a peeled prawn.

Setting out a spread of baits and techniques everywhere from the surface to the bottom will give you a better chance of ‘sampling’ what is around and what’s biting.

Berley is a good way to kick-start shut-down fish but be careful not to overfeed them. A smell and an entree is all you want to give them.

Good berleys include leftover fish frames from your last catch mashed through the berley pot, and bran/laying pellets/bread mixed with a bit of fish oil.

Start your day by fishing the shallower areas first.

In Winter the water can become very clear and fish will not stay in the shallows long after sunrise.

Fish the shallows from an hour before sunrise to an hour after and then move to a deeper location.

In the afternoon, the reverse applies; fish the deep first and then move to the shallows on dusk.

Concentrate your effort around the turn of the tides. Baitfish are forced to change their holding position, which usually relates to eddies, when the tide changes. Predator fish take advantage of this move.

Keep moving about. If a spot hasn't produced the goods within an hour or so, move to another.

Fish are less inclined to move when they are shut down so it’s up to you to go and find them. Make sure, though, that you are well set up in your favourite spot for the turn of the tide.

There are a few fish that can usually be relied on to save the day if all else fails.

Blackfish (luderick) are an excellent standby, providing you can find some weed. Bringing some weed with you as one of your bait options isn't a bad idea and if it is looked after properly, good weed can last for up to two weeks.

Drummer and groper can usually be relied on but, once again, they require specific baits. Groper are suckers for live red crabs and the most of our southern coastline abounds in groper.

Drummer can be taken on cunjevoi or prawn baits. Cunjevoi is the superior but is much harder to obtain.

Prawns are an excellent second option and can be obtained from most bait outlets.

Leatherjackets are abundant throughout the system and are suckers for peeled prawns – something you should already have with you as part of your Winter bait selection.