I live on a canal on the Gold Coast. This artificial waterway has concrete walls and is about two kilometres from the main waterway, the Southport Broadwater. It is an interesting waterway and has a healthy population of marine life. This canal system is over 30 years old, and as such has had plenty of time to stabilise its marine plant life and bottom structure. This canal has a lot of floating pontoons, and most houses have boats. These form structure that fish can hide under and hunt their prey from. There are plenty of bream, mangrove jacks, flathead and mullet in this canal. I’ve been pleasantly surprised how good the fishing and crabbing is in this waterway.
This canal sees significant tidal movement, mostly over a metre to 1.5 metres in a single tide. As such I’ve had good opportunity to observe fish behaviour in different parts of the tide cycle. I feed the fish every day from the back of the house, and now have a resident school of bream most of the time, with in excess of a hundred fish. Some of these are close to a kilo in weight. The only type of scraps that they won’t eat are lemons and onions! Unlike nearly all the local estuary systems, canals water levels go up and down on the tide, whereas in the open estuaries and across the flats, the tide goes in and out, exposing the large and important inter tidal zones where most of the yabbies, worms and shrimp are found. There are very limited inter tidal zones in the canal system. As a result of this the fish in these canals behave differently and must hunt in different ways.
Mangrove jacks have proliferated on the Gold Coast since floating pontoons became common. They are also much easier to catch in daylight hours. In the distant past the best way to catch mangrove jacks was to troll or cast lures at dawn and dusk on a run out tide and as the water levels dropped it exposed ambush points used by the fish that could be exploited. With floating pontoons jacks have an all-tide ideal ambush point, regardless of the stage of tide. It is common to see jacks positioning themselves in the cracks in the pontoons facing into the current waiting for baitfish to arrive on the tide. They are one species that seem to be more common than they used to be which is probably due to the big increase in man made structure available to them. They can now feed easily on all parts of the tide.
Bream are like cockroaches. They thrive in man made water systems, adapt to different food sources eating everything from stale cakes to Brussel sprouts and form big schools in the local canals where they obtain shelter and food. They are adaptable and seem to be very smart. I have a fish cleaning table on the wall next to the canal, and as soon as I move to this area a school of big bream appears at my feet, even before I’ve started cleaning! Because the tide makes little difference to where they school up, they are present nearly all the time. In contrast, the bream out in the main estuary constantly moves up and across the sand and mud flats as the tide rises, then drop back to deeper water as the tide turns and the water levels drop.
I’ve always been fascinated by working out the tides in the waterways I fish. In some rivers, such as the Fitzroy River near Rockhampton, big spring tides see a lot of fish movement, but dirty up the water making lure fishing quite difficult. It is important to plan trips so you know the tidal movement will be at its best for the species you are chasing. In contrast, places like Darwin Harbour tend to fish best on bigger tides. This sees big high tides push up into the many sand flats and mangrove areas, but more importantly the low tide is very low, which makes for fish rich holes and drain run offs that produce a surprising number of decent barramundi.
I probably spend more time chasing flathead than any other species, and all these trips are totally dependant on tide and water quality, as well as the prevailing wind. This year we have had surprisingly good flathead fishing in early summer. The best way to fish currently has been casting big hard bodies and soft plastics on the top of the tide in about half a metre of water. An early morning high tide works best, and if the wind is from the south and there is a bit of cloud cover the chances of success are quite high. Most of the fish encountered have been over 60cm long. On the Gold Coast our flathead season tends to be between June and October, and it is quite unusual to see good quality flathead fishing in December. The excellent fishing in the Spring of 2022 may have seen many of the fish spawn twice.
Flathead are a fish of the inter tidal zones, and the biggest populations tend to be in areas where there are big mud flats and sand flats that fill with the tide then drain off through a series of narrow channels. In simple terms, chase the fish up onto the flats as the tide rises, and follow the draining channels as the tide recedes. Unlike the bream in my local canal, flathead tend to move quite a bit of distance on each tide cycle. They eat a wide variety of prey and many of the prey species are only accessible when the mud and weed flats are inundated on a rising tide. While low tide commonly sees bigger aggregations of fish in a smaller area, which makes them easier to catch, a lot of the flathead feeding takes place on the top of the tide, particularly with bigger fish chasing prey species such as whiting, mullet and garfish.
Mulloway are another species where an understanding of the tide is so important to success. In general, these fish hunt by ambush, and they are the silver ghosts of the estuaries. I find I have my best results fishing the hour either side of high tide. It seems that these fish hunt more effectively as the water movement slows. They are also a species that is capable of hunting mullet and similar baitfish in extremely dirty water. I try to plan my mulloway trips around a tide change. On many of the offshore grounds fish are quite active on the change of low tide. I’m not sure why tide change makes such a difference in water depths of forty or more metres, but the bite is linked to the tidal change. On the beaches mulloway like to feed on high tide when there is plenty of water in the gutters. I used to catch a lot of mulloway from the beach in my twenties. I’d catch a few tailer before dark, go home, and then use fresh tailer fillets when the tide was high.
While tide is predictable, wind is not. In every port there will be wind directions associated with good fishing, and winds that are associated with poor fishing. In my local waters a strong north westerly is associated with dirty water and poor fishing. This greatly effects flathead in the estuaries as well as many of the offshore species, from snapper through to billfish. Southerly winds, particularly if they are light, are associated with good fishing in my area. On the offshore grounds in summer periods of strong south easterlies push the warm water of the East Australian Current close to the shore, whereas northerlies bring cooler dirty water to the inshore grounds. The ideal winds in my local area are a south to south easterly at ten knots or less. Obviously, the ideal wind varies from port to port and place to place, but in most areas, it isn’t too hard to get a bit of local knowledge.
As I’ve written about many times before, tides matter even on the wider grounds off the continental shelf. For unknown reasons blue marlin strikes always seem to be concentrated around a tide change, even though, to us, there is no perceptible difference to the water and current at this time. Closer inshore I have noticed that slimy mackerel tend to rise to the surface and feed voraciously on high tide, and these rippling slimy schools attract the attention of plenty of predators. Black marlin often congregate in big numbers adjacent to these bait schools. At these times a live bait is generally much more effective than a lure, as the fish are totally focused on the bait school and don’t tend to chase lures on the surface. The mystery of why tide change makes such a significant difference to fish behaviour in 300 metres of water remains! I’ve been amazed at listening to the catch skeds in marlin tournaments, where every competing boat provides the numbers of strikes, hook-ups and captures every few hours. The activity is almost always at least double in the hour around a tide change.
Tide changes and the water differentials they create vary greatly across the Australian continent. In some areas such as around Broome in Western Australia, a big tide may see the water rise by up to 13 metres in a few hours. In contrast, areas such as Weipa commonly have ‘no tide days’ where the difference between high and low tide may be less than 0.1 metres and this takes place over 12 hours or more. In every area fish behaviour will be dictated by these tidal movements. In general, moderate tides between the neaps and spring tides provide the best opportunities for anglers.
Fast flowing large tides are used by many species to travel upstream. The big rivers in the Northern Territory flow brown and dirty on big run-in tides after the wet season is over. This can be a time of plenty for the keen barramundi angler. This muddy highway of water sees vast schools of mullet move upstream with the tide, and big adult barramundi chase them in a hunt more reminiscent of an active tuna school offshore. The barra “boof” continually, mullet fly through the air and hundreds of thousands of fish move many kilometres upstream, where they hold on to the snags when the tide turns. Despite the dirty water, big barra seem to easily find your lure, and most of the big wild metre long fish are caught trolling big lures up the middle of the river on a big run-in tide. This big tide also gives a free ride to sharks, crocodiles, catfish and many other predators. The two days before the spring tidal peak and two days after the peak offer the best mid river fishing.
Curiously, when barramundi fishing in dams where there is no tidal movement, tide changes still seem to matter. Bite times in the dam commonly occur on tide changes, and while a lot of this is linked to the moon phase at the time, the feeding behaviour of impoundment barramundi is still tide related. While there are dozens of variables at play, tide is at least predictable.
The modern phone allows anglers to download many applications, and most keen fishermen will have a host of available information on their mobile phone. While you will know when a tide change is due, it is important to keep your own records as to what you caught on a particular day and what the water and wind conditions were. Previous information and experiences are often repeatable, but without documenting, it is almost impossible to remember the nuances and subtle changes in conditions. There is so much to learn about tides, and regardless of where you fish along the coast, they will play a major influence in your results.
