BLOG: Theory busting

There are many theories that we read about in fishing literature and whilst many are likely to hold true, anomalies in fish behaviour will sometimes prompt exploration to put a theory to the test.

Migration patterns are an interesting one - if you can figure out where the fish will be based on the time of year then chances of a decent catch can improve significantly.

My last four fishing trips have involved chasing blackfish (or luderick) in the estuary. My understanding of their behaviour is that they frolic around the ocean rocks and open water in summer then migrate to the lower reaches of an estuary (and the beaches) in autumn to spawn, continuing their spawning run through winter where they tend to enter the estuary and travel up river before coming back downstream in spring for a last post spawn play before repeating the cycle.

Based on that theory, right now you should be hitting the upper reaches of the river if you wanted to target a few blackies.

Another theory is that is often mentioned suggests that the further up river you travel, the more likely the fish will be feeding on weed, rather than cabbage, as weed is the common food source available upstream.

So in winter you should be fishing up river with weed - makes sense right? But surely these fish move around and were eating cabbage only a short while back, so they'd be able to recognise the stuff no matter where they are?

In those four fishing trips I fished three different locations each trip and traversed the entire length of Sydney Harbour and Parramatta river – I fished 12 spots and used a variety of baits in order to put those theories to the test. What I found was that the fish encountered downstream tended to be a smaller average size but seemed to be more prevalent - i.e. we caught a stack of little fellas.
Up river the fish were bigger on average and would eat cabbage with gusto. There was a definite schooling pattern - a couple of spots up river seemed to hold numbers of large fish suggesting a spawning aggregation while the little fellas seemed to school down river, presumably to hang out with their pre-pubescent buddies. More insights will follow in an upcoming feature.

The migration theory was validated and the bigger spawn run fish seemed to be holding upstream while the lower reaches held more juveniles with the odd bigger fish thrown in for good measure. The jury is still out on whether string weed is the best bait for the winter run of fish up river – they still recognise and eat cabbage even though it doesn’t grow prevalently up river.

Another couple of theory busting examples is that I have jigged big kings in summer well offshore (generally a winter time activity) and have seen some spectacular catches of mahi mahi in winter (a summer time species) – if the current is right and the baitfish are around then certain offshore predators will usually make an out of season appearance.

Regardless of what the experts say, it's always worth testing known fishing theories to develop that first hand experience which will help you figure out how to catch those sneaky little fish at any time of day, stage of the tide or time of year.

I'd be interested to hear of any theory busting adventures you've encountered.