Puppy Pre-school: Fishing mangrove gutter runoff

Welcome everyone to another Puppy Preschool!

The weather here in Central Queensland has been excellent lately, so I have been spending some quality time on the water like a lot of others. While I haven't had any trophy catches, time on the water with family is reward enough. 

People are creatures of habit, we put the same shoe on first every day, and the same extends to our fishing. For me it's hitting structure with my favourite GM100 in Banana, it's what I feel most comfortable doing and it's what I always look to do while fishing. On one of my recent trips around the Keppel Islands, Cod were in plague numbers. We couldn't get away from them, so I decided to try another lure. On went a GM100, but instead of Banana, I tried Purple Rain. And guess what, Cod, Cod and more Cod! This got me thinking, are we limiting our fishing potential by sticking within our comfort zone? 

One method of fishing I've never been successful doing is using shallow diving lures. Sure I have a large collection of shallow divers in the tackle-bag, but I always seek out the deep structure I know. On my last trip to a local creek, I went looking for situations where shallow diving lures would be successful. The creek I was in is your typical tropical creek, mangroves and mud lined banks and the random sandbar to make getting around at low tide a challenge.

I started looking at these banks, and along the bank, there were numerous small gutters. I've looked for these gutters in the past, as they are a great place to find live bait. It was then I had a light-bulb moment. If these gutters hold bait, the fish that eat the bait would also be there! At low tide, these gutters are generally empty of water, but as the tide gets higher, water pushes up these gutters and into the mangroves. The mangroves provide food and protection for small fish and other marine animals at high-tide but at low tide, the water flows back to the main creek leaving the mangroves once again dry for a number of hours.

It was the emptying of the mangroves by these gutters as the tide drops that got me most excited. The gutters concentrate the water and bait into a single flow, which is perfect for ambush predators like Barra, Jacks and King Salmon. But the problem for me is that these gutters are shallow. Every gutter I looked at during the day was less than 1m deep, so my normal deep divers are useless. But I knew fish were there as I could see them on the side-scanning sounder. This was the perfect situation for some shallow diving action.

As I was watching the gutter, I noticed a few things. The water coming out of the mangroves was a different colour to the main creek, and it was also a different temperature. The gutter itself also had a deep channel within it, and this channel wasn't straight.

Pictured above and below: Examples of some gutters at low-tide. At high-tide all the mud is covered in water. Just because they are small doesn't mean they don't hold fish.

So how do you fish these gutters and channels?

There are a number of different methods, and with time you'll work out what one works for you. Here are a few examples for you to try.

Method 1: Casting straight up the middle of the gutter and slow-rolling, with pauses, back to the boat ignoring the channel location. This method is good until you work out where the channel goes.

Method 2: Casting to the side of the channel and working your lure along the channel. You can use your rod to change the swim direction of the lure, driving it along the channel.

Method 3: Casting across the gutter, targeting the fish that are not sitting directly in the gutter, but rather waiting in the main creek for the food to come to them. This method works for larger fish, but you need to be running your lure right where the gutter and creek meet. Look for colour changes in the water and run your lure along these lines.

If you know ahead of time where you are going fishing, use Google Earth to get an idea where the channel is.

Above: This is what a gutter and channel looks like on Google Earth. Notice that the channel within the gutter isn't straight”

Another feature I noticed in the creek was where the mud-bank had collapsed, leaving a large piece of the bank missing but the introduction of a large mud-pile under-water. This opened up 2 different fishing situations, fishing the deep-water side of the mud pile, but also the shallow side of the mud-pile back towards the bank. Fish these mud-piles in much the same way you would fish a rock-bar, but remember the bank side of the pile might be less than 1m deep. Your sounder will tell you exactly the depths involved. Just don't ignore the shallow side of the mud-pile or the shallow-side of any structure.

Three pictures above: These 3 photos show the same collapsed mud-bank from 3 different angles. In this case, the collapsed mud ended up in 3m of water. Using Google Earth, you can check an entire system for collapsed mud banks from home.

As with all lure-fishing, you want to use the lure that best matches what bait is naturally around at the time. Most of the bait that pushes up through these gutters and into the mangroves is less than 100mm long, so using a GM100, GM80 or the new GM60 is a perfect fit. I just received my GM60 from the Old Dog (in Banana of-course) and I can't wait to run it in some gutters in the coming weeks.