In the previous article of this series we made a beginning to putting it all together. This is the next in the series and takes this a bit further. The knowledge of "the food shelf" means we know where the fish feed. Think about this ... that is also the place where they can be caught. Not where they rest, but don't feed.

So a very very big part of the problem of having success on large lakes boils down to the specific difficulty of finding the fish after they go onto the food shelf. That is the purpose of this article.

Close your eyes and picture it -  we are looking at a lake as blank as the sea, flat water for miles.
We should go out beyond the shallows into the permanently submerged, weed growing zone, and then we should stop before we go too far.
If we go out too far we are extending our search into the resting, less fertile deeps, and the tradeoff is that we cover more fish, but they will be less active, and we have doubled or tripled the amount of lake to search. That is like wasting time and effort searching for a previously undiscovered fishy reserve. It doesn't exist. It's usually better to concentrate on where they feed and are active. That's why - after many years of fishing down in 25 - 40 feet of water, I now place that zone down my list of priorities. Sure there are big ones down there, but there are also other big ones in the middle depths, and they are far more likely to take a properly presented bait.

This is Ireland and we usually have no thermocline to warm the top layer and push the fish down. If I were in mainland Europe the lack of wind allows the top layers to warm up, and the fish go down into the cooler zone below, and in that case fishing deep becomes our standard starting point.

We can adapt to that here by having a two pronged approach:
A prolonged calm period of warm summer weather, high pressure, warm, with no wind, sheltered lake location, should make us adopt a continental approach first: locate the thermocline and fish the cool layers where it goes from warm to cool. In Irish lakes this usually means fish the deeper edge of the food shelf down say starting 16 feet down to 30 feet.
On the other hand - when we have had the more usual low pressure mixed blustery weather in the last week and a half, go and fish the food shelf, then work shallower if there is a wave, or search deeper if there isn't a wave. That means for Irish lakes start at 15 feet, then try 14 and 18 feet, then come up to 9 - 12 feet and then down to 20 - 25 feet if that is necessary.
These are summer strategies. Early season has it's own considerations which override the standard plan, and we looked at those in a previous article of this series. Night fishing also has other different considerations.

So we have chosen an approximate depth to concentrate on. The next thing is to decide where.
The places are anywhere there is a definite fish attracting feature on the food shelf. You need to look for dropoffs, channels, and humps and saucers in the lake bed for all fish. Map their locations so you can come back to the feature later.
For predators add broken ground, deeper than usual weeds, open water where waves can reduce light below the surface and make hunting more successful, and fish concentrations.
For cyprinids add hard bottom (where mussels have a greater density) "islands" within muddy bottom areas (few or no mussels), sheltered bays with softer mud where chironomids can be filtered.
A good sonar will locate most of these features.
Binoculars during an evening calm can locate more as fish rise from the bottom to cruise surface layers at dusk.
Tench, bream and carp roll at dawn and also have regular migration routes and will give away some more locations to those anglers fishing at these times.
Study the action of fly catching birds on calm days to locate the bloodworm holes. It has to be calm, because if there is a wind, lake currents will move the hatching pupae before they reach the surface and the birds tell you there is a hatch, but not the place the bloodworms live on the lakebed.

The single biggest feature I want to see in a food shelf area is a channel of deeper water through it, or a channel leading to it from another feeding area. That can be a channel in the conventional sense, or it can be an inlet of deeper water penetrating into the raised food growing area. It can be a narrow entrance to a bay, though these seem to have non feeding fish a lot of the time. A sunken river channel is excellent.
Either way it's a place where large fish can fade away and vanish into when disturbed. The large fish always prefer this, and one of the main reasons dropoffs are good is the fact that for a large fish cruising a dropoff, all of one side is "escape route".
Google Earth and the online maps come in very useful here. Get the satellite view or aerial photo view. The shallows are usually visible, fading to black. Sometimes there is an area of black (deep) enclosed by the shallows. That would be an interesting place. An area of shallow surrounded by black is even better.

A deeper channel through the shallow productive area can be a goldmine, never ignore it on reservoirs. Reservoirs have the same big long channel extending through the deeps this being the old flooded river bed. Big fish can cruise to within catching distance from afar on this major feature.

There is a different version of the same feature for natural lakes. On a natural lake over the thousands of years, the bottom has been eroded much smoother than reservoirs. Features are ground down and fewer in number. By comparison the reservoir bottom is full of features.
But the lowest drawdown level represents a magic place in a natural lake. It is the place above which the lake has dried out every so often, maybe once every 20 years only. However, when that happens, and the lakebed dries up, the streams that flow into the lake begin cutting a new channel through the sand and muddy flat bottom. The deeper channel gets re-cut, re-etched in the lakebed, while the water is low, and later after the lake rises back to normal level it is still there. At normal water height the waves erode the channel at the shoreline (normal level) and remove the visual clues as to the magic feature lying within casting distance a little offshore, leaving it for the fish to colonise and feed on, and us to fish if we recognise it for what it is.

The next excellent feature to look for in this depth of water is a sunken tree, or section of one in deep water. When a tree merely overhangs a pool fish lodge under it for cover. When the tree is in the water it becomes a better fish holding spot. If this tree is located in about 15 to 20 feet of water the place can be a really hot fish holding structure.
I'm specifically thinking here of trees that flow down a river during floods, into the lough, and then after floating for a while maybe tethered by the little branches the wood becomes waterlogged and the tree sinks. On sunny days carp of size will bask here, and pike will hold in these places too. Wood in the water is a superior trout attracting structure. And perch are also attracted to such places. The key is that the tree (snag) must be lying in a depth and location that is already good for fish to be in, but the tree gives it added attraction to fish.
I once had a magic hour on Blessington, a water noted for the small quantity of good pike and the many hours required to get them. Well on this particular day I found a full size sixty foot beech tree lying on it's side in 18 feet, only the thick timber left, and then had 5 pike and lost 2 others in consecutive casts, not jacks, all doubles to about 18lbs and one (not landed) a big twenty. On another trip my partner had a 26 pounder from this spot. Another reservoir I regularly fish usually gives one to three pike per session from three sunken trees I am acquainted with, best so far 23lbs. Those trees are in 12 to 18 feet water along a dropoff and the cruising fish seem to stop and accumulate in these places.

There are deep banks where the shore drops off into deep water in close. In these places a fallen tree which is still attached to the shore will have fish around the sunken branched end. The greatest number of fish will not be located under the thin branches themselves, but more towards the middle section of tree where the trunk forks into thick branches, and then they fork again, and there is usually clear water underneath and around for big fish to move when they want to.

So sometimes the food shelf appears to be a sandy flat bottomed bay a mile wide with weeds sprinkled around, and your first impression is "where are the fish holding features? It's too big to fish it all.". But if a sizeable river flows into the lough nearby, there will often be some sunken trees to be found and fishing these will usually answer to your question. The bigger the inflowing river the bigger the logs are there to be found. Look for the ones laying on the bottom on or outside the dropoff. Find and fish any "underwater inflow channels". Try to be there at dawn and dusk for few days at first. And use heavier tackle than normal because you will need to have plenty of stopping power near that wood .

Norm

This is the sixth of The Reading Large Lake Series, articles on How to Study and Read Large Irish Loughs & Large Still Waters written and published in the FishingTalkIreland.com Forum