SEEING THE UNSEEN (READING A RIVER)
SEEING THE UNSEEN (READING A RIVER)
SEEING THE UNSEEN
Reading a Stream
(By: Ali H Husaini)
The most often asked question while fishing a River is “where shall I fish”? and on guided by a friendly local, the angler sets his rods, little knowing about the fish species found in that particular spot. I have been guided by locals to spots, locally called as Kunds (कुंड) which were supposed to be as deep as one could imagine but on examination turned out to be only four feet deep! Fishing a River blindly may produce a fish or so but many a time the angler returns home empty handed, not even realising that his bait was lying in an area where there were no fish! If one really wants to exploit the full potential of the river or wants to target a specific fish, he should learn to read the many features and currents found in a River and associate them with specific fish species.
Fortunately, even though the term used here may sound very complicated, reading a river and choosing appropriate spots is simple. The habitat of different fish is primarily governed by factors like availability of food, water currents, temperature and place to take shelter from predators and currents. Understanding the migration pattern of different fish species also helps as one can target them during that time also.
Classification & Features:
From the point of view of angling, Rivers can broadly be classified into three different types, namely Streams, Rivers and Estuaries. Streams are basically small flowing water bodies, draining in a river or lake. The stream is fed by rain, spring or seep and can be seasonal or permanent. The River mainly originates from a glacier and is also fed by many streams and empties in another River or Ocean. The part of the River which is affected by the tidal activity of ocean and alternately carries fresh or Salt water due to high and low tides is known as an Estuary (Brackish environment). These three differ considerably in many characteristics and carry some different fish species so studying them separately will be advantageous. In this chapter, I will limit the topic to geographical, hydrographical and biological characteristics of different features in a Stream only.
Before going any further, let’s understand different terms (Glossary) to be used in this discussion. I want you to remember few words. These words may appear alien to you on first glance but once explained, you will immediately co-relate them with such kind of features you must have seen hundreds of times, while fishing or passing a River. These words being Meander, Knickpoint, Riffle, Rapid, Pool, Point Bar, Cove and Confluence. Don’t get daunted by these fancy words, if fish can understand them and use it to their advantage, we too can understand them easily.
The Meander is simply a bend in a stream. The flowing water current cuts the outer bank and deposits the sediments on the inner banks. The main channel of the stream will pass close to the outer bank. It will be of interest to note that the water current in all part of any stream is neither constant nor unidirectional. The topography and hydrology defines the velocity, direction and patterns of current in any flowing water body. Below is a pictorial description of Meandering of a stream.
Learning the complex subject of Hydrology will not be possible for us anglers but having a bit of idea about flowing water will serve our purpose. In a flowing stream, no part of water is stationary. Either the water is flowing downstream or is rotating. Even, as we will discuss later, in some cases the water is moving upstream! Though the velocity of current is different and with the varying speed, the scouring of the bottom and banks is different. The fast moving currents scour and displace sedimentation, sand, shingle and other particles and deposit them where the speed of current is lesser. This is a very important point to bear in mind because, the same factor affects the accumulation of food in a stream environment and those are the places one should look for the fish.
In actuality, the outer bend of Meander will not have a cove unless there is an obstruction causing whirlpool or a seasonal inflow of water within the bend. These pools can also be created due to man intervention or cattle. These coves may seem inconsequent but are gold mine to target some very good fish.
The above diagram depicts the cross-section view of a Meander. One can see that the outside bend is the place, where the flow is fastest and it is also the deepest spot, but the water current deposits the sedimentation, sand; shingle and other particles on the slip off slope of inside bend.
In very simple terms, Knickpoint is a geographical formation of a river or stream, on either side of which the speed of current is considerably different. This phenomenon occurs due to abrupt change in slope or gradient and is best described as a water fall. The downstream currents of a Knickpoint have much greater speed and so have much more scouring capacity. Invariably, due to this, you will find a deeper pool at the bottom of a Knickpoint. As the water is falling over a space, the dissolved oxygen percentage (DO %) of this water is higher than the preceding water.
The varied current speeds and the geology of the place combine to give the Knickpoint a particular shape. The complex dynamics of various currents creates many structures which becomes an ambush point for many predator species. The fast currents disorient the bait and these predators find them easy prey.
From the above illustration, it is easy to understand about the characteristics of the lateral current patterns but it is almost impossible to ascertain various multidirectional current patterns. The many currents combine to make a unique biodiversity which are really good spots to explore.
A shallow and short span of river or stream flowing over cobbles or gravels is known as Riffle. The water flowing through Riffle is turbulent and is rich in oxygen. A breeding ground for many fish and micro-organism and insects, Riffle play an important part as a habitat requirement for fish.
The calmer water of Pools, adjoining a Riffle provides shelter to a fish from fast currents and extreme temperatures. The fast and turbulent currents associated with Riffle have increased scouring capacity and thus create pools on the downstream side. The same currents create Meanders and are very much instrumental in rejuvenating a Stream or River. The water coming in these pools from the Riffle is rich in nutrition and Oxygen. A preferred habitat for fish, specially Carps.
Rapids are section of streams where the bed of the stream slopes considerably and the water flowing over it is very fast and turbulent. The bed of Rapids is rocky and is uneven. Some rocks also protrude out of the surface and due to the turbulence and speed of water passing over these rocks; the water mixes with the air bubbles and appear foamy and white.
The water flows through these Rapids, cascades down the rocky formation and empties in a Pool or deeper channel. The upstream of channel is also a Pool. Many a predators take advantage of these fast flowing currents to ambush bait fish moving from one Pool to the other. Any calmer water along the edges of these Rapids also holds some good Carps but the main target from a Rapid is a predator species.
In a meandering river, carrying course sediment and gravels, the Riffles and Pools form alternately. Due to sinusoidal pattern of a Meandering River, the variations and patterns of corresponding currents, the flow scour the bed from one place and deposit it on other places. The riffles are the part where the flow deposits the material whereas; the Pools are places from where the bed and banks are scoured.
Pools have much deeper and calmer waters and the bed construction is of finer sand and silt materials. As discussed earlier, the aerated water of the Riffle and abundant food supply keeps these Pools healthy habitat for fish. The calmer water also gives refuge from faster currents and extreme temperatures. Given a uniform geological condition, the depth of the Pool will be maximum near the outer bend in a concave shape along the course of the river and decrease gradually towards the inner bend across the course. These Pools are very good Habitat for Carps and other small fish and in turn, are also preferred by many predator species.
The currents, when the flow passes the inner bend of Meander, it creates a Vortex. In simple words the water passing does not go in a straight line but rotates there. These rotating currents have the characteristics of depositing heavier particles like silt, sand and gravels.
This accumulation occurs below the Slip-off Slope and gradually increases in mass till it reaches the top of the water. These formations are crescent shaped with a flat top and have very gentle slope. During the time of flooding or water rise, they submerge and catch lot of driftwood and other debris on the inside. The flow of water is also very slow in the shallow waters of a Point Bar. Many Carps feed on decaying wood and insects breeding therein and so, the inside of a point bar, even though shallower, is a very good fish Habitat. During high flow period, the Point Bars, especially the ones with vegetation growth on it give refuge to fish from fast flow and are a good habitat for them.
Cove formation occurs due to hydrological and dual geographical conditions. The scouring currents, due to different geographical conditions, scour the softer strata whereas the harder strata remain the same. The variation in varied shaped banks further creates different currents (Eddy Current, Vortex, etc) and these currents scour the banks further. In time, a cove is formed which is extended from the bank and often holds deeper waters.
These formations act as food trap and hold some good fish. These are also excellent ambush points for predator fish and they are bound to patrol these area. Overall they are as productive as Pools and can give you a record fish.
Confluence is a meeting of two streams to form a separate stream or river. Due to the varied speed and temperature of two different flowing streams the water joins in a way that it doesn’t mix for a period of time and flows alongside for a considerable distance.
There is a well defined ‘V’ shaped formation of calmer water where these two streams are meeting. Varied temperatures, food source from two streams and increased volume of water makes these confluences a very good fish habitat. In case, the flowing water from one stream is murky, the predators lie in wait on the edge of the murky water to prey upon the unsuspecting bait fish passing by.
The combined volume of water, coming from the two streams have more scouring capacity and that makes the downstream of any confluence deeper and wider. This deeper water is good fish habitat and holds many species of fish.
Special feature occurrence in a river can be natural, accidental or manmade. Bridges, Jetties, dams etc are some Manmade Features.
To understand the characteristics of currents associated with these kinds of structures, it is imperative to understand a bit of Hydrology. Few characteristics of flowing fluid which are of interest here being:
- During the flow, if the channel decreases, the speed of the flow will increase. Similarly, if the channel size is increased, the speed of flow will decrease.
- Any obstruction in the path of flowing fluid creates vortex and Eddy current (The current which flows opposite to the main flow)
Due to these varied currents, while moving from one current to the other, the bait fish gets disoriented and the predator species takes advantage to prey upon them using the depression behind the obstruction as an ambush point.
Dual geological conditions also create obstruction in flowing streams. An outcrop of rocks, small islands, dunes etc is natural obstruction and are very good places to target fish.
Accidents like landslides, falling stones, trees falling in the Stream during flooding etc also create good fish habitat and can be exploited to catch some good fish.
The submerged trees are fantastic place to target carps as well as predator fish. These are also nurseries of small fish and provide them ideal hiding spot.
The behaviour of any stream and subsequently the fish holding areas changes with weather and the increased level of water, temperature and time of the day all governs the fish movements. During high temperature period, fish take refuge in deeper water. Look for them on the deeper banks lined with trees. In the colder periods, targeting them from deeper water will not result in success as that is the time when they are lying in shallower and warmer waters.
During the time of increased flow or flooding, looking for the fish in an area of the stream which provides refuge from fast currents is a smart Idea. Side channels, ditches and other such structures are good places to fish during flooding. Submerged slopes with vegetation growth become a feasting ground for carps and other fish and are a very good place to catch them. Vegetation covered point bars and concave bank are also known to hold fish during increased flow periods.
As the water returns to normal levels after flood, once again the fish return to their pools, riffles and channels. While going fishing after a flood, don’t forget to have a look at the side channels, ditches and pools cut-off from the main stream as they too can provide some amazing sport.
The channels, which are cut-off from the main stream, hold water year long through the seep of main channel and are one of the best places to catch some good fish. Even vegetation choked, oxygen deprived water of such places are heaven for fish like Snakeheads and can produce specimen fish. Look for these predators under the cut banks as they are known to patrol there.
In case, in a slow flowing stream passing through plain, there is lot of underwater vegetations, follow cattle tracks and you will find the place where these cattle ford the stream. The bottom, constantly eroded by the hooves of cattle will be deeper and clear of any vegetation. This is the place of your dream as the excreta dropped by these cattle are a good ground bait and this ground baiting is happening on a daily basis. The edge of the vegetation on either side of the opening is the place to catch a good carp using bait, spin for Snakehead or Catfish and float fish for Knife fish and loads of Tiddlers. This is the place where action never ceases to happen and the excitement level and adrenaline rush is always high.
Selecting your Spot:
The selection of spot is governed by many factors like the speed of flow, time of day, temperature, target species and kind of fishing one intends to indulge. The combination of factors, especially the numerous fish species, makes it impossible for me to catalogue locations for them. It will be prudent then, to understand few basic rules to select a productive spot and starting from it, build our knowledge on experience.
The basic rule while selecting spot for all kind of fishing is governed by the famous adage ‘If you are not snagging, you are not fishing the right spot’. All snags, rocks, weeds, submerged trees; underwater structures etc. are good fish holding spots. Bait fishing and lure fishing equally work well from these places.
Prefer a bend in the stream over straight run. Remember that the inner bend is shallow whereas the outer bend is deep. Also bear in mind that fish are cold blooded creatures and have to regulate their body temperature. They are in deeper water while it is hot outside but prefer warmer shallow waters during the colder period.
Any slack or change in currents are very good food traps and are frequented by fish. Check them by passing a lure from the edge of these slack and you will invariably get a hit.
Shores covered by trees overhanging over the edge are a constant food source and insects, fruits and branches falling as well as shade provided by them keeps fish holding in those areas. Bait fishing and lure fishing, both are a good ways to catch few fish from these areas. Bringing the lure along the bank will provide maximum hits. Dropping a fly, imitating the insects falling or bait fishing from under the tree can also give good results.
Wilder but smaller side channels may look barren during the day time but comes alive during the night. Some very good fishing spots can be found along these channels if you have a means to reach there!
Smaller bait fish prefer these side channels and the predators leave the security of deep waters and chase them during the night. These waters are also good place for Carps. Look for woody debris on the bottom and other likely holding places that are a good habitat for carps.
Never ignore a confluence; even a trickle emptying in any stream is a good place to target a fish. The upper pool, the lower pool, the slack water at the head of confluence, the line defining the two water flowing alongside are all good places to target a fish.
The vegetation or weedy bed along the banks is a very good food source and traps. The presence of the weedy bed is a proof that the currents there are not very fast and there is a slack there. Try bait fishing as well as lure fishing from these places.
Last but not the least, look for places where there is a constant food supply. Many religious places along the bank are such kind of place.
The places where the local wash their utensils etc, commonly known as Ghat (घाट) or Panghat (पनघट) are also regular feeding ground for fish. Be discreet and ask before fishing these spots as catching a fish there may not be allowed. Fishing downstream of such spots in a likely holding area is the smart thing to do. The influx of soap water, due to fat contents in it, attracts lot of catfish and these places are frequently visited by these Cats along with Carps.
Plot your Fish:
Please don’t forget to plot your fish on the spot from where you are catching it and share it with AIGFA. Over a period of time and with inputs from all of you, the data collected can be plotted on the given structures and features to understand specific fish habitat for the benefit of all anglers and scientific consumption.
Next time when you visit a stream, give some time to study the different features, select your SPOT, catch a good fish and after plotting it on the given structure, share it with AIGFA.