What makes fish bite?

For centuries fishermen all over the world have pondered this question but we are seemingly none the wiser. Sometimes you can catch fish, other times you can’t and, although we might give one of a hundred excuses as to why we’ve come home empty-handed (too bright/too dark/too hot/too cold/too windy/too still etc), more often than not we don’t have a clue.

Austen Goldsmith

Just like any other animal, fish need to eat to survive. If their stomachs are empty, one would think they would be hungry and likely to take a bait. You could also be forgiven for thinking they’d be opportunists. Wild animals seldom seem to pass up an easy meal, so why not fish? But that assumption alone doesn’t stack up. You may have witnessed yourself, as I have, hundreds of fish on a fish finder while not a single bite or offer is forthcoming. It’s infuriating and somewhat baffling.

So what’s behind this and what, if there is one, is the pattern? Surely it must be possible to draw up some kind of chart with which we could compute the likelihood of ‘bagging up’ and tell us exactly when to fish and when not to bother? Isn’t there an app for that?!

Sadly it hasn’t been done… yet, so while we wait I’ve listed below the main factors that appear to play a part. It doesn’t always work out – I’ve been fishing on seemingly perfect days and caught nothing and I’ve fished when it’s hopeless and caught plenty – but nevertheless, there are some things I look out for that regularly seem to correlate with good catches…

Wind

You may have heard the sayings, “when the wind is in the east, the fish bite the least” and conversely “when the wind’s in the west, the fish bite the best”? Well, where there’s smoke there’s fire and I believe there’s some truth to these sayings for two main reasons:

  • Firstly, Easterly winds are often cold, whereas Westerlies are usually warm (see ‘Temperature’ below).
  • Secondly (and for this wise insight I must thank Jonn Graham) fish, like most animals, seem to be most comfortable in conditions they are used to. They don’t like excessive heat or cold, they don’t like heavy rain, or drought; they don’t like floods; they don’t like heavy frosts. In short, it seems that fish don’t like change. In the northern hemisphere’s temperate region, which includes the UK and much of North America, the prevailing wind is westerly. It may well be that our fish’s apparent preference for westerly winds is nothing more than their preference for ‘the norm’.

Global Prevailing Winds

Whatever the explanation, typically I think it’s safe to argue that a bitterly cold, blustery east wind is not a good thing. Equally, on a mild day with a warm, westerly breeze, I genuinely feel pretty confident I’m going to catch fish. Obviously it doesn’t always blow from the east, or indeed from the west, so my rule of thumb is this: if the wind is blowing out of the north, east, or anything in between, I don’t get my hopes too high. If it’s coming from the south or west, I’m generally more confident. If it’s north west or south east, it’s anyone’s guess!

Temperature

Fish, along with amphibians and reptiles, are ectotherms, which means their bodies don’t produce much internal heat. Unlike warm-blooded animals, or endotherms (like humans) a fish cannot significantly affect its body temperature internally. Where a human’s internal organs (heart, brain, muscle, liver etc) produce metabolic heat that warms our bodies, a fish’s body temperature depends almost entirely on the temperature of the water around it. In warm water, the fish’s body temperature is warm and in cold water, it is cold.

Like most animals, fish need a specific or optimal body temperature in order for their bodies to function properly. This means that their behaviour and, indeed survival, relies heavily on the ambient temperature. In the depths of winter, where we might regulate our temperature by putting on more layers, eating a hearty meal or jogging on the spot, fish effectively do the opposite. When the water becomes cold, their bodies adjust and begin operating at a lower metabolic rate. They enter what’s known as ‘torpor’. At such times they tend to seek out the warmest pockets of water, probably as far from the surface as possible – and rest on the bottom, where they remain still and simply wait for conditions to improve. I’m sure we’ve all caught freshwater fish in the colder months and found them to be covered in blood-sucking leeches? These leeches have almost certainly been taking advantage of the fish’s proximity to the lake/river-bed and its relative inactivity.

So where you might assume that fish, in the colder months, might go on a feeding frenzy in an effort to stay warm, they actually do the opposite.

A similar reaction can be observed in extremely high temperatures. Just as in extreme cold, when the water temperature rises too high, the fish’s body ceases to function efficiently, which can cause the fish to somewhat shut down. The outcome is that the fish is less likely to feed and you are less likely to catch it. How long this state of ‘torpor’ or inactivity lasts depends on the conditions but clearly these are not the best times to get a bite!

Tide

Most sea anglers agree that tide is a major factor in fish feeding behaviour.
Generally speaking, whether inshore or offshore, fish feed when the tide is running and don’t when the tide is slack. There’s nothing you can do to change this, so when the tide stops running, take a break and gather your energy for when it restarts in the opposite direction.

When fishing inshore or on shallow flats, understanding the tides can be crucial. Predatory fish often patrol the surf, around rocky outcrops or on the flats, using incoming tides to reach food that may have been uncovered or become stranded during the ebb. For this reason a rising tide is usually the best time to fish from shore. As the sea falls on a receding tide, predatory fish may either retreat into the deeper water or may decide to wait at a safe distance, ready to ensnare other creatures that are forced to abandon the shallows.

As a rule of thumb, I like rising tides best, falling tides second and no tide the worst. The latter is a good time for a nap!

Current

Most fish prefer current to stagnant water. For example, logic might suggest that a salmon, as it battles its way upstream and up waterfalls to spawn, would take every available opportunity to rest up in the slowest moving pools. Those who have observed them, however, could probably tell you that no, in fact, salmon seem to ‘rest’ mid-stream. Not only are salmon, and indeed most other river fish, so streamlined that they need very little energy to maintain their position, but also, perhaps, the faster moving water supplies more oxygen to their gills. Certainly when it comes to hooking a salmon, the taking spots are pretty much exclusively the smooth glides and fast runs – to pick one up from the slack water is almost unheard of.

Whether in the sea, in rivers and streams, or even in lakes, all fish feed facing into the current. This helps them maintain position while intercepting food that is washed towards them. Where there is no discernible current, as in a reservoir, fish may feed facing upwind. I have spent many fond afternoons drifting across a large trout fishery, intercepting trout as they work their ways upwind in search of hatching nymphs. Marvellous sport!

Spawning

In nature, there is only one thing that ever outweighs the instinct to survive – the desire to reproduce. I know that this is true, as I have witnessed it first-hand. When I was about twelve years old, I sat perched in a tree, watching roach in my local fishery as they attempted to spawn in tree roots overhanging the bank. The roach were so intent on their purpose that they seemed entirely unaware of, or at least completely ambivalent to, the presence of some rather large and hungry pike. Every now and then, one of the pike would casually cruise up and, as slowly as you like, pluck out one of the roach and eat it. The other roach remained totally unperturbed.

If this is the power of the urge to reproduce, it is little wonder that we struggle to tempt spawning fish with our baits! I have many memories of carp fishing trips, where we arrived at the venue only to be met with the sight of large carp thrashing and spawning in the shallows. At such times, knowing that our timing was off, we would simply resign ourselves to a nice weekend of camping!

Just as in very cold or very hot conditions, I think it’s safe to assume and universally accepted that spawning time is best avoided. Or is it? You see, in the case of some fish species, spawning time can be a very productive time for anglers. Predators like pike, chub and trout, for example, may become more aggressive than they would otherwise be, making them far more susceptible to a brightly coloured or flashy lure. I’ve caught sixty pike in two days with my father, fishing Bristol’s Chew Valley Lake, just as the pike were gathering to spawn. All of the fish were small – presumably the smaller male or ‘jack’ pike – the ones you would assume to be the more aggressive at such times.

In all species it is the males that seem to be the most aggressive during spawning and it the males who seem to be the easiest to catch. Take the male salmon, which actually changes its body shape prior to spawning – growing teeth and a bigger jaw to help it win its battles! So spawning is a mixed bag – generally not ideal (and probably not a very noble time to be targeting a fish!) but with the possibility of taking advantage of aggressive males.

Storms

While I wouldn’t advocate fishing under thunder and lightning, for obvious reasons, I have known several occasions where fantastic catches have been taken in extremely stormy conditions. Possibly the best ever catch of perch I have ever heard of was taken from a Northamptonshire stillwater during a prolonged and heavy storm; and one of the best hauls of bass I’ve heard of was taken by Arthur Cove, in broad daylight and gale force conditions, while most anglers waited for the evening (I know this because my father, to his shame and regret even to this day, was there waiting for the storm to end so he could fish at night. He saw Arthur’s bass with his own eyes, including at least one of double figures, which were all taken on spinning tackle from the shore. I don’t think he’ll ever forgive himself!). It is not a unique story – most anglers will have at least one story of the ‘bonanza’ they had just before or during a storm. Perhaps it’s connected to the folling…

Barometric pressure

There fact that these feeding frenzies are so often reported close to a storm can be no coincidence and perhaps, as the theory goes, it is linked to barometric pressure. Studies have shown that, as barometric pressure drops quickly (as happens in advance of an impending storm or a dramatic change in weather conditions), fish will start feeding. Conversely, fish don’t seem to feed well when a storm has passed and is replaced by an area of high pressure. Perhaps this is simply because the fish fed so voraciously before the storm, so they are no longer hungry, or perhaps fish don’t like high pressure. It’s unclear but it’s worth bearing in mind when planning your trips.

Floods

While I have no doubt it varies from species to species, by and large a flood is not a fisherman’s ally. Not only does high water often turn coloured, making a bait harder for the fish to find, it also brings various flotsam and jetsam that can tangle tackle and hamper your efforts. Floods also seem to unsettle the fish, making them less likely to feed and harder to catch. Salmon fishing a river in spate, for instance, is a total waste of time, as is, in my experience, lure fishing for pike.

Water clarity

Just as muddy water can hinder an anglers ability to catch fish, when the water is too clear, it can also make things difficult. As a rule of thumb, if you can see the fish, they can probably see you, your boat and your line. Fishing in very clear conditions often necessitates a much more delicate approach, with lighter leaders, smaller flies or baits and a more stealthy approach.

What do all these factors have in common?

Each of the elements above can dramatically impair your ability to catch fish – often in a bad way. Whether it’s very windy, very cold, very hot, flat calm, a flooded torrent, a stagnant pool, a dead tide, crystal clear or as muddy as chocolate, you are probably going to struggle to catch fish.

But there’s something else. Although these conditions themselves can be responsible for our worst ever days fishing, I believe they also provide our best. I’ll explain how.

The conditions we have talked about, when at their most extreme, can stop a fish feeding altogether. You’d be better off going to the fish market. But each day that fish doesn’t feed, is a day when it effectively grows more hungry. And I believe the fish are onto it. Somehow they have the ability to predict these natural events before they happen and they know that they are about to go for several days, if not weeks, without food. And that means one thing – feeding.

To my mind, without a doubt the best times to go fishing are just before or just after each of the events we’ve discussed: before or after a period of extreme temperature, before the wind turns to the east or once it returns to the west, just after a drought – when fresh rain breathes new life into a dwindling river, or just after a flood when the water clears and the level returns to normal. Or how about just before or just after spawning, when males and females alike are intent on packing on wight to help them survive the ordeal of finding a mate and fighting off unsuitable suitors. These are the times we should be focussing our efforts on.

And what do you do when the fish aren’t biting?

Needless to say, there are all kinds of things you can try in an effort to improve your fortunes: change retrieve, jerk the rod, change bait, change location, change venue, even change your fishing buddy!

Of course sometimes, no matter what you try, no matter how much equipment and knowledge you have, no matter how many times you change baits, and no matter how much you pray, you simply don’t have the power to make fish bite.

What then, can we learn from all this?

For me, the answer is obvious – there is one standout, indisputable ‘best time to go fishing’. The best time to go go fishing is when you want exactly that: to go fishing. It is not when you want to catch fish. If catching fish is your only goal, I’m afraid you are facing countless days of frustration, confusion and disappointment. But if you can genuinely enjoy the fishing itself – the nature, the peace, the fresh air, the camaraderie, the very being alive – then you have learned the most important lesson any angler can learn. You will never have to suffer another frustrating day’s fishing in your life. And when you do catch that fish of a lifetime, as spectacular as it may be, if the truth be known it is just a bonus.

[Bass photograph courtesy of Austen Goldsmith]