Fish & Colours – by Dr. David Ross

I came across this article recently. Although it primarily relates to choosing colours for fly fishing, it is an excellent scientific explanation of how fish view colour. I thought I would share it just to give everyone another excuse to buy some different coloured lures!

Fish Eyesight: Does Color Matter?

by David Ross
Read this article and you may never look at your flies the same way again.

Do fish see color?IS COLOR IMPORTANT? This is a serious question for fly tiers and fly fishermen to ask. Some anglers maintain that the choice of color is critical, while others say it is not important. Scientifically speaking, there is evidence to suggest that both points of view may be correct. There is good evidence that picking the appropriate color or colors will, under certain conditions, improve your chances of attracting fish, but science can also show that in other situations, the color of your fly is of limited value or no importance whatsoever.

Fish have been around for more than 450 million years and are remarkable creatures. Over the thousands of centuries, they have made many superb adaptations to survive in the marine environment. Living in the world of water is not easy, but it does present some environmental opportunities as well as serious challenges. Sound, for example, travels almost five times faster and much better in water than it does in air. The ocean is actually a very noisy place. Fish capitalize on this by having an excellent sense of hearing, using both their inner ears and lateral lines to detect prey or avoid enemies.

Water also contains unique chemical compounds that fish utilize to identify other members of their species, tell when reproduction time has arrived, find food, detect predators, and perform other functions. Fish have evolved a remarkable sense of smell that is thought to be about one million times better than that of humans.

Water, however, presents a serious challenge for fish and fishermen when it comes to vision and color. Many characteristics of light quickly change as it moves through water. The first thing to realize is that the color of your fly in the water is almost always different from what it is in the air. I have to be a little technical to explain this, but I think if you bear with me, you’ll have a better understanding of how fish perceive color and how this impacts the flies we tie and use. And while I mostly refer to fish and fishing in salt water, these same principles apply to the freshwater environment.

Attenuation of Light

The light that humans see is just a small part of the total electromagnetic radiation that is received from the sun. We see what is called the visible spectrum. The actual colors within the visible spectrum are determined by the wavelengths of the light: the longer wavelengths are red and orange; the shorter wavelengths are green, blue, and violet. Many fish, however, can see colors that we do not, including ultraviolet.

When light enters water, its intensity quickly decreases and its color changes. These changes are called attenuation. Attenuation is the result of two processes: scattering and absorption. The scattering of light is caused by particles or other small objects suspended in the water — the more the particles, the more the scattering. The scattering of light in water is somewhat similar to the effect of smoke or fog in the atmosphere. Coastal waters generally have more suspended material due to river input, material stirred up from the bottom, and increased plankton. Because of this greater amount of suspended material, light usually penetrates to a lesser depth. In relatively clear offshore water, light penetrates to a greater depth.

Light absorption is caused by several things, such as the light being converted into heat or used in chemical reactions such as photosynthesis. The most important aspect for fishing is the influence of the water itself on the absorption of light. The amount of absorption is different for different wavelengths of light; in other words, various colors are absorbed differently. The longer wavelengths, such as red and orange, are absorbed very quickly and penetrate into the water to a much shallower depth than the shorter blue and violet wavelengths.

Absorption also restricts how far light penetrates into the water. At about three meters (about 10 feet), roughly 60 percent of the total light (sunlight or moonlight) and almost all the red light will be absorbed. At 10 meters (about 33 feet), about 85 percent of the total light and all the red, orange, and yellow light have been absorbed. This has a direct bearing on how a fish perceives a fly. At a depth of 10 feet, a red fly appears gray, and it eventually appears black as the depth increases. With the increasing depth, the now dimming light becomes bluish and eventually black when all the other colors are absorbed.

The absorption or filtering out of color also works in a horizontal direction. So again, a red fly that is only a few feet from a fish appears gray. Similarly, other colors also change with distance. For a color to be seen, it must be hit by light of the same color and then reflected in the direction of the fish. If the water has already attenuated or filtered out) a color, that color will appear gray or black. (Fluorescent colors, which I will come to shortly, behave a little differently.)

It should now be clear how the depth of the water or distance from a fish affects the visibility of your fly. In extremely shallow and very clear water, colors may look similar to their appearance in the air; as your fly gets just three feet deep or three feet away from a fish — or less if the water has limited clarity — the colors will start to change, often with surprising results.

What Do Fish See?

Scientists really do not know exactly what fish see, or in other words, what images reach their brains. Most research on the vision of fish is done either by physical or chemical examination of different parts of their eyes or by determining how laboratory fish respond to various images or stimuli. Making broad generalizations about a fish’s vision is complicated by the fact that different species may have different vision capabilities and that laboratory results may not represent what happens in the real world of an ocean, lake, or river.

Physical studies of the eyes and retinas of fish show that the majority can obtain a clearly focused image, detect motion, and have good contrast-detection ability. A limited number of experiments have shown that a minimum level of light is necessary before a fish can recognize colors. Another finding, but one that needs more study, is that some fish favor a specific color. This point may contradict or affirm your own fishing experiences, but remember that the attractiveness of your fly is a combination of many things, including its motion, shape, and color, as well as the scents in and depth of the water.

Most fish have an adequate sense of vision, but this is usually not so impressive as their sense of smell and ability to detect vibrations through their lateral lines. Fish usually use their sense of hearing or smell to initially perceive their prey, and then use their vision only in the final attack. Most fish can see in low-light conditions or dirty water, and a few can see objects over moderately long distances. Fish such as tuna have especially good vision; others less so. Fish are usually nearsighted, although it is believed that sharks are farsighted.

The majority of fish have developed eyes that will detect the type of colors typical of their environment. For example, inshore fish have good color vision, whereas offshore pelagic fish have limited color vision and detect only a few if any colors other than black and white. This is not surprising from an evolutionary point of view, because nearshore waters are lit with many colors; offshore waters, on the other hand, are mainly blue or green and contain few other colors.

The actual ability of a specific color to attract or even repel fish has fascinated both anglers and scientists. While there are no uniform answers, scientists have conducted experiments on this interesting question. For example, studies of sticklebacks during their spawning season have shown that males, which then have bright red coloring on their bellies, become very aggressive to decoys that also have bright red bellies. Similarly, decoys with extended bellies, which look like females carrying eggs, attract the males. But it isn’t that simple: it wasn’t just the case of a perfect decoy imitation, but rather the color or shape of the decoy. In addition, it was noted that a passing red car, seen from the fish tank, also excited male sticklebacks.

Color Suggestions

This is perhaps the most important point to remember: Most gamefish detect their prey by seeing the contrast of the forage against various colored backgrounds. The level or type of contrast depends upon many factors: time of day, type of bottom, transparency of the water, whether it is cloudy or sunny, and perhaps even the time of year. I wish I could be more specific, but such scientific information is not available. The best I can do is provide some general suggestions and information; determining the right color or color combinations will take a lot of fishing and experimenting under various conditions. Keep these ideas in mind the next time you tie or select flies.

  • Try to consider what the colors in your fly will look like at the depth you are fishing, and chose appropriately. For example, since red is the first and blue is the last color absorbed, it makes more sense to use a blue fly when fishing deep.
  • If you are trying to match a particular bait, the color of your fly should match the color of the bait for the depth you are fishing. In other words, try to match the underwater color rather than the color of the bait in air.
  • Many fish feed by looking up toward the surface of the water. In doing so, however, they have difficulty distinguishing specific colors, and the contrast of the prey against the surface becomes more important. When a feeding fish is looking up, a dark silhouette, even against a dark night sky, provides the maximum contrast and is attractive to predators. Selecting a fly based on contrast, rather than on specific colors, is often the key to enticing a fish to strike.
  • Black is the least transparent color and gives the best silhouette at night. Black is probably the most visible color under most conditions.
  • If your fly has two or more colors, the darker color should be over the lighter colors. Almost all baitfish have this color arrangement, and dark over light usually produces good contrast.
  • Different colored flies may be equally effective or ineffective simply because they are similar in color at the depth the fish see them.
  • If you are fishing your fly in deep water, the motion and any noise or disturbance it makes might be much more important than its color.
  • Increase the contrast of the fly if the water is dirty; decrease the contrast if it is clear.
  • A good profile is important when vision conditions are low (nighttime or dirty water). Black and red flies offer good profiles.
  • Some colors, such as chartreuse, always seem to work better than other colors. Yellow-and-white and chartreuse-and-white are also favorite pairings. Red and white, which provide good contrast under many conditions, is a popular combination for many anglers.

Understanding Polarized Light

Recent research shows that many fish sense polarized light. Humans do not have the ability to separate polarized from regular light. Regular light vibrates in all directions perpendicular to its direction of travel; polarized light, however, vibrates only in one plane. When light is reflected off many nonmetallic surfaces, including the ocean surface, it is polarized to some degree. This explains how polarizing sunglasses work: they block out the horizontally reflected polarized component of light from the ocean surface which causes most of the glare but permit the vertically reflected component to pass through.

It is not fully understood why some fish have the ability to sense polarized light, but there are interesting possibilities. Being able to detect polarized light might help fish in their migrations and ability to swim closely with others of the same species. The ability to sense polarized light must certainly be related to the fact that when light is reflected off surfaces, like the scales on a baitfish, it is polarized. Fish that can detect polarized light have an advantage in finding food. Polarizing vision can also enhance the contrast between almost transparent prey and the background, making the prey easier to see. Another conjecture is that having polarizing vision can let fish see objects that are farther away — perhaps three times the distance — as fish without this ability. If this speculation is correct, it may answer the question why some fish can feed under very low-light conditions. And there is more polarized light at dawn and dusk, which might explain why some fish, such as striped bass, seem to feed more aggressively at these times of the day.

If the ability to sense polarized light helps fish to find food, then it follows that flies that reflect polarized light should be more attractive to such fish. Some natural fly-tying materials, such as polar bear fur, are especially good reflectors of polarized light. Bucktail, on the other hand, is a relatively poor reflector of polarized light. There are artificial materials that simulate fish scales and various tinsels that claim to be excellent reflectors of polarized light. Flies with irregular surfaces may reflect more polarized light than smooth flies. I suspect that in the coming years, as we learn more, there will be an increased use of polarizing materials in flies and lures.

Fluorescent Colors Increase Visibility

Fluorescent colors, especially chartreuse, are very popular with saltwater fly fishermen. I almost always start fishing with a chartreuse Half & Half, even if it’s just to see if there are any fish in the area. Under the right conditions, fluorescent colors, which are not naturally found in nature, can be very visible under water and seen for considerable distances. A fluorescent color is one that will be bright when exposed to light having a shorter wavelength. For example, fluorescent yellow appears as bright yellow when exposed to ultra-violet, blue, or green light. Alternatively, fluorescent yellow does not appear yellow when struck by red light that has a longer wavelength. Because of this unique characteristic of fluorescent colors, they do not have as dramatic a change of color when they are fished deeper.

The fluorescence of fluorescent colors is mainly due to ultraviolet (UV) light, a color that is invisible to us. Humans cannot see UV light, but we can see how it brings out the fluorescence in certain colors. Ultraviolet light is especially dominant on cloudy or gray days, and when UV light hits something having fluorescent material, its color becomes especially visible and vibrant. On bright sunlit days, the fluorescent effect is considerably less, and of course if there is no light, there will be no fluorescence.

Research shows that fluorescent colors are visible and distinct for longer distances than regular colors, and that a fly with fluorescent materials often attracts fish. To be more precise, a fluorescent color having a slightly longer wavelength than the color of the water has better long-distance visibility. For example, in greenish waters, the brightest colors would be fluorescent green or chartreuse. As good as fluorescent colors may be, they will usually not work if the fish are actively feeding on a specific bait, since it is highly improbable that the fluorescent color will resemble any color in that bait.

As you can see, light and color can get pretty complicated. But let’s not forget what we are trying to do: have our flies imitate pieces of fish food. Fish are not very clever, and they attack prey — or flies — as an instinctive behavior motivated (or so we think) by one or more stimuli. These stimuli include movement, shape, sound, contrast, smell, color, presentation, and certainly other things unknown to us. Successful flies should probably include some of these stimuli, and then we need to consider other variables such as the time of day, the tide, and the presence of other fish or fishermen. This is a complicated venture, of which color can sometimes be an important aspect, but only if the fish can see the color.

MidCurrent Fly Fishing

Dr. David Ross is a scientist emeritus at the Woods Hole Oceanographic Institution and the author of The Fisherman’s Ocean (Stackpole Books). He is also a regular columnist for Saltwater Fly Fishing Magazine. He can be contacted This article first appeared in Fly Tyer Magazine. Copyright © 2005-2006 Dr. David A. Ross and Fly Tyer Magazine.

Rockhampton – Fitzroy River – 29 October 2013

I came across this keen angler a few weeks ago, on the banks of the Fitzroy River. He was fishing with live bait and told me a few good stories about catching monster barramundi and salmon in these waters. He has already caught more metre plus barramundi than I probably ever will. Glad to see that not all the youth of today are glued to facebook and the playstation.

Landangler’s View – Tackle Shops

Like many other mad keen fisherman I am a complete sucker for a tackle shop. I can’t walk past without going in and once I am in, I rarely leave without a bag full of gear. Of course I don’t need it all but that never stops me thinking I do.
They say fish can only see light and dark – the lures are patterned and coloured to attract us – not the fish, and it works every time. On each fishing trip you convince yourself that if you had only bought that 150mm orange and blue, twist wiggle, walk the dog, kill the cat, deep diving dribble popper, you would have caught a bigger fish. And of course that’s the point – if the retailers only had a rod, reel, spool of line, bag of hooks, some frozen pillies, a grey soft plastic minnow and a metal slug, it would not be much of a shopping experience – would it.
I thought I would share a few of my tackle shop experiences. As usual, I apologise in advance to all those who work in them. I love you all really!
Tackle shops and those who staff them, come in a myriad of formats. The small independents are getting rarer as the ‘big box’ (BCF / Anaconda, etc) outlets make it harder for them to compete – but there will always be those of us who are willing to pay a bit extra for good advice coupled with some local knowledge.
Each type has its advantages – I like the big ones where, on a rainy day, you can buy a coffee and watch your way through all the stores’ fishing DVDs on the demo flat screen. Fortunately if your legs get tired, they also have camping gear so you can unfold a chair. No need to worry that anyone will bother you as nobody has worked there for longer than three weeks, so they don’t know where the fishing section is yet. The only exception to this rule is the manager, who is usually out making a fishing video with the professionals his store sponsors. But all the staff have shiny new uniforms and, thank goodness – that universal symbol of retail humiliation – a name badge. I used to think this was to assist us, the customer, so that when we brought back the really crap pink kids fishing combo that fell apart 3 minutes after we reached the beach, we could remember who sold it to us. Now I realise it is much more straightforward – the staff turnover is so rapid that this is the only way the manager can figure out their names.
Most of these chains also have shonky Japanese sounding, own brand tackle that is all actually made in China, like everything else. This is universally crap quality but it is also incredibly cheap. Reputation risk is not an issue for these retailers – they have such a bad reputation that quality does not worry them too much. In their defence, at least they never tire of exchanging their crap for new when it breaks, which is fairly often. I am currently on my twelfth own-brand fishing headlamp from one of them – they last about a week on average.
The independent fishing stores offer another set of challenges. It can be a bit like Mitre 10. You may think you know what you want, but first you have to get passed the “helpful” staff.
“I’d like some size 4 fishing hooks, please?” I announce.
“What are you chasing?” asks fishing shop man with a knowing smirk.
“Fish”, I feel like responding. “Whiting” I reply.
“You’d be better off with size 6. Where will you be fishing?”
“Mind your own business” I feel like responding. “The Nerang River”, I say.
“Forget it. At the moment, what you want to do, is go after Flatties up at Bribie Island – have you tried the Didgeridoo pinkshine Vicks vapour Rub flavoured 5” dancing stickleback soft plastic – their magic.”
“No I’m just after the Whiting hooks actually.”
“Whiting love poppers you know – How about these Kamakazi Sushi twinkle poppers, in the used toilet paper colour, there only $23 each – the Japanese swear by them.”
“Oh really” I say. What I want to say is “How the hell would you know – get a lot of Japanese anglers in here do you? I bet they don’t even have bloody Whiting in Japan.”
He pauses, disappointed that, like some kind of reluctant reef species, I seem to have gone off the bite. But then he gets that twinkle in his eye.
“Ok then – What bait will you be using, what sinker size, what size mainline, what size leader, run in or run out tide?”
If you hesitate, for even a moment at this stage, you are doomed. If your answers are not spot on you will have a lecture on sinker weights, the merits of regular vs lead free and a detailed run through of popular sinker shapes and sizes in common use, in Australian tidal waters, since 1923. You may even get sold the DIY make your own sinker set complete with zinc furnace. Before you know it you will have bought 5 mini snaffle snip death adder wiggle blades which you will never get out of your tackle box again and you will need to auction a kidney on e bay, to pay for them.
He is only doing his job, but sometimes it’s enough to drive you straight back to the ‘big box’ outlet. Never ever let your wife visit this shop in the week before Christmas. The wife is the perfect target for the fly rod combo sale. As if it is not hard enough to catch fish with regular tackle! She mentions she is looking for something for her husband for Christmas and you can hear fishing shop bloke rubbing his hands together. She leaves with the complete fly rod combo and a whole bag of pink feathers, cotton and other lint (which she could have just picked up from under the sofa) and a bag of ludicrously expensive tiny hooks, so her delighted husband can learn to tie his own flies. He doesn’t want to tie his own flies, he wants to go fishing!
Then there is the riverside fishing shop located in the middle of a top tourist location. The bloke who runs this one is the ultimate frustrated fisherman. It must be torture. A steady stream of customers wanders through the shop all day. But they never buy anything because they’ve already stocked up with the pink and blue kids combos from the ‘big box’ Boasting, Crapping and Farting chain store at home. This means he cannot flog them his slightly poorer quality, more expensive combo, that he has also had made up in China. All day long they arrive asking where the fish are biting. It’s a miracle he doesn’t eventually respond with the only truly appropriate answer: “In the f***ing river”. Instead he has a generic fishing guide, that he mumbles to them as he slips into a coma of desperation. “Flathead on the weed beds, Whiting on the sandbanks, Bream from the jetty. Dawn and dusk are the best times to fish and they like fresh bait”. His worm man is constantly on the grog during holiday periods, so despite the blackboard saying otherwise, he has no live worms and can only offer a bit of frozen squid and a cheerful – “Good Luck!”.
Then there is the tackle shop at the rarely visited, but excellent fishing spot. The bloke who owns this one is in fishing heaven, but somehow he has to pay for his habit. He usually opens late and closes early. Or, if the fish are really biting, he does not open at all. The shop is stocked with a selection of extremely out dated but, consistently overpriced tackle. You find extinct lures, and brands that perished long ago. A bag of ice goes for around $9.00 and it is just under half the size of a normal one. Tide guides are $2.50 each and it’s only when you start fishing that you realise they are last years. This chap knows what you need – so he has simply scrawled a mud map on an A4 sheet showing three fishing spots – one on the beach, one in the river and one on the rocks. He has photocopied it and sells these at $2.50 a pop. If it’s pouring with rain and blowing a gale and you ask about the weather it’s always ‘looking good for tomorrow’.
All these outlets share one thing in common – their ability to separate anglers from their cash. We are like lambs to the slaughter. If the fish had any idea how much we spend on trying to catch them, it would be a major boost to their self-esteem. I couldn’t live without the tackle stores, but my catch would certainly work out cheaper, if I bought it at the fish and chip shop.

Landangler’s View – Fishing Forums

I bet they wish they had BFO/ AUSFISH/ NUGGET/ TACKLEBOX in those days

Warning this is not a fishing report or a tackle tip or even a “How to catch Mullet on my Grannies week old banana fritters” article. This is Landangler’s view. My take on something vaguely related to fishing that I have decided to share with you whether you like it or not.
What is it about the keyboard? It removes inhibitions faster than Bundaberg rum. People will happily type things they would not dream of saying. Punctuation goes out the window, correct spelling is optional and text speak creeps in, LOL. It’s so much easier to just blurt out a verbal vomit in an email or a tweet, or on an online forum, which brings me to my topic for today – Fishing Forums.
Over the last few years, prior to starting the Landangler Blog, I have been regularly posting fishing reports in online fishing forums – and overall, I love them. They are a great way to share information and stories. They put like minded people together. They provide solace when you think you are the only sad bugger who fished all day for one undersize Moses Perch and a 23.5cm suicidal blind Bream. But lurking out there in cyberspace are some interesting characters, with fairly fanatical views.
Let’s call our first on-line fishing forum poster – Big Boat Big Esky Bill. Bill loves to catch anything and everything and loves to tell anyone and everyone, all about it. Whatever you have caught, Big Bill has caught a bigger one. However many fish you have caught, Big Bill has caught more. He usually posts to let you know that even though you thought you had a great session, you have used the wrong; bait, line, rod, lure, sinker, leader, hook and were wearing the wrong sunglasses. He also lets you know that he knows all about that spot and used to get more, bigger fish there, when he was nine. Of course back then, he fashioned hooks from old safety pins and used his unravelled old school jumper wrapped around an empty ginger beer bottle, for line. Despite his forthright opinions, Big Bill can rarely string together a fishing report. When he does manage something it reads along the lines of: “Went to super secret spot X, one day last week and caught a massive snapper on my favourite secret lure/bait. It was 25 kg but unfortunately didn’t have the camera.” Thanks Bill.
Next is Newbie. Newbie has just joined the forum and he will do anything to escape his novice status. He logs on every 30 seconds to check if anyone has read his posts. He posts a response to everybody else’s posts. This is usually something highly informative or insightful like: “Nice fish”, “Well done” or “Good on ya”. I can imagine that Newbie has the attention span of a small insect. He is permanently plugged into his iplod whilst constantly texting, Tweeting, Facebooking and probably twitching. After about five hundred posts Newbie finally reaches ‘Gold’ status – then we never hear from him/ her again. Thank goodness for that!
Now onto EcoFish Ed – Yes, you guessed – Ecofish Ed is a committed environmentalist, but you didn’t need to guess that because he is going to tell you all about it. You can almost smell his Birkenstock sandles and see him sitting in his Toyota Prius deciding on which lead free hooks to use. He actually pays the electricity company the extra cash every month for the ‘green’ power. Ed releases every fish he catches – in fact, he rarely catches anything so as not to harm the environment. He never eats fish or anything else – he is a vegan – so he survives on soy sawdust bars and organic vegetables. He vigorously patrols the forums pointing out our environmental failings at every opportunity. He attacks, without mercy, anyone who keeps more than one fish for dinner and if he uses his forensic photoshop techniques to determine your flathead is 39.8cm long – God help you.
One of my favourites is Optmistic Ollie . He makes even the crappiest of us look good by never catching anything – but he has always got something chirpy to say about it and his positive attitude cannot be dented. “Took a run out into Moreton Bay this arvo to look for some Snapper. I crashed the car at the boat ramp, scraped the hull on some shallow reef, the young fella vomited all over the sounder, forgot the bait and we snagged all our lures, didn’t get a touch from the fish all day. Unfortunately a storm came over and the wind whipped up to 25 knots. Got done by the water police on the way back in, because of a hole in a life jacket. Sorry no pics as I dropped the camera over board. Even though we came home empty handed – we all had a great time – what a wonderful day to be out on the water.”
Then there is Inappropriate Ian. Ian uses the forum a bit like the telephone. He does not seem to realise that the whole world can read his posts and is therefore listening in. He responds to every report by his mates in a chummy fashion with a reference to some private joke or shares some totally inane private titbit with us, just to emphasise that he knows the bloke who is posting. “Great bag of Snapper you got there Dave. Saw Marge at Aldi yesterday she was buying some lamb chops, they were on special – How is she going with the piles?” or “Nice Bream Brucie – can’t believe Dazzer did the dirty on Suzie and is now shacked up with the Kinde teacher.”
Finally there is Tedious Tim. He likes to start from the very very very beginning. You get it all from Tim. Which rod, which reel, which line, which lure, when he went fishing, where he went fishing what the tide was doing, what the wind was doing, what the moon was doing, which hat he was wearing , when he put his sunscreen on, which brand of insect repellent he used, which underpants he chose etc. His posts frequently have to be broken into two parts and you are often fast asleep by the time you reach the bit where he catches a fish. He rarely gets to go out fishing as he spends most of his time writing his reports.
Keep up the good work fishing forums – there maybe be a few nutjobs around and we may not all agree on what makes a good days fishing – but the fishing world is a better place for all those posts!