Length-weight Relationship of rod caught Warwickshire Zander (Sander Lucioperca)

Piscatorial Quagswagging and obviously bored blogger Mick Newey presents the relationship between total length (TL) and wet weight (W) for rod caught Warwickshire Zander. The Zander a non-native species in the UK are now very much naturalised and established within Warwickshire waterways.

In 1878 20 odd Zander averaging 0.9kg in weight were netted from Bothkamper Lake in Schleswig-Holstein, Germany and transferred to the enclosed waters at Woburn Park Bedfordshire. Apparently a number of successful stockings from Woburn to enclosed waters in Southeast England took place between the end of the Second World War and 1962.

A release of 97 fingerlings in 1963 to the Great Ouse Relief Channel is where the situation changed dramatically, and the species subsequently bred very successfully in the wild and spread through the adjoining rivers of East Anglia. Currently the colonization of the extensively interconnected rivers of this region of England is still only partial but the species is steadily extending its range and has been illegally introduced to other parts of the U.K. by anglers.

Zander can now be found in most of the Midlands Canals the Warwickshire Avon, River Severn, the Nene, the Trent as well as the East Anglian fens and ditches and also various lakes in England, now even in the Thames apparently which has given rise to fears of further extensions of the species range over a considerable area in the future.

This data is generated from Zander caught from the Warwickshire Avon, the Stratford-Upon-Avon and Grand Union Canals and many a fish is featured in this blog of mine if you want to peruse the archives, there is plenty to look at.

One of many from Hatton Locks that turned me in to a Zed Head

Length-weight relationships are important because they allow the conversion of growth-in-length equations to growth-in-weight, for use in stock assessment, allow the estimation of biomass from recorded length and also allow an estimate of the condition of the fish and also the between-region comparison and life histories of this particular species.

Could I find something similar online, not a sausage, I found lots of good reading material mind you and enjoyed the research….

Zander tend to spawn in spring (March-April) when water temperatures reach 8 to 12 degrees. Eggs are generally deposited on the roots of aquatic plants, gathered together in the form of a nest by the male, in sites where the depth of water is between 40 and 50cm’s. Sexual maturity generally occurs at 2-3 years in males and 3-4 years in females when the fish have reached a length of 50cm and a weight of around 1kg.

8lb 10oz From the Canal

Fecundity is very high and after hydration the eggs are 1.5mm in diameter. The male appears to guard the nest during incubation which lasts between 13 to 14 days.

Due to the excellent eyesight of the Zander which love to hunt in low-light conditions, at night, murky water and certainly in rivers and lake large depths, puts them ahead as the waters predator to be feared.

The Zander’s eyes shine with a silvery glow even by the most delicate light source. Its reflective guanine layer covering the inside of the eyeball is unbelievably sensitive and allows it to see perfectly in conditions and water clarity when other fish, let alone humans, cannot see anything at all. Having fished for them on countless occasions they are intriguing fish to catch as they are very unlike the indigenous species that share the Midland waterways.

One from the River Severn Zander

They like lures too, green particularly works well....

In this study the records over many Zander captures have allowed fish to be measured for total length (TL) in the field and weighed (W ,wet weight) to the nearest oz for ease of excel chart generation. For the wooden-headed 1 lb = 16oz.

Fish may weigh less than expected for their length for many reasons. Lack of food/prey being a likely cause but maybe because of the overpopulation of the Zander as a predator and competition from other similar fish. A fish may also well weigh less than expected due to change in activity levels or metabolism due to environmental factors.

An 8lb 3oz Warwickshire Avon Zander

Over many field trips/fishing for Zander which is consequence of keeping and maintaining this fishing blog of mine I really have enjoyed catching them and I will continue to do so. I’d grown to love one particular area of habitat on the Stratford-Upon-Avon canal which not only brought me some much needed solitude but it was home to young but seemingly very well fed fish due to their characteristic larger girth compared to the neighbouring stretches I fished.

Having being given some location tips previously I happened upon some shared knowledge and these fish were more than likely down to a fruitless electro fishing exercise by the waterways authority at the time to remove Zander and by way of compensation for the fish removal, it was heavily stocked with a large number of silver fish.

Greedy they are....

Someone who witnessed the day of the electrofishing was amazed at the amateurish way the task was carried out and subsequently large areas of the canal remained untouched.

Those lucky Zander that avoided the cull thrived on these new introductions and are still there to be caught today (transient mind you), and despite the apex predator being present (I haven’t seen an Otter on the canal yet), large numbers of prey fish appear to still exist and as on most stretches I fish there has been a balance reached on the often neglected stretches of the canal.

The Roach section rig used on the canal....

Boats aplenty, anglers not so….

Anglers are a rare sight on the waters I fish you see, why? many factors I suppose, commercial fisheries have sprung up everywhere over the last number of years, Carp fishing has taken over for the tackle tarts and those with bottomless pockets and also many don’t know how to approach a canal, let alone to try and catch an ickle Roach, you can ditch that 6lb line and size 12 hook, try a 1lb bottom and a size 20 hook, you might do a little better.

The fish are there to be caught despite the often misguided notion that the Zander have eaten everything.

A 7lb 8oz Canal Fish

A long but very lean 7lb 6oz canal Zander caught from 'Mick's Bush' swim

Anyway back to the job in hand, length and weight feature in this graph. Girth is factor for sure, but I’m not Einstein so it isn’t featured but it surprised me just how accurate the chart was for predicting weight on a given length of Zander that populate and seemingly love the Warwickshire waterways.

I added some references too, one being detail from the 1979 book Zander from Rickards and Fickling and also generic Walleye data for comparison which seems to fit very well indeed. The curve,well I've used canal data and a polynomial line.

My Patch

There isn't a secret to catching these fish, certainly for the canals travel light, alternate your tactics and methods and rove around as much as you can. It also helps fishing with fellow Zed Heads as apart from the social side of it, it's far easier to cover as much water as possible and also how different approaches can single out fish from stretches that may prove difficult.

Predators thrive on neglect so one last tip is so fish waters where others don't. 

Having caught hundreds now there doesn't appear to be a feeding pattern either, certainly the larger canal fish unlike the river fish are transient and the lower the clarity the catch rate improves but one thing to mention is even the most sunny of days I've caught, even on the river, so get that bait in the water.

So the graph, here you go….

The conclusion, well, to get a life me thinks, the Wife's eyes rolling once again....

Canal Zander - On thin ice

Kettle on, tablespoon of Maltodextrin, Monosodium Glutamate, Disodium Inosinate, Disodium Guanylate, Carboxymethylcellulose and hidden in there somewhere, chicken extract and chicken powder, thing is when it’s cold after preheating ones flask, Bovril certainly keeps ones neather regions from doing a full retreat and when looking out the window to a frozen car coffee wouldn’t cut the mustard.

I fully expected the canal to be frozen over as the pattern the frost has made on the car roof overnight was a stunning bit of artwork, but having parked up at first light a stick chucked over the bridge in to the canal waters didn’t bounce but luckily splashed.

So that meant plan A was ok and I didn’t need to resort to running water and plan B….

The thing was as the morning went on I did wonder if I made the right decision as it was a frustrating session, there was cat ice hanging around on the surface in areas that moved around seemingly in a random fashion. That meant having to move the float over and over again until eventually a clear area could be found so it could be left for a decent amount of time.

The lure approach didn’t fair that much better either as often the braid hit the thin layer of ice on the retrieve and eventually the sodding guides started to freeze.

What a pain in the proverbials….

Now I had a Zander first cast on the lure which was a 2lb schoolie scrapper and that made an effort to break up some of the mobile iceberg but the clarity of the water wasn’t conducive for chasing that elusive double figure fish. You could almost see the lure all the way to the bottom, it was that clear. There is also limited boat movement this time of the year also, so not ideal.

I don’t usually fish down the edges but bouncing a lure up and down in-between some ice a tiny Zander grabbed the lure, easily the smallest Zander I’d ever seen, probably only 6 inches in length or something like that, it dropped off sadly but another hard nibble of the lure I decided to position the deadbait tight to the margin.

It didn’t take long for the float to receive some attention too and sure enough a fish had taken interest. I wait till there is a confident movement of the float and then lean in to the fish, no need to strike. Again, after breaking up the ice that remained another schoolie was banked.

Two more small fish on the lure, one missed run on the deadbait, at least I’d managed a few fish.

The sun started to rise and it was a little more pleasant but then that seemed to put the fish off, it was stupidly clear after all, having fished many sessions on the canal now, dirtier the better for me, the clarity or lack of it really does make a difference.

Warwickshire Avon – The Green-eyed Globster

Out of the blue the owner of the local farmshop we used for years announced he was closing having apparently received a ridiculous bid for their archaic but well served premises, and it was an offer quite frankly he couldn’t refuse.

The shoulder of pork we used to buy was utterly fantastic and unlike the water injected rubbish you get at the local supermarkets you could never cook it wrong.

Even the Wife, made a good job of it, such was the quality….

The meat was tasty, moist, and succulent and those overcooked outer bits used to melt in your mouth, so much so, come resting and carving time there was a queue in the Newey household.

Let’s not talk about the great crackling….please, don’t….

The shin of beef they supplied too which I used for casseroles and curry’s was also worth a mention as the meat was a always a proper colour, you know, dark red not like the bright red stuff they sell in huge quantities for the rank and file that if there were a blind taste taste, you’d be hard pushed to guess the planet it came from, let alone the animal it came from.

For the regulars they could bag any of it up and sell it without a problem, a blind bargain if you will. You didn’t have to worry about the change in quality, it was either excellent or superb and cheap too on the most part. Remember It was a common trick in days gone of substituting a cat for a sucking-pig, and trying to palm it off to the unsuspecting.

Not so this place….no cats out of bags to be seen there.

So the first bit of pork from an apparently reputable local butcher was such a disappointment I’m on a mission to find where they have relocated.

My taste buds demand it, as does my wallet….

So why for God sake didn’t I open the bag of deadbait I’d bought at a tackle shop I’d not been in before. I can only assume it had been stuck at the bottom of the freezer waiting for a mug like me to come knocking, sadly being convenient at the time was its ultimate downfall.

you see….

I’d been sold some manky looking lamprey rather than the Roach I was after. A tinge of green in places and they had almost fused together like a couple of Cadbury’s chocolate fingers clutched by a distracted child sat in a hot car.

To the layman unrecognisable….a globster if you will.

What a great word, I heard that term recently when Sam my youngest was watching some Sea Monsters program on TV and it is used to describe unidentified organic mass that washes up on the shoreline or other body of water. A globster is distinguished from a normal beached carcass by being hard to identify, at least by initial untrained observers, and by creating controversy as to its identity.

Maybe I should have become a cryptozooligist as it seems quite a bit more interesting than working on cars.

Sadly I was in a rush as I’m happy with a company online I’ve been using for a few years now, the quality of their deadbaits are pretty good, the cost reasonable, packing excellent with freezer bags and polystyrene boxes and the most importantly next day delivery where they are happy to leave it on the doorstep. The thing is I didn’t want to break in to the ‘Zander Packs’ just yet as those I’m saving for the cut which are ideal 15-20 2-3” Roach that make bite-sized Zander snackets.

I’d used lamprey before when I used to fish Hatton Locks, somewhere I’ve not fished in ages although chock full of Zander, the size not what I’m after, then again who knows with this canal Zander lark especially as this session wasn’t on the canal but on the river again.I was back  river to try and track down the lunker of a Zander that escaped from ones clutches that has been bugging me ever since it's happened.

The conditions not ideal but hey, put a stomach filler in front of a hungry fish, they are hard pushed to refuse it surely Shirley. I was a little green-eyed with Dave's capture of a 8lb 13oz, after all if it wasn't for me he wouldn't have caught the fish, but it was great to see and considering it was the first River Zander he had caught, it certainly was a good'un and would have battered my own PB.

He gave me a pat on the back as a sign of thanks and that was good enough for me, oh and also the sight of when a big fish surfaces, as an angler, that is also a fantastic sight and it gives our hobby and pastime such an appeal and it's only us as anglers that can appreciate that.

The river was running clear, very clear indeed and I knew it would be a tough morning, if I was going to catch anything it was going to be in the first hour or so and sure enough the first bite came from a Pike within half an hour that took fancy to the manky Lamprey.

Maybe it was the fish from a trip out last Friday as it weighed more or less the same, 10lb on the nose.

Lovely markings mind you and at least it wasn't a blank.

I gave it another hour and with the sun now coming up, I decided to call it a day.