Zander cull

[flightliner]

Back in the eighties there was a zander cull on what ,if I remember, was the middle level drain/s. Anyone here remember it and what were your veiws at the time?. Were you for or against, and, after all these years has your opinion changed.

 

[pointngo]

It's not my area so don't have any first hand experience of it on the drains but it still goes on in the canals around Birmingham. The EA have been electro fishing them for years and although it reduces numbers in the short term, electro fishing never catches all the fish so they just repopulate. You then get an explosion of small zander until they balance out again so all that is achieved is that the bigger fish are killed and the silverfish fry numbers are reduced by the small zander.... pointless and counterproductive imho. Zander are one of those fish that shoal so if you find one you find a few.. I think that gives the wrong impression that there are loads of them in a venue when in reality it's just a passing/resident shoal. I have it on good authority though that the EA are slowly realising that culling zander doesn't really work so are looking to change their "invasive species" status.

 

[mick b]

The worst thing about the culling of Zander during that period was that no accurate records were kept and the fishery science applied was severely flawed.

Just a knee jerk response to a balls-up by the water authority.

Sadly, with Zander then becoming fishings enemy No:1 those that had a mind to were able to seed waters to repay perceived grievances, which I think is how they turned up in some very unwelcome places.

A very sporting fish, I just wish everyone would cease calling them 'Zeds' ......ugh! mg:mg:mg:

.

 

[symonh2000]

I would love to be able to catch Zander. I wouldn't mind betting that they do far less damage to a waters ecology than many other non-native specises such as signal crayfish.

Signal crayfish have had a huge impact on the fishing in my local river, as well as destroying the banks.

 

[Peter Jacobs]

I seem to recall that there was a cull on and around the Norfolk Broads which were once really prolific Roach and Bream venues that suffered badly form the original introduction of Zander.

 

[richiekelly]

There are a couple of waters near me along with canals that have Zander in them, the canals used to be electro fished and the Zander removed, as said previously it just led to more small Zander many of which would previously been eaten by larger fish if they had been left alone.

One of the stillwaters that have them used to have a club rule that all Zander should be killed which to me was a stupid rule and one that was ignored by the predator anglers on there, I don't know if that was the reason why the rule was later changed to only fish below 7lbs to be removed but that rule is also ignored.

The Zander did have an initial impact for a few years on both canal and Stillwater but now both have healthy populations of silver fish, the only thing that has suffered is the pike fishing with competition for food they seem to have dropped in numbers and size or could it be that these waters are now so balanced that the pike are still there but harder to catch due to the amount of food available to them.

Once Zander are in a water they are there to stay and no amount of culling will get rid of them its a waste of time and money and the waters will eventually reach a balance if they are left alone.

 

[mick b]

Blanker said
"The Zander did have an initial impact for a few years on both canal and Stillwater but now both have healthy populations of silver fish, the only thing that has suffered is the pike fishing with competition for food they seem to have dropped in numbers and size or could it be that these waters are now so balanced that the pike are still there but harder to catch due to the amount of food available to them"

Your Pike are probably targeting immature Zander.

Zander make excellent baits for Pike, use one around 1.5lbs fished mid depth in deep water and cast around with a frozen mackerel every 15mins or so, you wont get much on the sloshing around with the mack but it will sure wake up any biggies in the area (thats the way to do it, eh Derek )

 

[tiinker]

Plenty of Zander in the lower Thames and plenty of bait fish plenty of fish from Teddington upstream Molsey weir can be very good and the moorings around Kingston.

 

[schwendy2]

Pike are easily pushed out by other predators in my experience.

Zander certainly can become top dog and even perch on some venues can out the pike.

 

[Derek Gibson]

Pike are easily pushed out by other predators in my experience.

Zander certainly can become top dog and even perch on some venues can out the pike.

There have been times over the years when I have felt along similar lines, then out of the blue along comes a catch which includes both pike and Zander. All this flies in the face of the oft quoted ''territoriality''. It's all speculation at the end of the day, all we have to work with is empirical experiences based over many years, and crucially many fish.

Cull's, I have no scientific training, so once again empirical experience is the only base from which I can offer an opinion. In the case of pike, which after all is a predator like the Zander, I am certain that if larger fish are removed by a proffessional approach, ie:- water authorities etc, or by persistant idiot anglers, in the belief they are protecting the water, the result equals an explosion of smaller fish. I cannot see that the same scenario would not apply with Zander. IMHO.

 

[sam vimes]

Back in the eighties, I doubt I gave it a second thought. Zander may as well have been extra terrestrials for all the chance I had of seeing one. Between then and now, my fishing travels have taken me a bit further afield, including to places where they are known to be present. In all that time, I've seen just one zander in the flesh, that was on the Trent.

I suspect culls, be they of zander, wels catfish, random sturgeon types or pike, are likely to be futile, no matter how good the intent. I've no desire to see zander culled. However, I'd sooner not see them get into any river/waterway that they aren't already present. I'm less concerned about stillwaters that can't be flooded by watercourses. However, I don't suppose stocking any stillwater with zander would be legal anyway.

 

[pointngo]

zander seem to be able to oust pike as top predator for some reason. Maybe zander are more successful than pike when it comes to numbers of juveniles surviving? Zander are better parents than pike during the early stages as they protect their nest vigorously. Because of that perhaps baby zander eat more small baitfish (and maybe juvenile pike) and so reduce the available prey for juvenile pike? I expect water clarity has a bearing as well. That's all just a hypothesis though.. not sure we will ever know for sure.

 

[S-Kippy]

However, I don't suppose stocking any stillwater with zander would be legal anyway.

I think they are still classed as an "invasive species" but I also heard that there is talk of revoking that. In theory that ought to allow them to be legally stocked.
I'm a big fan [as you all know] and I would love to see them stocked in more stillwaters [preferably in the Colne Valley near me] but I doubt it will happen as old attitudes/prejudices will prevail I suspect.

---------- Post added at 18:52 ---------- Previous post was at 18:44 ----------

zander seem to be able to oust pike as top predator for some reason. Maybe zander are more successful than pike when it comes to numbers of juveniles surviving? Zander are better parents than pike during the early stages as they protect their nest vigorously. Because of that perhaps baby zander eat more small baitfish (and maybe juvenile pike) and so reduce the available prey for juvenile pike? I expect water clarity has a bearing as well. That's all just a hypothesis though.. not sure we will ever know for sure.

That's interesting. My zander experience is limited to Bury Hill [and I dont know very much anyway] but it is noticeable how skanky the BH pike are compared to the zander. You get the odd "old" zander but on the whole they are in fantastic trim. I've had several good fish that were absolutely mint and clearly had the potential to grow very much bigger. The pike by comparison are long,skinny,half starved looking things...more like eels than pike. I do my best to avoid them but I had a 14lb fish that I thought ought to have weighed 4/5 lb more. Great big head...long thin body and not an old fish going back either. Maybe they are getting out-competed despite BH being absolutely full of baitfish. It might be cyclical....there is no doubt in my mind that the big pike in BH are long dead and even the mid-range fish are not common. Maybe the hordes [?] of zander are predating poor old esox and rather than get beaten up by a pack of hungry zander he is forced to scavenge the margins for discarded bait.

As long as he doesn't pick my bait up I'm happy. I cannot be doing with pike.

 

[keora]

There have been a number of scientific reports on zander in England, the best I've found is this one:


http://www.clw.csiro.au/publications/controlling_carp.pdf

Although the title refers to Controlling Carp in Australia, pages 82 to 92 consider the effect of zander on English fish populations and the methods used to control them.

Here's the summary at the end:


"The establishment of zander populations in some canals has resulted in a
number of problems for fishery managers. At present, the addition of zander
does not improve the fishery value of waters in the UK as anglers
do not want to catch them. Furthermore, anglers claim that zander reduce
the abundance of other fish and advocate removal programs.

A review of the UK literature found that the impact of zander is not
known. Culling zander has been attempted but the evaluation of 18 years
data of harvesting a canal population suggests that culling at a low level
has little effect on population dynamics. Increasing culling intensity to the
1988–1991 level altered the population dynamics. It resulted in a decrease
in the average size of the zander, but did not affect total biomass.

However, as the size of prey eaten by zander is related to its size (Figure
6.5) this will have shifted predation pressure towards smaller prey. As the
type of prey consumed also depends on the size of zander (Figure 6.4), a
population of small zander would consume more cyprinids than a
population of larger ones.

Consequently, the reduction of the average size of zander by culling may
have exacerbated its impact on native cyprinid fish. As cyprinids form the
basis for the recreational fishery, culling zander may actually increase its impact."

 

[reeds]

I grew up in Norfolk on the banks of the middle Level and Relief Channel (in fact very close to where the original 97 (I think?) fingerlings were introduced.

I well remember the persecusion they suffered, it was very common to see them thrown up the bank. Pike too, in fact.

All sorts of myths about zander used to be perpetuated, and to my amazement some still are. As others have already said, the cullings and the ad hoc killing of individuals when encountered made no difference to the overall populations, which simply grew each time to fill the available niche as apex predator, along with the pike. Also as others have said, the only other species to suffer overall with their arrival was the pike, as the overall food source they both relied on stayed the same, and the pike and zander were then competing with each other. Over the years on the various drains, these two conflicting populations ebbed and flowed, with sometimes the zander overtaking the pike and then the pike overtaking the zander.

It's been a while since I fished the fens so I don't know what the current situation is like.

One of the reasons zander got a bad press was due to an unfortunate coincidence. At about the time when they were booming in the relief channel there was a dramatic drop in the roach and bream populations, and so 2 and 2 were put together and the zander got the blame, and more weight added to the view they were 'wanton killers'. The truth is that because of water mismanagement by the then NRA, the relief channel was pumped far too hard in the spring, leaving that years spawn high and dry in the exposed reedbeds, and immature fry sucked out to sea.

As usual, the apex predator was the obvious (but incorrect) culprit!

Since moving from Norfolk I've enjoyed fishing for zander at the Severn, and the Anglian reservoirs (Grafham and Rutland), but these days with lures rather than camping out all night legering little deadbaits. They're a fascinating fish. There's no getting rid of them, however hard you try. The best thing is to leave them be and let things settle; if you need proof just look at the aforementioned waters.