In my last piece I discussed how the meres were formed and the processes that have shaped them since. I’d like to continue briefly with the shaping process before moving on to the ecological aspects.

The meres of the three counties are in my opinion national treasures because of their uniqueness. Whilst this is recognised in ecological terms most, if not all, being SSSI’s (Sites of Special Scientific Interest), their landscape value is not. This fact I find somewhat remiss of the powers that be. Anybody who is involved in conservation work will tell you, on average, nationally, one SSSI site is damaged per week. With the added protection for their landscape value, those who may consider damaging them would have to think long and hard before doing so, as the penalties are more severe.
One of the great meres at sunset
Notwithstanding the above, natural damage has occurred and will continue to do so through evolution in the shape of succession. The process of succession is as follows: annually the marginal aquatic vegetation grows and dies. With each passing year, a layer of sediment is set down by this process in close proximity to the bank. The sediment builds up over time and is colonised by less aquatic and more terrestrial herbage, bushes and trees.

This type of vegetation then stabilises the ground by drying it out. As a result of the drying process, the marginal aquatic vegetation, which needs its feet in water so to speak, advances outward into the mere. It is perhaps clear from this that the meres most susceptible to succession are the shallow ones. However, ultimately it’s likely over the millennia of geological time that all the meres will succumb to the process. There are at least two meres that I know that are at a very advanced stage of succession, and are likely to completely disappear in the next 100 to 200 years; those being the Norbury meres. As I write, those meres are very shallow, perhaps 4 ft at their deepest, with willow and alder carr encroaching rapidly across their water-bodies. Several others; Quoisley, Ossmere (Osmere colloquially), Barmere and Blakemere, are also vulnerable to the process, but over a longer time span, 500-1000 years.

Whilst the above is the inevitable outcome for the meres over the geological time span, there are measures that can be taken to slow the process down, thereby giving the worst affect ones an extended life span. The measures would involve some form of management regime that included weed cutting and carr removal on an annual basis, and possibly silt trapping on the input streams, etc. However, the costs of such measures are extremely high and there needs to be the Conservation Will there to carry it out, which frankly, I don’t think there is.

To close this section I should point out that there is also a way to speed up the process as well. Whilst no one would want to do this I don’t think? It can occur through misguided so-called fish refuge enhancement projects. Such projects these days are tempting due to the increase of predation by fish-eating birds. The method involves deliberately planting reeds and allowing them to encroach into the mere. And, believe it or not, I do know of one club that plans to carry this out on a mere that is bowl-shaped and a maximum depth of 12 – 14ft. In my opinion, if this plan is carried through, they will all be, albeit unwittingly, dramatically accelerating the succession process on that mere.

The meres are very rich environments in aquatic ecological terms and teem with life. That said, it does not follow that they are stuffed with fish. They are (where man has not interfered) naturally balanced ecosystems. Naturally balanced ecosystems, it might surprise you to know, are dynamic systems that wax and wane and are rarely in a stable state for very long. The reasons for this are complex and beyond the scope of this article. In short though, it’s about the relationship between predator and prey through each stage of the food chain (and there are predators other than fish at each stage of the chain), annual climatic swings, water chemistry, etc.

In accepting the above, it is also recognised by scientific evidence that fish have the most significant impact on the whole system as they have the ability to feed at most levels of the chain. As anglers we perhaps only view the predator-prey relationship between fish and their natural food (other fish and aquatic insects) and not the fact that all life in a food chain has a predator-prey relationship with one another. Whether that be of their own kind, such as bloodworm, which has members of its family that are totally predatory on other members. Or the dragonfly larvae, which will feed on most other invertebrate species, as well as small fish.

It is perhaps relevant here to list the main players in the food chain regarding fish. Without doubt bloodworm is possibly the most plentiful animal, followed by freshwater shrimp (Gammarus pulex), Water Hog-lice (Asellus) and Daphnia. Other larger animals are found in the meres, such as caddis fly larvae (Trichoptera), but are less plentiful. Strangely, mayflies larvae (Ephemeroptera) whilst present, never seem to be visible in great quantities in sediment samples. That said, however, on warm still nights in June/July thousands can be seen hatching. This leads me to the conclusion that unlike daphnia and bloodworm they don’t aggregate together, preferring perhaps a more solitary life. I should pointed out here that in the families Trichoptera and Ephemeroptera there are several species present in the meres.

Phil and his PB 13lb 2oz Cheshire mere bream
It perhaps will interest you to know that in the case of daphnia there is a wildly fluctuating population from year to year. The reason for this is mainly down to water temperature and reduced food supply, as they are algae feeders. A cold spring stops the algae from blooming until much later into the summer. As a result, there is always less daphnia present that season. This fact also has implications for the fish fry of that year, as they are the staple diet of most non-predatory species. Several cold springs on the run would have a severe impact on the fry of each subsequent year’s spawning due to starvation. For instance, the longer the run lasts, the more depressed the stock of daphnia becomes and the less food there is to feed the subsequent year’s hatchlings. I’m convinced that on the meres that this is one of the main reasons for the population crashes that happen, particularly to roach stocks, coupled with the fact that the roach are fast-livers and have a short life span. On average, the roach on the meres only live to 5 years at best. This fact is backed up by the thousands of scale readings I’ve done over the last 10 or so years, along with the combined historical knowledge of anglers who fish the meres, spanning the last 80-plus years.

I’d now like to put a bit more detail to the above statement, as I find it both fascinating and intriguing at the same time.

It’s long been known that the mere’s fish stocks run in cycles, as one species declines another is in the ascendance. The most prevalent of these to track is the roach, as they are the easiest to catch. Based on the above two sources it would appear that the roach cycle lasts between 10 -12 years. The make up of the cycle is this:

Year 1
Starting with no roach being caught at all. What I’m not saying here is that roach are not present in the mere. However, I am saying the population is so depressed and few in number, that they are to all intents and purposes, uncatchable.

Year 2
The weather in this year is good with a conducive hot spring and summer. The depressed stocks successfully spawn and small roach fry shoals start to show up in the margins later in the summer.

Year 3
Last year’s hatchlings fed well over the good summer and had a good survival rate over the winter, attaining a size range of 2-4 inches by the start of this year’s season. Anglers who venture onto the mere and fish maggot start to catch them but the fishing is patchy as their numbers are low.

Year 4
The fish by the start of this season have reached 5-8 inches but catches are still patchy. However, given a good spring and summer they will spawn well because they are at the optimum age and size for this to happen. There is also the possibility that they may even spawn twice under such conditions. As the season progresses through the summer vast shoals of hatchling fish can be seen in the margins.

Year 5
The mere is alive with roach of all sizes and year 2. fish have reached 10-12 inches. For the pikers who may read this, the winter of this year is the time to make it a fun water to visit, as there are plenty of fish from 4 -14lbs to be had, and runs are plentiful.

Year 6
The roach by this year have become a bloody nuisance if you’re fishing for other species, as they take anything and everything you use. Year 2. fish by now are getting interesting as they’re 12-16 inches long and are 1 1/2 – 2

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