Wednesday, July 04, 2012
Is it time to research Fens pike decline..?
It's great news that the EA is working with the pike angling community on an innovative tagging project on the Norfolk Broads. I just wish they'd do the same in the Fens.
We know that our pike population is changing too. While we all like catching big pike, there are one or two waters where smaller fish seem to have become thin on the ground. The worrying thing is what's going to happen when the bigger pike die off in these places.
We all have our own theories regarding what's happening. Mine is that pike no longer spawn successfully every spring on many of our waters in the Fens. This explains why the pyramid of pike sizes which you'd otherwise expect to see has become disrupted, leaving - in one or two extreme cases - waters with a dearth of small pike.
On run of the mill, bread and butter drains and rivers, you'd expect to catch more pike under 10lbs than over. You wouldn't expect to blank most times you went but catch more twenties than jacks.
Small pike should be more numerous, according to the widely-accepted pyramid theory. Another reason for this is that male pike rarely grow any larger than 10lbs. They are smaller than their female counterparts, because they spawn eye-to-eye with each other, the male's shorter length means its milt fertilises the eggs the female deposits during their nuptials.
On one water I fished, I watched pike spawning before the end of the season on an area of grassy bank which had been flooded to a depth of 18ins or more as the water level rose after heavy rains. Within a week, the levels had receded, leaving the spawn high and dry before it had hatched.
It's no secret our weather's changing fast. After one of the driest winters on record, we're experiencing one of the wettest summers. During those crucial few weeks around spawning time, levels should have remained fairly constant this year, hopefully meaning a strong year class in a season or two's time.
If two extreme cases cited above become waters where you get 10 runs a day but finish the season with just a handful of doubles and the odd battle-scarred twenty, this spring will have been the exception that proves the rule.
Some blame the burgeoning otter population for declining catches. Otters are far more numerous than they've ever been. Up until five years ago, I'd seen just two in more than 20 years of pike fishing.
Three or four years ago, I began seeing them on a water I was fishing regularly. By the 2009/10 season, there were areas where you saw them every other time you went.
The otters could have been there all the time, of course, perhaps losing some of their caution as they became accustomed to seeing anglers. I say otters, because by the back-end of that season, I'd seen them sufficiently closely to identify at least two individuals, while on one occasion, I saw an adult otter and a kit together.
Otters are a high-risk issue for anglers. While the general public probably doesn't care too much whether the rules are relaxed when it comes to culling cormorants or goosanders, most would probably rather see otters than us on waters if it came to a choice.
Otters eat other fish, besides pike. While commercial fisheries have the option - albeit a costly one - of otter-proofing their stock with fences, this clearly isn't possible in the Fens.
The only way of otter-proofing pike stocks, to a degree, is ensure their spawning success, so there are enough fish to replenish those eaten. In parts of America, where pike are routinely eaten as part of the angling experience, they have an answer which may well be the way we have to go to preserve our own pike.
On some waters, spawning areas are carefully managed to ensure that pike can use them successfully. If the EA can spend tens of thousands on eel passes, or efforts to safeguard the sea trout which run up the Nar and the Wissey, why not look to pinpoint and preserve the pike's spawning areas.
A survey of barbel in the Upper Ouse, conducted using radio-tracking methods, revealed that the siltation of spawning areas was the reason for their declining numbers. We know that pike are in decline across the Fens. Maybe it's time we threw a little science at the question, to find out why.
Click here for more on the Broads pike tagging project.
Click here to find out how repeat captures show there are less pike than you think in the Fens.
posted at 13:40