May 26 2013 Latest news:
by Roy Webster
Friday, April 27, 2012
In the letter pages of the Eastern Daily Press this week, indignant members of the farming industry felt they were wrongly in the firing line regarding Prymnesium Parvum in Hickling Broad.
And they present a fair case for being blameless.
Actually last Wednesday’s analysis on the causes of this latest outbreak of the toxic organism did not infer that the careless application of granulated phosphate and nitrate was the cause.
These substances, occurring naturally in waste matter deposited by mammals and birds and in plant decay, are known to be conveyed by land drainage into a main water column such as Hickling Broad.
Lowlands to the west of the Thurne catchment reaching as far as Happisburgh channel surplus water into Horsey and Hickling via the Waxham Cut. Other sources are the Hickling Commissioner’s Cut and Catfield Dyke that run from the villages.
Significantly the Environment Agency confirms that total phosphate elevated in Hickling Broad comes from diffuse sources.
Brian Moss, professor of botany at Liverpool University, has researched the P.Parvum phenomenon. He identified the eutrophication (over enrichment) that triggered the fateful 1969 algal bloom as saline from land drainage, phosphate and nitrate from the gull roost and agricultural run-off.
A Broads Authority Upper Thurne working party meeting, chaired by Emeritus professor Tim O’Riordan in 2006, concluded that the saline originated from rivers, aquifers and land drainage and that the nutrients phosphate and nitrate were leached from the soil by rainwater.
Neither of these two eminent scientists actually accused the farming industry of lack of due care in its husbandry.
Last week Rita Penman at the Environment Agency stated: “It does appear that the most important factors involving P.Parvum bloom is the relative amount of nitrogen and phosphorus found in the water.”
Since simple farm economics demand that the distribution of expensive fertiliser should be strictly calibrated to plant uptake, it seems most unlikely that significant residues are being leached out into the Thurne broads.
For the record, a history of Hickling Broad appears to be bloom or bust.
Originally much of the Thurne valley was estuary and saltmarsh. In 1794 the estuary was sealed by coastal erosion deposits isolating the flooded peat diggings at Hickling and Horsey.
These waters in 1808 were allotted along with sporting and fishing rights to landowners under the controversial enclosure awards but the right of access remained with the general public.
Coarse fish rapidly became accustomed to the high salt content and the first fish kill attributed to Prymnesium occurred in 1894, with eight more episodes before the disaster of 1969. There followed three more in the 1970s and others in the 1980s include the highest ever reading of algal bloom that devastated pike stocks in 1985.
Hickling’s heyday was between the two world wars when the legendary Jim Vincent caught 30lb-plus predators on Hickling to order.
And although Norfolk angler Peter Hancock established a new British record with a 40lbs 1oz specimen from Horsey Mere in 1967, neither Horsey nor Hickling ever fully recovered.
Since 1980 the great majority of prize pike over 30lbs, including the 45lb 8oz county record, bagged by John Goble of Caister on Sea, have come out of the River Thurne hotspots between Potter Heigham and Somerton.
This suggests that Hickling and Horsey may never recapture the joys of pike fishing there during those halcyon decades either side of the second world war.
Is there a remedy? Pumping land rainage saline directly into the North Sea might be a start.
• A splendid 34lb 14oz common carp tempted from Taswood Lakes by Jamie Walpole of Coltishall was the fish of the week, with other commons, mirrors, ghosties and grass carp over 20lb falling to Gary Palmer and Ian Kilroy of Norwich, Luke and Brian Mann of Colton, Kevin Smith of Lingwood, Eddie Stevenson of Hempnall and Geoff Benson of Coltishall.
Taverham Lake was in form for Norwich new member Tony Ambrose, with three double figure carp to 20lb and tench to 5lb also featured.
At Hempstead the fishery run by Philip and Carol Platt has been restocked and fenced in following otter damage.
For £5 per day carp to 20lb, perch to over 4lbs and shoals of bream and roach are available.
Big event of the week was the Cross Drove two-day final, the winner of the £1,000 top prize Neil Parkinson (Dynamite) with an aggregate of 133lb 11oz.