bliss2 Posted March 9, 2006 Report Share Posted March 9, 2006 Just a small piece of information, following on from a comment I made at the last club meeting, regarding the silt deposits in the harbour. Last month a team of divers carried out some research in Poole Bay to see how much silt had built up since the dregding, this is an on going project but the lastest information was reported at a meeting that I went to, that the silt build up on Poole Patch was an average 20mm deep, the PHC report that their was only going to be a maximum 4mm build up!! There is also some growing concerns about the build up of silt along Rockley and Hamworthy beach. Hopefully there will be more information and hard facts at the next meeting, so I'll report back again at a later date. Lets hope that this bream site hasn't been runined. Quote Link to comment Share on other sites More sharing options...
Afishionado Posted March 9, 2006 Report Share Posted March 9, 2006 quote..........Poole Patch was an average 20mm deep, the PHC report that their was only going to be a maximum 4mm build up Just as a check we are talking millimeterers here not centimeters? 20mm is slightly less than an inch 4 mm is about 3/8th inch I wouldn't have thought that 20mm would make too much of a difference and if it is nutrient rich silt it might actualy encourage the growth of smaller members of the food chain. Mad Mike Quote Link to comment Share on other sites More sharing options...
Swainiac Posted March 10, 2006 Report Share Posted March 10, 2006 Mike, please correct me if I'm wrong, but I thought that Bream laid eggs in rocks, and rocky areas held the breeding shoals giving better protection for the hatchlings. If the sea bed silts up too much, A it hides many crevices discouraging the breeding shoal, B the build up of silt may take years to disperse, leaving the area barren of bream for many seasons. Maybe the researchers didnt reasearch hard enough! Rich Quote Link to comment Share on other sites More sharing options...
Afishionado Posted March 10, 2006 Report Share Posted March 10, 2006 Mike, please correct me if I'm wrong, but I thought that Bream laid eggs in rocks, and rocky areas held the breeding shoals giving better protection for the hatchlings. If the sea bed silts up too much, A it hides many crevices discouraging the breeding shoal, B the build up of silt may take years to disperse, leaving the area barren of bream for many seasons. Maybe the researchers didnt reasearch hard enough! Rich Rich, I didn't know about the Bream, and fair comment to you, but I was quierying the measurements. In as much as, less than an inch of fine silt in collodial suspension didn't seem enough to cause harm, and as the fine silt would be in semi liquid form it would disperse over a short time due to tide and current. But I am no biologist and stand to be corrected on any of this. Mad Mike Quote Link to comment Share on other sites More sharing options...
Newboy Posted March 10, 2006 Report Share Posted March 10, 2006 A quick blow should get rid of most of them, shouldn't it? Quote Link to comment Share on other sites More sharing options...
Mike Fox Posted March 10, 2006 Report Share Posted March 10, 2006 A good sustained blow from the South or South-East, during a spring tide period would be ideal. Can't imagine anything else that could do so well. If March is as windy as usual, with a fair bit of luck, it might just clear the bulk of it. It would be more interesting to know : - If the 20mm of silt is an average depth (meaning it could be a lot deeper in some areas - probably the gullies)? - If the silt covers the general stony area around the rocky patches, where I know the female bream can be found? - If the main rocks themselves are engulfed, and if the barnacles, weed, and invertebrates that the bream feed on are no longer available as their food source? - Will the divers check each month? Updates on here would be good! Mike Quote Link to comment Share on other sites More sharing options...
Fugazi Posted March 10, 2006 Report Share Posted March 10, 2006 I've dived Poole Bay rock patches for over 30 years and have always found them clean and covered with marine life. The small fry on these rocks need food as well as shelter to develop and grow, which they find in amongst the tube worms, anemones, soft corals, weed, algae and hiding holes. These things are the start of the food chain which ultimately supports the bream, bass and Pollack, so if there is now nearly an inch of silt covering them this sounds like a environmental disaster. Unfortunately as most of the patches are around the 10 metre mark, only tidal flow will have an impact in dispersal and I have no idea how long this will take. A good blow won't change much unless we get wave heights in excess of 5 metres. Gordon H Quote Link to comment Share on other sites More sharing options...
TomBettle Posted March 10, 2006 Report Share Posted March 10, 2006 I don't know what the answer is here, but can we point out the "misjudgement" to some environmental type people and see if someone can do something with a hoover type thing to move the silt WAY offshore. We seem to wreck our surroundings, environment, ecosystem over and over again and never seem to learn from it. Some "Scientist" tells us it will be ok as they have done calculations, but nobody actually talks to those of us that can see the true impact. Quote Link to comment Share on other sites More sharing options...
Fugazi Posted March 11, 2006 Report Share Posted March 11, 2006 I Quote Link to comment Share on other sites More sharing options...
Coddy Posted March 11, 2006 Report Share Posted March 11, 2006 I Quote Link to comment Share on other sites More sharing options...
Mike Fox Posted March 11, 2006 Report Share Posted March 11, 2006 No truth in the rumour then about other club members being good at sucking at the bar? Quote Link to comment Share on other sites More sharing options...
Ferret Posted March 11, 2006 Report Share Posted March 11, 2006 yes alot of truth in the rumour but only when ive forgotten my teeth bill smith Quote Link to comment Share on other sites More sharing options...
shytalk Posted March 11, 2006 Report Share Posted March 11, 2006 4 mm is about 3/8 inch ?????????? not on my ruler it isnt Quote Link to comment Share on other sites More sharing options...
Afishionado Posted March 11, 2006 Report Share Posted March 11, 2006 4 mm is about 3/8 inch ?????????? not on my ruler it isnt Picky! Mad Mike Quote Link to comment Share on other sites More sharing options...
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